Aftercooler or Desiccant?

stlcardinalsguy

Promoted Users
Finally got my sandblaster finished and it works great until about 1 hour in. Then it starts getting clogged at the base from the moisture in the lines. I have a 5 leg copper water trap and a cheap moisture trap/regulator attached to the blaster but the two together aren't working well enough. I assume this will be a problem when I start to paint as well. Has anybody had any experience with aftercoolers? I figure I can make an aftercooler out of a 16" fluid cooler and 12" fan for about the same price as the desiccant filter that Chris posted in another thread (https://www.zoro.com/arrow-pneumati...scfm-2-qt-12-d12-04xl/i/G7821005/#description). I would like to have both but funds are limited and I'm getting tired of spending all of my money on tools. What would be the better option assuming I will be painting in the near future as well?
 
I used an old dorm fridge with a 5 gallon bucket inside, and a copper coil in the bucket filled with water to chill the air enough to condense any moisture out. After that a regular water trap will work since there's no water vapor in the lines. We had it all laying around already so there really wasn't any cost involved.

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first make sure its just moisture and not oil. Oil gums up desiccant quickly. Both are trying to get the dew point of the air down. If its oil the motorguard is the cheapest way to go with replaceable filters. Either way with water, you need to get the water out of the lines after you cool it. If you dont have a constant pisser drain somewhere since you probably want all the pressure you can get for blasting, then you probably already have a known time you should be stopping to drain condensate. If your compressor is running constantly while blasting, there probably wont be anything affordable that can keep up with the heat generating from the air compressor.
 
imo dessicant sux and is only good to further reduce the dew point after your air runs through a refer dryer. if you look around, many times you can find good used refer dryers for cheap or the harbor freight one is actually good up to about 25 cfm and you can find it on sale usually under 400 bucks. dessicant as a stand alone dryer may be ok in some place like arizona where the humidity is low but places here along the east coast the humidity is so high in the warmer months that a 10lb deccicant cartridge would be full of water in about 20 min of use. they are basically useless but really depends on where you are. dessicant is cheaper up front but in the long run will cost more then a refer unit so keep that in mind.
 
Thanks for all the replies, I would have loved to get the HF refer dryer but I was only allowed to spend a set amount. I picked up the 1 gal Arrow Desiccant filter from Zoro, hopefully it will do a halfway decent job. I'm 100% sure it's moisture in the blast media, I let some sit out for the past couple days and it dried out so no oil. The compressor doesn't run constant while blasting but the air does get a little warm, I'll just have to take a few more breaks than I would like to....maybe try to get the old aftercooler/intercooler thingy from my grandpa working again if there are still some issues. Thanks for all the input, you all are awesome!
 
I would just try to t in something with a drop off before the drier, put a little 1/8 or 1/4 drain in to get as much water out before it get to the drier. You get something small enough you can let it piss when you are blasting and not lose much. Its either that or a timed electric drain that will just blast out whatever is in that pipe. The drier still helps, but wont get overloaded too fast. AS quick as your sand is getting mottled up, so will the beads.
 
I would just try to t in something with a drop off before the drier, put a little 1/8 or 1/4 drain in to get as much water out before it get to the drier. You get something small enough you can let it piss when you are blasting and not lose much. Its either that or a timed electric drain that will just blast out whatever is in that pipe. The drier still helps, but wont get overloaded too fast. AS quick as your sand is getting mottled up, so will the beads.


I have a 5 leg 3/4" copper trap that looks similar to this that will be before the desiccant dryer:

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It has a drain on the bottom of each leg...should I leave one or more of the drains partially open while blasting? The 3rd leg seems to accumulate the most water.
 
I have a 5 leg 3/4" copper trap that looks similar to this that will be before the desiccant dryer:

View attachment 14321

It has a drain on the bottom of each leg...should I leave one or more of the drains partially open while blasting? The 3rd leg seems to accumulate the most water.


No. Just drain them every so often as you are blasting. Keeping it open just costs you CFM and makes your compressor work that much harder.
 
I have a 5 leg 3/4" copper trap that looks similar to this that will be before the desiccant dryer:

View attachment 14321

It has a drain on the bottom of each leg...should I leave one or more of the drains partially open while blasting? The 3rd leg seems to accumulate the most water.
depends on how they fill up, usually, you can set one up to piss and its not long before it clogs since its just pinched open. If you can get it set, with a needle type valve small enough, it should just drip nicely and not blow out air. The automatic drains use a blast of air when the timer hits. Since you already have ball valves there you should be able to just crack them open. Just depends if you feel you need to run to drain every 5 minutes or each hour. You can also do something on your blaster before the air goes in to put a drop there to fill as well.

I am pretty sure we might have commented to make the drops as long as you can to retain as much as you can when you built it. At least over this time you learned its just the third that is loading, maybe you can extend that with some extra copper you have left to get more space before it goes in the line and clogs your sand and leave the other two alone.
 
Got everything installed this morning! I added 6 inches to legs 2 and 3 so that they would retain more over a period of time. I was able to blast for 2 hours with no issues at all and the blaster isn't sputtering at all like it was before...and I don't have to keep fiddling with the mixing valve like before either. It's a much better experience. The longer 3rd leg seems like it's pulling a lot more moisture out, it's still the only one that really accumulates any moisture but now is much more than before. After the 2 hour session I pulled the desiccant beads and almost all of it is still blue with just a little of it turning pink. I did leave all the drip leg valves closed hoping to keep all my CFMs but might try barely cracking the 3rd next time as my compressor is handling the blaster well. All in all, I think I now have a good-enough-for-me moisture removal setup, thank you all for your input!! I was almost ready to scrap the whole blasting idea and farm it out to somebody else, you guys gave me the confidence to keep going.
 
Good for you. Just shows no matter how much engineering goes into something, the fit and function needs to win when its over. Almost sounds like if you ever come up with a small metal reservoir tank of some sorts (old little wheel around air compressor tank) you can just attach it to the third drop off and let it fill.
 
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