Ali sheets

[Peter-C]

I've obtained / scrounged some ali panels, they are off local council bin wagons I think. The problems are 1 they are painted and 2 they consist of 2 thin sheets probably 1mm stuck together with sikaflex or an equivalent. I've been told that nitromors will remove the paint but I've tried it and it removes the top layer ok but struggles with the bottom coat. It'll cost a fortune in nitromors to clean it all off. Also when you bend it at a sharp 90 degrees, it cracks on the outside. Large radii as per the rear tube are ok.
So I think I'll be ok for the floor, just paint it black, and the seat rear plate should be ok. Its a shame about the side panels as these have to be bent over at 90 degrees. The panels are approx 3m X 1.5 so would have done the car from front to the rear wheel arch in one go.
Any ideas ?

Cheers


Peter

[HandyAndy]

how about a fine grade sanding machine to remove the paint ? then either buff it up or repaint in your choice of colour

As for cracking when being bent , apply a little heat as you bend the ali, I say...." A little heat" , just to help tease the ali whilst bending is taking place, just a thought

cheers
andy

[Peter-C]

Hi Andy,

I've had a go with a an abrasive flap type thing in a drill and it produces a nice brushed finish but I read somewhere ( could have been the ron champion book ) that it wasn't good to take off the top coat of the aluminium, I guess because its hardened. I'm confused but open to all suggestions !!!

Cheers

Peter

[HandyAndy]

Hi Peter,


I must admit to not knowing about technical aspects of the way Ali is produced,
but, in my bike racing days, all the chassis,s of our race bikes were ali & even after crashing a bike ( fact of life when racing ) we always managed to make the chassis frames come up like new after being gravel rashed,

As the sheets of ali you have will be non structural on the car, I can,t see what harm it would do to get the paint off & buff the ali up, maybe the floor being the only part that needs to "have strength integrity",
Now you know I like a bargain, thats what i,d be doing to make use of the ali you have aquired .

cheers
andy

[Peter-C]

Cheers Andy,

I'm proud to be associated with he who is the bargain hunter !!

Peter

[HandyAndy]

Originally Posted by Powler

Cheers Andy,

I'm proud to be associated with he who is the bargain hunter !!

Peter

"speechless"

have a go at making use of that ali, nothing to lose really, maybe just a little time & elbow grease.......now where can I buy that type of grease

good luck, & let us know how it turns out.

cheers
andy

[Bonzo]

Hi Peter

I am far from an expert but it sounds as if you have managed to get hold of some laminated alloy.

Can't remember it's proper name but have seen it being used by my brother on a super Yacht conversion taking place at my local dry dock

The stuff they were using was Two sepperate sheets bonded together with some sort of laminating film in the middle.
I was told that it added strength, reduced noise & vibration.

To be honest I would not try to remove the bottom layer of paint with paint stripper.
That would have been given a good coat of Etch primer, in my experience paint stripper hardly touches it

You'll probably be better of removing it all with a DA or just rub it down & re-paint it.

As Andy has said, when bending try a little heat to help soften the material.

Try it with a small off-cut.

To give it a go all you need is a small blowlamp & a bar of soap
Rub the block of soap on the area you want to bend, just a nice wide strip on the bend line will do.
Start to warm the opposite side with the blowlamp, keep the lamp on the move so as to not concentrate the heat in one spot.

When the soap starts to bubble then turns brown ( Like toast ). The alloy will be as soft as its going to get.

It will bend easiest whilst still warm but the alloy should still remain slightly
softened when cold ( It will work harden again once you have bent it )

With a little luck this may help you to get some bends into it without the material cracking.

One final tip.

Don't try to put to tight a radius bend in that material.
2 X 1mm + the thickness of the laminate .... Going to be a big ask trying to put a sharp break into that.

Try & find a former that has a nice radius on the corner ( Not unlike the radius needed for IVA )
Hopefully you'll be able to bend that material to 90deg without cracking

[Talonmotorsport]

You will not be able to bend laminated ali sheet with out making a mess of the top radious even with heat. The heat or anealing to call it by its proper name will need to be about 300 'c plus and will distroy the the laminating compound between the sheets. The top sheet will need to strech 1.5-1.75 the times of the bottom sheet and thats why it cracks it just receives to much tension going round a larger radious than the bottom sheet. Ali sheet comes in about 4-5 different grades some are cheap and soft easy to bend and the more expensive is for structural work. If you are planning on using any ali and you don't know what it is or what grade it is I'd say only use it as a covering not some thing structural like the floor. I worked in sheet metal shop for 5 years learning as I went and ali is not like steel, if you use the wrong stuff in the wrong place it will tear like tissue paper.

[Peter-C]

Cheers Lads,

Just when I thought I'd got something for nothing !!!! I'll have a test tonight on some scrap pieces.

Peter

[Peter-C]

I've just had a few tests with a heatgun and a hammer, seems quite favourable - no cracks at all. It only takes a few seconds to heat the ali up. Next I'm going to try putting a strip over the ali thats bent over as it does look a bit ugly.

Peter