I was going to say fiberglass body filler. I use it on stocks that will be painted. McMaster sells large diameter heat shrink tubing in different thicknesses. I've used .040 and .080 thick tubing for creating a nice even gap along the barrel channel on guns. It works nicely. The fiberglass works well too. It's light, cheap, strong and works fast and easy. I use a product called smc resin to assure a good bond to the old base material. It can be mixed with the fiberglass resin that I use and improves the bond to many synthetic materials. That's what it is made for. Of course, anything you use for these repairs will be pretty unsightly until painted. --Mikejonbearman said:You could use bondo I suppose as it is lighter.
Yep, it'd probably work fine. Good idea!JRS said:Gel-Coat would work very well, and can be purchased in virtually any color 8)