Sandblaster troubleshooting

[jtyson]

Hoping you guys can help me figure out what is going on. I snagged a little pressure pot style media blaster off craiglist. Guy said it worked perfectly, but didn't have a compressor to test it with. I should have turned away, but, stupidly, I did not. The picture I attached is the type it is, but much older and uglier.

This thing was caked with rock hard sand. After about 6 hours worth of cleaning, it flows now. However, when hooked up to my compressor, all the valves open, when I open the nozzle to spray, it POURS media out at the rate of about a cup every 3 seconds. I have plenty of air being supplied. If I close the nozzle, detach my air supply, air and sand will shoot out the inlet, at a rate that would be acceptable for blasting.

I'm confused. Could my hose from the siphon be too large? Or the ball valve? It is going through a rather small nozzle, but still, it won't take even the smallest amount of surface rust off.

 

[xtremek]

I used to have issues with one very similar. It usually happened when the pressure dropped in my compressor. I have a 5hp, single stage, 60gal. IR compressor and it's not even close to big enough to run a pressure pot blaster for any real length of time. I'd get about 5minutes max before it would start having similar issues. Also, wet sand can cause the same issue.

 

[sgs236]

I have the eastwood version and it can be a pain getting it adjusted just right. Too much sand means you have the bottom valve opened too much. I usually adjust the top valve for the airflow that I want (1/2 to 3/4 opened), then slowly open the bottom valve. When it is working right, the bottom valve will be barely opened. I find that even when adjusted right, I have to play with the bottom valve to keep the right amount of sand while I am blasting. The more you open the top valve, the quicker you will drain air tank. These blasters do not like wet sand and I dry my sand before using it. Sieving the sand helps as well as it is easy to clog up the nozzle.

 

[PCO6]

sgs236 - I had similar problems and finally found the "sweet spot" re the valve. It's still finicky but at least I know where to start fiddling.

xtremek - I have a similar set up. Although not ideal the adjustments suggested by sgs236 will help a lot.

I agree with you both ... wet/damp sand isn't going to work. Also, cover the top of your blaster pot when it's not in use. Mine differs from the one pictured in that it has a concave top for easier filling. You manually pull up a stopper when you pressurize the pot. I had a mouse fall in the pot once. Months later I had to take the thing apart only to find that a dead mouse was stuck in the valve at the bottom.

 

[xtremek]

..........These blasters do not like wet sand and I dry my sand before using it.......

Adjusting the valve was necessary just to get it going when the pressure was high and the sand was dry. I know part of my problem was that I didn't get the air out of my compressor dry enough. Wet sand kills it every time. How do/did you dry the sand?

 

[sgs236]

Adjusting the valve was necessary just to get it going when the pressure was high and the sand was dry. I know part of my problem was that I didn't get the air out of my compressor dry enough. Wet sand kills it every time. How do/did you dry the sand?

I use a large roasting pan and bake it in the kitchen oven until completely dry.

 

[countryroad82]

I hate those things. I have one, I lend it out all the time, when it comes back people understand why I'm so readily able to loan the SOB out. I don't want it back!!! It requires finding that sweet spot, plus it's a 2 man operation. 1 man kicks, shakes, rattles, pecks with a rubber mallet (not the best idea in the world I know with a pressurized tank but how else do you make the $%^&* thing work?). While man 2 does the actual blasting. Did I mention I hate those things?

 

[jtyson]

I didn't realize I had to find a sweet spot with the valve. I've had everything completely wide open. I'll try playing with that a bit this afternoon and see if I get any better results and I'll report back.

Luckily, here in NM, humidity, and really water in general is hard to come by, so dry sand is no issue. I have a pretty decent air dryer on the compressor too because I use it for paint.

As for my compressor, I have a 5hp 60 gallon compressor as well. I've run DA sanders and air tools constantly with no issue before. Guess it is possible it still won't be enough for this blaster though.

 

[jtyson]

Sure enough, played with the valves a little and it shoots fire now. Stripped a piece of furniture this afternoon. Thanks for the help guys!

I will say though, I hate how messy it is. Even outside in my dirt driveway it still makes a mess.

*Edit - My compressor never had a problem running the blaster non stop. Not sure specs on it, but apparently it is adequate. I wonder why the previous poster's was not?*

 

[xtremek]

I bet your's is a 2 stage pump. Mine is a single stage and has issues with die grinders and DA's. I've been tempted to upgrade to a 2 stage.

 

[stratman977]

I saw a mod somewhere where the guy used long hose clamps and mounted a cheapo 1/4 sheet sander to the side of tank to keep the sand shaken at the bottom of the tank. It does prevent you from kicking it all the time.

I'm with countryroad I had one as well, tried to sell it at a yard sale for $10 and when it wasn't sold I put it out by the road with a free sign on it. Some other sucker is probably saying their share of curse words at it now.

 

[Catamount]

Sure enough, played with the valves a little and it shoots fire now. Stripped a piece of furniture this afternoon. Thanks for the help guys!

I will say though, I hate how messy it is. Even outside in my dirt driveway it still makes a mess.

When I use my pot blaster I setup a cheap/quick frame using whatever lumber I have and then hang some sheet plastic over it. Blast into that and it contains most of your sand.

Filter it, and then use it again.

 

[jtyson]

That is a good idea setting up a mini booth. It'd probably save some. At this point, I'm just blasting with the fine grit stuff you get from tractor supply for $8/50lbs. I think I want to try a finer grit though. This stuff is a little harsh stripping varnish and etching glass. I'm just playing around at this point. Cool that I got it working right. I'm trying not to do too much though, because I am only using a respirator, not a supplied air suit and I don't want to end up with black lung.

 

[Repsolracer22]

I have a media blasting business. I started out with cabinets and little pressure pot blasters. I know your struggle very well! My advice is give it up now while you have some hair on your head left!

Cabinet blasters are fine and can be used with a normal compressor. I believe they require about 19-20 CFM. But the pressure pot blasters are a whole other animal. Don't go cheap on those. To do it right, you need a real pot blaster like a Schmidt or Clemco. And you need a beast compressor like a screw type or diesel. But not cheap. My blast setup is probably $20-$25k worth of stuff. I have a metal sea container that I blast in. If you don't want to go that big, just get a local place to do it for you. You'll stress out too much and wanna kick your dog

 

[oldtractors]

I have been real happy with this blaster: B-300D-10 http://www.badboyblasters.com/id115.html

I have a 5 HP two stage compressor and it runs it fine. We have run over 2000 lbs of black blast media through it this summer.

 

[ratdoggy]

I just lay A big tarp out and recycle the sand that ends up on it