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Remove of paint on glasfiber

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germanmichel

germanmichel

Jedi Hopeful
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Hello @all,

I bought currently a Austin Healey glasfiber hardtop.
I don`t want to remove the paint with a chemical stripper. I start to remove the paint very carfully with hot air equipment. ( no overheating, with brown hot spots, but the glasfiber is good warm)
It works very well, but I have concerns that I damage the glasfiber or the clearcoat. Does it make brittle ?
Some sugestions please.

Bye michel- who like this forum
 
Sanding with a rotary sander will probably smooth everything out so you can see if you have any cracks in the glass....don't try to take the paint off unless it's been repainted after the factory.
 
Hi ,I am curious as to why you are removing the finish ? Is the finish bad?
It sounds like you already have some removed. My neighbor used to have his Corvettes soda blasted if I remember right. Tony is right you can remove the finish also with a rotary sander. You might want a professional tackle your hardtop, fiberglass is more finiky then steel parts when repairing. You may remove too much material and sand past the barrier Gel coat .Gel coat is a barrier between the fibers/resin and sealer/primer coat. It gives a foundation over the fiber glass . If it becomes too thin old repairs may show up. Not knowing what coat is the Gel coat and sanding past it is my concern.
 
Hello ,
thank you all for answering.
I would like to remove 2 layers of no factory paint.
Under this two layers is the Gel coat in the old english white.
I think about to polish this Gelcoat, because this is the colour what I want to have. Was Gel coat the final finish ?
Or the original hardtop was painted ?
My primary question was see anyone a risk to remove the paint with hot air ?

Bye Michel-who post from rainy germany
 
germanmichel said:
My primary question was see anyone a risk to remove the paint with hot air ?

Bye Michel-who post from rainy germany
Click to expand...

I can't imagine you could hurt the fibreglas with hot air, if it is coming off that way, go ahead.
 
Think I'd just use a rotary sander so as not to nick or damage the gelcoat.
 
Hello guys,

yesterday I worked again with the hot air (it is not a hair dryer... :smile:)it works with 600 °c.... . Yes, the rotary sander should be the better way, but with more dust. The hot air makes the gelcoat temporarly soft and so I get a raw surface and I create some nickes with the tool :cry:.
I also find some small old cracks in the gelcoat. But not caused in fact of the paint remove.

Thank you for feedback.

Bye michel- mistakes are created to entertain the nativ speakers
 
Hey, you're doing a job lots of us have done but differently - let us know how it works out!
 
I am starting to get nervous thinking you are lifting the paint with a heat gun.
when re flowing old products they may not have the same adhesion they once had if you intend to not remove everything and start back from ground zero up.
If there is any chance or question of a product failing or becoming a problem it must be removed. My worry is ,will that intense heat effect the resin in the glass,making it briittle or worse??? Will the Gel coat loose adhesion to the glass.
 
Britishautobody said:
I am starting to get nervous thinking you are lifting the paint with a heat gun.
Click to expand...

I think I may have been wrong in my previous statement. Here is a quote I lifted from the boat cruisers forum

https://www.cruisersforum.com/forums/f55/gelcoat-crazing-part-1-a-944.html

<span style="font-weight: bold">5. Thermal shock or direct sunlight can heat darker colored composites to beyond the heat distortion temperature of the resin causing warpage, creeping of built in stresses, over expansion of trapped air or moisture - causing laminate separation (de-lamination), blistering, or even catastrophic collapse of entire structure.</span>

and


<span style="font-style: italic">Thermal fatigue Cracks:
Thermal fatigue cracks are a result of repetitious expansion and contraction of the gelcoat film. Whether in a parallel pattern or an isotropic (nondirectional) configuration, thermally induced cracks are characterized by short discontinuous sections, and are usually grouped in forming in a dominate stress field.

Isotropic thermal cracks are a result of the surface expanding and exerting a tensile strain within the gelcoat film in a unidirectional fashion.

Parallel thermal fatigue cracks usually are propagated by expansion of the surface in conjunction with localized flexural stress.</span>
 
Hello,
:thankyousign: you all for feedback.
I have personally experience in paint remove of metal panels, it works very well with the heat gun with no negative influence also on aluminum parts. This was the first time, that I work on glasfiber.
So in my conclusion, the rotary sander is the best way ( the last 70% I will remove with the rotary sander. This is not a big surface, but in my small german garage I don`t want to produce dust...on my rebuild engine... :wall:
I have to go in the garden at the coming weekend, to entertain my neighbours...

One last question. The old fine cracks in the gelcoat , what shall I do with this ? Cover with paint, or grind out and fill with gelcoat ?

Bye michel- who is made in Germany :cheers:
 
Michel - I've used a heat gun to separate the glue on Corvette panels so I could remove them....when I gont my hardtop down to the cracks, we used a 2-part epoxy pirmer on the top - it filled most of the smaller cracks & we used a body filler on the others.

Here's a thread I started some time ago when I redid my last top....lots of good information in it...you'll probably want to read through the entire thing:

https://www.britishcarforum.com/bcforum/u..._Nex#Post527604

After I finished the Old English White paint on it, I wrapped it in brown paper & stored it without reassemblying it. But, the thread goes over taking all the old stuff off, filling cracks, painting, etc.
 
Tony,
You should write a book, or put what you have already written into HOW TO book form, from buying to repairing, modifying, etc.
 
They've already been written by the experts.
 
GFRP on the 'vette is nearly four times thicker than any of the English hardtops (or car bodies) I've redone. I'd do the removal mechanically, sanding board and a fortune in heavy grit paper before I'd take heat or chemistry to it...

...but I'm a Lotus owner. They're THIN "frozen snot" bodied thingies. :smirk:
 
Cracks in the gel coat, I was told to either v groove them out and fill with Duraglass or resin and re gel coat. Just priming/sealing or painting a product over a crack will produce another crack .It may not be right away but it will show back up . I don't do alot of glass work, I used to work across from a Corvette restoration guy. He was always more then happy to give me advice on glass.
When we used to have to paint over old checked laquer areas <during my autobody production days> it would hide but down the road it would show back up, same principal etc. There are a ton of ways to cheat and band aid a job or process, but only a few ways to have a lasting product .
 
True, if they are real cracks...if they are just "spider lines" we smear resin over them & sand smooth...on the final go-over, I just use 'spackle'.
 
Hello,
thanks again for good advices.
I have only the spider cracks, with a zero-distance. Nothing for to fill epoxy material in.

Bye michel- who is currently not so motivated to make progress... :whistle:
 
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