Fibreglass problem

A couple years after painting this car in the late 90's, blisters started to appear on the DS fender. The problem got so bad that the car was sidelined until recently, when it was decided to try and remedy the paint problem. After the shop stripped the paint, and wiped it down, a stain started to appear where the blisters were. It was determined that this stain is silicone brake fluid wicking it's way into the fender.

The area in question has been treated with Prep-sol, to no avail. The next level was an aircraft quality silicone remover, which does ok on the surface, but the stains bleed back up after a couple hours. There is also another product, we used, that is supposed to penetrate, combine with and remove silicone, but it appears to have 'energized' the stuff and now, it's spreading further.

The origin was obviously the master cylinder and the fluid has wicked it's way around to the front of the car now Anyone have any suggestions as to what approach to take on removing this stuff from the panels, so it can be painted. Is there anything you can use over it to seal it in?

Replacement of the panels isn't an option.

Any advice wiould be greatly appreciated... Mine is "never use silicone brake fluid"

thanks BobJ Great Falls, VA

Reply to
SilverStude
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Reply to
robrjt

Interesting problem caused by a poor substitute for brake fluid.

Use your silicone remover as a wash inside and out and with a high powered shop vacuum suck it on through the panel and bake for 4 hours. Repeat until you no longer see the stain. Then do it again with slow lacquer thinner and then re-sand with 36 grit and wash and vacuum again, then bake again. Now re-resin (epoxy) the entire panel, reshape with 36 grit and re-resin again. Rough it up with 180 grit and bake then apply a self etching primer and finish as normal.

Reply to
Dad

There is No solution to your problem..once you get that silicone brake fluid on fiberglass it's all over... Silicon fluid has ruined hundreds of paint jobs and much fiberglass...cost to car owners has been in the thousands..and yet people continue to use it ..why...????

Reply to
Redbull

It will always come back..there is no solution except to replace the panels....been there done that...!!!!!!!!!!!!!!

Reply to
Redbull

that's our next approach, thanks

Reply to
SilverStude

This sounds like what it needs. I'll see if the painter is up to doing this... thanks

Reply to
SilverStude

I hear you..

Reply to
SilverStude

Snip>

By the way this happened to a '66 black coupe that had the entire left side wiped down with a rag that was used to clean up after a brake bleed with silicone fluid. It took allot of work to correct that little misstep but the car has never shown any paint separation and that was in 1991.

Don't let Redbull discourage you, he's on the negative side of earth.

Reply to
Dad

It would be cost prohibitive to replace the panels... and I believe if the silicone can get into the panel, there should be something that can chase it and remove it. I, currently, have a product called Digesil, used to remove silicone sealer in aircraft fuel tanks. It does good where you can immerse the object, but we can't apply that technique to the panel. So far, we've kept a soaked rag against the panel and allow it to sit a while. Once washed off, the panel will dry out, but a couple hours later the stain reappears. Hopefully, it will get a lot of it out, but there's a limit to this shop's patience. Our next attempt will be to use "Eliminator" epoxy primer and try to force dry it before the oil has a chance to wick back up. I was told by an expert in FRP from Dow Corning, to seal it with (long chemical name here) epoxy paint, then proceed with the normal automotive finish process. Of course, he couldn't guarantee the result. Thanks, everyone for your insight.

Reply to
SilverStude

This is very interesting, since the reason most old car people began to use the DOT 5 silicone brake fluid was the safety of using it around car finishes.

This is great (sarcasm), since I have a car with the fender down to factory primer and had the master cylinder blow DOT 5 all over it while trying to pressure bleed the MC.

Reply to
Tom in Missouri

This old car person never used it and anything that contains silicone is in another building. Never thought of the coupe having had the fluid changed and paid dearly for not paying attention.

As I said in the earlier post you need to eliminate as much of the silicone as you can and then cover the effected area with a tough coating, epoxy resin and/or self etching primer. Anything that can break surface tension as well as silicone needs all the attention you can give it before you try to color coat. On metal and fiberglass I still flash out the area with a torch as a start to kill its affect on adhesion and then clean while still hot. On the '66 the paint started breaking up just as I was finishing the first color coat and it had to be washed down and prepped all over to even consider another color coat.

Reply to
Dad

What's your email address?

Reply to
SilverStude

Normally, I never give it out. Too many spam bots pick them up and flood the mailboxes. I've had a couple of addresses I've had to shut down as they got several hundred spam a day. And on the public newsgroups, I've seen people bombarded and harassed too much to give it out too casually.

What's up?

Reply to
Tom in Missouri

I have a few of them free/disposable accounts just for this reason.

g'day

Reply to
'Key

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