Oh boy.. need help quick

S

sprayerman

So I normally shoot my SP 2100 in two passes. Thinner tack coat followed with a thicker second coat 30 min later. Well decided to shoot one coat and got some runs ugh. I went ahead and shot a wet second coat about 45 min later (30 min ago) in hope that this will allow me to sand the runs without fear of breaking through to my metallics and airbrush work ugh..

Question is how many coats max can I shoot in a session? My guess is three but four or five would be ideal for me.

To note I'm using a cold weather activator (all I have left) and my booth is about 65 degrees.
 
the most I have ever personally sprayed with the production clear is three, but I would think four with those temps and long flash times would be ok. with that many coats though I would give a extra day before I started sanding them out. when you put that much material over a run it can stay a little soft for a day or two, especially when is cool.
 
I haven't used Production Clear, but with those flash times, and knowing SPI, I would not be afraid of a third coat at all.
 
Last edited:
Just shot the 3rd and it went on great. Shooting a 4th now since reading guys have done it with the UC.

Is there a way of knowing when not to razor blade the runs comes morning? Too soft mean risk of solvent burying down? Should I put them outside in the sun to harden em?
 
I think waiting is the best plan. Maybe break them open so they can breathe, but don't do too much right away. Sun is good.
 
Appreciate the help guys.. 4th coat went down well.

Wondering if I should shoot another session in the morning or should I wait and stick them outside in the sun, razor the runs late in the day, let 'em breathe another day then start sanding? Followed by another session of clear.
 
Appreciate the help guys.. 4th coat went down well.

Wondering if I should shoot another session in the morning or should I wait and stick them outside in the sun, razor the runs late in the day, let 'em breathe another day then start sanding? Followed by another session of clear.

I've fixed a lot of runs with only 3 coats in the 2100.

Four coats will give you plenty of room for sanding, you may have to let it sit a bit longer.
 
You will have plenty to do what you want, should flow out that run a little overnight, I might look at wet sanding it out today instead of the razor, as far as time?? Just do it when it feels right, my guess about noon today with the fast activator.
 
I am more for wet sanding the runs than using a razor. Had the razor pull a hole in the clear more than once so now I use a piece of wood and a coarse sandpaper to sand just the run down to almost level with the surface then change to 1000 grit to get it level.
 
Thing about sanding runs too early is that the clear under the run will shrink more than the surrounding normally applied clear, because the thickness of the run traps more solvent. So if they are sanded and buffed to fast, the run will actually suck in a little later and look bad. That's why my own recommendation is to cut the runs down most of the way, but then get some heat on them and wait a good while. You can smell when the solvent release starts to taper off.
 
Thanks for the input everyone.

Looks like I have enough room to either cut or sand the runs out. The runs are still soft however.

For the best adhesion how soon should I get back on and clear? 2 days,3days? When is it more of a mechanical bond vs chemical?
 
Thing about sanding runs too early is that the clear under the run will shrink more than the surrounding normally applied clear, because the thickness of the run traps more solvent. So if they are sanded and buffed to fast, the run will actually suck in a little later and look bad. That's why my own recommendation is to cut the runs down most of the way, but then get some heat on them and wait a good while. You can smell when the solvent release starts to taper off.
Good point. I guess since I work at a snail's pace that hasn't been an issue with me.
 
Thanks for the input everyone.

Looks like I have enough room to either cut or sand the runs out. The runs are still soft however.

For the best adhesion how soon should I get back on and clear? 2 days,3days? When is it more of a mechanical bond vs chemical?


Makes no difference , next day or a year.
 
Back
Top