I am using my uscomposite epoxy on some parts for a top clear coat. Ended up having TONS of bubbles, and moreso when I heated up the epoxy. Should I just try “wiping” on a small bit instead?
I need a way to patch some holes in my part from sanding, and I might as well give it a nice shiney finish. Stupid prepreg porosity.
What about adding alcohol to it as a thinner, and just adding a few layers till the entire surface is coated?
Is there anythign else I can be using, like automotive spray clearcoat? Is that durable?
What temp did you cure your prepreg?
Bubbles…try vacuum bagging the top coating unto it.
I was going to ask the same thing as if you cook 350 degree Pre-preg at a lower temperature or not long enough, the resin doesn’t flow, so you get a grainer part.
Also, if the pre-preg is old and has been out of the freezer too long too…
In the classroom, we are working with 1 to 2 year old CF PP and it still works but doesn’t really flow great. I just got the oven parts to add a digital read out temp gauge for 10 locations and thermocouplers too so we can see the actual inside oven temp, the tool and laminate temps too.
But I’m also working on a killer knock down PUR foam Oven for large scale CF PP parts curing, gravity & blow molding sheet stocks and a rotisary (?) spit to be able to place a vacuum bagged skim/body board and cure it in there too! I want to make some CF PP skim / body boards!
Lordy, that is all too much work! 
It’s 250f prepreg. I wouldn’t cook the epoxy at that though, it smells like hell. if I bag it, I’m scared of bridging, since that already happens in the top apex (simple rt ang. bracket, and shitty tool pieces)
Eh, I’ll just try to not mess up the piece in the first place to HAVE to clear coat.
problem is, the machine shop is months backlogged, so it will take them forever to simply bend some scrap metal.
We use general rule for ramp up 3-5F per min. Now keep in mind that this will depend on how thick your part is and on the application of the part sometimes it is also customer request driven. Make sure to debulk your first ply on to the tool surface for 5-15 min. If your lay up is thick debulk every 3 plies and you are ensured a good part. Now if you go 1-2F per min ramp up your part should turn out mint. Slow ramp up ensures that your tool gets to the same temp as your plies. So that will in turn ensure a good flow of resin. Bag it with perforated release.
it has nothing to do with the part and how it was cooked. It is cooked on the same program as our other parts. The problem is, as I progressed a thrown together part for myself, after sanding, I got holes. I figured I would fill in the holes with epoxy. HOWEVER, I ended up with bubbles from the porosity of the CF. I can’t avoid that unless I use a thicker epoxy i think, that way the bubbles won’t come up through the coat.
or, like I said, I should just redo the peice.