*Thin* overlays and cutting out holes

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#1

Hi all,

Second post - couple of months stalker (on the website of course). I searched on “thin overlays” and just a view threads showed up.

I am eager to try overlaying some parts but just as a hobby for now. I was thinking to do a thin epoxy layer, wait till it gets to tacky and than lay the cloth down.

An extra step that I think will help is to vacuum the part…since the parts that I would like to do are small, a food saver will do. As this is a good way for the cloth to adhere to the part via the resin. Would it cure properly if I seal the bad and let it stay in the bag overnight?

With that dry, since I put on a thin layer of epoxy - hoping that it didn’t soak through the fabric, how would I go along on adding the next layer of epoxy? Would another 1 layer of thin epoxy suffice? Or would I need 2 or 3 thin layers, sand down a little and then spray on clear coat for it adhere?

Also I was curious, I seen tons of overlays that have holes cut out for the screws to fit. Since I am just thinking of doing one layer 3k, how would this affect the cutting process? And would it be easier to cut once I lay down the fabric when it is still in stage b - or wait till it cures?

The resin that I would like to use is Kleer Koat by US Composites. I heard that It was thick and the viscosity of this thing is high, so the first thin layer of epoxy would be good for the fabric to adhere to the part.

#2

Welcome.

What type of plastic are you over laying? Some need to be roughed up or small holes drilled to act like rivets in them.

You should be able to do all the layers at one time to save time and resin.

#3

bear in mind that using vacuum on overlays, will leave you with resin lines, where the vac bag has pleats, and it might even trap some part of the bag inside. it’s not recommended. Based on the shape of your part, the easiest way is to lay resin or gelcoat first, wait till its tacky, and then stick your fabric on it, and apply more resin. An other thing you can use, is spray adhesive, but this dissolves under resin so its not to be 100% trusted, the edges of the fabric should most of the time , be stuck down with adhesive tape.

#4

I’m currently fighting with a part i’m overlaying…it needs to be vacuum bagged. problematic part!

Also overlaying my pc mouse. It will be nice to have that thing back in use.

#5

I was thinking of motorcycle fairings (body parts). I know that the epoxy sticking to the part depends on what type of plastic it is. So for body parts, 1 layer shall be enough correct? When I lay down the fiber to the already tacky part, how thick should the new resin be on top? ~ THIN is what I am aiming for. And would I also cut out the holes before I lay the resin on top?

Also, I had the idea of making a carbon fiber overlay on the new macbook unibody’s. They are aluminum, so I don’t think epoxy would stick to it good. It’s not an overlay, more like a thin “shield” or “case” on top of the aluminum. The unibody would more be like a male mold for the part.

With all of those round square holes for the keyboard, and the rounded rectangle for the cd slot, and other “unique” hole shapes, how would this go about? Cut the holes out of the fabric in stage b - before I lay another lay on top of the fabric?

#6

Just a word of caution overlaying computers… take the case completely apart and seperate all electronics from the part you plan to overlay…sanding may cause static electricity that could damage components. Plus you want to be able to wet sand the part.

Yes after you stick the cloth down …wait 24hrs then use a sharp exacto knife to trim out the holes. Then lay down your resin as thick as it permits you. Do not worry about how thick/thin the resin is because your going to sand it down very close to the carbon fiber cloth. Be careful not to sand the cloth… it looks bad.

So building up 2mm to 3mm is fine with resin.( 3/32 - 1/8" thick. ). Any resin, especially epoxy will stick good to aluminum… just rough up the surface with 80grit paper before. always roughen up surfaces before overlaying.