Large flat CF sheets with no mould - bond CF to sheet aluminium?

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#1

I’ve been thinking of a way to create large flat sheets of carbon fibre to fit out my van. Yes, it’s just for the bling - the ply wood look just doesn’t do it for me. :stuck_out_tongue:

Anything involving large moulds or giant panes of glass are definitely not ideal. So I was thinking why not make a CF/aluminium composite sheet? Starting with a thin ally sheet, say 0.6mm and adding a layer of carbon fibre (or maybe a layer of glass & CF, or starting with a thicker ally sheet according to the required properties), and finishing it with a hot coat or flow coat similar to how surfboards are made?

I’m painting some parts for my supermoto project which is ongoing, and have some aluminium cleaner for the ally parts that I’m going to paint. It’s basically an acid which removes any oxidation and small bits of dirt in pitted areas etc. Then you can paint with etch primer, etc. So if that’s a good prep for painting, then why not for laminating?

The only additional step I could think of would be to use a fairly coarse sandpaper to roughen the surface before using the cleaner, which ought to give a better mechanical bond with the laminate?

Just wondering if anyone has tried something like this before? I will have to get around to making a little sample piece and see how it goes.

#2

If you’re using polyester, it will not bond to the aluminium, you would have to use an epoxy or VE. You might be able to get a mechanical bond if you drill holes in the ali and the resin seeps through, making little rivets. Polyester is NOT an adhesive, even pritt stick will bond better to ali than polyester. No joke.

You could also just laminate your existing plywood.

I know you said deffinitelly not, but if you can, get a pane of glass, coat it in clear resin. I would use Seabase’s iso 7x. Its a surfboard resin, but it’s isophthalic, which is harder wearing than the ortho resins normally used for surfboards. Lay your carbon, then back it with a layer glass cloth. You can then bond this to the plywood. The reason I say this is because no matter how much you try, you will not get a perfectly flat surface if you try to do male lamination.

#3

Aluminum + carbon fiber = galvanic corrosion

You will need to put some fiberglass between the two to function as an insulator.

#4

I heard this at some point by an ali honeycomb manufacturer. He did say it would take a very long time to see any effects.

#5

I was waiting for someone to say this. I think in the case of a van’s interior non structural panels one need not stress over galvanic corrosion. Unless you intend to fill the van with salt water or live next to the sea and leave the doors open a lot.

I feel that sometimes we get so wrapped up in the details when making parts that we forget the end use. I do it all the time and need to tell myself to step back and look at the bigger picture.

#6

My point is that for $10 you can add a thin layer of fiberglass to the layup and never have to worry about.

#7

Cheers for the comments.

I was planning to use epoxy, but interesting point about polyester resin not being an adhesive. Never thought about that… although I just automatically defaulted to epoxy when thinking about anything requiring adhesive properties.

The panels will have a slight curve in them when installed, so as long as the surface is not too irregular/lumpy then it may be okay.

I’ll have a bunch of ally soon, so I’ll do a test on an offcut and see how it goes. I’ll start out using the regular laminating epoxy for the surface coats and see how it goes.