Maybe I’m missing something or we are just saying it in different ways.
I don’t think there’s too much confusion about referring to the other boards you did that work than creating a template. When I do that I do a “rocker scribe” for bottom and/or deck. If you do both then you have an accurate foil of the entire board. You just set up vertical posts on each end of the board, vertically position material of choice (like masonite, PC foam, wood plank, whatever) so that it is centered like a rocker stick, attach a marker or pencil to a decent vehicle to hold it while you run the bottom (and/or) deck to scribe the curve. You can use this same method for rail to rail deck contours or bottom vee, roll, or concave configurations if you want to.
The other method I’ve used when doing replicas that are one offs that I didn’t have material for the first method, or didn’t want to spend the time cutting stuff out is as such:
Stick the board you want to copy on your shaping racks. Run a piece of masking tape the entire length of the bottom, find center point, and mark it as such. Make additional marks on the tape at whatever intervals relative to center out or from nose and tail as desired. The smaller the distance between the points you measure and note on the tape, the more precise you will be to a point of overkill. Once I pull that tape, I sometime stick it on a wall where I can access it later on, or I do a quickie drawing on a piece of paper and write all that stuff down for record keeping. I developed a little system of drawing that maybe I can find one or do a little example for you.
As far as the blank you choose to use, it sounds as though your approach to shaping is more advnaced than the actual modest number of boards you have shaped. Judicious use of a TRUE ROCKER STICK is key for any serious handshaper. Otherwise you will have destined yourself to hit or miss success, and you will not be alone in that curse among too many shapers to even wanna think about. Place your rocker stick on the bottom and determine where you want center to be in order to allow you to cut in the nose and tail rocker you need WHILE MAINTAINING THE NECESSARY THICKNESS FLOW aka FOIL. At this point, if you have READ THE FOAM CORRECTLY you will know before starting that you have enough to achieve your goal for rocker and finsh thickness or not.
At that point, clean up your bottom from any glue up crap or nastys and draw your outline (in this case) on the bottom (some guys outlline their planshapes on the deck, and I even met one riend who does top AND bottom). Once drawn and you approve of the planshape, cut the thing out and stick it on the rack.
I have two different rocker sticks that have premeasured increments from center out on the sticks to save time in order for me to determine where I want certain numbers to be. I measure how much I need to “drop” the rocker to at nose and tail and make a mark to use my planer to cut down to those marks. I use a pencil punch kind of method to place points along the bottom run so I know where to plane down to.
Once I have all those punched measurements into the bottom, I don’t waste a lot of time with gradual “cutting on the fly” to get to the nose and tail measurements. that would drive me nuts and take forever. I weight the blank and quicky cut, hack, whatever you wanna call it to get down to where Iwant to end up at eachend. Now you are “there” on each end and you make the cuts you need in relation from center to each end until you get all the numbers you need. I don’t cut perpendciular to the rail like a lot of guys do… I always feel like I’ll blow the stringer up, but to each their own. I do "cut on the fly on stuff that I already know intimately (like models) and I can put in bottom contours while thicknessing at the same time I am modifying the bottom arc in specific spots… once you learn to do this, it can save you a lot of time versus several separate stages.
The punch method is fast and works well to get you down to where you need to be. Obviously more caution is needed cutting in the areas between center and the ends with a good degree of diligence, but by cutting those ends first, you now know where that arc will finish, and you just need to envision where and how much you will cut to create that desired arc (a “line in space” as Barnfield likes to envision it).
Some shapers believe iit makes no difference if you plane out thickness using a constant cut depth while scrubbing the blank. Then put your nose and tail rocker in. I disagree. Chronology of cuts are very important when maintaing foil thickness and the rocker you want. Also whether you intersect cuts or not, esp. at the nose and tail… The chronology of how you approach this creates a different result and few shapers realize this. They will reason that the arc remains consistent so what’s the difference.?Try both ways then tell me if you get the exact same result… particulalrly when we are talking about foil thickness. Intersect cuts at nose and tail and tell me
Deck rockers just add to the challenge. I just picked up a Yater that Lauren shaped that the customer wants me to replicate. Lauren is not currently shaping citing some health issues. This board is a favorite for the customer and it is buckling in the middle. So I will dissect and duplicate it using the methods I mentioned here as well as rail contour calipers. I’ve done many magic board replicas for people over the years, sometimes of shapes that the shaper passed on or has quit shaping or is no longer contactable. Whatever the case may be, it CAN be done with a lot of diligence and ability w/o the need for scanning.
I guarantee the result, and have never had one return yet.
Handshaping rules… pull the plug.
at best.I hope this helps.
