I have a mold that requires a few releaf cuts to get the carbon fiber to lay properly. The cuts are made in an area that is not seen. Instead of spending a lot of time making a nice seam or transversely leaving the loose ends, can you use a simple rattle can black to paint the area on the gel coat before laying the reinforcement? Didn’t know if the paint will react to the gel coat or contaminate the PER when laying the carbon over it.
I didn’t want to mix up a small batch of black gel coat for the tiny area if I didn’t have to.
I could do that. I was just thinking if I put in on after the gel coat but before the reinforements then the part would have a nice consistant outside finish.
Best way would be to do a test of the paint and gel coat…but I don’t see why it wouldn’t work.
How big an area would you be blacking out? The only concern that I would have is if it’s too large an area, it would create a weakness in the composite, as the paint would act as a barrier between the layers of resin, so that spot would be more suceptible to chipping off.
It’s a triangle about 3" wide and 6" long. I may just lay it without the black out area overlapping the carbon for strength.
I also have a corresponding question. When laying up this part into the mold I was planning to use the clear PER as a “glue” to hold down the carbon. What I mean is brushing a small ammount of the resin on to the valleys and contours and letting it hit B stage for some tackyness. Then following up with freshly catylized PER for saturating over/through the carbon fiber. Does this effect the strength by doing it this way? Is it a justifiable laminating method?
I experimented with vac bagging this part and even with high elongation film I had some bridging issues. I figured I would try the good old squeege and persistance.
per is an improper resin for carbon fiber. the binders do not break down properly and only breakdown with epoxies or Vinyl esters.
You could use a polyester to "glue it as you say, but I would stick with a vinyl ester or epoxy to wet it out. I would also vacuum infuse it.
