Blasting and painting

[[email protected]]

We had a cold front pass through Friday evening here in New England,
and the forecast was for cool abeit windy weather for Saturday, with
the cool remaining on Sunday but the wind diminishing somewhat. Great
weather for sandblasting, I thought.

Did I ever mention how much I hate sandblasting? It's a necessary
evil in order to get a tube part ready for painting, especially after
it's been welded as there is slag that will not come off by hand
sanding in and around the welded joints.

I have a newish Sears air compressor, one of the oilless varieties
that is capable of 150 psi. It works fine, if somewhat noisily. I
moved it outside the shop and set up with several bags of Black Beauty
blasting sand.

I had my remaining seat frame for the passenger side to do, plus the
seat rails which anchors the seat. In addition I thought I might as
well do the rear bench seat too. All the components are welded 3/8 or
7/16" tubing. The bench frame has a number of gusset plates in the
corners that double as anchors for the aluminum sheet that will cover
the frame.

That's four seperate and fairly elaborate tubing structures to blast
and paint. Oh yeh, almost forgot, I decided to do the engine test
stand as well. But the test stand got only the most cursury of
blasting jobs: I just moved back a few inches and swept quickly over
everything that had rust or scale on it. This item wasn't going to a
show, would not be flying, nor would it be exposed to weather. All it
had to do was stop rusting.

It took me half of Saturday and most of Sunday to blast them all.

Monday was planned as a painting day.

I have a nice blasting hood, such as it is. Having a full hooded and
air supplied suit would be the best choice, of course, but I don't
have such a suit. The hood had a plexiglass type view window, but
it's kinda blurred now after various blasting jobs. The viewpiece
also fogs quickly if the temperature is even 60. So it's a bit
frustrating to use, but it's all I have.

Sunday when the temperature moderated and the wind calmed down, I got
frustrated with not seeing well and donned an old brimless cap and put
on an old full face shield and finished. Even though I was wearing a
pair of coveralls, sand got everywhere on me, of course. It even got
between the nose supports for my glasses and the glasses themselves.
The grit got glued there with sweat. Did I mention how much I dislike
sand blasting?

Anyway, done is done. By Sunday afternoon, the engine test stand was
done enough and all the other parts looked like what blasted parts
should look like.

Monday was paint day.

Painting, when using a spray gun, is such a pain in the ass that I
always try to pull together a bunch of parts that need painting, all
of the same color. Otherwise you are forever cleaning stuff and
mixing different paints.

The test stand was different, in that I chose not to even prime it.
Initially I tried using a can of spray paint but ran out, of course,
before it was finished. I'd tried painting that thing Sunday evening
and it worked out well enough, until the can ran dry. So Monday
morning, when things had warmed up enough, I mixed up some yellow to
finish the job.

I decided to use the HVLP sprayer that Bruce Frank had sent me, rather
than my regular syphon type spray gun because the noise of the
compressor was driving me crazy by then. Not that the little turbine
of the HVLP didn't make noise, it was just different noise. This is
one of those really cheapo devices, but it sprayed just fine.

It was a little gummed up since the last use. I thought I'd cleaned
it well but I guess not. The plunger that moves back and forth with
the trigger was binding in it's tube so I disassembled everything,
soaked it in lacquer thinner and burnished what I could. When
re-assembled, it now worked properly.

The paint. The paints are two part urothane, even the primer. The
primer is mixed 1 to 1 with the catalyst and the top coat gets mixed 4
to 1 with the reducer.

Even at the 1 to 1 mixing ratio, the primer is a bit thick. I had to
play with the sprayer adjustments to limit the amount that was coming
out of the gun. Otherwise, so much came out that it would have been
difficult to spray into corners and inside slots without really
slathering it on.

I'm getting a little ahead of myself. The test stand did not get
primed and I began with it first (well, finished it since it was half
done with can paint).

The yellow that I had was a close match to the spray can stuff and I'm
not sure I would have cared if it wasn't. The point was to coat it
with something, not turn it into a work of art. The color paint is
much more thin than the primer, which is why it only gets a little
reducer.

The HVLP system works fine although the tube supplying the air heats
up from the turbine, which is why the cooler days are good days to
paint outside. On hot days, the paint may dry too fast. Some people
connect another length of hose to reduce the heat of the air at the
gun.

Thought I'd mixed enough yellow to finish the test stand but I was
mistaken, I had to mix another batch. Why yellow? It's what I had.

Then, it was time to do the airplane parts. I mixed up plenty of
primer and made sure that I had places to hange the pieces when they
were done.

Years ago I'd built a box with a large mesh screen to set parts on top
so I could paint them and have the paint go through the screen and not
bounce all over the place. This is fine for the top side of the part
but if you don't wait for the part to flash dry, it messes the paint
job when you flip the part over.

Since I had a lot of parts to do, I strung a wire and hung them from
it. That way I could do all the parts, one after the other, and all
sides of the parts.

But since the gun is a syphon type, it doesn't like spraying upside
down. To get the bottom side of the tubing, I had to get the pickup
filled, and spray them till it ran dry, then hold the gun rightside up
again while spraying to load the pickup tube again. Oh well, you get
what you pay for.

The rest of the painting went reasonably well. All the parts got
their coat of primer. By that time I'd gotten the adjustments to the
point where I could spray slowly and carefully, to make sure
everything got it's coat.

Then I took the dogs for a walk into the woods while I waited for the
primer to dry.

The top coat is gray. The primer is gray. Making sure you are
covering the part with the proper coat is a little difficult at times,
especially when looking past the part towards the brightly lit lawn.

Luckily, the topcoat is a shade or two lighter than the primer so I
could at least tell where I still needed paint.

By three in the afternoon, all was done and the parts had dried enough
to move them inside the shop to finish hardening and to get them out
of the carport which is also our house entrance.

Then it's final assembly of the seat base, which has bearings and
spring loaded pins to lock the seat in location in the seat rails, and
will be time to wrap it and the seat back with aluminum.

Corky Scott

[Richard Lamb]

wrote:
>
> We had a cold front pass through Friday evening here in New England,
> and the forecast was for cool abeit windy weather for Saturday, with
> the cool remaining on Sunday but the wind diminishing somewhat. Great
> weather for sandblasting, I thought.
>
> Did I ever mention how much I hate sandblasting? It's a necessary
> evil in order to get a tube part ready for painting, especially after
> it's been welded as there is slag that will not come off by hand
> sanding in and around the welded joints.
>
> I have a newish Sears air compressor, one of the oilless varieties
> that is capable of 150 psi. It works fine, if somewhat noisily. I
> moved it outside the shop and set up with several bags of Black Beauty
> blasting sand.
>
> I had my remaining seat frame for the passenger side to do, plus the
> seat rails which anchors the seat. In addition I thought I might as
> well do the rear bench seat too. All the components are welded 3/8 or
> 7/16" tubing. The bench frame has a number of gusset plates in the
> corners that double as anchors for the aluminum sheet that will cover
> the frame.
>
> That's four seperate and fairly elaborate tubing structures to blast
> and paint. Oh yeh, almost forgot, I decided to do the engine test
> stand as well. But the test stand got only the most cursury of
> blasting jobs: I just moved back a few inches and swept quickly over
> everything that had rust or scale on it. This item wasn't going to a
> show, would not be flying, nor would it be exposed to weather. All it
> had to do was stop rusting.
>
> It took me half of Saturday and most of Sunday to blast them all.
>
> Monday was planned as a painting day.
>
> I have a nice blasting hood, such as it is. Having a full hooded and
> air supplied suit would be the best choice, of course, but I don't
> have such a suit. The hood had a plexiglass type view window, but
> it's kinda blurred now after various blasting jobs. The viewpiece
> also fogs quickly if the temperature is even 60. So it's a bit
> frustrating to use, but it's all I have.
>
> Sunday when the temperature moderated and the wind calmed down, I got
> frustrated with not seeing well and donned an old brimless cap and put
> on an old full face shield and finished. Even though I was wearing a
> pair of coveralls, sand got everywhere on me, of course. It even got
> between the nose supports for my glasses and the glasses themselves.
> The grit got glued there with sweat. Did I mention how much I dislike
> sand blasting?
>
> Anyway, done is done. By Sunday afternoon, the engine test stand was
> done enough and all the other parts looked like what blasted parts
> should look like.
>
> Monday was paint day.
>
> Painting, when using a spray gun, is such a pain in the ass that I
> always try to pull together a bunch of parts that need painting, all
> of the same color. Otherwise you are forever cleaning stuff and
> mixing different paints.
>
> The test stand was different, in that I chose not to even prime it.
> Initially I tried using a can of spray paint but ran out, of course,
> before it was finished. I'd tried painting that thing Sunday evening
> and it worked out well enough, until the can ran dry. So Monday
> morning, when things had warmed up enough, I mixed up some yellow to
> finish the job.
>
> I decided to use the HVLP sprayer that Bruce Frank had sent me, rather
> than my regular syphon type spray gun because the noise of the
> compressor was driving me crazy by then. Not that the little turbine
> of the HVLP didn't make noise, it was just different noise. This is
> one of those really cheapo devices, but it sprayed just fine.
>
> It was a little gummed up since the last use. I thought I'd cleaned
> it well but I guess not. The plunger that moves back and forth with
> the trigger was binding in it's tube so I disassembled everything,
> soaked it in lacquer thinner and burnished what I could. When
> re-assembled, it now worked properly.
>
> The paint. The paints are two part urothane, even the primer. The
> primer is mixed 1 to 1 with the catalyst and the top coat gets mixed 4
> to 1 with the reducer.
>
> Even at the 1 to 1 mixing ratio, the primer is a bit thick. I had to
> play with the sprayer adjustments to limit the amount that was coming
> out of the gun. Otherwise, so much came out that it would have been
> difficult to spray into corners and inside slots without really
> slathering it on.
>
> I'm getting a little ahead of myself. The test stand did not get
> primed and I began with it first (well, finished it since it was half
> done with can paint).
>
> The yellow that I had was a close match to the spray can stuff and I'm
> not sure I would have cared if it wasn't. The point was to coat it
> with something, not turn it into a work of art. The color paint is
> much more thin than the primer, which is why it only gets a little
> reducer.
>
> The HVLP system works fine although the tube supplying the air heats
> up from the turbine, which is why the cooler days are good days to
> paint outside. On hot days, the paint may dry too fast. Some people
> connect another length of hose to reduce the heat of the air at the
> gun.
>
> Thought I'd mixed enough yellow to finish the test stand but I was
> mistaken, I had to mix another batch. Why yellow? It's what I had.
>
> Then, it was time to do the airplane parts. I mixed up plenty of
> primer and made sure that I had places to hange the pieces when they
> were done.
>
> Years ago I'd built a box with a large mesh screen to set parts on top
> so I could paint them and have the paint go through the screen and not
> bounce all over the place. This is fine for the top side of the part
> but if you don't wait for the part to flash dry, it messes the paint
> job when you flip the part over.
>
> Since I had a lot of parts to do, I strung a wire and hung them from
> it. That way I could do all the parts, one after the other, and all
> sides of the parts.
>
> But since the gun is a syphon type, it doesn't like spraying upside
> down. To get the bottom side of the tubing, I had to get the pickup
> filled, and spray them till it ran dry, then hold the gun rightside up
> again while spraying to load the pickup tube again. Oh well, you get
> what you pay for.
>
> The rest of the painting went reasonably well. All the parts got
> their coat of primer. By that time I'd gotten the adjustments to the
> point where I could spray slowly and carefully, to make sure
> everything got it's coat.
>
> Then I took the dogs for a walk into the woods while I waited for the
> primer to dry.
>
> The top coat is gray. The primer is gray. Making sure you are
> covering the part with the proper coat is a little difficult at times,
> especially when looking past the part towards the brightly lit lawn.
>
> Luckily, the topcoat is a shade or two lighter than the primer so I
> could at least tell where I still needed paint.
>
> By three in the afternoon, all was done and the parts had dried enough
> to move them inside the shop to finish hardening and to get them out
> of the carport which is also our house entrance.
>
> Then it's final assembly of the seat base, which has bearings and
> spring loaded pins to lock the seat in location in the seat rails, and
> will be time to wrap it and the seat back with aluminum.
>
> Corky Scott


Oh, Corky, I feel your pain!

Richard

[Blueskies]

Thanks for the write up Corky! Wish it was as simple as you make it sound ;-)

--
Dan D.
http://www.ameritech.net/users/ddevillers/start.html


..
> wrote in message ...
> We had a cold front pass through Friday evening here in New England,
> and the forecast was for cool abeit windy weather for Saturday, with
> the cool remaining on Sunday but the wind diminishing somewhat. Great
> weather for sandblasting, I thought.
>
> Did I ever mention how much I hate sandblasting? It's a necessary
> evil in order to get a tube part ready for painting, especially after
> it's been welded as there is slag that will not come off by hand
> sanding in and around the welded joints.
>
> I have a newish Sears air compressor, one of the oilless varieties
> that is capable of 150 psi. It works fine, if somewhat noisily. I
> moved it outside the shop and set up with several bags of Black Beauty
> blasting sand.
>
> I had my remaining seat frame for the passenger side to do, plus the
> seat rails which anchors the seat. In addition I thought I might as
> well do the rear bench seat too. All the components are welded 3/8 or
> 7/16" tubing. The bench frame has a number of gusset plates in the
> corners that double as anchors for the aluminum sheet that will cover
> the frame.
>
> That's four seperate and fairly elaborate tubing structures to blast
> and paint. Oh yeh, almost forgot, I decided to do the engine test
> stand as well. But the test stand got only the most cursury of
> blasting jobs: I just moved back a few inches and swept quickly over
> everything that had rust or scale on it. This item wasn't going to a
> show, would not be flying, nor would it be exposed to weather. All it
> had to do was stop rusting.
>
> It took me half of Saturday and most of Sunday to blast them all.
>
> Monday was planned as a painting day.
>
> I have a nice blasting hood, such as it is. Having a full hooded and
> air supplied suit would be the best choice, of course, but I don't
> have such a suit. The hood had a plexiglass type view window, but
> it's kinda blurred now after various blasting jobs. The viewpiece
> also fogs quickly if the temperature is even 60. So it's a bit
> frustrating to use, but it's all I have.
>
> Sunday when the temperature moderated and the wind calmed down, I got
> frustrated with not seeing well and donned an old brimless cap and put
> on an old full face shield and finished. Even though I was wearing a
> pair of coveralls, sand got everywhere on me, of course. It even got
> between the nose supports for my glasses and the glasses themselves.
> The grit got glued there with sweat. Did I mention how much I dislike
> sand blasting?
>
> Anyway, done is done. By Sunday afternoon, the engine test stand was
> done enough and all the other parts looked like what blasted parts
> should look like.
>
> Monday was paint day.
>
> Painting, when using a spray gun, is such a pain in the ass that I
> always try to pull together a bunch of parts that need painting, all
> of the same color. Otherwise you are forever cleaning stuff and
> mixing different paints.
>
> The test stand was different, in that I chose not to even prime it.
> Initially I tried using a can of spray paint but ran out, of course,
> before it was finished. I'd tried painting that thing Sunday evening
> and it worked out well enough, until the can ran dry. So Monday
> morning, when things had warmed up enough, I mixed up some yellow to
> finish the job.
>
> I decided to use the HVLP sprayer that Bruce Frank had sent me, rather
> than my regular syphon type spray gun because the noise of the
> compressor was driving me crazy by then. Not that the little turbine
> of the HVLP didn't make noise, it was just different noise. This is
> one of those really cheapo devices, but it sprayed just fine.
>
> It was a little gummed up since the last use. I thought I'd cleaned
> it well but I guess not. The plunger that moves back and forth with
> the trigger was binding in it's tube so I disassembled everything,
> soaked it in lacquer thinner and burnished what I could. When
> re-assembled, it now worked properly.
>
> The paint. The paints are two part urothane, even the primer. The
> primer is mixed 1 to 1 with the catalyst and the top coat gets mixed 4
> to 1 with the reducer.
>
> Even at the 1 to 1 mixing ratio, the primer is a bit thick. I had to
> play with the sprayer adjustments to limit the amount that was coming
> out of the gun. Otherwise, so much came out that it would have been
> difficult to spray into corners and inside slots without really
> slathering it on.
>
> I'm getting a little ahead of myself. The test stand did not get
> primed and I began with it first (well, finished it since it was half
> done with can paint).
>
> The yellow that I had was a close match to the spray can stuff and I'm
> not sure I would have cared if it wasn't. The point was to coat it
> with something, not turn it into a work of art. The color paint is
> much more thin than the primer, which is why it only gets a little
> reducer.
>
> The HVLP system works fine although the tube supplying the air heats
> up from the turbine, which is why the cooler days are good days to
> paint outside. On hot days, the paint may dry too fast. Some people
> connect another length of hose to reduce the heat of the air at the
> gun.
>
> Thought I'd mixed enough yellow to finish the test stand but I was
> mistaken, I had to mix another batch. Why yellow? It's what I had.
>
> Then, it was time to do the airplane parts. I mixed up plenty of
> primer and made sure that I had places to hange the pieces when they
> were done.
>
> Years ago I'd built a box with a large mesh screen to set parts on top
> so I could paint them and have the paint go through the screen and not
> bounce all over the place. This is fine for the top side of the part
> but if you don't wait for the part to flash dry, it messes the paint
> job when you flip the part over.
>
> Since I had a lot of parts to do, I strung a wire and hung them from
> it. That way I could do all the parts, one after the other, and all
> sides of the parts.
>
> But since the gun is a syphon type, it doesn't like spraying upside
> down. To get the bottom side of the tubing, I had to get the pickup
> filled, and spray them till it ran dry, then hold the gun rightside up
> again while spraying to load the pickup tube again. Oh well, you get
> what you pay for.
>
> The rest of the painting went reasonably well. All the parts got
> their coat of primer. By that time I'd gotten the adjustments to the
> point where I could spray slowly and carefully, to make sure
> everything got it's coat.
>
> Then I took the dogs for a walk into the woods while I waited for the
> primer to dry.
>
> The top coat is gray. The primer is gray. Making sure you are
> covering the part with the proper coat is a little difficult at times,
> especially when looking past the part towards the brightly lit lawn.
>
> Luckily, the topcoat is a shade or two lighter than the primer so I
> could at least tell where I still needed paint.
>
> By three in the afternoon, all was done and the parts had dried enough
> to move them inside the shop to finish hardening and to get them out
> of the carport which is also our house entrance.
>
> Then it's final assembly of the seat base, which has bearings and
> spring loaded pins to lock the seat in location in the seat rails, and
> will be time to wrap it and the seat back with aluminum.
>
> Corky Scott
>

[Stealth Pilot]

On Tue, 01 Jun 2004 11:12:30 -0400,
wrote:


>
>I have a nice blasting hood, such as it is. Having a full hooded and
>air supplied suit would be the best choice, of course, but I don't
>have such a suit. The hood had a plexiglass type view window, but
>it's kinda blurred now after various blasting jobs.

here a tip that came to me after replacing about a dozen viewing
windows. find yourself a plastic bag that is fairly transparent. cut
and tape a piece of the bag over the transparent viewing window.
in use the bead bounceback hits the bag surface and the bag gets to go
translucent and not your viewing window.
replace the section of plastic bag as often as desired. you'll never
need to replace another window.
Stealth Pilot
Australia

[[email protected]]

On Wed, 02 Jun 2004 11:14:07 +0800, Stealth Pilot
> wrote:

>here a tip that came to me after replacing about a dozen viewing
>windows. find yourself a plastic bag that is fairly transparent. cut
>and tape a piece of the bag over the transparent viewing window.
>in use the bead bounceback hits the bag surface and the bag gets to go
>translucent and not your viewing window.
>replace the section of plastic bag as often as desired. you'll never
>need to replace another window.

Oooohhh good suggestion. Thanks.

I still have the fuselage to do. I won't be able to do that with my
air compressor, it would take too long and the compressor would
probably seize from running continuously for days. I'll be renting a
commercial blasting rig that comes on a trailer and has a V-8 running
the compressor and blaster. I've used it before and it definately
doesn't lack for capacity.

It will likely still take all day though. I think by that time I
should have a regular blasting suit and remote air supply. My friend
with the Waco is telling me that we need to tag team blast it or I'll
never make it. It would be good for one guy to be standing aside and
come in to inspect when a section is done to point out the inevitable
places that got missed.

Painting will be the same extremely tiring process, except that I may
actually create a plastic paint booth so I don't have to frantically
drag it under cover if it starts raining.

Corky Scott

Corky Scott

[Veeduber]

>find yourself a plastic bag that is fairly transparent. cut
>>and tape a piece of the bag over the transparent viewing window.

----------------------------------------------------

Why not use Saran wrap like everyone else?

-R.S.Hoover

[Stealth Pilot]

On Wed, 02 Jun 2004 07:57:06 -0400,
wrote:

>On Wed, 02 Jun 2004 11:14:07 +0800, Stealth Pilot
> wrote:
>
>>here a tip that came to me after replacing about a dozen viewing
>>windows. find yourself a plastic bag that is fairly transparent. cut
>>and tape a piece of the bag over the transparent viewing window.
>>in use the bead bounceback hits the bag surface and the bag gets to go
>>translucent and not your viewing window.
>>replace the section of plastic bag as often as desired. you'll never
>>need to replace another window.
>
>Oooohhh good suggestion. Thanks.
>
>I still have the fuselage to do. I won't be able to do that with my
>air compressor, it would take too long and the compressor would
>probably seize from running continuously for days. I'll be renting a
>commercial blasting rig that comes on a trailer and has a V-8 running
>the compressor and blaster. I've used it before and it definately
>doesn't lack for capacity.
>
now you're talking. that will give continuous air. I spent over a week
solid on two occasions and even with 2 compressors teed together I
spent lots of that time waiting for a pump up.

>Painting will be the same extremely tiring process, except that I may
>actually create a plastic paint booth so I don't have to frantically
>drag it under cover if it starts raining.
>
another tip borne of sheer necessity.
no matter how much you look, no matter how much all your mates look
you will miss painting entire tubes. ...honest.
buy yourself a few bags of spring clothes pegs, the type you hang
washing out on clothes lines to dry with. when you commence painting
put a peg in the centre of every tube section. as you come to paint it
paint each end weldment then remove the peg and paint the middle.
complete each tube all round before moving to the next one.
you'll be bloody amazed at how many pegs remain when you have
completely finished painting :-) :-)
when you come to paint on the second coat start with pegs on each tube
section again. this time you'll really appreciate them :-) green on
green is a real challenge for "did I just paint that?"


your tubes are no more than half an inch across so using a huge spray
gun will paint your entire workshop floor with hundreds of dollars of
expensive paint overspray.
believe it or not I painted my entire Auster fuselage with a chinese
copy of a revel aeromodellers airbrush. it is the simple type (made by
humbrol as well) and I even used the little jar. (used 3 of them
actually as each one got clogged eventually by the epoxy paint)
I mixed my polyfiber epoxy primer in cut down soft drink cans and just
decanted into the little bottle as needed.
it is actually no slower than any other spray gun but it has the
advantage of having minimal overspray. minimal overspray equates to
minimal use of solvents and minimal lung damage and no wasted paint.
I managed a breeze through the hangar and only used a paper dust mask
over my face.
being simple they are a breeze to clean out as well.
the little airbrush runs at 30 psi and I made a fitting to attach the
little 1/8th tube to the end of my full size airline. for getting in
close to tube clusters it is without equal.
they cost me $14 each. The last one I bought for $5 in a throw out
sale.
after painting the entire fuselage the overspray on the floor almost
wasnt enough to sweep up.
Stealth Pilot

[Daniel]

Veeduber wrote ...
> > find yourself a plastic bag that is fairly transparent. cut
> > and tape a piece of the bag over the transparent viewing window.
>
> ----------------------------------------------------
>
> Why not use Saran wrap like everyone else?
>
> -R.S.Hoover




Didn't realize you were that old Bob!*

* When Carl Reiner asked Mel Brooks' 2,000-Year-Old Man to name the
greatest invention in the history of the world, Brooks replied, "Saran
Wrap."

Daniel