ajmacdon wrote:
How did you selectively leave the foam reinforcements on there and get the rest so clean? More details on your fiberglass process would be awesome, looks amazing!
Thanks,
Alex
Thanks! My process was basically as follows:
1. Create a wood frame that was oversized in the areas/edges that would require final trimming but 1/2" undersize in width and height to account for the thickness of the foam. I also had to make sure I could disassemble it from the inside.
2. Lightly glue the 1/2" insulation foam down with some spray contact adhesive and shape the radius edges using a long board with 40/80 grit sandpaper.
3. Layup the outer fiberglass layers.
4. Disassemble the wood frame and gently separate the plywood from the foam. This is were it really pays of to use the glue sparingly.
5. Mark out and remove the areas of foam that I needed. This was all of the finished edges, anywhere bolts pass through, and anywhere I needed extra clearance for the frame that holds the coolers. I used a utility knife to cut along the lines and then cut in between the foam and fiberglass to remove the bulk of it. 40 grit sandpaper makes quick work of any leftover bits and cleans up the now exposed fiberglass.
6. Feather the foam edges using the utility knife and 80 grit sand paper.
7. Layup the inside fiberglass layer. Because this increases the stiffness so much you need to make sure that the part isn't distorted when curing. For the hood I had to make a cradle to support it from underneath and hold the exact shape. For these scoops I put a light elasticated cord around the outside and a cardboard brace inside to hold the top and bottom the correct distance apart. You can put packing tape over the edges of the cardboard so it doesn't soak up any resin or stick to it afterwards.
8. Trim all the edges to fit.
9. Filler, sand, repeat until happy or you just can't take working with fiberglass/body filler any more.
10. Paint and wrap in vinyl
Page 7 has some good step by step pictures of when I made the hood.