Laying fiberglass directly on plastic?

Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=62715
Printed Date: May 15, 2024 at 12:31 AM

Topic: Laying fiberglass directly on plastic?

Posted By: sawblade02
Subject: Laying fiberglass directly on plastic?
Date Posted: September 15, 2005 at 2:12 AM

I'm planning molding in a pair of speaker pods I built out of MDF into my truck's door panels and painting the whole thing with 2 step silver paint afterwards. If I lay the fiberglass directly over the plastic, will a crack eventually show in the paint where the fiberglass ends? What are some tips to pull this off smoothly?

-Sawblade

Replies:

Posted By: 5150azn
Date Posted: September 15, 2005 at 3:17 PM

sawblade02 wrote:

I'm planning molding in a pair of speaker pods I built out of MDF into my truck's door panels and painting the whole thing with 2 step silver paint afterwards. If I lay the fiberglass directly over the plastic, will a crack eventually show in the paint where the fiberglass ends? What are some tips to pull this off smoothly?

-Sawblade

Yes, Your gonna have to rough up your plastic or like something because plastic bends and twists, FG doesn't. My suggestion is just to use your plastic parts as a mold and just remake everything out of FG.

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Posted By: gus1
Date Posted: September 15, 2005 at 5:13 PM

There are primers that can be applied to plastics that make autobody repair material adhere properly. Rough it with 60.... prime with several coats to give a good bonding surface. Use a primer specifically for TPO based plastics (EPDM, PP, E/P)

Gus

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Posted By: sawblade02
Date Posted: September 17, 2005 at 4:00 PM

Thanks gus, I'll check into those primers.

Posted By: jlord16
Date Posted: September 18, 2005 at 7:30 AM

Id be more worried about the FG not sticking to the plastic and eventually coming off. In Australia they have "Grip Lock" primer thats used for priming plastics and very glossy surfaces, but they shuld have similar products in the US, just go to ur local auto store. Do a few good coats and you shuld be set

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