Need opinion on compressor blowing oil, spraying primer

[bandit]

Have a compressor that I know is blowing oil because it has a small leak at the exit fitting on the compressor and it bubbles with water and oil (i know i need to fix that leak). Tank is drained every day, just humid here. After the compressor, I run the line through two filters. One is an old industrial water seperator(??) and the other is the standard filter with the clear see-through cup. The water separator catches water very well. The second glass/cup filter after the water separator appears to stay dry because I can see nothing in it ever.

I held a paper towel up to a blow gun at the end of the line(after the filters) and held it there for a good 10 minutes and saw nothing at all come out on the towel. When I run my DA though, it will start spitting speckles of stuff out of it after 5-10 minutes or so of use. This could be the oil already in the DA just starting to come out but I have no idea. (I add a few drops before every use)

What do you guys think? The paper towel staying dry when testing, plus I am going to add a small desiccant filter into the line at the paint gun, should I chance it and spray primer?? Going to take it to a shop to spray the color but I need to lay this primer.

 

[Jonnyuma]

The oil is most likely coming from the DA...air tools will do that.
Buy or borrow a new hose for spraying.

 

[bandit]

Thanks Jon. That is very good to know about the DA. I just started using mine so don't know what is normal for these things. I think I am going to spot epoxy prime over some bare metal areas I need to cover and see how it goes.

I do have a new hose I bought just to do the painting.

Crossing my fingers.....

 

[Jonnyuma]

If you're just getting started with bodywork...use the DA down to about 200 grit. Then hand sand w finer paper (up to around 400) until all the DA "squiggles" are gone. Use a good cleaner (wax and grease remover) over the bare metal, epoxy will stick to just about anything but you're miles ahead if you start with a clean surface.

 

[bandit]

Thanks for the tips. I hooked up my hvlp with new hose and started spraying some epoxy today and notice water dripping down right before the desiccant filter at the gun. I know leaks leaks leaks..... I got a couple of swipes of the epoxy down before I noticed it. None of it dripped on the primer but have no idea if anything made it through the filter and to the gun. I pulled the line before the filter and it was spraying a decent amount of misty water out. Let it go for a couple of minutes and it dried up. Apparently all that water was in the new hose!?!? Never thought to blow it out before using. Anyways all was fine spraying after that episode. It dried looking good but can there be hidden problems if water happened to get in the gun on those first few swipes or should I have seen any problems that would come up during curing?

 

[eric383]

Bandit are you running the air through some pipe before it goes to the filter and have a valve to drain the excess moisture right before the filter? This link is just an example. If the air isn't run through some pipe first the compressed air won't cool enough to allow the water vapor to condense and seperate from the air.
https://www.google.com/search?q=com...w.tptools.com%2Ftech-metal-piping.dlp;671;646

 

[bandit]

I have it running through black pipe between the two filters with a drain valve at a drop off. Not as elaborate as that diagram but similar. The first 25 feet that plugs into the first filter is regular hose. Didn't have enough room or budget to run 15-20 feet of hard line before the filter. I probably would have had to snake it up and down the wall to get that distance with hard pipe.

I did some reading last night and it looks like if water got into the gun, it should show up as blisters or craters on the dried paint/primer. Mine looks good and smooth so going to move on to the next panels. Thankfully I had that desiccant on the gun otherwise it would have been a mess. Still can't believe that new hose had that much water in it. Lesson learned. Blow out all new hoses before use!

 

[eric383]

You will know if you have water/oil in your compressed air. Sounds like you didn't and that is a good thing. I always have 1 air hose that I dedicate to painting just to make sure there is no junk in it.