Hom-made Sandblaster Pressure Pot Project...

I didnt get any work done on my F100 this weekend. Instead a layed some tile, put brakes on my F150 and waxed her up real good..........AND....... started my sand blast build

Heres some pics.......


Old Craftsman compressor (burnt up) tore apart


A/C parts repositioned....


Fill Cap (about 20 mins with a hole saw.....WOW)


But its together and so far I've only got 7$ in it......

 

My friend and I made one up at least 30 years ago ( when they were high priced) and it still works well but, the same friends brother in law recently decided decided to copy our unit and his blew up sending him and his friend to the hospital. Units are cheep enough now to just buy one why take the risk.

 

What was his made out of???? If it is made right there is NO-WAY one will blow up, you put a pressure relief valve on the tank just for peace of mind, use a continuously open end nozzle versuses a trigger fed type with the air shutoff in line ahead of the pot and there is NO WAY it will blow....... someones engineering wasn't quite right......

 

Cool. Looks good.

 

I like what you're sayin!

 

IMHO, It would have been a better choice to weld a steel bung onto the tank instead of
the cast iron hex bushing.

 

I guess that depends on how comfortable you are welding cast metals.....

 

Agreed, MIG + Cast iron + 100psi = grenade
it has nothing to do with your welding ability, the cast will detach from the side of the weld....

 

LOL

No. 1....... It depends on the "Cast" metal..... specifically how it has been cast and what percentage of materials were used in it during casting....

No. 2.......Cast pieces for pressurized water pipe typically tend to be of a higher quality metal and contain a larger steel concentration than lets say cast housings.....

No. 3......There is more to welding than just welding and praying it holds. You observe the metals as you weld, penetration etc. you observe them as and after they cool.......When you weld cast in my experience, you keep the cast iron as cool as possible (while still penetrating the cast) and keep the steel you are welding as hot as possible (I.E. spend more time with the wire on the steel than the cast).....Notice the discoloration of the tank vs the discoloration of the galvanization on the bushing...... that helps to even out the rate of thermal expansion or contraction properties of the two metals which in return keeps the weld and steel from cooling to fast and pulling away or cracking at the point of penetration of the cast iron.......of course im sure thats over your heads....

No. 4......Just in case you missed my above posts....there is a RELIEF VALVE on the tank......Air is like water, takes the path of least resistance.......which means it will only build to the point that the continuously open end nozzle will allow it......

Sorry if I step on any toes, but pessimism truly annoys me, especially from people who assume, or post without enough experience or wisdom to do soooo.

 

OHHHHHHHH and one more thing, take a close look at your aircompressors at home....odds are pretty damn good that they have cast bushings welded into them.....Go Check and see, I dare yah......

 

Wasn't being pessimistic, overall the build looks good, just trying to save you a trip to the hospital, but perhaps I don't have " Enough experience or wisdom to do soooo "
Why would you post a project on the board if you can't accept constructive criticism?

 

Nice work, keep us posted.

 

I apologize for coming off as a jerk. I can accept constructive criticism as well as anyone as long as that is what it is.

Now, I agree that a steel bung is better than the cast, however it is more expensive and not as readily available as the bushing. Before I used the bushing I put thought into welding it (I've welded other cast items before and through trial and error and using some metallurgical research have figured out how to actually get it to hold). As far as "grenading", who knows it may....I may not be here to post anything else. But I have put research and precautions into it to help ensure it doesn't, and I guess that's where I get defensive. However I do realize that people half/ass stuff everday without any thoughts about what they are doing and stuff goes wrong, but thats not me.

FYI, I'm comfortable Mig'n Cast to steel (if it shows decent properties when I start) but not cast to cast. Cast to Cast is harder to control the heat, You have a Slow to cool Cast piece----Quick Cooling Weld-----And another slow cooling cast piece. The weld cools fast and contracts causing fractures where it meets the casts...

I don't know how many people view this thread, but I hope it gives them the initiative to try some mig cast welding.......because it can be done.

OK Im off my soap box for a bit.

 

you can buy steel fittings just the same as cast...any plumbing supply

 

You mean "black" pipe????

 

dang buttons!!! ignore those last two blank PMs, was going to say that your on the right track, tee of at the tank, regulate your tank pressure down to like 7 psi, keep your blasting hose at 90 psi, kind of a hybrid between syphon pressure, works good

 

Here you go, read this
http://www.jalopyjournal.com/forum/showthread.php?t=270519&highlight=frankenblaster

 

The frankentank...lol... (I've actually reference that thread ^^^ for my build)

Heres a link to for a purely pressure pot build

http://www.vintageprojects.com/metal-welding/SandBlaster-plans.pdf

 

no....... i mean quality steel fittings....... when i built mine i made the top opening with steel pipe fittings at 3" for a fast fill. i cut a 3" steel coupler in half and gave the leftover to my bud for his blaster build..the used a 9" nipple cut in half with a plate welded to it for the cap ..we both used large propane tanks w/top cut off and flipped over ....phone a plumbing supply and ask. stack your hole saws and redo your cast to steel welds, steel to steel. or don't . you will know when you fill it with air and it leaks like a sieve.

 

BTW.....no compressor company would go thru the trouble and risk of welding a cast iron fitting into a compressor.


don't get me wrong your project is super and the weld looks good . anything homemade is a achievment. and more dollars toward the vehicle ...

 

FYI I plan on doing a water pressure test before it goes into use.......Take it up to about 180 psi.....about twice what it'll be used at.

Besides black iron, or galvanized no one local carries the "quality" steel fittings you refer too.......

 

i hear ya ....nearest general store to me is 20 minute drive anything else is 40 min. anything specialized is an all day event. you do what you gotta.

 

good use of stuff you had lying around. too many people would have trashed the stuff and bought more "disposable" stuff. good luck with your blasting. i too built one years ago with a threaded coupler welded in the tank and a plug. i switched it out after one or two uses to a pipe with a cap. reason being it always gets sand in the threads and with the pipe you can just blow the threads off. try doing that with a female thread in the tank. i did!! good build and good luck.

 

You know, I feel dumb now. LOL, using a threaded pipe and cap never crossed my mind....

 

You need to do some research about welding on a pressure vessel, you could potentially be building a bomb. Pressure vessels require special treatment as far as welding procedures, and expansion testing after the vessel is finished. 100 psi, or even 50 psi is more than enough to seriously hurt or kill you. Those cheap little craftsmen air compressors are scary to begin with, let alone using an old one that has been cut and welded.

 

Water pressure test.........see above^^^^

 

Are you going to have a company test it or are going to test yourself? Either way I don't think it will hold 180 psi; judging by your welds. what is that 6010- 6011?

 

clintonvillian,

Copy down this number and place it on your new sandblaster.








911

 

haha judging by my welds........wtf

and ill test it myself.....except at 150 (thats as high as my compressor will go) Fill it full of water and put 150 psi on it. It will hold or burst. What makes someone else using the same procedure better?

I'm still curious about the weld comment???? I wanna know WTF is wrong with the looks of those welds period........

 

OH btw did i mention Im a mechanical effin engineer, I know athing or two about pressure vessels jackwad......