If the thickness of the blank is 2 5/8 do I take about 1/8 off the bottom and 1/8 off the deck, leaving my width 2 1/2? Do I even need to skin the blank before glassing? How close should I buy the blank to the thickness I want?
You’ve got it just about right. Any less than about an 1/8 inch and sometimes the foam will rip rather than cut smooth. The least amount that I will usually cut is a half cut from the Clark Foam Hitachi Planer. After the skin is cut though, you can cut as little as you want. You definatly need to cut the skin off before glassing. I have seen it work but looks real bad. Plus, that takes all the fun out of shaping. Your first few blanks should be alittle thicker than you want (you usually cut and sand more than you think you will). But for the most part, get a blank with at least 1/4 inch thickness to play with. http://www.foamez.com
Always skin the deck to remove surface blemishes and those extra-hard spots. I like to use the electric planer to within 1/8 of an inch of my final board thickness on each the bottom and deck. That remaining 1/4 of an inch will work itself out as you dial in your deck foil and rocker with your block planes and Surforms. You should be able to find a blank suitable to just about any shape you wish (the Clark Foam Catalog alone describes at least 70 different models, each with a host of variations), but if you have to cut down a larger blank, try to take more volume from the bottom than from the deck. Leave your hardest, outermost foam on the deck for paddling and standing. Definitely read the Clark Foam specs for each blank before you start. Plenty of info in there on maximum recommended board dimensions.
Everyone knows you take as little off the deck as possible to increase the board’s durability. On one board that I wanted to be extra tough, I used a small block plane and took maybe 1/16 off the deck (just enough to get to through the crust to “almost white” foam and no more - I actually got close with the planer and sanded to an acceptable whiteness). I glassed it with a single 4 oz top with a 4oz patch and 4 oz bottom and got at least 4 years out of the thing before selling it to a buddy. Can’t say enough about leaving as much foam in the deck as possible. A bro of mine wanted to shape his first board and enlisted my help. After I set him loose he mowed over 1/4" off the deck. The board had a 6/4 deck and lasted like 3 sessions before it caved in and delaminated. If you want pinched-rails be sure to get a blank with a lot of crown in the deck so you don’t over-shape the board.
You did well Arron, it was recomended to me by the owner of the blank company that I use, that on average the minimum amount of crust to take off the deck is 3/16, so as not too have the foam go brown or to take the chance of delamination because of the foam being to dense (close celled)for the resin to hold effectivley, made sense to me so I have followed his rule and dont have problems, You will mainly find cave ins on boards that have been through computer machines because the inconsistantcy of glue ups it is hard to always take an even cut off the deck, oops I hope i haven’t upset any of you cnc lovers with some more home truths. KR http://groups.msn.com/MyKRSurf/krcomweb.msnw
KR wrote: “You will mainly find cave ins on boards that have been through computer machines because the inconsistantcy of glue ups it is hard to always take an even cut off the deck, oops I hope i haven’t upset any of you cnc lovers with some more home truths.” But doesn’t this also meen that because of the inconsistantcy of the blanks that two boards shaped from the same blank will not be the same with handshaping? Atleast if you use the blank rocker for reference. Even if you messure rocker accuratly and handshape, wouldn’t you run into similar problems as with the CNC machined board? It’s either that, or a different rocker or a different foil. Bdw. How do you keep from overshaping the deck with your profiler. regards, Håvard http://www.earthlife.net/birds/flight.html
Harvard, I am not talking mm’s when refering to CNC foiling, when you get the plugs from some of these machines the nose and tail area outlines are still attached and you can see where and how much foam has been taken out. And I know for a fact that alot of the bigger companies use the one plug for many different variation of thickness and foil because it would be too cost affective to have each blank bent to individually rockered board or to adjust the pinning of the blank to gain best deck strength. KR http://groups.msn.com/MyKRSurf/krcomweb.msnw
You must learn to tweak before hitting the start cycle.