Rivnuts

[Ozzy]

Can you use a Rivnut on the nosecone, or is it likely to crack it?

 

Thought I'd ask on here first, before disaster ensues!

 

Oz.

[Klunk]

I've used them on fibreglass before. As long as you don't overtighten them it's fine. I think I used a bit of araldite to allow me to use less pressure on the fibreglass.

 

Regards,

 

Giles

[Stationary M25 Traveller]

Do you mean fit the nut part in the fibreglass or CF nose ? If so - then yes it will crack.

[Ozzy]

Nosecone is fibreglass.

 

Not sure what you mean Ian? The rivnuts are one piece things. I just wondered, as obviously I've used pop rivets on the nose, and the rivnuts just a large version with a thread inside, isn't it?

 

 

 

[DJ.]

If you need a captive nut on fibreglass, it would be better to fit your rivnut onto some steel sheet with plenty of holes in it and then to fibreglass over the the sheet to bond it onto the inside.

 

Duncan

 

edit: just seen your last post. The pressure needed to fit a rivnut is much higher than an aluminium pop rivet.

 

Edited by - DJ. on 3 Dec 2012 19:17:49

[Stationary M25 Traveller]

Quoting ozzy: 

Nosecone is fibreglass.

 

Not sure what you mean Ian? The rivnuts are one piece things. I just wondered, as obviously I've used pop rivets on the nose, and the rivnuts just a large version with a thread inside, isn't it?

 

 

whether you were going to fit the rivnut itself to the nose, or use a bolt through the nose into a rivnut fitted to the chassis.

[Bricol]

Yep - done it. Just don't clinch them so far as you would in metal, and the GRP won't crack. Git to undo if they seize through corrosion tho.

 

Bri

[Roger Ford]

Or use the proper item. You'll need another tool, though.

[Phil B]

for MEMfast, helped me out a couple of years back when I wanted to fix 2 of M8 steel rivnuts, they loaned me the insertion tool so all I paid for was the rivnuts and postage.

 

Phil B

[Klunk]

Roger's option looks like a better solution.

 

I used a memfast tool to fit my ordinary rivnut as it is easier to control the pressure applied compared to traditional rivnut tools

 

Forgot to say the fibreglass mustn't be too thick so as to stop the rivnut compressing - that will crack the fibreglass.

 

Not sure what you're using the rivnuts for, but I fitted them in the nosecone to secure the front number plate with no issues.

 

Giles

 

[Ozzy]

 

Number plate. I've gone off the idea of velcro, as I'm looking for something that looks tidy when the plates not on, rather than a strip of velcro stuck on the nose!

 

 

 

[Klunk]

Precisely the reason why I used them 😬. Just proceed with caution and you'll have no problem.

 

Giles

[Ozzy]

Sounds like it's worth a go then.

 

I've got a rivnut kit, but I've never used it yet! I assume you can just apply as much pressure as you need to just expand it so it holds. Unlike pop rivets which you need to apply a lot of pressure to, before they snap off!

 

 

 

[Klunk]

Correct. Normally you would pull them tight if in steel but not so tight as to strip the thread.

 

In this instance, you want it to just grip the fibreglass so they can't rotate. I would practice to get the feel of it first then go for it

 

Giles

[Ozzy]

Cheers

 

I've got a fairly sympathetic touch, so I'm sure I'll be fine.

 

 

 

[Wrightpayne]

Why not just use std plastic bolts. Not a major issue to get your fingers inside to undo or even take off the nosecone. You could probably araldite in place.

 

Or as suggested rivnut in a bit of ally bonded in place.

 

Ian

[Roger Ford]

I've got a rivnut kit, but I've never used it yet! I assume you can just apply as much pressure as you need to just expand it so it holds. Unlike pop rivets which you need to apply a lot of pressure to, before they snap off!

First time I used a rivnet: Cor, these rivnuts take a lot of force. SQUEEZE ... . There - done it. Oh, hang on a moment...

[Ozzy]

That's why I thought I'd ask first Roger. Didn't fancy learning the hard way

 

 

 

[Benedict.]

How about a rubber captive nut?

As per the dwgs on the page, they "clinch" themselves when tightened, but release when undone. You could then pop them out and fit some (coloured?) blanking grommets, or even keep then fitted, and screw in some coloured dome-head aluminium screws, when running from the law not wanting a reg-plate on 😬

 

Ben

 

 

Edited by - _Benedict_ on 4 Dec 2012 05:33:43

[myothercarsa2cv]

Can you not just put a washer around the rivnut behind the cone? Spread the load? Works for rivets ok? Rivnut would grab the washer, not the GRP.

[Golf Juliet Tango]

I fitted a few rivnuts into the body of the 21, so they will hold. I think that the bodywork GRP may be thicker than that of a nose cone.

 

Roger's link looks like a better solution, however.

[Golf Juliet Tango]

Looking at the Memfast page, I think those were the fixings used to locate the headlights in the original cars. When I fitted new lamps, I improvised (using hollow wall fixings). The fittings designed for the job would probably be better and certainly would have been quicker. (The problem with the 21 is that there are nearly no flat areas, everything is on a 3d curve)

In fact Benedict's link to the rubber coated nut might have worked even better.

 

Edited by - Golf Juliet Tango on 5 Dec 2012 16:59:13

[Roger Ford]

I imagine you could do those Memfast screw anchors up with either a simple bolt and washer, or use a normal rivnut tool. Speaking of which, my Memfast rivnut tool arrived a couple of days ago (which was why I'd been looking through their website), and it really is a lovely thing. At £60 + post, it's a lot more than a standard "squeezy" tool, but it's much nicer to use, and I've broken two of the squeezy ones before (though admitedly the first one was due to the episode mentioned above). Well recommended.

[Klunk]

+1 . I bought the original one about 4 years ago at Stoneleigh and have never regretted paying the higher price. Excellent piece of kit, built to last, and the new ones are even better

 

Giles

 

Edited by - Klunk on 5 Dec 2012 17:06:03

[Ozzy]

All done

 

Rivnuts were no problem, I just pulled them up gently until I'd got a nice bubble behind it, and then a very slight extra squeeze, and they were fine. No cracks at all.

 

Just for good measure, I also put a smear of Araldite behind the head/lip, along the shank, and a large blob around them on the inside of the nose. Looks very tidy, and I don't think they'll ever come loose!

 

Thanks for responses/ideas.

 

Oz.