black77

i recently removed & filled the luggage rack holes & painted my black 77 buffed it looked great . after being inthetx sun for about 30 min noticed that where i did my work you can see now ( WHERE THE HOLES ARE ) DOES ANYONE KNOW WHAT THIS IS FROM & HOW IT CAN BE FIXED? THANKS

RIO68

Many possible reasons--starts with how did you fix/fill the holes, what did you use as to materials, what paint/primers used, heat range on thinners/reducers, dry/cure times etc.

black77

filled the holes with fiberglass mat & resin , ppg primed , deltron base , ppg clear coat 3 coats of clear . its not just the holes you can see the fiberglass cloth when its real hot in the sun when it cools down its not that noticable ? but still there

Alan 71

Hi b,
You used the words 'mat' and 'cloth'. Which did you use? Cloth often shows the repair, while mat doesn't.
Did you use ANY filler at all? Don't really want to.
How much did you 'v' the hole on EACH side of the deck? About the size of a silver dollar is good.
How long did the repair cure before paint? Months outdoors in the sun is good.
I'm out of possible causes.
Regards,
Alan

billcarson

as i have removed my carrier also and read every thread on filling in the holes i finally decided that the results could be iffy no matter what i did so i filled in the holes with ss carriage bolts.would look hot on a black car too.good luck!

markids77

Your 1977 is a SMC car and auto parts store polyester resin is not compatible with the resins in your body. Your repair should have been done with an epoxy resin like West Systems 105 (or similar) and 1.5 ounce fiberglass mat... not woven cloth. Like Alan71 states, it is best if no "Bondo" type fillers are used in this area as they also tend to expand and contract differently than the factory panels.

PPG what primer... Epoxy, urethane or lacquer? How many coats, with what dry time between and sanded with what to what grit before topcoat? Was the entire car stripped to bare glass or is this a "spot, sand and shoot" ? No sealer between primer and color?

The only way to cure this issue is to redo the repair using compatible materials and respray the car; which really sucks because I know how much effort you have already gone through.

black77

i didnt use any bondo or putty , used the cloth , omni urethan pimer , could i just go back down to the fiberglass repair & put a smc compatible putty over it reprime & paint or do i need to grind all off & start over ? thanks for the help

Roco71

There is a guy that hangs out in the paint and body section of the forum his name is DUB he can tell you exactly what you need to do. He really knows his stuff. Post this there and he will help.

markids77

Cloth is prone to telegraph through topcoats. Mat less so. I'm going to recommend you start from scratch.

69FASTFUN

I patch from under the car and on top. That is the way that I have done it in the past and I have never had the holes show up. I also use powdered fiberglass and resin mixed together to make a filler. I then use epoxy primer followed by 2k primer.

69 Chevy

I notice you didn't mention using a sealer coat over your repairs. If you intend to start over, I'd recommend you use it.

Also, when someone mentions the word 'putty' I always think of the thick red primer in a tube for pinhole patching by the name of Nitro-Stan. It was prone to shrink if used for anything more than a pin sized void. It became obsolete when acrylic lacquer paint did.

black77

im a idiot i was looking at the areas today i did use mat, not cloth maybe i should have used a different primer ? i use no sealer ever . so with that said what would be the best way to repair ? thanks

RIO68

You didn't say if you filled from the underside. If you didn't you should the only area you really can't reach is the holes in the top side of the rear cross brace that is under the rear deck just in front of the leading edge. You would have to enlarge the holes to get to it.

PPG activated primer is good stuff can't remember the number I'm thinking of. They used to make a primer that was green in color that was great stuff but I understand they don't make it anymore. Someone may have better undated info on what current PPG primer/surfacers are avilable.

Still like Featherfill as a first coat over the area worked then block it. Then use PPG primer last. Sealers are good--like Ins useless unless you need it then you wish you had more. A good sealer that works means you never knew you needed it.

Learned some lessons years ago about lacq. putty--don't use it. Prep your area so you don't have imperfections that would temp you to use any putty (the stuff has a tendency to rise or fall).

Good luck--just my 2 cents!

mffi115

Definitely contact DUB. He has been helping me with loads of advice on my repair work. He is very knowlegeable and doesn't mind sharing.

black77

thanks for all the help