Helicoil for plastic body NH TC40

[mphymel]

Does anyone have a suggestion for this problem:
I removed the lower cowling to access the relay panel on my NH TC40, and ran into a problem with one of the firewall bolts.

Instead of nuts on the backside, they molded in a Dodge style thread body in the plastic cowling. The threads were frozen, and instead of the threads breaking, the thread body spun in the plastic.

I managed to fit a drill motor in the space with a nut driver and was able to spin the living sh~t out of it until I was able to get the cowling off. I would really like to have that fastener do its job, there are only 4 total.

Does anyone know if there is a helicoil product that can be used in plastic, or some sort of epoxy kit that can be used with a threaded insert that could be used to fix this?

 

[TheKid]

I would think that some knife thread inserts would work.

Knife Thread Inserts for Wood Press Inserts for Plastics Thread Inserts

 

[Sticklizard]

I had the same problem with one of my bolts and have been looking for a suitable replacement. Ace Hardware had some that were close but I'd like to use the same bolts so they'll be interchangeable - I'll have to figure the proper size and thread. Some antisieze compound would probably help. The threads on the original parts seem to be either damaged or are very cruddy which contributed to the problem.

 

[sweep]

I would tap it and use a threaded insert and doubly secure it with a plastic to metal epoxy such as Fusor. Fusor and like products such as SEM are expensive and take special guns so I would just hit up your local body shop and have them put some on the threads from their gun and immediately screw in the threaded insert. Working time varies per product but usually 10-15 minutes. I can't imagine them charging you more than $5-10 or so if they charge you at all.

And as the poster said above use anti-sieze on the bolt.