Repairing stripped screwthreads in fibreglass.

[Scott Barton]

Removed my twin engine fan set up at the weekend to make way for my mirrored finish version and a lot of the screw threads in the fibreglass engine lid are shot. Some are split, some have no thread in etc and was wondering what other people have done to repair...?

I have some chemical metal that I was thinking of using and filling the holes, and then lightly drill them so that I can use new screws on them. Thoughts?

[Draven]

fill it with a strong epoxy and then drill and tap..

[C35Rob]

use speed fastners/spire nuts, or drill out and insert alloy rivnuts

[Scott Barton]

fill it with a strong epoxy and then drill and tap..

That is what I was thinking with the chemical metal. M4 suitable size to tap to you reckon? M6 maybe too big, or maybe M5?

Alternatively I was going to fill and drill out to use some new S/S self tappers.

[Scott Barton]

use speed fastners/spire nuts, or drill out and insert alloy rivnuts

Are you talking about these Rob?

http://www.ebay.co.uk/itm/Screw-Size-6- ... 1138892951

[Scott Barton]

I reckon this should do the trick....

http://www.henkel.co.uk/2838_UKE_HTML.h ... 2703015937

[Peter Gidden]

Since the engine lid is GRP, i've always mixed my own paste out of GRP polyseter resin and talc. The the chemical base of the filler is the same as the engine lid.

Then drill for new scews when cured.

[Scott Barton]

That is what I am thinking Pete.
Another option I have toyed with is get some M4/M5/M6 riv nuts (whatever size fits), drill out the existing holes to suit, and Araldite/Chemical metal them into place. I don't fancy squishing the riv nut using the tool as the GRP would split.

Then use something like this: http://www.ebay.co.uk/itm/16-Peice-Kit- ... 25914c282d

[Draven]

Since the engine lid is GRP, i've always mixed my own paste out of GRP polyseter resin and talc. The the chemical base of the filler is the same as the engine lid.

Then drill for new scews when cured.

Interested as to why you use talc?

[Peter Gidden]

Since the engine lid is GRP, i've always mixed my own paste out of GRP polyseter resin and talc. The the chemical base of the filler is the same as the engine lid.

Then drill for new scews when cured.

Interested as to why you use talc?

It's an accepted and widely used filler/thickener medium for use with GRP and epoxy resins.

Lightweight, good mixing and adhesion properties and easy to sand.

Many GRP specialists in the marine and automotive sectors mix their own fillers.

[Draven]

Ah cool. think that will come in handy.

[C35Rob]

That is what I am thinking Pete.
Another option I have toyed with is get some M4/M5/M6 riv nuts (whatever size fits), drill out the existing holes to suit, and Araldite/Chemical metal them into place. I don't fancy squishing the riv nut using the tool as the GRP would split.

Then use something like this: http://www.ebay.co.uk/itm/16-Peice-Kit- ... 25914c282d

I've used alloy rivnuts into GRP on many occasions and never split anything yet, I wouldn't try it with steel rivnuts though.

[mr2magic]

I use this to repair the damage to the fibreglass and mould a suitable mount...

www.henkel.co.uk/2838_UKE_HTML.htm?nodeid=8802699313153

then, while it's still wet, I place something like this, only sealed at the bottom into the mixture making sure everything is aligned....

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[Scott Barton]

I use this to repair the damage to the fibreglass and mould a suitable mount...

www.henkel.co.uk/2838_UKE_HTML.htm?nodeid=8802699313153

then, while it's still wet, I place something like this, only sealed at the bottom into the mixture making sure everything is aligned....

Image Replaced With URL For Quote http://www.wellot.com/p/d/Inner-Outer%2 ... %20Nut.jpg[/code]

Liking that! I carried out my repairs today.
I bought some aluminium riv nuts and drilled out the holes to 7mm and secured them in place.


A couple had completely disintegrated so managed to secure in place using some chemical metal, ensuring the riv nut was straight and true.


God bless the inventor of riv nuts!

[Scott Barton]

Now just got to decide on either the KO Racing mirror finish engine fan shroud, or my original Rogue version. Stickers have all been removed now, would like something a bit cleaner.

[mr2magic]

Mirror finish doesn't last long if the car is used regularly - can you really be ar$ed to polish it every other day?

[fred130111]

This is very handy information Just bought a turbo lid of someone on here and the rain tray is pretty much hanging off / also bent

[Draven]

Nice work. I think i'll redo mine with some riv nuts as well.

[Scott Barton]

Just be careful when squishing the riv nut in. It only needs to pinch in, too much and it will crack the fibreglass. The first one i did, I did gingerly until I heard the first crackle...then I knew how much force for the rest of them. I am thinking of putting a blob of Araldite just on the edges to make double sure they are secure.