Do HVLP Paint Guns Clog Between Coats?

[Metalman]

Urethane. I could have gotten a shop to do it for under a hundred bucks, but I am determined.

Well that's the spirit and you will learn something new. One of the problems is getting all the right materials and having to buy more that you actually need.
Mind the pot life on the primer after you activate, try to mix small amounts enough to apply 2-3 coats with flash time between coats. Go by that primer's tech sheet. After one go around you will know more accurately how much to mix. Get the primer out of the gun prior to the pot life time, it likely will still be liquid but none the less shouldn't be applied. Clean well with the urethane reducer. I clean the guns with auto lacquer thinner first then rinse with a small amount of urethane reducer. Give the primer plenty of time to cure, sand and paint too soon you may have issues with shrinkage-sand scratches that can show up after all is done weeks later.
You won't have any issues with the base mixed with just with reducer as far as pot life. You can however add a small amount of your clear catalyst for better adhesion, the ratio is one ounce per reduced quart of base, optional.
Same deal with the catalyzed clear for pot life, check the tech sheet.
Your painting some small parts so I don't expect you will be having any of the materials in the gun for very long. Just mentioning so you don't foul the gun. I've seen a few plugged solid guns and some of them were expensive.

Edit: Where I stated above: "Clean well with the urethane reducer." I'm referring to the gun, not the surface prep.for the painted parts. That should be wiped with automotive WGR (wax & grease remover) either solvent or water/Isopropyl based.

[SteveHGraham]

Everyone thinks painting is easy, but it's one of the hardest things to do right. They think it's easy because they do a really crappy job.

[tapkoote]

The bike is a Moto Guzzi Jackal. The original side covers are garbage.

Just curious
What year Jackal?
I've got an 02 Stone. Actualy a couple.

[Metalman]

Everyone thinks painting is easy, but it's one of the hardest things to do right. They think it's easy because they do a really crappy job.

I've been painting for about 44 years, a lot of changes in materials and equipment, and I think its getting harder .
Kind of like baking (vs cooking); you skip an ingredient or a procedure and you have failure.

[SteveHGraham]

Just curious
What year Jackal?
I've got an 02 Stone. Actualy a couple.

It's a 2000.

[SteveHGraham]

Can anyone tell me the best way to get the Krylon primer off the parts? I assume lacquer thinner won't hurt them.

[SteveHGraham]

I will answer my own question. Either acetone or lacquer thinner will work, but it's a pain. I had to use like 50 paper towels.

I tried some spray stripper on the back of one cover, and it appeared to eat the resin, so that appears to be a bad idea.

[SteveHGraham]

Well, I blew up a regulator. I read the gun manual, and it said not to attach the regulator to an air line over 120 PSI, and I figured that meant it was okay to run 120 to the gun's regulator. Apparently not. A little plastic cap popped off of it and shot across the garage.

I am wondering why I need a regulator on the gun when I can adjust the compressor to low pressure.

[BadDog]

Secondary regulators on low pressure guns may not be able to handle unregulated pressure. Years ago when I sprayed cars using a standard siphon JGA, I ran that regulator (at the gun) on lines regulated to around 90 psi in the paint booth. But when we were testing out an HVLP (long before they were common), I remember having a requirement for something like 60 psi max (or lower?) on the inlet of the low pressure regulator. I don't recall the exact numbers, just remember having to adjust the main regulator on the paint booth down to run the test on the HVLP gun (I hated it). I don't know if that's still the case, or if you just got a bad unit, but it's something I remember from roughly 25 years ago...

[SteveHGraham]

Because the gun I have came with a two-gun kit, I had an extra regulator. I turned the compressor regulator down to 40, and nothing blew up.

The side covers are primed. No runs, but lots of orange peel. I put 3 coats on the back and 5 on the outside. I had no idea how much primer to mix, and it turned out I made twice as much as I needed. Twelve bucks down the toilet.

I was disturbed that I was sometimes able to smell the paint through the respirator, but the cartridges are new, so I guess it worked. I sure hope I don't die.

It's nice to put my air dryer to work. I got it on Ebay, probably from someone who found it in a warehouse. Brand new Arrow. I gave them a pathetic best offer, and they took it.

[Harold_V]

You likely realize that pressure, when there is no demand, is equal at both ends, but when you start using air, that is no longer true, as the friction of the air moving through the supply system causes a drop in pressure. That's why you should have a higher pressure from the source, reducing to the desired pressure at the point of application.

Harold

[dly31]

I don't know the details but I do know that some of the modern paints are so toxic that respirators are not adequate protection and a forced air mask/hood is required. I would be concerned if I smelled the vapors from those types of paint.