Air compressor question

[Frederick Wilson]

I am still working on home remodel so it will be some time before the
airplane gets started. I am pretty darn convinced that I am going to do an
all wood and fabric airplane. More than likely, the Fisher Tiger Moth.

Anyway, I have come to the point in my home remodel that I am going to need
an air compressor. But instead of just getting one that will do the job
here, what might I need one for when it is airplane time?

What size and compressor (one or two cylinder) should I look at?

Any name brand preference?

Thanks,

Fred

[Corrie]

For sure you're going to want it for doping and painting. Might use
an air hammer to drive the occasional rivet, even in a woodie.
(expensive tool to buy, but you could rent it. You could also use a
ball peen.) Haven't read of folks using air-powered staplers or
nailers; not sure if you could even get the teeny things we use in a
form for a powered stapler. Somebody else might know. You might also
use it for sandblasting steel parts prior to painting them.

A dual-cylinder compressor refills the tank faster. So for high-volume
operations it'll let you work more continuously. If your home project
involves an air-gun nailer or sprayed-in insulation, that'll probably
be the driving factor, rather than the airplane project.

BTW - If you haven't already poured concrete, and you're going to buy
battens, you might take extra care selecting the 2x12s at the
lumberyard. They're often made from Douglas Fir - look for a stamp
that says D FIR (not H FIR or HEM FIR). Weyrhauser(sp?) uses a
triangle stamp with D FIR inside. With some careful picking, you
might find a few boards with clear, tight grain in usable dimensions
between the knots. (Be sure to knock ALL the concrete off before you
take the saw to it, though!)

"Frederick Wilson" > wrote in message news:<FmC9b.365132$Oz4.142857@rwcrnsc54>...
> I am still working on home remodel so it will be some time before the
> airplane gets started. I am pretty darn convinced that I am going to do an
> all wood and fabric airplane. More than likely, the Fisher Tiger Moth.
>
> Anyway, I have come to the point in my home remodel that I am going to need
> an air compressor. But instead of just getting one that will do the job
> here, what might I need one for when it is airplane time?
>
> What size and compressor (one or two cylinder) should I look at?
>
> Any name brand preference?
>
> Thanks,
>
> Fred

[Rich S.]

"Frederick Wilson" > wrote in message
news:FmC9b.365132$Oz4.142857@rwcrnsc54...
> I am still working on home remodel so it will be some time before the
> airplane gets started. I am pretty darn convinced that I am going to do an
> all wood and fabric airplane. More than likely, the Fisher Tiger Moth.
>
> Anyway, I have come to the point in my home remodel that I am going to
need
> an air compressor. But instead of just getting one that will do the job
> here, what might I need one for when it is airplane time?
>
> What size and compressor (one or two cylinder) should I look at?
>
> Any name brand preference?

Whichever model you choose, be SURE to listen to it run before you plunk
down your money. Some of the new compressors are loud enough to shred your
neighbor's panties.

Rich S.

[Craig]

"Frederick Wilson" > wrote in message news:<FmC9b.365132$Oz4.142857@rwcrnsc54>...
> What size and compressor (one or two cylinder) should I look at?
>
> Any name brand preference?
>
Assuming that you will end up using it more than you think, shop
around for a two stage, 220VAC unit with at least a 60 gallon tank.
Stay away from the oilless units for noise reasons. The lower the rpm
of the compressor, the lower noise factor it will have. Keep an eye
out for Champion, IR, and any other big name vendor. Be aware that the
ratings on Crapsman units are very inflated. When you compare units,
use cfm @ pressure to make the comparisons meaningful.

Lots of people have built a/c using the litle hotdog tanked units and
the small household units, but if you have to spend much time waiting
on them to return to the required pressure to do the job, then they
are way too small if you have minimal time to devote to the projects.
For average usage, if the compressor has to cycle one more than once
every minute and a half or less, you need either a bigger unit or more
tankage.

What ever you do, DO NOT...I repeat DO NOT use PVC or CPVC for
pressure piping on your system. Many people use it, but do not
understand that it is not rated for or intended for use with
pressurized air. When it fails, and it will, it will almost always
fail explosively and send shrapnel all over the place. If you don't
belive me, I will show you the pressure rating for PVC with all the
derating factors applied....it's very scary.

More questions? ask away....

Craig C.

[Morgans]

"Rich S." > wrote in message
...
> "Frederick Wilson" > wrote in message
> news:FmC9b.365132$Oz4.142857@rwcrnsc54...
> > I am still working on home remodel so it will be some time before the
> > airplane gets started. I am pretty darn convinced that I am going to do
an
> > all wood and fabric airplane. More than likely, the Fisher Tiger Moth.
> >
> > Anyway, I have come to the point in my home remodel that I am going to
> need
> > an air compressor. But instead of just getting one that will do the job
> > here, what might I need one for when it is airplane time?
> >
> > What size and compressor (one or two cylinder) should I look at?
> >
> > Any name brand preference?
>
> Whichever model you choose, be SURE to listen to it run before you plunk
> down your money. Some of the new compressors are loud enough to shred your
> neighbor's panties.
>
> Rich S.

Part of the things to consider is if you will use a lot of air tools, or go
electric. For a wood airplane, I could see a bit of sanding, and spraying
finish. A small 30 gal 3 HP compressor would not keep up with a air sander,
or spray gun very well. I like air tools cause they are usually cheaper,
lighter, and don't get hot under heavy usage.

If you can swing it, get a big upright 5 HP , NOT oilless unit, and put it
outside if you can. It saves the ears and the space in the shop. All it
needs is a small lean-to roof.
--
Jim in NC

[Frederick Wilson]

Jim,

I can see where that would be good, but it would be a bit hard lugging
around that compressor to the different parts of the house for the remodel.
;-)

I liked the pawn shop idea. I might be able to get something functional and
cheap right now to figure out the features I want for the real one.

It is starting to cool off here in Indiana so, I guess, the new two car
garage/hanger/building shop is out for this year.

<Fred Speculating> I wonder what the average time difference is between
deciding to build an airplane and actually starting the project.

Thanks for the input,
Fred

"Morgans" > wrote in message
...
>
> "Rich S." > wrote in message
> ...
> > "Frederick Wilson" > wrote in message
> > news:FmC9b.365132$Oz4.142857@rwcrnsc54...
> > > I am still working on home remodel so it will be some time before the
> > > airplane gets started. I am pretty darn convinced that I am going to
do
> an
> > > all wood and fabric airplane. More than likely, the Fisher Tiger Moth.
> > >
> > > Anyway, I have come to the point in my home remodel that I am going to
> > need
> > > an air compressor. But instead of just getting one that will do the
job
> > > here, what might I need one for when it is airplane time?
> > >
> > > What size and compressor (one or two cylinder) should I look at?
> > >
> > > Any name brand preference?
> >
> > Whichever model you choose, be SURE to listen to it run before you plunk
> > down your money. Some of the new compressors are loud enough to shred
your
> > neighbor's panties.
> >
> > Rich S.
>
> Part of the things to consider is if you will use a lot of air tools, or
go
> electric. For a wood airplane, I could see a bit of sanding, and spraying
> finish. A small 30 gal 3 HP compressor would not keep up with a air
sander,
> or spray gun very well. I like air tools cause they are usually cheaper,
> lighter, and don't get hot under heavy usage.
>
> If you can swing it, get a big upright 5 HP , NOT oilless unit, and put it
> outside if you can. It saves the ears and the space in the shop. All it
> needs is a small lean-to roof.
> --
> Jim in NC
>
>

[Morgans]

"Frederick Wilson" > wrote in message
news:2uX9b.372665$Oz4.149020@rwcrnsc54...
> Jim,
>
> I can see where that would be good, but it would be a bit hard lugging
> around that compressor to the different parts of the house for the
remodel.
> ;-)
>
> I liked the pawn shop idea. I might be able to get something functional
and
> cheap right now to figure out the features I want for the real one.
>
> It is starting to cool off here in Indiana so, I guess, the new two car
> garage/hanger/building shop is out for this year.
>
> <Fred Speculating> I wonder what the average time difference is between
> deciding to build an airplane and actually starting the project.
>
> Thanks for the input,
> Fred

Hose is cheap! ;-)
--
Jim in NC

[Larry Smith]

"Craig" > wrote in message
om...
> "Frederick Wilson" > wrote in message
news:<FmC9b.365132$Oz4.142857@rwcrnsc54>...
> > What size and compressor (one or two cylinder) should I look at?
> >
> > Any name brand preference?
> >
> Assuming that you will end up using it more than you think, shop
> around for a two stage, 220VAC unit with at least a 60 gallon tank.
> Stay away from the oilless units for noise reasons. The lower the rpm
> of the compressor, the lower noise factor it will have. Keep an eye
> out for Champion, IR, and any other big name vendor. Be aware that the
> ratings on Crapsman units are very inflated. When you compare units,
> use cfm @ pressure to make the comparisons meaningful.
>
> Lots of people have built a/c using the litle hotdog tanked units and
> the small household units, but if you have to spend much time waiting
> on them to return to the required pressure to do the job, then they
> are way too small if you have minimal time to devote to the projects.
> For average usage, if the compressor has to cycle one more than once
> every minute and a half or less, you need either a bigger unit or more
> tankage.
>
> What ever you do, DO NOT...I repeat DO NOT use PVC or CPVC for
> pressure piping on your system. Many people use it, but do not
> understand that it is not rated for or intended for use with
> pressurized air. When it fails, and it will, it will almost always
> fail explosively and send shrapnel all over the place. If you don't
> belive me, I will show you the pressure rating for PVC with all the
> derating factors applied....it's very scary.
>
> More questions? ask away....
>
> Craig C.
>

Good advice. I would go for the biggest 2-stage affordable. Two stage
because it runs cooler and makes less moisture in the lines when you're
painting.

[Rich S.]

Check out item 47065-2VGA at http://www.harborfreight.com/.

4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
Two Built-in Universal Quick Connect Couplers for Convenient Air Hose
Connection
Long-life oil lubricated compressor with precision machined cast iron sleeve
Twin capacitor motor with thermal overload protection
Wheel kit with 6'' wheels and ergonomic for smooth portability
Oil level indicator window for easy maintenance
Reduced vibration with rubber foot stabilizers
4-1/2 peak horsepower; 120 volt, 60Hz
125 PSI max; 4.4 CFM @ 90 PSI; 11.1 CFM @ 40 PSI
Shipping weight: 152 lbs.
$169.99

Rich S.

[wmbjk]

"Rich S." > wrote in message
...

> 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
>> 4-1/2 peak horsepower; 120 volt, 60Hz

<chuckle>

Wayne

[Rich S.]

"wmbjk" > wrote in message
...
>
> "Rich S." > wrote in message
> ...
>
> > 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
> >> 4-1/2 peak horsepower; 120 volt, 60Hz
>
> <chuckle>
>
> Wayne

Can't be any good, 'cuz it don't cost enough - right?

Rich S.

[wmbjk]

"Rich S." > wrote in message
...
> "wmbjk" > wrote in message
> ...
> >
> > "Rich S." > wrote in message
> > ...
> >
> > > 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
> > >> 4-1/2 peak horsepower; 120 volt, 60Hz
> >
> > <chuckle>
> >
> > Wayne
>
> Can't be any good, 'cuz it don't cost enough - right?

Not at all. I was just chuckling about the 4.5 hp on 120 part. I've got
a shop full of HF stuff, and I resent it when the tool bigots make fun
of that equipment. Making fun of my low budget tools is *my* job. :-)

I checked on the compressor link you posted. Seems like a good deal, and
should be fine for most projects. Output is too small for much painting
though.

Wayne

[Rich S.]

"wmbjk" > wrote in message
...
> Not at all. I was just chuckling about the 4.5 hp on 120 part. I've got
> a shop full of HF stuff, and I resent it when the tool bigots make fun
> of that equipment. Making fun of my low budget tools is *my* job. :-)
>
> I checked on the compressor link you posted. Seems like a good deal, and
> should be fine for most projects. Output is too small for much painting
> though.
>

My apologies. I wouldn't buy one of those sight unseen, but the original
poster gave me the impression that he was shopping for the most bang for his
buck. I have a Craftsman 2-cylinder compressor which I got from my dad when
he died in 1978. It's still going strong, but I doubt that I will pass it
along to my son. He's already got a better one.

Up at the hangar, I have one which I assembled fifty years ago. A 2-cylinder
refrigeration compressor, a washing machine motor, and a tank welded up from
10" pipe. In the past I painted my '54 Corvette with it, but had to use
lacquer. You could only paint one fender and then drink beer until the
pressure came back up. Now I use it to blow up tires, a task well-suited to
its capacity.

Rich S.

[Dave Hyde]

wmbjk wrote:

> I was just chuckling about the 4.5 hp on 120 part.

Must be a Craftsman knockoff ;-)

Dave 'math challenged' Hyde

[Morgans]

"Dave Hyde" > wrote in message
...
> wmbjk wrote:
>
> > I was just chuckling about the 4.5 hp on 120 part.
>
> Must be a Craftsman knockoff ;-)
>
> Dave 'math challenged' Hyde
>

They didn't give the amps. Maybe it is a 25 amp unit!


--
Jim ( when pigs fly) in NC

[Tim Ward]

"Rich S." > wrote in message
...
> Check out item 47065-2VGA at http://www.harborfreight.com/.
>
> 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
> Two Built-in Universal Quick Connect Couplers for Convenient Air Hose
> Connection
> Long-life oil lubricated compressor with precision machined cast iron
sleeve
> Twin capacitor motor with thermal overload protection
> Wheel kit with 6'' wheels and ergonomic for smooth portability
> Oil level indicator window for easy maintenance
> Reduced vibration with rubber foot stabilizers
> 4-1/2 peak horsepower; 120 volt, 60Hz
> 125 PSI max; 4.4 CFM @ 90 PSI; 11.1 CFM @ 40 PSI
> Shipping weight: 152 lbs.
> $169.99
>
> Rich S.

I dunno beans about air compressors, so maybe someone else can explain it to
me:
The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 watts.
746 watts in a horsepower, so how do you get 4.5 HP out of a wall socket?

Tim Ward

[John Ammeter]

On Wed, 17 Sep 2003 20:08:08 -0700, "Tim Ward"
> wrote:

>
>"Rich S." > wrote in message
...
>> Check out item 47065-2VGA at http://www.harborfreight.com/.
>>
>> 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
>> Two Built-in Universal Quick Connect Couplers for Convenient Air Hose
>> Connection
>> Long-life oil lubricated compressor with precision machined cast iron
>sleeve
>> Twin capacitor motor with thermal overload protection
>> Wheel kit with 6'' wheels and ergonomic for smooth portability
>> Oil level indicator window for easy maintenance
>> Reduced vibration with rubber foot stabilizers
>> 4-1/2 peak horsepower; 120 volt, 60Hz
>> 125 PSI max; 4.4 CFM @ 90 PSI; 11.1 CFM @ 40 PSI
>> Shipping weight: 152 lbs.
>> $169.99
>>
>> Rich S.
>
>I dunno beans about air compressors, so maybe someone else can explain it to
>me:
>The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 watts.
>746 watts in a horsepower, so how do you get 4.5 HP out of a wall socket?
>
>Tim Ward
>

You DON'T.....

John Ammeter

[sleepy6]

In article >, says...
>
>
>"Rich S." > wrote in message
...
>> Check out item 47065-2VGA at http://www.harborfreight.com/.
>>
>> 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
>> Two Built-in Universal Quick Connect Couplers for Convenient Air Hos
>e
>> Connection
>> Long-life oil lubricated compressor with precision machined cast iro
>n
>sleeve
>> Twin capacitor motor with thermal overload protection
>> Wheel kit with 6'' wheels and ergonomic for smooth portability
>> Oil level indicator window for easy maintenance
>> Reduced vibration with rubber foot stabilizers
>> 4-1/2 peak horsepower; 120 volt, 60Hz
>> 125 PSI max; 4.4 CFM @ 90 PSI; 11.1 CFM @ 40 PSI
>> Shipping weight: 152 lbs.
>> $169.99
>>
>> Rich S.
>
>I dunno beans about air compressors, so maybe someone else can explain
> it to
>me:
>The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 wat
>ts.
>746 watts in a horsepower, so how do you get 4.5 HP out of a wall soc
>ket?
>
>Tim Ward
>

2 answers Tim. It is common to run seperate higher amperage circuits
to larger users. For instance, your electric range is probably on a
seperate circuit (but 220 volts). In a shop, it is common to have
seperate circuits to each of several higher powered machines.

The real kicker here is the way the ad is worded. They use the term
"peak horsepower" which could be defined anyway they want.... such as a
30 second life span:) They carefully fail to mention the recommended
breaker size or normal current drawn which would indicate the real
world horse power. It is much more effient to run larger motors on
220 volts so you can be certain that this motor is actually much lower
in real horsepower.

[Ed Wischmeyer]

> The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 watts.
> 746 watts in a horsepower, so how do you get 4.5 HP out of a wall socket?

If it were DC, you'd be correct. AC has more or less sinusoidal voltage
and current, not necessarily peaking at the same time, and a whole bunch
of other stuff I used to know about.

Ed Wischmeyer

[Tim Ward]

"Ed Wischmeyer" > wrote in message
...
> > The usual wall circuit is 15 Amperes, times 120 volts peak is 1800
watts.
> > 746 watts in a horsepower, so how do you get 4.5 HP out of a wall
socket?
>
> If it were DC, you'd be correct. AC has more or less sinusoidal voltage
> and current, not necessarily peaking at the same time, and a whole bunch
> of other stuff I used to know about.
>
> Ed Wischmeyer

Yep, but that makes it worse, not better. I'd expect RMS power to be about
70 % of that 1800 watts.
That's about 1300 watts, or less than 2 HP.

Tim Ward

[Rich S.]

"Tim Ward" > wrote in message
...
>
> Yep, but that makes it worse, not better. I'd expect RMS power to be about
> 70 % of that 1800 watts.
> That's about 1300 watts, or less than 2 HP.

Well, if 4.5 hp out of a wall socket isn't enough, how about this one???

Rich "To infinity and beyond!" S.

6 HP, 20 GALLON COMPRESSOR

Oil-free design for lower maintenance. Easy-grip cushioned handle.
Quick-connect, regulator, dual gauges and tool tray.
Horse Power: 6
Power supply: 120V
Air pressure: 135 PSI maximum
Air Delivery:
@ 40 PSI: 8.3 CFM
@ 90 PSI: 5.8 CFM

Tank size: 20 gallon
Shipping weight: 100 lbs.


Porter Cable# CPF6020

ITEM 45158-1VGA
$299.99

[RogerN]

"Tim Ward" > wrote in message
...
>
> I dunno beans about air compressors, so maybe someone else can explain it
to
> me:
> The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 watts.
> 746 watts in a horsepower, so how do you get 4.5 HP out of a wall socket?
>

The 120VAC is not the peak voltage, it's the RMS voltage. The peak voltage
of a 120VAC system is around 170V. If you take peak volts X peak amps, you
get peak VA, then multiply it X the power factor to get the peak watts,
divide by 746 / %effeciency to get peak HP. errrr.... I think.

[Corrie]

"Frederick Wilson" > wrote in message news:<2uX9b.372665$Oz4.149020@rwcrnsc54>...

> <Fred Speculating> I wonder what the average time difference is between
> deciding to build an airplane and actually starting the project.

Define "starting the project" :-)

Corrie (owner of several sets of plans, a bunch of tools, and a small
amount of wood)
http://www.itasca.net/~corrie/homebuilt_plane_blog.htm

[Roger Halstead]

On Tue, 16 Sep 2003 19:17:35 -0400, "Morgans" >
wrote:

>
>"Rich S." > wrote in message
...
>> "Frederick Wilson" > wrote in message
>> news:FmC9b.365132$Oz4.142857@rwcrnsc54...
>> > I am still working on home remodel so it will be some time before the
>> > airplane gets started. I am pretty darn convinced that I am going to do
>an
>> > all wood and fabric airplane. More than likely, the Fisher Tiger Moth.
>> >
>> > Anyway, I have come to the point in my home remodel that I am going to
>> need
>> > an air compressor. But instead of just getting one that will do the job
>> > here, what might I need one for when it is airplane time?
>> >
>> > What size and compressor (one or two cylinder) should I look at?
>> >
>> > Any name brand preference?
>>
>> Whichever model you choose, be SURE to listen to it run before you plunk
>> down your money. Some of the new compressors are loud enough to shred your
>> neighbor's panties.
>>
>> Rich S.
>
>Part of the things to consider is if you will use a lot of air tools, or go
>electric. For a wood airplane, I could see a bit of sanding, and spraying
>finish. A small 30 gal 3 HP compressor would not keep up with a air sander,
>or spray gun very well. I like air tools cause they are usually cheaper,
>lighter, and don't get hot under heavy usage.
>
>If you can swing it, get a big upright 5 HP , NOT oilless unit, and put it
>outside if you can. It saves the ears and the space in the shop. All it
>needs is a small lean-to roof.

I have one of the big 80 gallon units set at 175 psi tank pressure. I
get very little tank condensation, but it is going outside into a
small shed/leanto. If you are doing some fine work and that sucker
kicks on you will have to go hunting to find where the work landed.
It's not terribly noisy, but enough that when it comes on unexpectedly
it will startle you.

However, if I keep it outside I need to figure out how to get the
condensation out without if freezing in the tank.

OTOH it'd be wayyy to big for home construction. Yet when doing metal
work such as grinding and cutting with the pneumatic tools it kicks on
quite often. I have a smaller one like the ones used on construction
sites for nailers and other portable pneumatic tools that works fine
for that. It's just a bit heavy for hauling around, but still not
bad.


Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

[Roger Halstead]

On Thu, 18 Sep 2003 03:10:59 GMT, John Ammeter
> wrote:

>On Wed, 17 Sep 2003 20:08:08 -0700, "Tim Ward"
> wrote:
>
>>
>>"Rich S." > wrote in message
...
>>> Check out item 47065-2VGA at http://www.harborfreight.com/.
>>>
>>> 4-1/2 HP 21 GALLON CAST IRON VERTICAL COMPRESSOR
>>> Two Built-in Universal Quick Connect Couplers for Convenient Air Hose
>>> Connection
>>> Long-life oil lubricated compressor with precision machined cast iron
>>sleeve
>>> Twin capacitor motor with thermal overload protection
>>> Wheel kit with 6'' wheels and ergonomic for smooth portability
>>> Oil level indicator window for easy maintenance
>>> Reduced vibration with rubber foot stabilizers
>>> 4-1/2 peak horsepower; 120 volt, 60Hz
>>> 125 PSI max; 4.4 CFM @ 90 PSI; 11.1 CFM @ 40 PSI
>>> Shipping weight: 152 lbs.
>>> $169.99
>>>
>>> Rich S.
>>
>>I dunno beans about air compressors, so maybe someone else can explain it to
>>me:
>>The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 watts.

Most of the circuits in our house are 20 amp with ground fault. There
is one 30 amp and my den has two 30 amp 220 volt outlets( for the ham
station)

>>746 watts in a horsepower, so how do you get 4.5 HP out of a wall socket?
>>
>>Tim Ward
>>
>
>You DON'T.....

Ohhh come on John, you can too...It's just I use a 220 volt 50, or 60
amp socket like the one for the kitchen range<:-)) Well that and it's
mounted on the surface and fed through conduit. It's gotta be close
to a 90 foot run from the breaker box. No, I didn't use #14
either<:-))

Did I mention it's out in the shop too?

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)


>
>John Ammeter

[Roger Halstead]

On Wed, 17 Sep 2003 20:55:03 -0700, Ed Wischmeyer
> wrote:

>> The usual wall circuit is 15 Amperes, times 120 volts peak is 1800 watts.
>> 746 watts in a horsepower, so how do you get 4.5 HP out of a wall socket?

It's probably more like 15 or 20 amps and that is 115 to 120 volts
RMS, not peak. Peak is 1.414, or roughly 162 volts. On single phase
they current and voltage should be close enough for all practical
purposes to call them in phase. (except during starting)
>
>If it were DC, you'd be correct. AC has more or less sinusoidal voltage

So, using RMS at 115 volts he's still close.

>and current, not necessarily peaking at the same time, and a whole bunch
>of other stuff I used to know about.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

>
>Ed Wischmeyer

[L.D.]

<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
I've got air piped with pvc and it's been there over 25 years. Never read
anywhere it wasn't supposed to be used for that. Of course never read that
it was intended to be used for that. Guess it's kinda like an apple, I
never read it was intended to be eaten, we just do it. I've seen pvc used
for air supply pipe in many places and been there many years and never
heard anything dangerous about using it. Send me some documentation of
it failing and hurting or killing someone. Not just one incident but a
pattern. People get killed by slipping getting out of the shower but not
enough to get people upset every time they shower.
<p>Roger Halstead wrote:
<blockquote TYPE=CITE>On Tue, 16 Sep 2003 19:17:35 -0400, "Morgans" >
<br>wrote:
<p>>
<br>>"Rich S." > wrote in message
<br>><a </a>...
<br>>> "Frederick Wilson" > wrote in message
<br>>> <a @rwcrnsc54</a>...
<br>>> > I am still working on home remodel so it will be some time before
the
<br>>> > airplane gets started. I am pretty darn convinced that I am going
to do
<br>>an
<br>>> > all wood and fabric airplane. More than likely, the Fisher Tiger
Moth.
<br>>> >
<br>>> > Anyway, I have come to the point in my home remodel that I am
going to
<br>>> need
<br>>> > an air compressor. But instead of just getting one that will do
the job
<br>>> > here, what might I need one for when it is airplane time?
<br>>> >
<br>>> > What size and compressor (one or two cylinder) should I look at?
<br>>> >
<br>>> > Any name brand preference?
<br>>>
<br>>> Whichever model you choose, be SURE to listen to it run before you
plunk
<br>>> down your money. Some of the new compressors are loud enough to
shred your
<br>>> neighbor's panties.
<br>>>
<br>>> Rich S.
<br>>
<br>>Part of the things to consider is if you will use a lot of air tools,
or go
<br>>electric.&nbsp; For a wood airplane, I could see a bit of sanding,
and spraying
<br>>finish.&nbsp; A small 30 gal 3 HP compressor would not keep up with
a air sander,
<br>>or spray gun very well.&nbsp; I like air tools cause they are usually
cheaper,
<br>>lighter, and don't get hot under heavy usage.
<br>>
<br>>If you can swing it, get a big upright 5 HP , NOT oilless unit, and
put it
<br>>outside if you can.&nbsp; It saves the ears and the space in the shop.&nbsp;
All it
<br>>needs is a small lean-to roof.
<p>I have one of the big 80 gallon units set at 175 psi tank pressure.&nbsp;
I
<br>get very little tank condensation, but it is going outside into a
<br>small shed/leanto.&nbsp; If you are doing some fine work and that sucker
<br>kicks on you will have to go hunting to find where the work landed.
<br>It's not terribly noisy, but enough that when it comes on unexpectedly
<br>it will startle you.
<p>However, if I keep it outside I need to figure out how to get the
<br>condensation out without if freezing in the tank.
<p>OTOH it'd be wayyy to big for home construction. Yet when doing metal
<br>work such as grinding and cutting with the pneumatic tools it kicks
on
<br>quite often.&nbsp; I have a smaller one like the ones used on construction
<br>sites for nailers and other portable pneumatic tools that works fine
<br>for that.&nbsp; It's just a bit heavy for hauling around, but still
not
<br>bad.
<p>Roger Halstead (K8RI EN73 &amp; ARRL Life Member)
<br>www.rogerhalstead.com
<br>N833R World's oldest Debonair? (S# CD-2)</blockquote>
</html>

[Rich S.]

PVC makes great potato guns. Note the one in BWB's grasp at
http://www.jouster.0catch.com/jean-02/p2190041.jpg.

Rich s.
"L.D." > wrote in message ...
I've got air piped with pvc and it's been there over 25 years. Never read anywhere it wasn't supposed to be used for that. Of course never read that it was intended to be used for that. Guess it's kinda like an apple, I never read it was intended to be eaten, we just do it. I've seen pvc used for air supply pipe in many places and been there many years and never heard anything dangerous about using it. Send me some documentation of it failing and hurting or killing someone. Not just one incident but a pattern. People get killed by slipping getting out of the shower but not enough to get people upset every time they shower.

[dann mann]

We have PVC plumbing 140 psi all over our shop in San Diego. It
occasionally blows out at a joint and it really hurts people's ears. I
don't recommend it but you might get away with it.

[Fitzair4]

We have PVC in our full time shop for 23 years. Never a problem. Just clean
and seal all the joints right. Have 120 psi.

Larry

[butch burton]

(Craig) wrote in message >...
> "Frederick Wilson" > wrote in message news:<FmC9b.365132$Oz4.142857@rwcrnsc54>...
> > What size and compressor (one or two cylinder) should I look at?
> >
> > Any name brand preference?
> >
> Assuming that you will end up using it more than you think, shop
> around for a two stage, 220VAC unit with at least a 60 gallon tank.
> Stay away from the oilless units for noise reasons. The lower the rpm
> of the compressor, the lower noise factor it will have. Keep an eye
> out for Champion, IR, and any other big name vendor. Be aware that the
> ratings on Crapsman units are very inflated. When you compare units,
> use cfm @ pressure to make the comparisons meaningful.
>
> Lots of people have built a/c using the litle hotdog tanked units and
> the small household units, but if you have to spend much time waiting
> on them to return to the required pressure to do the job, then they
> are way too small if you have minimal time to devote to the projects.
> For average usage, if the compressor has to cycle one more than once
> every minute and a half or less, you need either a bigger unit or more
> tankage.
>
> What ever you do, DO NOT...I repeat DO NOT use PVC or CPVC for
> pressure piping on your system. Many people use it, but do not
> understand that it is not rated for or intended for use with
> pressurized air. When it fails, and it will, it will almost always
> fail explosively and send shrapnel all over the place. If you don't
> belive me, I will show you the pressure rating for PVC with all the
> derating factors applied....it's very scary.
>
> More questions? ask away....
>
> Craig C.
>

Always wondered why people use PVC/CPVC when copper is marginally more
expensive. Some places have large diameter plastic pipes to increase
their air storage "capacity". Kind of like sleeping with a rattle
snake-sooner or later.....

[wmbjk]

"Bryan Martin" > wrote in message
...
> in article , Tim Ward at

> wrote on 9/17/03 11:08 PM:
>
> > I dunno beans about air compressors, so maybe someone else can
explain it to
> > me:
> > The usual wall circuit is 15 Amperes, times 120 volts peak is 1800
watts.
> > 746 watts in a horsepower, so how do you get 4.5 HP out of a wall
socket?
> >
> > Tim Ward
> >
> >
> You would run a 30 Amp, 120 Volt circuit with a 30 Amp receptacle.
Most
> likely this compressor can be wired for 240V by moving some jumpers in
the
> motor then you could run it on a 15A, 240V circuit. By the way, the
nominal
> voltage for an AC system is given in RMS voltage not peak.
>

If it's 4 CFM and 30 Amps at 120 Volts, then the crankcase must be
filled with used oil and wood chips. ;-)

If you check some of HF's other ads, you'll see that they have similar
compressors with similar output that are rated at 2 hp (only inflated a
little). The 4.5 hp thing is just something some ad weenie thought he'd
try to see if Sears would notice and call with a better job offer.

I like HF, but some of their ad writers are goofy. My favorite was the
caption for the little combo lathe/milling machine which for years read
"every plumber needs one". For what? Making all those short pieces of
pipe with straight threads? For his night job as a master machinist?

For yuks I just picked up the topmost HF catalog from my stack of 17 (I
threw out the ones from last week). I knew there'd be something
brainless on the cover. Sure enough, a $70, 600W inverter featuring the
"latest sine-wave technology" that can run "compressors" and "toasters"
among other things. Certainly you need the latest sine waves for
toasters. :-)

Wayne

[Craig]

(Fitzair4) wrote in message >...
> We have PVC in our full time shop for 23 years. Never a problem. Just clean
> and seal all the joints right. Have 120 psi.
>
> Larry

Been in lots of places that used it and seen lots of failures. You do
know that Sch 40 and 80 both have an ultimate tensile strength of
only 7400psi at 73 deg. F.,( black iron is about 10-15 times that )
and that by the time you get to around 90deg F., that is reduced by
almost 50%? By the time you run the numbers for the data given in ASTM
D1784, the code that your pvc pipe is rated by, when you do all the
required derates and apply all the safety factors required for sound
engineering practices, 1" PVC is rated to handle about 4psi working
pressure. It also might interest you, in that the code specifically
states that the rating is good for incompressible liquids only and
that pvc and cpvc are to never be used in a compressible gas system
without revising the pressure ratings to those found under ASME B31.3.

BTW...if you are a commerical shop, the use of pvc like this will get
you some nice little code violations if the inspectors ever look
notices it, or OSHA visits.

Craig C.

[L.D.]

<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
I'm no engineer and don't have a lots of formal smarts but common sense
tells me&nbsp; if the following is true, then PVC is useless as tits on
a boar hog for any use. 4 psi???
<p>"when you do all the required derates and apply all the safety factors
required for sound engineering practices, 1" PVC is rated to handle about
4psi working pressure."
<p>L.D.
<p>Craig wrote:
<blockquote (Fitzair4) wrote in message >...
<br>> We have PVC in our full time shop for 23&nbsp; years. Never a problem.
Just clean
<br>> and seal all the joints right. Have 120 psi.
<br>>
<br>> Larry
<p>Been in lots of places that used it and seen lots of failures. You do
<br>know that&nbsp; Sch 40 and 80 both have an ultimate tensile strength
of
<br>only 7400psi at 73 deg. F.,( black iron is about 10-15 times that )
<br>and that by the time you get to around 90deg F., that is reduced by
<br>almost 50%? By the time you run the numbers for the data given in ASTM
<br>D1784, the code that your pvc pipe is&nbsp; rated by, when you do all
the
<br>required derates and apply all the safety factors required for sound
<br>engineering practices, 1" PVC is rated to handle about 4psi working
<br>pressure. It also might interest you, in that the code specifically
<br>states that the rating is good for incompressible liquids only and
<br>that pvc and cpvc are to never be used in a compressible gas system
<br>without revising the pressure ratings to those found under ASME B31.3.
<p>BTW...if you are a commerical shop, the use of pvc like this will get
<br>you some nice little code violations if the inspectors ever look
<br>notices it, or OSHA visits.
<p>Craig C.
</blockquote>
</html>

[Morgans]

"L.D." > wrote in message
...
> I'm no engineer and don't have a lots of formal smarts but common sense
tells me if the following is true, then PVC is useless as tits on a boar
hog for any use. 4 psi???
> "when you do all the required derates and apply all the safety factors
required for sound engineering practices, 1" PVC is rated to handle about
4psi working pressure."
>
> L.D.
>
> Craig wrote:

It works great at what it is intended for, when installed correctly, and
that is cold water supply. The temperature is the big issue, when dealing
with pressure. Any building inspector has a piece of pvc blown up from 3/4"
up to about 3", found after someone incorrectly installed it hooking up a
hot water heater.
--
Jim in NC

[Del Rawlins]

On 22 Sep 2003 08:40 PM, Roger Halstead posted the following:

> As for my air system I run 175 psi and plastic is "to me" out of the
> question. I have 1/2 galvanized installed. I gotta figure how to get
> that monster out into a leanto on the back of the shop...even if it's
> insulated with a little heat...It has to stay warm enough to keep the
> condensate from freezing. It's not terribly noisy, but noisy enough
> to startle you when it starts and you don't want to be doing some fine
> work when it does. <:-))

Get one of those orange 110v heating pads that you stick to the oil pan
of your car or airplane, and stick it to the bottom of your compressor
tank. I've got a similar sized compressor (used) sitting out in my shed,
and if/when I get around to hooking it up, that is what I am going to do.
No way am I going to put that sucker inside my workspace.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[Eric Miller]

"Craig" > wrote
> Been in lots of places that used it and seen lots of failures. You do
> know that Sch 40 and 80 both have an ultimate tensile strength of
> only 7400psi at 73 deg. F.,( black iron is about 10-15 times that )
> and that by the time you get to around 90deg F., that is reduced by
> almost 50%? By the time you run the numbers for the data given in ASTM
> D1784, the code that your pvc pipe is rated by, when you do all the
> required derates and apply all the safety factors required for sound
> engineering practices, 1" PVC is rated to handle about 4psi working
> pressure. It also might interest you, in that the code specifically
> states that the rating is good for incompressible liquids only and
> that pvc and cpvc are to never be used in a compressible gas system
> without revising the pressure ratings to those found under ASME B31.3.

OK, I can accept at face value that PVC isn't meant to handle compressed air
Compressible vs incompressible fluids, no problem.

But out of curiosity, how do you get from a 7400 psi under ANY conditions to
a safe working pressure of 4 psi?
That requires dividing 7400 by 2 almost TWELVE times!!!
Are there twelve (or more) separate conditions that each compromise the
tensile strength by 50% (or more)??!?!?

Just wondering, Eric

[Morgans]

"Roger Halstead" > wrote > As for my air system
I run 175 psi and plastic is "to me" out of the
> question. I have 1/2 galvanized installed. I gotta figure how to get
> that monster out into a leanto on the back of the shop...even if it's
> insulated with a little heat...It has to stay warm enough to keep the
> condensate from freezing. It's not terribly noisy, but noisy enough
> to startle you when it starts and you don't want to be doing some fine
> work when it does. <:-))
>
> Roger Halstead (K8RI EN73 & ARRL Life Member)
> www.rogerhalstead.com
> N833R World's oldest Debonair? (S# CD-2)
>
>
>
>
Put sides on that lean-to and insulate the crap out of it. Wrap a couple
lengths of pipe heat tape around it near the bottom, then some more
insulation around the tank. If the shop has heat on it all the time, a
couple muffin fans blowing hot air into the lean-to will keep it warm, too.
--
Jim in NC

[wmbjk]

"Richard Lamb" > wrote in message
...
>
>
> wmbjk wrote:
> >
> >
> > For yuks I just picked up the topmost HF catalog from my stack of 17
(I
> > threw out the ones from last week). I knew there'd be something
> > brainless on the cover. Sure enough, a $70, 600W inverter featuring
the
> > "latest sine-wave technology" that can run "compressors" and
"toasters"
> > among other things. Certainly you need the latest sine waves for
> > toasters. :-)
> >
> > Wayne
>
> Actually, isn't a toaster something of a challenge for an inverter?
>
> Mine basically said not to use for any kind of heating device.
>
> (Nearly pure resistive load?)

Not sure about others, but our Trace SWs work just fine with toasters.
They have trouble with some clocks though, including the clock in one
bread maker. The clock ran double quick, which caused the loaf to mix
and bake in a much shorter time. But sometimes shorter isn't better.
;-)

Wayne

[Mark W. Ahlborn]

On 22 Sep 2003 02:31:48 GMT, Del Rawlins
> wrote:

>On 21 Sep 2003 04:31 PM, butch burton posted the following:
>> (Craig) wrote in message news:<3ca216ab.
>>> more tankage. What ever you do, DO NOT...I repeat DO NOT use PVC or
>>> CPVC for pressure piping on your system. Many people use it, but do
>>> not understand that it is not rated for or intended for use with
>>> pressurized air. When it fails, and it will, it will almost always
>>> fail explosively and send shrapnel all over the place. If you don't
>>> belive me, I will show you the pressure rating for PVC with all the
>>> derating factors applied....it's very scary. More questions? ask
>>> away.... Craig C.
>>
>> Always wondered why people use PVC/CPVC when copper is marginally more
>> expensive. Some places have large diameter plastic pipes to increase
>> their air storage "capacity". Kind of like sleeping with a rattle
>> snake-sooner or later.....
>
My two cents in; I have used pvc (white plastic) for TEMPORARY
compressed air lines @ 120 psi + and > 90 cfm and also Victaulic
grooved in the 2" size. As has been alluded to, but not nailed down,
it is mostly the temperature and time constraints that make pvc an
iffy solution. I do agree that a permanent solution involves STEEL
pipe or IRON pipe (not copper) or properly welded SDR 17 or better
HDPE pipe (use the proper mechanical couplers!) because of the
thermodynamics thing -- rapid expansion results in extreme cooling, or
solid connections near the source will experience extreme heat. This
is what kills pvc -- temperature extreme. This is an engineered
approach for 120 psi (8.3 bar) with sch 40 pvc as a TEMPORARY solution
far from source (thousands of feet/meters) with Victaulic couplers or
equivalent based on a FOS (Factor of Safety) of near 1. Kids, don't
try this at home.

[Peter Dohm]

The resistance is very low, and the load highly inductive, until the wires
heat up. It doesn't take long, in human terms; but it could be too long
for the inverted unless adiquate protective circuits are designed in.

Peter

Richard Lamb wrote:
>
> wmbjk wrote:
> >
> >
> > For yuks I just picked up the topmost HF catalog from my stack of 17 (I
> > threw out the ones from last week). I knew there'd be something
> > brainless on the cover. Sure enough, a $70, 600W inverter featuring the
> > "latest sine-wave technology" that can run "compressors" and "toasters"
> > among other things. Certainly you need the latest sine waves for
> > toasters. :-)
> >
> > Wayne
>
> Actually, isn't a toaster something of a challenge for an inverter?
>
> Mine basically said not to use for any kind of heating device.
>
> (Nearly pure resistive load?)
>
> Richard

--
Catbird Realty Phone: 561-395-0055
Peter Dohm, Lic. Real Estate Broker