[OP]
Member
What is this stuff? This is an old compressor my father-in-law gave me and I pumped up the tank and opened the drain-cock and this is what dribbled out. Thick mud. Should I remove one of the end caps and flush the inside of the tank with solvent or something?
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Member
I've taken the petcock off and sprayed a good amount of brake cleaner into the tank. Then put it back on and swish it around and drain.
If there is rust it might just be dangerous long term but I would put some oil in the tank and swish it around as well to have a protective coat.
Member
More like sludge. It is a mixture of water and oil.
Member
Mike
When you mix oil and water in a compressor it comes out looking like what you have in the picture. I would clean it out with hot water and dish soap. If is is and old tank you may want to have a pressure test preformed on it before you use it.
Contributor
That oil will help prevent rust.
Never, under any circumstances, consume a laxative and sleeping pill, on the same night
Contributor
It's a mixture of oil (bypass from the rings) and water (condensation.) If it were red, then I would be concerned about tank rust. Normal in any compressor tank, IMHO.
Member
We call it mayonnaise,and like posted above it's blow by oil from compressor head mixed with moisture.It will kill a spray finish,and isn't all that good for anything else downstream....to include the hose.If you google images for old compressors......you're looking for an expansion tank.The nicer ones are often "ribbed" aluminum pcs.They get plumbed in between compressor head,and the tank.We have one that's even water cooled.They eliminate somewhere N. of 90% of mayo/moisture/heat that gets to the tank.They were phased out because of expense and the "notion" that downstream filtering is going to catch it.The problem with this is an expansion tank is passive,dosen't eat anything,dosen't cost anything to operate,is very effective,but....adds cost to the product.
It's one of those subjects that's hard to discuss because everyone's expectations and requirements are different.And,we've been led to believe that downstream measures are what's needed.......this is spread by folks who....wait for it.....sell downstream filters.We've(our shop) always looked at it as,catching the problem sooner vs later.But then we also require extremely clean air for spraying/finishing........so,we use an expansion chamber,AND downstream controls.Best of luck with your compressor.
[OP]
Member
Thank you for all the replies! I'm a but freaked out though. We went from completely normal to killing a spray finish. It seems that there are more finishers using compressors rather than turbine outfits. That said, how do all these people avoid problems from typical tank sludge? I did buy a filter/regulator Unit thinking that would be the ticket - untrue?
Member
Don't take my one reply on killing a finish as representative over the whole spectrum.What one shop deems acceptable may be completely "whack" under other circumstances.Heck,finishers can't agree on much of anything....and it IS completely understandable.While I may know "X" amt of knowledge about say,humidity control,or "makeup air for your booth"....that may not be the case in Fla.
Member
To try to gather it all together.
As the guys say it's perfectly normal for a piston type compressor to add some oil to the air (if the compressor is badly worn or damaged they can dump large quantities of oil), and this with water that condenses out under the increase in pressure forms the cream coloured gunk you see - technically an emulsion.
Normal practice when spraying paint is to fit a combined oil and water trap and air filter (commonly available from pneumatics/engineering/automotive workshop supplies places - they offer all sorts of 'air service units') to catch and prevent it being blown through into paint guns and the like. Bear in mind that some tools with high speed air motors (e.g. die grinders) may need a clean mist of oil added to the air - and so may require fitting a suitable air lubricator as well - although many are OK with a shot of oil into the tool for intermittent use. (don't even temporarily use a lubricator on a line feeding a paint gun though for obvious reasons)
I'm a bit out of touch, but gather there's some cheap and nasty stuff that doesn't work very well on EBay and the like - so best to go for a respectable brand. e.g. http://www.festo.com/wiki/en/Service_units You may need some tubing and fittings as well, so best if you can go to a one stop shop and pick up everything you need.
Be careful of the compressed air tank - old ones can be dangerous. They can be thinned enough by rust and corrosion caused by the condensed water to go let go and explode like a bomb - modern Eastern made ones in particular often use much thinner material than would have been the norm in years gone by. To be safe they need regular pressure testing by a competent engineer - NOT using air pressure which is potentially very dangerous indeed but by filling the tank with ONLY liquid water (no trapped air left inside at all) and then bringing it up to the test pressure specified on the plate with a hand water pump working through a small bore connection. The key is that if the tank does split on test under water pressure it won't explode as it would if filled with air - the pressure is instantly released because the water does not compress...
Last edited by ian maybury; 01-20-2015 at 8:10 AM.
Member
It won't do anything to kill a finish if it stays in the tank and you have your air protected with water and oil separators. If you are spraying finishes that is a minimum anyway.Originally Posted by Mike Dowell
[OP]
Member
This good?Photo on 1-20-15 at 8.25 AM.jpg
Member
I've no idea Mike for the reasons above - i'm out of touch with what's on offer these days. Maybe somebody else is up to speed? Depending on what you have already you may need a suitable filter (to remove water and oil) and regulator (to set the supply pressure). Not a lubricator unless you plan to run air powered tools to a significant degree. The filter will likely require regular draining.
The most basic check is probably whether or not the compressor has the capacity to handle the jobs you need it for. After cleaning out and testing/proving the tank make sure there's a working pressure relief valve on it, and that the pressure/start/stop and power switches are working. You may need a stop valve too - mini ball valves are convenient. Keep an eye on the filter for a while to make sure the compressor isn't worn out and passing too much oil or otherwise not working correctly..
These guys are long standing in the industry, there's lots of info on their pages which may help you develop a feel for what you need: http://www.ingersollrandproducts.com...bricators-frls There's more related gizmos available than you will likely need, and they probably are expensive.
As before dropping into your local engineering/pneumatics/automotive supply outfit with info on the size (CFM and tube size) of your compressor and knowing the tools you want to run and asking them to set you up with something they can stand over may be the simplest route - but maybe ask your father in law about the history of the compressor before spending money….
Last edited by ian maybury; 01-20-2015 at 11:17 AM.
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