Just how bad are replica fiberglass parts?

Anything goes in the world of fiberglass and plastic

User avatar

Board Moderator
Posts: 5823
Joined: Tue Feb 24, 2004 7:00 pm
Location: central Ohio
Country:
USA
PostPosted: Mon Jan 04, 2021 11:53 pm
Yeah, I get it....and trust me guys are still doing it around me as well. But the big question is how long will it last? Weeks, months, a year. Guy I see now and then did an elaborate fender/ground effects kit on an older Supra. Looked great in the Spring going into Summer for shows. By the next spring though he had micro cracking almost everywhere the metal met the fiberglass. He ended up fixing the cracks and then took "molds" off the whole panels and hand laid up new one piece panels. Now he had panels made with just one material.
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!

User avatar

Board Moderator
Posts: 5823
Joined: Tue Feb 24, 2004 7:00 pm
Location: central Ohio
Country:
USA
PostPosted: Tue Jan 05, 2021 12:18 am
So, hey, are you painting or wrapping when done with the body work?
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!



Settled In
Posts: 18
Joined: Wed Aug 14, 2019 3:42 pm

Country:
USA
PostPosted: Tue Jan 05, 2021 1:51 am
DarrelK wrote:So, hey, are you painting or wrapping when done with the body work?

Paint! Seems like this dream of having a molded widebody just isn't gonna happen, unless I want to weld one up which I am definitely not skilled enough to do yet. Thanks for the advice, I appreciate it!



Settled In
Posts: 18
Joined: Wed Aug 14, 2019 3:42 pm

Country:
USA
PostPosted: Tue Jan 05, 2021 1:57 am
DarrelK wrote:So, hey, are you painting or wrapping when done with the body work?

Also seems like these guys are telling the same story as you https://www.pro-touring.com/threads/894 ... s-to-steel
It's a shame something like this can't be done yet, Is it the paint or the kitty hair that cracks first? I wonder if a flex additive in the paint might prolong the paint before it cracks (not that I want to try it anymore)

User avatar

Board Moderator
Posts: 5823
Joined: Tue Feb 24, 2004 7:00 pm
Location: central Ohio
Country:
USA
PostPosted: Tue Jan 05, 2021 8:54 am
So I have access to a lot of archival data on composites from my professional associations in the woods/metals field. You are working against the laws of physics here.... Honestly none of the fillers, glues, paints, etc., fail in this case. It is the action of the dissimilar materials that causes the problems. Ever wonder why even multi million dollar highway bridges aren't smooth? They are built with expansion joints because they are completely exposed and MUST move. I think one of the reasons some of these graft jobs last longer than others is because the cars are garaged with little to no exposure to the elements. So if your car is more like a daily driver.....boom, the process begins immediately.
When I take on new kit car projects I always look to see where there is any possible grafting of materials and try to figure out if I need to allow some type of mechanical compensation in my attachment process. If I see that there is going to be too much of that grafting process on the build I'll move on to a different project.
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!



Fully Engaged
Posts: 320
Joined: Fri Feb 03, 2017 7:36 am

Country:
USA
PostPosted: Tue Jan 05, 2021 12:36 pm
Listen to Daryl! Almost any bonding of dissimilar materials is bound to fail, on cars. Heat and cold cycles, vibration all work to break any bond between them. You can make it look great when it's first done, but time will eventually ruin it.
Similarly, I've also taken crappy parts, or made parts with crappy pieces temporarily, just to make a mold, and make a good quality fiberglass piece. I think I might have even did a how-to on the projects forum of this board. A Miata front bumper.



Top Contributor
Posts: 5184
Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
Country:
USA
PostPosted: Tue Jan 05, 2021 5:09 pm
I would graft metal with studs to the fiber glass flares then Bolt them to the fenders.
Paint the flairs to match the fenders separately, Add a rubber seal in between flare and fender and forget about filling & Blending fender to flare for seamless look.
Dissimilar material problem avoided. Look at How car mfg do it They rarly Bond or Blend its always attached with some sort of Hardware.

Playing with fiberglass isn't hard Just expect anything like what your looking at to be Junk needing a Lot of work to make look good, Expect it to some day crack, break, or fly off especially when hit.
Realize No two mfg are alike and no two use the same resigns! Again Expect to rework it.
Keep a Pair or two of your Ol' Laday's Old Nylon's around and Plenty of Baby Powder or Talcum powder around as well.
Dennis Barnett
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

User avatar

Board Moderator
Posts: 5823
Joined: Tue Feb 24, 2004 7:00 pm
Location: central Ohio
Country:
USA
PostPosted: Wed Jan 06, 2021 11:58 am
^^^^^^^^^^^^^^And see each of those options from the guys here make sense. Chopolds is talking about what I have seen done many times which really isn't a particularly hard thing to do....it just takes time.
Doright's method even has a name for the methodology in my kit car world. It is called "flange on flange" mounting. A lot of the old English clone kit cars were small in stature so the kit car people would design a main tub, hood, rear trunk lid, and then mount all the fenders using gaskets and flange bolts up inside. The fiberglass was laid up fairly thick and the fenders were very rigid. I still see these cars at local shows here with them being 30 to 40 years old. Still no cracking on them. Good fiberglass + good construction techniques= lasting bodywork.....
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!
Previous

Return to Fiberglass and Plastic

Who is online

Users browsing this forum: No registered users and 5 guests