blt91RS

iTrader: (3)

I VHT'd my taillights about a month ago and they came out great. Yesterday I decided to complete the job and VHT the 3rd brake light as well as the rear markers. While the markers came out fine, the brake light developed cracks in the VHT almost instantly after spraying. I sanded it down and attempted again, but cracks still appeared. Has anyone else experienced this? Its odd considering the tails and the markers came out fine but the brake light isn't.
HELP PLEASE

You could see the cracks in the remaining vht, the brake light appeared perfect before I began spraying.


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SparkyJJO

iTrader: (11)

VERY common issue.

The plastic isn't the same as the rest of the lights, and it doesn't like the VHT too well. The only way I got it to not crack was to apply in VERY light coats and wait a good 5 minutes (at least) between each coat.

blt91RS

iTrader: (3)

So sand it down and give it another go?

DukesOfHazard

Hmm, mine ran horribly bad when I first tried it. Used some lacquer thinner to get all of the VHT off then resanded and started over. Only two or three very light coats later and it came out nice and clean looking. I used about three coats of clear on it I think. I'll post up pics tomorrow once I snap some of the third brake light.

DukesOfHazard

Also, what grit sand paper were you using to prep with?

blt91RS

iTrader: (3)

I just used a 3m pad to scuff 'em up good.

FamousZ

iTrader: (4)

Mine did the same thing..

DukesOfHazard

May want to try some lacquer thinner or some other paint remover on them with some paper towels and get it back to stock as much as possible, then resand. When I did mine I got frustrated and started sanding with a grit in the 300 area I think, left huge scars in the plastic. Moved up to 1,000 grit and it helped a bit, but I wasn't as happy with it as I was the rest of the pieces. If it were me, I'd run some more coarse sand paper over it to get it smooth again and work your way up the grits to around 1k or 2k grit paper and repaint it. Should come out nice that way. Are you sanding by hand or with a power tool?

blt91RS

iTrader: (3)

I'm sanding by hand. I used some coarser paper to try and get it all off. I'll use some thinner then smooth it out with some 1k grit. I'll give it another try later i guess...

Trans Am Jam

iTrader: (7)

I had the same problem w/ my third brake light. What I ended up doing was resanding the entire thing again, sanding off all the lettering and reVHTed it w/ many light coats in a non-compromising position so that the paint won't run. came out perfect

DukesOfHazard

I did the exact same thing, but I used some lacquer thinner to get the nightshade off faster. Just applied it with a paper towel and then resanded everything down. The sanding is the important thing otherwise the runs will still remain in the paint, so make sure it's a uniform clean surface. It's a pain in the *** so don't be impatient like me and use too aggressive of a grit. Use a high grit like 600 or 1k and get that smooth surface again (the scuffed look I mean) and redo it. Light coats are the key with this stuff. Such a pain in the *** lol.

jb98camaro

iTrader: (1)

mine did it too. i just sanded mine off and did light coats every like 15 min and worked perfect..