Matching bare fiberglass on the floor of the C1's

[Dan P.]

I tried a lot of paint and other things to match the bare fiberglass on the floors . Especially were a repair was done . The 1957's were not Gel coated but they did have a resin that is on top of the fiberglass. That seams to be cracked on most 57's .They must have had a different process on the hood ,doors,rockers, coves and the front and rear valances . They seam to be alright.If you mix a little white with the resin you can reproduce that same colored resin . Maybe that's why they cracked . What ever white they used could have weakened the resin . If you notice on the corners were this coating is thicker the cracks are bigger.Some places you can actually sand the cracks out before you hit the fiberglass.Now for the repairs .I use a white resin that is for coloring gel coat to tint the resin ,you can also use paint to desired color. Do a couple of test samples because it changes color when it cures.Then make your fiberglass repairs like normal with your mat and resin. Always cover the repair with plastic and work out the bubbles .Painters plastic works great.When cured pull the plastic off and sand it down with 80 grit and all the way down to 320 grit . Blends in pretty nice.

[Chris S.]

Re: Matching bare fiberglass on the floor of the C1's

Dan - I think what you are seeing is the resin settling to the bottom of the mold - you are correct they were not gel coated - the press molded parts were created by spraying a mix of resin and rope fiberglass thru a chopper gun to a mold - then that was pressed and the resin settled to the bottom of the mold - especially in the corners, like around the hood opening, around the trunk opening, and conv top opening- there is a great photo of this in Nolans #2 book - the seams I see on the c1's is a mix of resin and or the gray bonding material - I too have played around with trying to tint repairs - I see it being more helpful on the bottom / floor / trunk repairs..... I do it too - I black to my white Glasin to create a "gray"..... I also have seen a person using a tan to try to match the color

[Jim C.]

Re: Matching bare fiberglass on the floor of the C1's

Dan and Chris,
The correct process for making C1 parts and many later Corvette parts is done with matched metal molds. The core and cavity of the molds are steel and drilled for steam heat to heat the molds to approximately 300 degrees F.
The parts were molded with either the preform process or mat process.
The preform process was done by blowing chopped glass against a perforated screen with a vacuum behind the screen. The shape of the screen was close to identical to the shape of the mold. A binder was then sprayed on the glass fibers and heated in a oven to cure.
The second method was just by cutting mat to the correct size and placing it in the mold.
In either process, the preform or the mat was placed in the mold and resin was poured on top of the glass. The mold was closed in a hydraulic press and the part was molded.The mold had core and cavity shear edges that would help contain the resin and shear the glass to size.
The resin in the corners is called resin rich where the glass was not during molding. This is caused by poor fitting preforms or the mat stretched across the corners.
I have worked in that industry for years and have also designed molds for fiberglass and my machine shop, Penco Tool, builds molds for the compression molding process.
Thanks,
Jim