In my infinite wisdom (and probably lack of building confidence) I've fixed lots of aluminium panels with rivnuts rather than rivets so I can get them back off again.
They are mainly stainless rivnuts with will hold stainless button head screws. There isnt anything flexible on my engine mounts so the car will vibrate lots and was thinking of threadlocking them but I've already noticed that button head screws (especially the smaller ones) wont take much torque before they round off so I'm a bit concerned about them seizing.
Should I go the other way and secure with wavy washers and use copper grease to make sure I cant get them out again?

Use a small blob of Hylomar (or similar) non-setting compound. It'll prevent fastenings from vibrating loose but be undoable if the need arises.

There are different grades of thread locking compound. Use a lower strength one.

Rivnut a for body panels are way over the top imho. It's extra weight and you are drilling far larger holes in the chassis then you would have done with rivets.

I wouldn't dare use any grade of threadlocker in a rivnut. The only thing worse than a spinning rivnut is a spinning rivnut with the screw/bolt still jammed in it and the panel being retained by it still in place.

Hylomar suggestion seems a good one to me.

I drilled 4.2mm holes into my chassis then tapped M5 holes. I used blue loctite which has medium strength and can easily undone, yet won't vibrate loose.
To prohibit vibration I used a rubber foam based tape so the GRP panel wouldn't rattle against the body, then sealed all open edges to prevent water ingress.

Sounds like a chore, but once it's done it's done.

[Edited on 4/6/16 by Toprivetguns]

Chris,

Depending on how far you want to go to (or how much to spend), Nordlock washers are excellent at keeping fasteners tight.

It wouldn't hurt to grease your threads a little too to make sure the stainless screws don't gall together with the stainless rivnuts, then you really wouldn't get them out. The hylomar suggestion probably kills two birds with one stone though.

Keith.

I wouldn't suggest this for loads of screws but for the odd few I wrap a couple of turns of PTFE tape round.


Anti gaul, anti vibe, and dust & grit doesn't stick.

If you use copper grease, you'll never have to take them out.

The day after you use threadlock, you'll need to get them undone.

The universal law of copper grease.

Hylomar it is then.

I have progressed onto tapping the metal in most cases rather than rivnuts as the hole isnt as large.

Thanks for the advice chaps, something new to add to the shopping list!

Hi Chris

Hope that doesnt include the floor ones !!!!

The J15 chassis does make me cringe having no "cross beam" between front and back i have thought about bolting a bit of steel across just for piece of mind.

Nick M

Hi Nick,

No not the floor ones - im not that paranoid!

It was the panels behind the seats (for engine access) and the tunnel mainly.

I'm sure I saw in a mag somewhere that the R1ot was tested for rigidty (australia I think) and it camne out really well.

Ho goes your build? Im making good progress and hope to be done this year.

Chris

Hi Chris

No sorry i was just taking the p***

Yes it was tested i think in Australia for rigidity

Nearly there tarting it up really all those quite satisfying jobs that make a visual diference with not to much graft !
Thinking about IVA i have Beverley 76 miles away (lovely drive but strict) Norwich 74 miles reasonable drive but unknown or Nottingham 68 miles bad drive around Nott ring road but kitcar friendly.

Hopefully finish off the exhaust today i chopped the tail pipe off to replace it more parallel to the road for a bit more access when the "boot" tips up and making up a handbrake cover and warning switch bracket.

You nearly there as well ?

Nick M

Getting there. Still have problems with exhaust exiting through rear clam. Hole needs to be quite big because of way clam swings open.
Most major stumbling blocks out of the way now. Hopefully start working towards an IVA date.