Embedding sheet metal in laminate?

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#1

Hi guys

I would like to embed a piece of sheet metal into a flat piece of Carbon fiber. It will be layed up via resin infusion with and hoping to get an A-class surface finish (which I started a thread about a few days ago).

How can this be done? I can imagine it would be difficult, but OTOH made slightly easier by the fact that it will be a simple flat board of CF. Also looks like I’m going to have to use stainless steel as galvanic corrosion will be a potential problem with mating a metal in contact with CF.

Any help much appreciated, thanks!

#2

What are the specifics of your lay-up, is the sheet metal within the laminate or on the tool surface or what?
What thickness, cloth specifics, etc?

#3

Unless the piece of sheet metal is only 10% the area of the CF panel, I think it will compromise the strength and integrity of the CF panel because it separates the the layers of fabric and resin from each other. There are most likely other ways of accomplishing what you’re trying to do, but you have to give a lot more details. In itself, placing a layer of sheet metal within a CF panel is counter-intuitive.

#4

the finish would reflect the surface of the tool used.
I have bedded aluminum in c/f on a few occasions. The life span has not been tested but pending the application corrosion would take quite some time. Stainless would need sanding to help with grip.

some of the steps I have used was to scotch brite the alum with water or acetone, alodine (1201) the surface. (to get a water break test)

I have bonded Boron (prepreg) to aircraft skin (747) many times.
the process was to clean, Phos anodize,& adhesive prime.

Here is the data on the project I worked on years ago
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19950008043.pdf

#5

Sorry folks! I should have included more information

Basically I would like to embed a very thin piece of sheet metal into the laminate on TOP of the cloth (but beneath the physical surface) so that it can be clearly read. The metal piece will have on various data tables and conversion tables cut into it, kind of like the stencil you see in this picture.

Do note, this is for aesthetics with no real consideration for strength. I could print the details onto the surface, but the surface will be used frequently and prone to wear, with the added benefit of looking pretty cool. Cloth is planned to be 0.65mm 2x2 twill weave, but will move to something else if appropriate.

I can find any examples of it having been done. I’d like to experiment trying it, I don’t even know if it will work but just wanted to ask around here to see if its been done and any pointers in the right direction.

#6

It would work, I’ve done similar things. As long as the metal has a lot of cut-outs for the resin to flow through; that stencil for example would be very easy.

You also shouldn’t need to worry about galvanic corrosion too much if it is completely encased in the resin, you’ve got no exposure to an electrolyte (water). If you are concerned about it, just paint the back of the metal so that it isn’t in direct contact with the carbon. There wouldn’t be any advantage in using stainless steel over aluminium, as the steel would still be the active material and hence experience accelerated corrosion. But as I said, not a concern if it is isolated.

#7

Yeah, this is my primary concern! Making sure the resin flows well around and to the front of the stencil to the mould face. I will make sure to design the stencil such that it has as little surface area as possible. Do you have any examples of your work?

I’m also little worried about keeping the stencil aligned as the bag pulls down under vacuum but I think thats less of a concern as I should be able to develop a solution for keeping it in place.

#8

A stencil like that would be very easy. I was thinking the sheet metal wouldn’t have any holes in it. Practice making a panel without the sheet metal until you get it right, then you’re ready to add the stencil into the mix.