Water in air line

[Corky Scott]

I am having a terrible time with water being sprayed on my work. I live in central Vermont and we are having a VERY rainy summer, almost all the days are high in humidity, except perhaps for a few hours in the evening. I am trying to repaint a Vespa scooter for my son and am using an oiless Craftsman air compressor with a horizontal 33 gal. tank. The paint is professional solvent based paint bought from an automotive store that specializes in automotive paint. I've had fhe compressor for five or six years and mostly used it for air tools and the occasional sand blasting project. I thought it would be fine for spray painting but have had a really tough time with it spraying water beads on the work, which are instantly painted over ruining the paint job. I have to re-sand and do it again when this happens. I've had to re-sand this one skirt three times now because of the water in the air line.

At first I had no water filtration at all, because I had not encountered this before. When it began happening and I recognized what was going on, I did some research and realised that water was going to be in the air line because humid air was being compressed.

So my first effort to fix the problem was to install a water seperator. No help, no discernable difference. I bought a different water seperator and installed that in line with the other. Still no help.

I finally decided that I really needed to filter the air through a dessicant cartridge and bought one of those online. I installed that, with the largest of the water seperators in line ahead of it and thought I'd really got it knocked now.

But I just wrecked the piece again. Same problem, water beads sprayed on the surface.

What do I have to do to dry the air out in the line? Professional shops can't be waiting until they get a day when the humidity is acceptably low. How can the water be getting past the water vapor seperator AND the dessicant filter?

I'm ready to slap the paint on with a brush and sand it smooth!

Many thanks to all who can help.

Corky Scott

[97TaurusGuy]

What kind of paint did you buy?? Where abouts in VT are you?? I work for an autobody supply company in NY we do a lot of business over there. Might be able to help you out.

[Corky Scott]

Originally Posted by 97TaurusGuy

What kind of paint did you buy?? Where abouts in VT are you?? I work for an autobody supply company in NY we do a lot of business over there. Might be able to help you out.

I bought "Omni" base coat and clear coat, my son insisted on using two part type paint, base coat and clear coat. Omni, as you probably know, is a cheaper version of PPG paint. I bought it from Bond Auto Parts. We painted another of his scooters using actual PPG paint, which we found to be shockingly expensive. He insisted on using PPG for the first scooter as he was heading west across country on it to get to LA where he starts his job next week. He made it by the way, driving the two stroke engined scooter. Surprised the heck out of me. We encountered the same water in the air line while painting this first scooter too, but there was less of it and we managed to paint it without too many fisheyes.

But that was earlier in the summer when the humidity was lower. We've had record amounts of rain this summer as you most likely are aware, and the result are days of extremely high humidity.

I live in Central Vermont, close to the Vermont/New Hampshire border. White River Junction is a nearby town, as is Hanover NH and Norwich Vermont.

I thought for sure that using the dessicant cartridge would fix the problem, but it obviously has not. So much water sprayed through the gun yesterday that it appeared to me that somehow the air was bypassing both the water seperator and the dessicant cartridge. The installation was straight forward and the arrows, or stamped directions (in/out) made it obvious which way the air was supposed to go. I even went down to the local hardware store and bought a 1 1/2' length of schedule 40 pipe to install ahead of everything with a valve at the base as per the illustration that came with the dessicant filter. You are supposed to drain it, as well as the water seperator and the dessicant filter before using the air. Draining the tank is recommended too, which I normally do as well. Lots of water comes out from the tank, but I've seen none from any of the canisters in the air line.

Yet the water is obviously in the air line as it comes out onto the painted surface while applying paint.

Thanks for the help, Corky Scott

[LearnAutoBody]

Here is something that may help a little. Open the water drain valve on the bottom of your compressor to drain water. Then leave it cracked just a little. A little air will leak out, but the water should as well. If that does not work, you may have to invest in additional equipment to clean and dry the air for you.

[Corky Scott]

Originally Posted by LearnAutoBody

Here is something that may help a little. Open the water drain valve on the bottom of your compressor to drain water. Then leave it cracked just a little. A little air will leak out, but the water should as well. If that does not work, you may have to invest in additional equipment to clean and dry the air for you.

Here's what I have invested in so far to eliminate water from the high pressure air: Originally, I bought a water vapor seperator. That didn't help much so I bought one more and mounted them one after another. That still didn't help, so I researched online and discovered dessicant cartridges. I bought one of those, for around $150, and mounted it next to the largest of the water vapor seperators. So at the moment, I have a Devilbiss water seperator and the dessicant filter mounted one after the other. I really thought that would take care of things.

But it did not.

I sprayed more base coat and wrecked the job because water droplets ended up in the work, again. Yes, high humidity conditions.

Discouraged, I spent a quality hour or so sanding things down again this afternoon, and then decided to reprime with rattle can PPG compatible primer. I figured that because I was using the rattle can, couldn't be any water in the spray.

But I ended up with several bubbles on the surface anyway. Now I'm totally mystified. How in the world can water end up on the work when I'm using a sealed system?

I bought a humidity gauge today and it's reading 80%. But the can should not have any water in it at all. I wasn't using my air system, just the rattle can.

I washed off the skirt after wet sanding, wiped it down with a clean cloth, then wiped it down with Sem Sol, a product designed to clean off the surface prior to painting.

Yet, I got water drops on the surface anyway. Not many, but some.

I'm beginning to wonder if I'm just not cleaning off the surface thoroughly enough.

Corky Scott

[97TaurusGuy]

I think you may be right about not cleaning off the surface good enough. The company I work for sells PPG Paint. Omni is pretty much junk. We don't even carry it any more. PPG makes Shopline and Shopline Plus. They are only available through PPG Platinum distributors (I don't Bond is a Platinum Distributors). We only deliver as far south as Burlington at the moment. We are expanding a little at a time more into VT (We are in Plattsburgh, NY). Do you have any solvent based products hanging around your garage??? They can reak havic in paintjobs.

[Corky Scott]

Originally Posted by 97TaurusGuy

I think you may be right about not cleaning off the surface good enough. The company I work for sells PPG Paint. Omni is pretty much junk. We don't even carry it any more. PPG makes Shopline and Shopline Plus. They are only available through PPG Platinum distributors (I don't Bond is a Platinum Distributors). We only deliver as far south as Burlington at the moment. We are expanding a little at a time more into VT (We are in Plattsburgh, NY). Do you have any solvent based products hanging around your garage??? They can reak havic in paintjobs.

Yesterday, after again attempting to prime what I had resanded, and having the same bubbling in a few areas, I realised that I wasn't seeing water in the air line, and probably never had once I installed the water vapor seperators and the dessicant cartridge. I was seeing instead contamination of the surface that was reacting to the paint and causing little gas bubbles.

I decided to sand down one more time, this time I would wipe down with a clean cloth, turning it several times as recommended by the directions on the can of cleaning solvent.

I spent a lot of time resanding, using water with the sand paper, to make sure I was getting all of the contamination off. Then I wiped down with Sem-Solv, blew that dry with air, then wiped it down carefully several times, using two fresh rags.

When I re-primed, no more bubble appeared.

So that appears to be what the problem was, perhaps all along. The reason I suspected water was because we were seeing water spray out of the air gun nozzle on occasion, and while painting the other scooter, sweat dripped out of my vapor mask (it was hot under there and I sweat profusely) onto the scooter while I was priming. These were big drops of water from the mask and the primer instantly coated them over. That's what appeared to be happening later, so I assumed it was water in the line.

Probably not.

So I will try to go ahead and finish the job now, scuffing all the parts with the gray scotchbrite pads I bought originally.

Thanks for all the help everyone.

Corky Scott

PS. What are the typical steps in cleaning off a surface prior to spraying? Does anyone wash it down with soap and water? If so, what kind of soap?

[fantasy88]

Discouraged, I spent a quality hour or so sanding things down again this afternoon, and then decided to reprime with rattle can PPG compatible primer. I figured that because I was using the rattle can, couldn't be any water in the spray.

[LearnAutoBody]

Be sure to to put rattle can primer on too wet. It may create a lifting issue.

[jhonson]

I am having a terrible time with water being sprayed on my work. I live in central Vermont and we are having a VERY rainy summer, almost all the days are high in humidity, except perhaps for a few hours in the evening. I am trying to repaint a Vespa scooter for my son and am using an oiless Craftsman air compressor with a horizontal 33 gal.