Adding Material to Fiberglass Panel

[Scott Clarke]

I've got a fiberglass 911 decklid I'm trying to fit. It's too narrow, leaving a good 10mm gap at the upper right corner. Is there a way to add material so that I can get a correct gap? I think the whole right edge needs go have material added.

Thanks!

[proffighter]

There are different ways to add material. Can you post pics from top and bottom view, so we can see, which way fits best

[Scott Clarke]

Roland-

I'll try to get a picture posted. I've done a little google searching, and have learned that the thing to do is feather the edge that needs to be amended, and add strips of resin soaked fiberglass mat, first on the bottom and then on the top. Then, I read, I'm to use a polyester filler that includes strands of fiberglass, and then some standard filler followed by polyester primer. Does that sound right to you?

Thanks!

[Bob Kontak]

Originally Posted by Scott Clarke

Does that sound right to you?

Good info Scott. I would add (just thinking here) to dremmel some thin shallow grooves in the feathered edge on one side at a time before the matting. Groove / apply mat / harden / flip over and repeat. I could see paint stir sticks and fat masking tape helping to keep the mat in place while hardening.

Drilling some pin holes in the fatter part of the feathered edge may help the mechanical adhesion as well.

However, the matting is tough stuff. Maybe just roughing the feathered edge with 36 grit would be all that would be needed.

How far do they say to feather? I would think an inch.

[962porsche]

its an ez fix ! remove the paint / jellcoat with 80 grit paper you can use 36 grit but don't grind the fiberglass with it . just use the 36 to remove most of the top coat if your going to use 36 grit . strip it back as far as you can top and bottom side if the lid going down to the raw glass . do not lay fiberglass over any jellcoat at all . if you want to add about 10 mm to the edge then strip it back right to the opening of the step were the grill sits . 4 to 5 inches bigger than the patch area . with some carb bord and some clear packaging tape make your mold right on the lid . cover the cardbord with the clear type of packaging tape . the fiberglass does not stick to that kind of tape so it will peal right off once you do your lay ups . cut little strips of glass mat and lay it next to the area that you want to build out . only do 3 to 4 layers at a time any more it will crack over time . after you build up the area so its just about even with the top and bottom edge of the lid . once the lay up are dry peal off the mold then change to a fiberglass cloth . shape the lay ups you did so the gap just a little bigger than your looking for . then rap the cloth from the bottom around the edge to the top then after that sets up do an other peice the same way but just a little longer covering the last lay up you did . that should now make the gap the size you want . let it dry over night or 8 to 10 hours then give it a skim coat of a body filler . then sand and prime .

[proffighter]

Originally Posted by 962porsche

its an ez fix ! remove the paint / jellcoat with 80 grit paper you can use 36 grit but don't grind the fiberglass with it . just use the 36 to remove most of the top coat if your going to use 36 grit . strip it back as far as you can top and bottom side if the lid going down to the raw glass . do not lay fiberglass over any jellcoat at all . if you want to add about 10 mm to the edge then strip it back right to the opening of the step were the grill sits . 4 to 5 inches bigger than the patch area . with some carb bord and some clear packaging tape make your mold right on the lid . cover the cardbord with the clear type of packaging tape . the fiberglass does not stick to that kind of tape so it will peal right off once you do your lay ups . cut little strips of glass mat and lay it next to the area that you want to build out . only do 3 to 4 layers at a time any more it will crack over time . after you build up the area so its just about even with the top and bottom edge of the lid . once the lay up are dry peal off the mold then change to a fiberglass cloth . shape the lay ups you did so the gap just a little bigger than your looking for . then rap the cloth from the bottom around the edge to the top then after that sets up do an other peice the same way but just a little longer covering the last lay up you did . that should now make the gap the size you want . let it dry over night or 8 to 10 hours then give it a skim coat of a body filler . then sand and prime .

Good advice here

[Bob Kontak]

Porsche962 - Nice write up - so when you wrap the second/longer covering of cloth how far should it extend onto the sanded deck lid? Like 2 inches leaving another 2 inches to step down the filler to the grill opening? That would make it really strong and eliminate the need for my "idea" of pin holes for strength.

[tmsautoart]

Porsche 962 is such a wealth of good info here. I would do pretty much whatever he suggests. 962..would have loved to see your shop as I was in CT this past week. Maybe next time!

[962porsche]

the 1st layup with the cloth should be just over the top and bottom edge (about 1/2 an inch or so ) . the next lay up should rap around an other 2 to 3 inches longer . that should make it about as thick as the jellcoat . the skim coat of body filler should make it the same thickness as the jell coat so there will be no low or high spot were you did the fiberglass work . if you do it the right way the fiberglass that your adding on should be just a little thinner than the total thickness of the lid were the jellcoat is . thats way i stated to make the patch a little thinner . terry i went racing in canada this past week . there is nothing great in the shop now . we are working on a ferrari bb512 , ferrari 365 2+2 , morgan 4/4 , tvr griffith , saab sonett 3 , 911 sc , 911 targa soft window , another 944 v8 swap . and building 2 944 spec cars for 3 brothers racing . 3 brothers racing but only 2 of them race i don't get it ???

[78SCRSMAN]

I did some very extensive FG work on both my bumpers. You can use the tag in my signature to see my thread. The photos are located on the last couple pages. Reading through this post, I did much the same thing.

I would like to add... if you allow your work to cure but require more layers later you MUST sand/scuff the area first if you want good adhesion.