From Bondline
Replacing the ABS plastic wheel pants with new fiberglass shells
After several crack repairs to the original ABS wheel pants I finally took Bob Steward's advance and ordered replacement fiberglass shells from Fletchair. There are many alignment holes predrilled and the fit and finish is great. I didnt have to trim anything on the new pant.
The caulk/adhesive helps to bind the bracket to the shell.
Initial work is the removal of the old mounting hardware from the ABS shell. The brackets are both riveted and glued/bonded with some type of caulk adhesive. I ground the heads off the rivets in order to not enlarge the bracket holes by drilling. This was easy since I didnt care if the old shell was damaged by the grinder. Using a thin putty knife I cut the caulk adhesive and was able to seperate the brackets from the ABS shell. Note: The outside bracket is made of two pieces that will seperate once the rivets are removed. Mark them so you know how they go back together. I used a spring loaded center punch to dimple the top edge of each one.
The compound curves in the hardware complicate their reproduction.
Right angle drill is essential to back drill the bracket holes.
Predilled holes in the new shell matched the holes in the bracket for the mounting bolts.
Attaching the brackets to the new shells consisted of figuring out which alignment holes worked best for my plane. The predrilled holes for the bolts that are used to attach the pant from the brake side matched my bracket almost perffectly. There were 4 alignment holes in the shell for the outside bracket. Only two of these aligned with the holes in my bracket. It was either the top holes or the bottom holes. Since I didnt want the shell to sit crooked I had to do a test fit. Using clecos I assembled the brackets to the pant and mounted it to the plane to see how it looked.
As it turned out I used the top two holes and glassed in the bottom two holes. Then I mounted both brackets using clecos and backdrilled the remaining holes in my brackets. I countersunk the rivets on the outside of the wheel pant for AN426 rivets and used AN470 for the inside of the pant since that area would be covered by the brake cover.
12 nutplates 2 rivets per nutplate....
Rubber hole plug works well.
Next was actually riveting the brackets in place. The original pants had both rivets and adhesive caulk to attach the brackets. This helped spread the load from the shell to the bracket so that it wasnt just held by the rivets. Proseal 3204B-2 has been used before and I think 3M 5200 Marine Adhesive/Sealant would also work well in this situation. Apply the adhesive, clecos, clean up the stuff that is squeezed out and set the rivets. Then I just had to locate, drill, countersink and rivet the numerous nutplates for the brake cover.
Painting, a whole different Bondline subject, that I will leave to the experts, is next. In my case it takes me longer to paint the pant than to do everything else. I use a Motorola radio hole plug to cover the hole for the attaching bolt. I did not transfer the lead weight to the new shell. The old ABS wheel pant with hardware and weight weighs 5.17 lbs. The new fiberglass pant with hardware but without the weight weighs 5.15 lbs.
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