Hello so I am looking to shape my first surfboard. Looking around I have found some different brands and I saw the US Blanks seem to have a shape to them already...? Are the US blanks already shaped and need to be glassed? Or is it just like a stock cut and then you shape from there? I am sort of confused because I see others selling blanks that are in the shape of rectangles.
Us Blanks are great blanks, tons of different options for different rocker and outline profiles, the blanks are basically molded to be a bit bigger than what you want, Most Polyurethane blanks will come with a pre dome on the deck and some come with a bit of concave in the bottom, depending on which blank you get and what you are trying to shape the closer the tolerance the better the blank, for instance if you are wanted to shape a fish that is 5'8" and 22" wide and 2 5/8" thick the 5'10 RP would be you best choice, at least in my opinion. it would be 1 planer pass of the top 1 pass of the bottom, do your foiling, concave, rails, than finish her. so the closer the tolerance the less work for you. you always need to shape a blank unless if it s "Pre CNC Cut" or "Pre Hand shaped blank" that you can glass. The Rectangle blanks you see are EPS Foam which you will have to do a bit more planer work to get a dome on the deck and concave on the bottom, EPS is lighter, and you can only Glass it with Epoxy, Polyurethane is a bit heavier not to much and can be glassed with polyester, or Epoxy. hope this helps a bit let me know if i can help you with anything.
No reason to sand on the lam beforeyou hotcoat unless you wrinkled the cloth and left a high spot. However, the laps will almost always have a rough edge after you glass. I wrap a bit of 40 or 60 grit sandpaper around a small block of wood and sand down the laps after glassing each side before hotcoating. Any bumpiness in the lam will inevitably show up in your hotcoat and will usually result in a sandthrough right there.
Good tip on sanding the laps, BUT there actually is a reason to sand your lam. If you are outside of the recoat window for your resin you will not get a chemical bond between the lam and the hotcoat. You will need to sand the lam to get a physical bond. If you lammed your board with epoxy and let it sit for a few days before hotcoating, you should really scuff it up with some 80 grit.
