Pressure/Vacuum setup using HF paint pot

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gketell

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Ok, this is old hat for most of you but I sat on the hardware store floor for almost an hour yesterday figuring out just EXACTLY what I needed to set this all up. I figured I would try to give someone else a jump start in the future.


Here is an overall photo of the entire setup.
20075105443_CIMG2394.jpg



Harbor Freight 2-1/2 Gallon Pressure Paint Tank (I call it "pot") http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93119 with the paint pickup tube cut off. (Unless you are Hercules, don't try to unthread the $%^&* thing or you will end up with pulled muscles.)

Harbor Freight Air Vacuum Pump
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3952

MSC Direct -30 - 0 - 100 vacuum/pressure gauge
http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1953302&PMT4NO=22417569

and a bunch of fittings/valves from my local hardware store (Orchard Supply Hardware (aka OSH) on the West Coast)

This is the Air Vacuum Pump with the vacuum outlet replaced with a 1/8" Female Pipe Thread (FPT) to 3/8" Compression (CMP) fitting and connected to a 3/8" CMP to 3/8" CMP braided line (sold as a dishwasher hookup line):
20075105950_CIMG2398.jpg

The back of the vacuum pump has a 1/4" Male Pipe Thread (MPT) to male air-hose quick-connect from your air compressor.


This is the Vacuum side of the Pot hook up. It is (from the pot out) a 3/8" FPT to 1/4" FPT reducer connected to a 150-psi valve with 1/4" MPT on one side and 3/8" CMP fitting on the other side connected to the other end of the 3/8" CMP braided line from the vacuum pump.
200751051244_CIMG2397.jpg



This is the pressure side of the pot hook up. It is (from the pot out) a 3" 1/4" to 1/4" MPT stand off (replacing the removed/leaky pressure relief valve), a 1/4" FPT "T", the top of the "T" is the 30-0-100 vacuum/pressure gauge from MSC Direct, the left side of the "T" is another 150-psi valve (you can't really see it because the handle is in back), this one a 1/4" MPT to 1/4" FPT connected to a 2" 1/4" to 1/4" MPT stand off connected to a 1/4" FPT 90-degree elbow connected to the bottom connection of the pressure gauge that came with the HF Paint Pot. The right connection of the pressure gauge has a 1/4" FPT cap. The left connection has the 1/4" FPT to male air-hose quick connect from your air compressor.
200751051627_CIMG2396.jpg


To use this, just close the vacuum valve, open the pressure valve then hook up the compressor line to the quick connect on the pressure regulator and adjust for your selected pressure.

For vacuum, close the pressure valve, open the vacuum valve and then connect your air compressor to the back of the vacuum pump. This took my vacuum to -29 psi within about 2 minutes (I'm at roughly 400' above sea level).


The sad thing is those 150-psi valves from OSH start leaking at about 50-psi even when tightened so much you bend the handle. A very slow leak, but I will be replacing them with something different. MSC Direct has some decent looking ones, just do a search for valves then narrow to 1/4", bronze, with a lever handle.


Happy Casting!!
GK
 
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Originally posted by gketell
<br />
The sad thing is those 150-psi valves from OSH start leaking at about 50-psi even when tightened so much you bend the handle. A very slow leak, but I will be replacing them with something different. MSC Direct has some decent looking ones, just do a search for valves then narrow to 1/4", bronze, with a lever handle.


Happy Casting!!
GK

Why not just use a standard WOG 1/4" brass ball valve from the Lowes or Home Depot with some nipples(reducers depending on where you are at) if necessary? I have never had a standard BBV leak. Various fittings have leaked, but ball valves no.
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gketell

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Sadly, because neither my local OSH, or Tru-Value, or Home Depot had a 1/4" ball valve and I didn't want to put a 1/2" on there. [:(]

These looked like they should work but their looks were deceiving. [V]

But the 1/4" ball valve is what you get when you search MSC as indicated so if you can't find them locally (as I can't)...

GK
 
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Originally posted by gketell
<br />Sadly, because neither my local OSH, or Tru-Value, or Home Depot had a 1/4" ball valve and I didn't want to put a 1/2" on there. [:(]

These looked like they should work but their looks were deceiving. [V]

But the 1/4" ball valve is what you get when you search MSC as indicated so if you can't find them locally (as I can't)...

GK

Let me look at the HD after I get some work done today. Maybe we can arrange something.

.
 

Fred

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Now IF you really want to see a professional's setup, check out this rig ...
http://www.talkbass.com/forum/showthread.php?t=176923

If you "register" at the site you can get a lot of information. About the ONLY THING they will not tell you is exactly what it is that they do to work their magic with the wood. Don't even bother asking as you will get no definitive reply aside what you will get reading all his information. It is interesting if you are wondering about the stabilization processes.

Just for 'kicks', try and find out how much that vapor pump costs ... Be seated if you find a price! [;)]

For now I do believe that the rest of us 'poor' souls will have to make do with things like the HF pressure pot. AT least we can try to make ourselves happy trying. [:D]
 

gketell

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Now that is just NOT fair.

Thanks to Glass Scratcher I was able to locate some of the ball valves at Home Depot. They were on a different aisle, several aisles away, from the rest of the plumbing parts. So I rebuilt the system and pressurized it over night. Started at 67 pounds, closed all valves and disconnected everything. In the morning I was down to about 18 pounds.

Where were the leaks? I sprayed it all down with soapy water and found that every one of my joints was air tight. But...


2007519184148_IMG_4669.jpg


2007519184226_IMG_4674.jpg


The freaking cast elbows/Ts/caps all leak through the cast. And the Paint Pot's original threaded joint leaks.

"What now?" Well, refusing to spend another penny on this contraption I decided to try to cheat. I cleaned them all up with Denatured Alcohol and then applied maximum vacuum (the gauge reads somewhere around -40 so I don't beleive it much)

2007519191559_IMG_4682.jpg


and then coated all the cast parts with thin CA and let the capilary/vacuum action pull it into all the leaky parts hopefully sealing them.

Ok, now for the new build out instructions with good valves:

2007519184715_IMG_4675.jpg


Pressure side: 3" long, 1/4"-Pipe Nipple, 1/4"-pipe 'T', top of the T is the dual-gauge from MSC (Leaves a bit to be desired in accuracty but for our purposes it is good enough), left of the T is a "close" 1/4"-pipe nipple, the new valve (UPC 0-32888-07701-0. Id #on the tag was 107-701HC each priced at $6.27 (thanks to Glass Scratcher)), 2" 1/4"-pipe nipple, 1/4"-pipe elbow, original HF pressure regulator, 1/4"-pipe cap, 1/4" air tool connector (female).


200751918485_IMG_4677.jpg


Vacuum side: 3/8" FPT to 1/4" FPT reducer, "close" 1/4"-pipe nipple, the new valve (same as above), "close" 1/4"-pipe nipple, 1/4" FPT to 3/8" compression adapter.


2007519191214_IMG_4680.jpg


Vacuum pump: 1/4" air tool connector (male), 1/8" FPT to 3/8" compression adapter, 3/8" compression braided hose ("washer hookup line).


GK
PS all joins have the male threads wrapped with 6 turns of plumber's teflon tape and then tightened as tight as I could without worrying about breaking the parts.

PPS The CA treatment worked perfectly. No more leaks from the cast parts. Just have to seal the one leak where the original HF 3/8" elbow joins to the pressure pot.

PPPS to save some money/complexity you could remove the 3/8" compression stuff and just use a short or coiled 1/4" air hose.
You would just have to change the 1/8" FPT to 3/8" compression adapter out for a 1/8" FPT to 1/4" MPT adapter.



Happier Casting!!
 

gketell

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Originally posted by Glass Scratcher


It looks great! Now when are we gonna see some castings???

.


Since you asked...

This is my first cast made for my neice who just turned 13 and is Very into "Brands". I made a mailing label of the Coach "Scribbles" pattern and glued it to a tube and cast clear PR over it. The bottom half is from Jeff in Indiana.

200752035353_IMG_4658.jpg

GK
 

doberman

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"Pressure side: 3" long, 1/4"-Pipe Nipple, 1/4"-pipe 'T', top of the T is the dual-gauge from MSC (Leaves a bit to be desired in accuracty but for our purposes it is good enough), left of the T is a "close" 1/4"-pipe nipple, the new valve (UPC 0-32888-07701-0. Id #on the tag was 107-701HC each priced at $6.27 (thanks to Glass Scratcher)), 2" 1/4"-pipe nipple, 1/4"-pipe elbow, original HF pressure regulator, 1/4"-pipe cap, 1/4" air tool connector (female)."

On the pressure side couldn't you use a vaccum guage only here, instead of the dual guage (vac and pressure)??
 

gketell

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You would have to rearrange it a bit so the vacuum gauge end up outside the valve on the vacuum-side so that the vacuum-only gauge does not get pressurized when doing the pressure side of your cast. But other than that, yes you could.

GK
 
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