For gloss coat no more than 180 grit hot coat sand needed. A good 120 is enough so next coat have something to grip on.
That will work. But it you wet your board after hotcoat sanding and can see scratches go to a finer grit to get rid of them. You can do as lemat says with epoxy, but to avoid scratches in Poly finer grits are usually needed. Poly just tends to show more. On hotcoat you want to be sure you see NO shiny spots or scratches caused by your sanding. Whatever grit you wind up at, finish sand by hand. First with a block and then a piece of folded paper. I usually take a half sheet and fold it in 1/3. Hit the rails and then look for shiny spots and scratches. If you stop occasionally and mop water over the board the scratches are more visible. It happens that you think you’ve got them and then you gloss. Once you gloss all the ones you missed show up, but you can’t sand them out because they are under the gloss. The water makes the board shiny and then you are able to see the ones you missed before gloss.
ok, so , sanded really good, opened the holes and filled with resin and microballons, gona sand everithing down and do a second hot-coat.
Thanks for all the help.
Problem solved
it will be a long time before i think about laminating channels
Yeah they are not any better than a “Single to a Double” with a “knubster” when it comes to a twin. They hold, but they’re not as loose. Not as maneuverable in the barrel.
honestly i also think surfwise channels don’t add much, just wanted to try to make them.
Originally guys from my generation (1970’s) added them to Twin Fins and Single Fins to create more grip and speed. We were just figuring out how to get down the line faster and how hard we could turn a shortboard and not spin out. The channels helped in both categories. Speed and hold… But along came the Thruster which solved any issues. Before shortboards not many surfers could turn a longboard hard enough to spin out. And a shortboard required speed, so it had to be ridden in the fastest part of the wave
Looks great - its all a learning experience. In the end looks clean and the overall shape looks functional.
Yeah Mr. Huck.
Now what i learned in the process:
1- adhesive spray in the chanels to lay the cloth before laminating. ( i used one from montana, repositinable adhesive, said the can)
2- work at proper room temperatures and don’t use cheap resin kicks relly fast at 1% and eats trough foam when curing. ( i tryed the cheapest one i found 5kgs 30€)
3- really wait for lamimation arround the cut laps on the channels and keep presuring it so it really sticks without bubbles.
4- sanding chanells its a lot of extra work arround the tail.
cheers and good waves