New here with a simple question kinda

[thecarboncartel]

Hello, i am a composite fabricator and have a few years experience building carbon fiber parts for atv's mc's and sidebysides. My techniques are wet lay up vac bag under 27-29hg. My parts come out of the molds very nice. The question i have is clear coating the parts to add uv protection and add depth to the piece. When i begin clearing my parts small pinholes develop. Usually i have to pretty much sag the clear to somewhat fill the pinholes and wait a couple of days to wetsand and apply the final coat of clear. I would like to eliminate the frist step of clearing and be able to be done in one coat to save time and materials. I am using a high quality epoxy resin with a 200 min pot life, house of kolor paints. Any ideas?

 

[tgrimley]

Do bag and mold side of the part show pinholes?

 

[thecarboncartel]

Im not sure. I have never tried to clear coat the non show side of the work.

 

[Compositepro]

Try different clear coats. Sanded carbon composite can be a challenge to coat. The surface energy of sanded carbon is lower than that of matrix resin or of the original carbon filament surface (which was surface treated to improve wetting). I have seen pin holing because the coating does not wet-out sanded carbon. You could also try flame treating which is often surprisingly effective. Just passing a propane torch very lightly over the surface can increase its surface energy. This does have to be done carefully to avoid burning the surface. A good visual feedback measurement is that water vapor from the flame will first condense on a cold surface. Apply only enough flame to evaporate this water.

 

[blakmax]

Is your process based on elevated temperature cure?

 

[mfgenggear]

To all

can you not clear coat, then gel coat in the mold then apply layup?

Cheers

Mfgenggear