Project Tonka - Rear Fender Construction

Have made some good progress on the TW200 over the last couple of weeks. Originally I was going to use a steel black fender and cut and shape to suit. However I wasn't happy with the outer radius as most of these off the shelf fenders that would fit the 7" wheel were flat.

Scrap Ply to use for the plug

I decided to shape my own creating a plug out of plywood to replicate the radius of the wheel. Once that was done I filled the spaces with expanding foam. I probably should have used the two part expanding foam as the builders foam left too many air pockets after being shaped.

Nailed into place

Expanding foam to fill the voids

Should have used 2 part expanding foam as there were so many air pockets
Then I glassed a female mould with 2 layers of woven cloth and a layer of chop strand. Because the foam wasn't perfect I had to spend a bit of time sanding and filling the holes left by the foam.

Next I created the final male mould, this time I used a Vinylester Resin for increased flexibility and strength compared to the Polyester.

Vinylester Resin with woven mat

Final result after sanding. Ready for primer and paint

It came up really well after a trim and a light sand and fits perfectly to the rear tyre and is also super lightweight. Now to fabricate the mounting hardware.