universal clear

danp76

danp76

Oldtimer
Hi guys, I'm not new here, but new to universal, have been using up my BASF supplies and just sprayed some universal on the front of a 57 t-bird, I'll have to get some pics. Being new to the clear I need to learn the quirks on spraying it properly. I used my lph 400 with a 1.3 tip. I thought I had to move quickly to not get it to run. I think I should of used a slower hardener, as I did get a little peel in the finish. I did get a small run and noticed that the runs are "thinner" then they are with basf clear. Coats seem to go on thin, but when I wet sanded there seemed to be plenty of material with 3 coats. I must say it buffs very nice! I think I need to just dial it in as I haven't used enough of it yet. I need to get it to lay a bit slicker, as I did get a fair amount of urethane wave in the finish. I blocked it with 800, 1500, and 2000, but still see some wave in the clear when looking at it from the side. Did mention it buffs GREAT..VERY NICE AND EASY TO BUFF!
 
When you wet sanded it, did you use a relatively stiff block? It needs to be blocked flat. One problem with "High solids" clears is that they will give you more wave, because of the higher build.

Don't worry..... you'll get plenty of practice. You will find that you love that clear so much that you will be doing extra projects just to use it.

Aaron
 
I've noticed that if the temp is on the high end of the range and there is a strong breeze, I need to go to the next slower activator or it dulls out some. I can't turn the fan off after the overspray is gone. Everyday there is a different variable to contend with.
 
I wonder if that's the problem...I left the fan running between coats, is that a no no? I did shut fan off after final 3rd coat, about 2 mins after last coat.
 
Mostly likely not. I do think going up an activator or at least mixing the two will make a difference. Yesterday,the bumper was 85deg. and the wind was in the low teens. Used the normal activator and it looked like it dulled some. I also use a small tipped gun that may squeeze out some solvents too.
 
Danp76, you may want to try a 1.4 tip when spraying the Universal. That's what Barry recommends. You won't have to fight to lay it down smooth. Correct temp or a little slower activator helps lay it down smoother as well. The fan only needs to be turned off after the last coat has cleared out of the booth.
 
hardest part of the job is getting the FAT out...as i call it. cutting with 800 does a pretty good job but doesn't get all of it. I cut the vette with 800.....and in certain areas and certain extreme lights, i can see a bit of urethane wave. Only way to completely get out is cutting flat with 600 or maybe down the 320 and reclear.....then cut and buff the hell out of that. BUT if you havent been cutting your primers flat with coarse grits....you are just spinning your wheels. Urethane wave exists in you undercoats also...and anything you put over top is just going to follow suit.

Flat, long panels are your enemy with urethane wave. coarse grits and a flat block, with tight fitting sandpaper are your friends.
 
jeremyb;9552 said:
Urethane wave exists in you undercoats also...and anything you put over top is just going to follow suit.
Click to expand...

Excellent observation, and one that took me some time to realize, for when I learned my trade, lacquer primer was still the rule. I think I have actually traced a slight degradation in certain appearance qualities to the increase in solids in all materials involved.

I have not ruled out going back to a lower solids clear (essentially, over-reducing SPI) and switching to more coats to get film build. The cars I do with long reverse curves have been particularly problematic, as the reverse tends to optically magnify urethane wave.
 
I still have a lot to learn about spraying SPI clears. So far it seems the MS lays out better then the Universal. I have more experience spraying BASF clears, particulary Glasurit and RM. I have foud some of the BASF clears lay slick as can be and others have urethane wave, and they are all termed "high solids." I think I have had better luck with my Sata 3000 hvlp for clear rather then my lph 400. Both run with a 1.3 tip. I'm considering purchasing the new Sata 4000 rp, but we'll see. I do all my body work very flat and straight, the ripple is in the clear. When you guys double clear and hit the initial clear with 400 grit, what grit do you begin with on the second session of sanding, that is, after applying the second round of clear. I'm thinking it would be easier to just apply more coats on first round rather then reclear and remask everything. I'm not sure the exra effort is worth the gain, as it seems like a small gain..or maybe not?
 
crashtech;9562 said:
Excellent observation, and one that took me some time to realize, for when I learned my trade, lacquer primer was still the rule. I think I have actually traced a slight degradation in certain appearance qualities to the increase in solids in all materials involved.

What would I have to screw up to see urethane wave from my primer? I never even considered this as a problem, because I thought it would be eliminated by blocking.
Click to expand...
 
if you are cutting your primers with coarse grits you arent going to have a problem in that area. i cut poly with 80 and finish out with 180......cut urethane primer with no higher than 180. only the last thin "sealer" coat of primer gets sanded with 320 or 400/500. then paint.
 
jeremyb;9589 said:
if you are cutting your primers with coarse grits you arent going to have a problem in that area. i cut poly with 80 and finish out with 180......cut urethane primer with no higher than 180. only the last thin "sealer" coat of primer gets sanded with 320 or 400/500. then paint.
Click to expand...

X2.. It all starts from the bottom
 
Ok, I should not have a problem then. I use 100 for my first rounds of primer, then 180 after that. Sometimes I use use 220 for the intricate parts.

Jeremy, do you normally sand your sealer? There must be different schools of thought on this. I'm pretty sure Jim C and Bondo King reduce it 1:1:1 and spray base 30 min to an hour later. I've heard of guys sanding it too, like Arrowhead on that Factory 5 rod he just did and now you. Can you guys please explain?
 
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