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I live in South Florida (very humid) and have my sandblaster on my screened porch that has been in use for 5 years. Using a 3 HP compressor. Been working well for me to remove kiln wash, etc., not anything heavy duty. I'm using it more and more these days and am having problems with moisture. After using it for 5 minutes or so, it starts to spray wet abrasive. I have a water separator on the line and even replaced it with a new one to see if that would help. Still sprays water after 5-7 minutes. I'm using aluminum oxide as my abrasive. The water separator I'm using is a cheap one ($6) - could that be the issue? I have no idea what one I should use. Would a better one make a difference? If so, which one would you recommend? Help!

Thanks!
Dot

Some things you might try:

Make sure your compressor is drained of water every day. In a humid environment, the process of compressing air heats the air and puts all the humidity into the tank. As the air cools, the moisture condenses out and settles to the bottom of the tank where it can be reintroduced into the compressed air.

Use the shortest length of hose between your compressor and sandblaster and make sure the air hose is drained regularly.

Install a water separator also known as a water trap at the compressor and another at the sandblaster. Find a type with a clear bowl so you can see the water level. These need to be drained regularly (maybe more than once a day).

In-line air dessicants are available as are refrigerated air dryers, but I can't testify to their effectiveness. I'm sure they are an expensive option.

The water separators are available at Grainger, Tractor Supply or good hardware stores (maybe not Home Depot).

At some point, you'll need to dump out your grit and dry it out. Fill a large foil baking pan with your abrasive and put it in the sun for a couple hours. Screen it to remove debris and break up clumps before reintroducing it into the sandblaster.

I hope this helps

Tony

Thanks SO much! I'll give your suggestions a try! Really appreciate the help, Tony!

Hey smallbitz.. I used to live in Naples so I too know all about 98% humidity... I bought a dryer from horrible freight and it worked well there. Just crack it open regularly and let it vent off until you no longer see water coming out it. Here's a link to the cheapy dryer I have. https://www.harborfreight.com/air-tools ... 68247.html

You can get the exact same dryer at eastwood, but it's 84bucks.. :-/

Jagboy,

Many thanks! I think I'll try that, too! Looks very promising

One way to get the water out of the compressed air so that the separator can do its job is to cool the air and a low technology way to do that is to install a coil of small diameter copper tubing between the compressor and the water separator.

I want to make sure I'm putting the dryer (or copper) whichever I end up using in the correct place along the line. I have my blaster hooked up to a foot pedal. Soooo my compressor hose goes into my foot pedal then another hose out of the pedal into a hose which then goes into the cabinet. Where along those lines should I put the dryer? Right now, I have the old water separator immediately before going into my cabinet.

Harbor Freight does have that dryer, so I think I'll give it a try - if I can figure out where to put it

Thanks!

Put the dryer right where the air comes out of the tank BEFORE the hose. Trying to cool compressed air with copper pipe is a bit on the advanced skill side of things. It's not necessary running a blast cabinet.

Thanks!

I'd like to circle back to Kevin's comment about the copper tubing. The reason this is effective is that for a smaller compressor that runs a lot while sandblasting, the compressed air coming out of the compressor is very warm and can retain a lot of moisture in the form of vapor. This moisture cannot be taken out by a water separator, but condenses out of the air as it cools while passing through the copper coil. This happens to a lesser extent in a rubber air hose of the same length due to the lower thermal conductivity of the rubber, but it will still happen especially if a long hose is coiled on the floor in a cooler area where your sandblaster is located. That puts liquid water in the hose that will either mix with the abrasive in your sandblaster, or will need to be taken out with another water separator at the end of the air hose just before the sandblaster.

Since you have extreme humidity where you're located, extreme measures are required. I would use an air separator at each end of the hose as I previously mentioned.

Tony

You bought a roll of copper tube lately? You can get a bigger cheap compressor at HF for the same money. I do HVAC work and you should hear the people climb the wall when I tell them they need a new lineset because of the swap to 410a. It's easier to just keep draining the dryer(s).

Just. Wow. And, thank you!

I did everything you suggested Tony - and Jagboy and Kevin. I also purchased the dryer that Jagboy linked me to and it is amazing! I am using 3' rubber hoses instead of the long coiled ones that I had previously been using, have the dryer installed at the compressor and another smaller separator right at the entrance to the blaster. Emptied out the abrasive and dried it, sscreened it and put it back in (really a bunch of junk in there)!

I blasted everything I needed to yesterday and had NO moisture whatsoever! The blaster didn't work this well when it was new. If I need to, I'll add the copper pipe, but for now this seems to be solving my problem.

Thanks again for everyone's help!

Excellent. I'm glad it's working for you.

I would suggest you make a sign reminding you to drain the compressor and each of separators before sandblasting and stick it to the wall next to the sandblaster. It'll be a constant reminder that the only way to beat moisture in SF is to drain as much water as you can every day that you blast.

Tony