The Stovebolt Site Forums The Shop Area Paint and Body Shop Air Filter Problems

I'm trying to use my sandblaster, but am having problems with my air filter. It is a relatively new Craftsman, being used with at 90psi with a relatively low CFM compressor. For the sandblaster, I need every little CFM I can get. Without the filter, the blaster works fine, but it inevitably gets wet and stops working well until it dries out again. I have tried using the filter both off of the compressor, and right in front of the blaster gun, and neither will let past enough air to make it work well. The flow of air is going the right way. I dunno what to do, other than go 20 min at a time, and let it dry out in between. Any Ideas?
Thanks,
Tyler

Ty,

I am not sure I fully understand what you are asking. Are you talking about a water filter between your compressor and your sandblaster. Here is what I would do. Use a water trap, sometimes called a separator that is sized for the CFM of the compressor. 1/2" would be more than adequate. This device usually has a plastic bowl and a drain on the bottom. The inlet and outlet are sized in standard pipe. The problem you have is using a small compressor running at 100% duty cycle and no adequate aftercooler to cool the air so the moisture will drop out.

Could you be talking about a dessicant filter? If this is what you are referring to, then you will need a seperator in front of it. A dessicant filter will take out oil and water particles suspended in the air but it is not intended as the primary means of removing large quantities of water. I would dump the dessicant filter in favor of a conventional water trap. It wouldn't be out of the question to run the compressor right to your blaster and skip the trap.


Stuart.

Watch out using a Sears Craftman. I have the 6hp, 150psi model. They just don't put out enough air for a sandblaster. I burned up one motor on the compressor and finally figured it was cheaper to have someone else finish it up. Cecil.........

51jimmy,

Notice you are from Aptos...I used to hang out on Porter Gulch Road in the '60s..it was beautiful then!


Stuart.

Thanks to both of you! I did go look at what I have sitting in my garage, and it is just a dessicant filter--oh well--only $25... While I was searching for sandblaster as the title of this post (could have sworn..) the google ads gave me a link to maxtools.com, and toolsusa.com . I looked at both of them for water separators, and they gave me a couple of different things. Here's what I came up with.

http://www.maxtool.com/cgi-bin/dbsearch.exe , and http://www.toolsusa.com/cgi-bin/sgi...0%20%
20%20PACK&UID=5448111013173279 --sorry if you have to edit the last one togather...

Both look ok for different purposes. Since my sandblaster gun, and the output from my compressor are both horizontal most of the time, I think the one from maxtool would work well (right up next to the compressor), but I was thinking of getting a set of the ones from toolusa for a final measure when painting (to use right next to the gun). But neither of them show a CFM or pressure rating... Can anyone give me suggestions of other places to buy a water separator? (I tried northern, and the cheapest one they have is about $150.) I do need a water separator, as I can only go a few minutes without water getting water applied to my newly, painstakingly, sandblasted part.

51jimmy, I have a few year old 5.5hp 125psi max 20gal. Craftsman compressor that has run for hours on end, and never given me any problems. But I will keep and eye on it. Thanks.

I do have enough air to work ok, but absolutely no extra. The initial reason I wrote in was because my other filter was loosing me WAY too much pressure and/or air volume--to the point where I got NO sand, at all, not even when the sand container was over my work by 2 feet. If you know where I can buy a good water separator for a good price, please let me know.

Thanks SO Much,
Tyler

Ty,

The small air compressors run very hard to make even a small sandblaster perform properly. When you have the compressor maxed out, it is hot, the compressed air is hot and this is compounded by a small tank. Even with a trap next to the compressor, the air is still too hot for the water to fall out of it. The secret is to somehow give the air time to cool below the dew point so the water can fall out and be trapped.

I have seen several suggestions in this forum. They ranged from a hose coiled inside a 5 gallon bucket filled with ice water to cool the air, to several long runs of iron pipe to help dissapate heat.

A 1/4" pipe will pass about 50 CFM at 150 psi, so don't worry too much about undersizing your filter. It should state a max capacity right on it.

No filter can pull water out of HOT air...this is the key, somehow, get the air to cool more. When you go to spray the finish on your rig, dry air is absolutely necessary. The small CFM requirement of the gun lends itself to the small disposable filters you can put inline ahead of it. This air can't be full of water here either, it must be almost dry..here is link to what I have been calling a filter, just so we are on the same page. Good luck.

http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?xi=xi&ItemId=1611777815&ccitem=


Stuart

when you have a water trap on a air compressor you need to run a line minimum 20 feet then have the water trap that way the compressed air cools enough the water trap will fuction correctly.

Thank You Both. I have to use 2 air hoses to reach the blast box anyway, so I'll just hang a trap between the 2 hoses. Anysuggestions on where to get the traps?

Thanks,
Tyler

Ty,

DUSTYG made a good point...try and get the point of use as far away from the compressor as you can, then mount your filter right near your blast box. Don't tell anyone I said this, but Harbor Freight has a sale on filter/regulator combos right now...$19.95. You can't beat that with a big old stick!

Stuart

You could use two of the $19.95 specials side by side, not inline, so each one would take 1/2 the air flow. They would last longer and not slow down the volume of air you need!

Have you check here( http://www.tptools.com/ ) , they have a pretty good web site with usefull information. Also check with(www.surpluscenter.com ), you never know what kind of good you might find. Joe