Rear Wing refitting / Fixings

[Scottart]

My offside rear wing got badly knocked ! Need to refix the wing with new fittings / bolts...the 'rivnuts ?' have popped out from the chassis 'arch'.

Any ideas what these are called and can I replace/redrill with larger fittings ?

Cheers, Steve

[Jonathan Kay]

Aluminium RIVNUTs from Car Builder Solutions with hole and thread sizes. You can also get stainless steel.

Jonathan

PS: There's a trick of using nylon bolts (and nuts where fitted) in the hope that they'll give way before the bodywork.

 

[Scottart]

Thanks Jonathon ! Will investigate - is there a special tool needed to secure the rivnuts, or does just tightening up the bolts secure them in place  ?

Steve

[EEK]

Suggest you get proper tool to set the Rivnut. Inner wing being pretty thin does not give you many opportunities to practice, I have used Sealey AK3985, very happy with it and will set larger ones for other jobs.

 

[Scottart]

Thanks EEK / Jonathon,

Should I go Aly rivnuts or Stainless.....I suspect using Aly means they can pop-out in another knock, but stainless....?

Steve

[DJ.]

Stainless will probably cause corrosion where they touch aluminium. Also use plastic bolts so in the future they break before the rivnuts and also don't corrode into them.

[EEK]

When I did mine I had to go up a size in Rivenut, the pulled out holes were the right size for the next size so 6mm I think instead of 5mm. I thought about a load spreading washer on the back side of the wing to limit it happening again but that made it all too thick for the rivenut to set properly.

In the end, having removed the inner panel, I went for aly rivenut (to avoid electrolysis risk) and a small fillet of thickened epoxy resin around the set rivenut to spread the load a bit with plastic cap head bots.

[elie boone]

I would use rubber rivnuts in this case, no need for any special tools. And use plastic bolts or plenty of grease on the bolts.

[Tony P]

I'd go with elie on this - rubber nuts (with a metal thread inside; sometimes called 'rawlnuts' - a brand name); they also help to keep the different metals separated. 

Useful to have a few of these in the toolkit too, for repairs 'in the field'.

[Jonathan Kay]

http://kojaycat.co.uk/WebRoot/Namesco/Shops/950000457/4F15/B806/2F7D/A0CF/62CB/C0A8/190A/1397/m8_well_nuts.jpg

Often called "well nuts". 

I use these for fixing the jack in the engine compartment. 

What are the advantages and disadvantages of these and RIVNUTs for wings, please?

Thanks

Jonathan

[Jonathan Kay]

Stainless will probably cause corrosion where they touch aluminium.

Yes, i think that would swing it for me.

Jonathan

[Tony P]

Ah - I was never sure what a 'well nut' is.

They typically have larger OD than a regular rivnut, so they can help when replacing a fixing in a hole that has already been damaged or enlarged by the escape of the previous occupant, and they are more tolerant of a slightly irregular hole.

As elie says, you don't need any special tooling (Ok - you *can* fit a rivnut without special tooling, but it's not ideal),

They can rip out again with (hopefully) a bit less further damage to the skin.

Flange is typically thicker than a metal rivnut, but you can work around that.

If a metal setscrew does become seized in the thread, you can hack the rubber away and then have a much slimmer metal insert to withdraw through the screw hole in the wing.

[Jonathan Kay]

Thanks

Jonathan

[SLR No.77]

For fixing the rear wings aluminium rivnuts are the preferred option (as o/e) with M5 nylon bolts as a breakaway point. There is no bi-metallic corrosion with this setup. If the rivnuts have pulled out, the preferred option is to go up a size of rivnut. If inserting new rivnuts, use a rivnut tool, there's enough around that you can easily borrow one and they're pretty inexpensive. You'll not successfully fit a rivnut without the correct tool.

Stu.

[Mrp]

I have lots of nylon nuts and bolts if anybody wants any, can post next week if required. That’s how I put my carbon rear wings on. That way if it gets knocked again the nylon is sacrificial. 

Mr P

[Shaun_E]

The Memfast rivnut tool is the best one I've seen but not cheap. Plenty of cheap ones that look like a normal pop-rivet gun but they never last long and can be hard to use.

[SLR No.77]

Or at the cheaper end .... I've recently bought this one at RS, it's inexpensive and quite honestly you'll not use it enough to need anything better. I only bought it because I couldn't find my old one ... which obviously I found a few days after the new one arrived! 

Stu.

 

[Scottart]

Thanks everyone for your thoughts ! I'll get the wing off first before deciding which way to go.

 

Steve

[Domus]

When using nylon screws just nick the shank of the screw, under the head, with a Stanley knife.  If needed to they shear at this point.  A full nylon screw could still pull out a rivnut.