Can I tap 4mm ali to mount a battery box

[Barreti]

Hello chaps,

I've replaced the battery in my Griff for a racing battery which is MUCH smaller.
But this left gaps where the GRP isn't carpeted.

So I've had a new battery 'box' made from high quality aluminium checkerplate, which will cover all the gaps, and a bracket to hold the battery to the box.

This new box has no front so its kind of like a rally floorplate.

I need to secure the battery bracket to the box, and the box to the car from underneath, through the body.

Is 4mm checkerplate strong enough to withstand being tapped and bolted to?
Would it make any different what type of tap and bolt I use (fine thread) ?

I could put rivnuts in the floor of the box for bolting it to the car if tapping a thread into the ali is no good.
Ali or Stainless rivnuts? Stainless would be stronger but react with the aluminium won't it?

Not really what you boys would call a 'Major Mod' but thanks for your help anyway.

Edited by Barreti on Wednesday 21st April 11:28

[teamHOLDENracing]

Sounds like a couple of flanges welded on that you can bolt through would be safer, although it's difficult to visualise what you describe

[Barreti]

Thanks for pointing out its difficult to visualise. I didn't realise.

I'll get some photos ASAP.

[Barreti]

Photos then chaps

I have two things.

I've got a bracket being made to attach this battery to this box.
The bracket kind of looks like this
http://www.demon-tweeks.co.uk/Performance/Electric...




And I need to attach the whole thing to the floor of the car in the same way as this one was

Edited by Barreti on Thursday 22 April 11:25

[clive f]

Ian, normal rule is only to tap into a thickness 1 1/2 times the diameter of the bolt being used, so m4 thread would need a 6mm thick plate.

I`d play safe and weld a strip across the back to beef it up a bit.

[Barreti]

Thanks Clive

[sgrimshaw]

Why not put it in the boot?

Your passenger will thank you.

Here's a picture of mine (albeit in a Chimaera) done by Dulford Automotive.

http://www.dulfordauto.co.uk/content/latest-tvr-ne...

[Barreti]

Its already in the footwell Simon

I designed a box to cover the missing carpet etc, made a dummy out of cardboard to make sure the idea would work, then had a made make it out of aluminium.

I've sorted out the pegs for attaching the battery bracket to the box. Now I just need to mount the box to the floor, which I think I might now do by fibreglassing a couple of nuts to the floor and dropping a couple of stainless countersunk head bolts in from the top.

Here is the (almost) finished article, which has gained my passengers 3 to 4 inches in physical legroom and even more if you consider you can now angle your toes over the battery. I'm 6'2" and my feet now don't touch the battery.

Edited by Barreti on Monday 26th April 21:34

[sgrimshaw]

Sorry Ian,

I really should read things more closely.

You did say you had already done it - Doh!

Simon