Clarke sandblaster gun - moisture?

"Ramsey" @##@.^net wrote

If you get tired of your trap fill up, you can get one automatically
drains now at Grainger. I installed one two years ago, and haven't seen
water in my 10 HP system since.

chuckle

Yes, I left that detail out. If you put a 1/4" petcock on the bottom of my
big diameter water condensing trap, you can leave it open, just a tiny, tiny
amount. Not so much you can even hear any air hissing, but it will be
enough to let the water out, unless you are really running the compressor(s)
hard, for a long time.
--
Jim in NC

On Fri, 8 Aug 2008 02:50:05 -0400, "Morgans"
wrote:


"Ernest Christley" wrote

Get the big, all-metal jobber from HF. It has a drain for any trapped
water. Set you back $20 or so, but I have it bolted to the side of my
compressor cart. The instances where you want water droplets in your
compressed air are few and very far between.

To the OP:

I made a homebuilt water trap, that seems to get the lion's share of the
water and moisture out of the air before it can get to any desiccant type
air dryer. Beware that a small desiccant will be wet and change color and
be used up very quickly at the high airflow that sandblasting requires.

Get a 6 foot length of 1-1/2" steel pipe, (or bigger, and bigger could only
work better) and an assortment of fittings, to adapt it to a configuration
like the following. You want to pipe your air supply into the bottom of the
pipe, which will be used straight up and down. You will want to put the air
into the pipe with a T fitting, so the air will be going into the T and
traveling upwards, but a few inches lower than the T will be a reservoir
area of a few inches of pipe and a drain petcock to remove accumulated
water. I also put a quick disconnect on the inlet and the outlet to make it
handy to hook up.

After the air enters, it will travel upwards, but pretty slowly which will
tend to let water drop out of suspension. Because it is in a big piece of
steel, the air will also cool and condense and let more water drop out, and
run down the pipe to be collected and drained out the petcock at the bottom.


Jim - I don't know if I told you but I took your advice, built the
coalescing filter, and used it today; took about 4T of moisture out of
the air after about :15 of work - Mike

"Michael Horowitz" wrote

Jim - I don't know if I told you but I took your advice, built the
coalescing filter, and used it today; took about 4T of moisture out of
the air after about :15 of work - Mike

Yep, it works like a miracle.

I got the idea after working in a shop with the air supply being distribute
overhead, then dropping down to a quick connect fitting. It only had an
elboe before the fitting, and it would constantly have water blowing out of
the fitting. I changed the elbows out with t's and a piece of pipe below
the outlet to collect the water. That was the start of the development of
my rig.
--
Jim in NC

Morgans wrote:
"Michael Horowitz" wrote

Jim - I don't know if I told you but I took your advice, built the
coalescing filter, and used it today; took about 4T of moisture out of
the air after about :15 of work - Mike

Yep, it works like a miracle.

I got the idea after working in a shop with the air supply being distribute
overhead, then dropping down to a quick connect fitting. It only had an
elboe before the fitting, and it would constantly have water blowing out of
the fitting. I changed the elbows out with t's and a piece of pipe below
the outlet to collect the water. That was the start of the development of
my rig.
*
*
How about gilding the lily with a flow spinner?
If that uptube airflow is spun up with a stainless butterfly inserted
near the base, you get two more winning assets:
1) centrifugal droplet spin out on the tube walls.
2) more flow turbulence near the tube walls, to cool and precipitate.....

Brian W

On Thu, 07 Aug 2008 16:39:51 -0400, Michael Horowitz
wrote:

I came upon a Clarke sandblaster gun, filled it with abrasive, ran the
pressure up to 100 PSI and tried it out. this is a syphon type blaster
that looks a bit like a paint sprayer.

I know when spraying paint folks advise you to have something in the
line to dry the air. Is a dryer necessary if I'm spraying abrasive?

Has anyone had results they were please with using a sandblaster gun?
- Mike


I spent weeks and weeks and weeks bead blasting my Auster Fuselage.
most of the time is spent waiting for the compresser(s) to pump up.
3 compressers Tee'd together work almost manageably to give near
continuous air. if you are doing it this way a good trick is to alter
the control valves so that they kick in at different pressures. just
by listening you can tell what pressure you have.

a better source is a trailer mounted diesel compressor, the type you
hire. these deliver full pressure on a continuous basis. I suggested
this to one of my mates. the bugger bead blasted an entire fuselage in
1 day.

moisture you will see as a dark spot in the centre of the bead spray
on the tube you are beading off. if you get the dreaded dark spot then
you should try the combined water traps pressure reducers in the line.
some people use 2 or three of them, placing them between line
sections. the dark spot is caused by condensation and will often
develop corrosion overnight.


you will need to replace nozzles on a regular basis. I machined
myself up nozzles in nylon that worked as well as the original ones.
you can tell when they need replacing because the internal passage
wears out oval and you lose the volume of beads you need.

you are wearing protective gear right?
a good timesaver is to cover the faceplate with some thin transparent
plastic. this will fog up gradually as the bounced beads abrade it.
you just tear off the transparent plastic and replace it. saves
stuffing up the mask's actual faceplate.

be sure to wear breathing protection.

Stealth Pilot

On Aug 10, 5:56 am, Stealth Pilot
wrote:

I spent weeks and weeks and weeks bead blasting my Auster Fuselage.
most of the time is spent waiting for the compresser(s) to pump up.
3 compressers Tee'd together work almost manageably to give near
continuous air.
------------------------------------------------------------------------

One way to tell a good Chapter from the other kind is that they're
always involved in projects developing equipment that would be too
expensive for an individual to managed on his own, such as pigs of
lead accurately marked as to their weight, or the scales and stands
needed to do your W&B. A portable compressor capable of driving at
least one sand-blasting gun is another example, especially when folks
find out they can have the thing virtually for free.

Herez How:

You start with an old VW engine, and I'm talking basket-case. Patch
it up so that cylinders 1 & 3 will run. Remove the rockers for
cylinders 2 & 4. Put a wipe of Permatex on the intake valves for 2 &
4 and install the stock spring & keeper. On the exhaust valves for 2
& 4 you want a very light spring, somehting having only a few OUNCES
of compression.

The exhaust ports for cylinders 2 & 4 become your air INLETS. The
sparking plug hole for those jugs becomes you OUTLETS (and are fitted
wtih a check-valve, which you can make from an old spark plug and a
ball-bearing.)

Back in the days of the Model T this arrangement was the most common
means of providing compressed air for jack-hammers and the like.

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a good timesaver is to cover the faceplate with some thin transparent
plastic.
------------------------------------------------------------------------------

Here in the States we use plastic wrap (brand name: Saran Wrap, et
al). You put four or five layers on the face-plate with one edge
aliigned, the other overlapping by aboout an inch. As it fogs up, you
simply peel off the top layer, keep on working.

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be sure to wear breathing protection.
---------------------------------------------------------------------

Roger that! Media-blasting has to be the worst job in the world.

-R.S.Hoover