Pin holes with clear coat

Talk Composites - The Forum for Advanced Composites

Back

Pin holes with clear coat

Author	Message
Nuno_Silva	N Nuno_Silva posted 6 Years Ago HOT Topic Details
N Group: Forum Members Posts: 6, Visits: 47	Hey there, I made already some carbon parts but I'm struggling clear coat them to a perfect finish and UV protection. I sand parts till 800 grid and I get a smooth superficie with no high or low spots. I clean parts with degreaser as I always do when painting or clear coating. As soon as I start spraying with 2k clear coat by spray gun, pin holes start to appear.. Should I use acetone instead of degreaser? This happens every time I start clear coating. Hope someone can help. Cheers Edited 6 Years Ago by Nuno_Silva
	Reply Like 3
Hanaldo	Hanaldo posted 6 Years Ago ANSWER Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Yeh it's got nothing to do with your preparation methods, the pinholes at there from when the parts were made and surface tension prevents the clear coat from flowing into them so they become very obvious when spraying. You either need to do a lot of spraying and sanding, or you need to work out why your parts have pinholes. Are they wet-laid, vacuum bagged, infused, pre-preg? Also, as a foot note because it does actually have nothing to do with the current problem you are having but can cause other issues; don't use degreaser to clean before spraying. Acetone isnt great either, both will leave residues. Use a proper preparation solvent like wax and grease remover, and use one cloth to apply it and another to wipe it totally clean. Edited 6 Years Ago by Hanaldo
	Reply Like 3
Lester Populaire	L Lester Populaire posted 6 Years Ago ANSWER Post Details
L Group: Forum Members Posts: 311, Visits: 13K	+x Nuno_Silva - 12/22/2019 12:32:53 AM Hey there, I made already some carbon parts but I'm struggling clear coat them to a perfect finish and UV protection. I sand parts till 800 grid and I get a smooth superficie with no high or low spots. I clean parts with degreaser as I always do when painting or clear coating. As soon as I start spraying with 2k clear coat by spray gun, pin holes start to appear.. Should I use acetone instead of degreaser? This happens every time I start clear coating. Hope someone can help. Cheers Yeah as Hanaldo said, the surface porosity is there before the cleaning and the surface tension of the varnish will accentuate everything. I would recommend to use some epoxy gel coat that you apply onto the surface with a squeegee and then wipe off excess with a rag. This is the method i had the best luck with to fill in tiny voids. Cheers!
	Reply Like 4
Nuno_Silva	N Nuno_Silva posted 6 Years Ago HOT Post Details
N Group: Forum Members Posts: 6, Visits: 47	+x Lester Populaire - 12/22/2019 10:07:21 AM +x Nuno_Silva - 12/22/2019 12:32:53 AM Hey there, I made already some carbon parts but I'm struggling clear coat them to a perfect finish and UV protection. I sand parts till 800 grid and I get a smooth superficie with no high or low spots. I clean parts with degreaser as I always do when painting or clear coating. As soon as I start spraying with 2k clear coat by spray gun, pin holes start to appear.. Should I use acetone instead of degreaser? This happens every time I start clear coating. Hope someone can help. Cheers Yeah as Hanaldo said, the surface porosity is there before the cleaning and the surface tension of the varnish will accentuate everything. I would recommend to use some epoxy gel coat that you apply onto the surface with a squeegee and then wipe off excess with a rag. This is the method i had the best luck with to fill in tiny voids. Cheers! Thanks guy's for advice...
	Reply Like 2