Fiberglass prep

Anything goes in the world of fiberglass and plastic



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PostPosted: Tue Sep 24, 2019 9:11 am
I'm really a "metal guy", but have done quite a bit of 'glass work , too. But this one I'm not sure of. Guy brings me an older kit car, a 41 Willys, I believe done by "Street Beasts". The were know by building most of their bodies all in one piece, even the 30's Fords. This one is all one piece, and needs quite a bit of 'adjustment' to get the doors, hood and trunk to fit. Not a problem for me so far.
My issue is, for an older 'glass body, some of it seems quite brittle, easy to crack, or break. The fiberglass is quite thick, not real thin stuff. Also, it is not quite straight and needs a really hard 80 grit cut to get it to look good. I don't want to re-gelcoat it, and my usual fix for slightly uneven surfaces is 4-5 coats of House of Kolor KP-2 epoxy, and then block out again (180 and up). Is there a stronger coating to put on the old 'glass that will make it hold up better? One or twice I used Feather Fill, and it works, bit it is so hard to sand! Are any of the newer poly primers easier to use?

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PostPosted: Tue Sep 24, 2019 7:50 pm
Darrell will be the guy who knows for sure.
I have been reading where guys just use epoxy primer on fiberglass. No build primer.
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PostPosted: Tue Sep 24, 2019 10:03 pm
And 68......we thank you for your support...... :)
Yeah....been down this road many times with older kit car bodies. Pretty much the problem with the old Street Beasts kits was that they were flipping out cars from their molds very quickly and using too much resin in their molding process. Resin rich bodies will continue to move/shrink and take "compression sets" over time. Again a tip off here is when you say the bodies are "thick." Best thing to do is just keep pulling everything as straight as you can (even if you have to "kerf" the glass), sand down the back of the panels somewhat, and add some more cloth/resin layers on the insides there. One car was so bad for me I ended up bonding an interior "exo skeleton" made of conduit tubing to stabilize it as I cut and squared it up. As for the exterior surface.....yes, you can do a Featherfill or Slicksand type poly filler but I don't think you are really "improving" the surfaces doing that. If you could just stick with regular epoxy primer you'd be better off. You might look at the Tamco products in the store front at this site. I've not used any yet but I hear good things.......
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!



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PostPosted: Wed Sep 25, 2019 8:08 am
Thanks DarrelK, much appreciated!



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PostPosted: Sun Feb 23, 2020 9:14 am
There was so much I had to correct on this body, waves, drip in the gelcoat, cracks, cracks that had big air pockets underneath..... SO I cut it down HARD with 80 grit, changed to 180, shot it with Slik Sand, and proceeded.
Came out pretty nice for what we started with, the owner is VERY happy. But I did warn him about more issues popping up in the future. Will post shots when competed.
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PostPosted: Sun Feb 23, 2020 10:11 am
Very nice....although I love working in it...fiberglass (especially older stuff) is a pain in the ****. In hand laid up stuff those air voids are really common especially when the lay up is done in sections and then "grafted" together "in mold" to get the main mono tub.
You might tell the owner this....the better he can get this car "riding" the longer his ride can remain crack/defect free. Air bag systems (and yes,they also have their own set of problems) are the best for isolating noise/vibration/harshness with kit cars. I've got a friend with an old kit similar to this that did it 20 years ago and on top of that it is finished in lacquer. He bagged it from it's first day on the road. He's had no major cracks show up and is just now getting a little (he had to point it out to me) micro cracking in the lacquer here and there..... If he doesn't go bags I'd get with a good chassis shop at least and work out the best spring/shock combos for it.
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!

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