filler for stripped self tapper threads in GRP

[davidmh]

I am revovating a heads area on a GRP boat and there are some panels which are screwed on the GRP moulding with self tappers, most are around 4-5 mm in dia. Some have begun to stripp the threads. some are though holes and some are blind. What is the best filler to use to fill the hole before redrilling and fitting the self tapper. Is Isopon P38 ok or would Isopon P40 be better, how easy is it to get the P40 into the small hole. All suggestions welcome. I already have P38 and P40.
David MH

 

[2Tizwoz]

I've succesfully used gelcoat to fill stripped grp threads, however as your holes vary and don't need to be watertight why not just drill out the grp and use plastic wall plugs?

 

[William_H]

Any filler should be fine. The viscosity at the temperature will determine how easy it is to get into the hole. (and if it is going to flow out the other side) I would far prefer to drill and tap the new hole for 4mm screws than self tappers which tend to crush their threads into base material. ol'will

 

[wonkywinch]

I used Araldite then drilled a new pilot hole.

 

[Graham376]

A piece of a match or other thin wood such as toothpick in the hole often works, without need to fill and drill a pilot hole.

 

[VicS]

I always set self tappers into grp with Araldite. I don't clean the threads, or deliberately make them very slightly greasey, then they can be unscrewed leaving nicely tapped holes.
It's the only time I use the "rapid" version.

 

[Refueler]

Forget fillers ... if you manage to drill and tap - they are brittle ...

Use plastic Rawlplugs ... cut short of necessary ... or those brass inserts that are pressed in and the screw expands it to grip.

 

[vyv_cox]

A man who repaired my chainsaw used short pieces of strimmer nylon to take up enlarged holes for self tappers in GRP. Rather like the matchsticks suggested above but stronger and more able to take up the thread shape. Highly effective

 

[rogerthebodger]

I use epoxy steel as a filler in all kinds of holes as epoxy sticks better to most materials than polyester resin.

we get epoxy steel in both a putty form or a liquid adhesive

 

[Bobc]

As said above, poke a match in the hole then break it off at the surface.