Help, sanding showing thru carbon fiber

Hi again swaylocks :slight_smile:


Well in my 5th board i made a huge mistake, i sanded the freelap and now its showing throughout the carbon as a white powder. I need help, is there any way to minimize or fix this? Im really sad with the result, im still learning and i thought it would dissapear when i poured down the hotcoat, but it didn’t. Also first time uploading a photo here, hope i did it right.

I know it looks ugly, i just had a bad judgment, and honestly didn’t knew any better because im still learning, dont go harsh on me :wink: …








Sand the board, tape off the rail and paint the rail. Hotcoat or gloss to seal.  Black most likely will look the best. That’s about all you can do.  Another possibility;  smear black pigment around with a paper towel on the burn thru. Wipe off the excess.   That probably won’t work.  I suppose it’s worth a try though.  The Carbon should have gone under a layer of 4 oz.  in other words the Carbon should have been under cloth instead of on top.  It fills the texture of the Carbon and gives you a surface to sand.  Makes a much smoother cosmetic surface.  You freelapped too far over onto the bottom of the board.  Should have cut your freelap just barely onto the bottom.  Maybe one inch.  I can see the edge of the lap way over on the bottom under your Carbon.  Can see the stringer as well.  Black Carbon is like a black car;  shows every flaw.

PS ;  Further thinking your situation.  Try wiping that area around the lap with Styrene.  See if it disappears before you move onto the other remedies.

Thank you for the help, there is nothing under the carbon tho, what is sanded is the fiberglass not the carbon, under the carbon the only thing is the fin boxes and the blank itself tho. The freelap sanded thru is the fiberglass.

Painting might be the best and easiest solution but nothing looks good on carbon due to the fiber pattern imo.


If that’s just your lap from the deck;  try the Styrene wipe.  Then try the black pigment smear.  I would think that if you were to sand the bottom and hotcoat or gloss,  the edge of the lap would disappear.  I’ve done it many times.

The thing is, this is the hoatcoat result, thats what i thought as well, i thought with the hoatcoat resin the sanding would dissapear, but it didn’t. :frowning: maybe black pigment it is

What ounce cloth?

4oz s-glass from hexcel :wink:

Aha!  My opinion is that this happened because it is S Cloth.  Regular E or Warp 4 oz disappears.  Did you Carbon the deck as well?   You don’t need the extra strength over Carbon Fiber.  Putting the 4 oz. over Carbon is cosmetic more than anything.  So no need for S.   S is hard to conceal.  I put 4 oz E over Carbon so that it fills the weave and gives me something to sand.  Pretty sure it has to do with the fact that it is S.