To each their own, but I prefer fishes to have a moderate weight so as to get a little more glide out of them and to take the corkiness out of the equation. We don't build them to do airs and they're already wide/short. As well, the combination of short/thick(er) will basically inhibit flex regardless of the glassing. You'll get a nice ride out of the PU/Epoxy build but beyond that you'd probably have to cut the thickness of a 5-7 length down to less than 2" and really foil the ends to get anywhere near the flex of a longboard that's 9-0 x 2.1/2". IMO
Long story short, you've got an expensive blank, a short/thick shape and you're using epoxy over PU. That's a good combo all by itself. I wouldn't paint it and if I did any color at all in the resin it would just be a light tint to offset any yellowing the glassjob might take on over time. OTOH, you're doing this board in part to express yourself so if you want to do the acid splash or opaque glass job or some elaborate airbrush then that's what makes it your's.
For your consideration:
If your glass cloth is 27 inches wide, then cut two squares for what I'll call here a "diamond-doubler." On the diagonal, that'll give you 38 inches. Use the 4-ounce. Always use s-cloth. Always use Epoxy. Put one tip of the diamond-doubler a bit behind where the fins will go. The other tip will end up past the wide point on your 5' 7". Round it out in the middle. It doesn't need to wrap around the rails. Do the same on the deck as the bottom, but add a little extra patch under your back foot since the diamond-doubler will leave areas where your foot will go with only one layer of cloth. Then single 4 oz. top and bottom over that. This glass schedule will keep your board light, keep the worst of the weight out of the nose, but significantly strengthen the board where it needs it the most - under your center of gravity where the maximum bending moments result. On guns that are too long for the diagonal, I'll cut a piece of cloth that is laid out straight to the tapered shape; I'll also run the doubler all the way back into the tail since the leash is a significant source of torque and board breakage - board goes over the falls and you don't frequently results in a broken board.
Here's a picture of my current 5' 11" x 21" project laid out on the concrete. It'll use a pair of twin fins I found in my bin that are likely from the early 80's. They'll need significant foil modifications to work properly, but they have a proper template and area for this project. The actual foil and rocker are drawn on the concrete too. It is obviously more "Dave Rastovich" than "MR" or "Lis." Above it is a 6' 6" x 18.5" that I shaped in '91 that is the progenitor of everything I've done since and is appropriately called "Grandpa Board." Grandpa Board was the first board that used my 6.9% nose rocker / 2.7% tail rocker tuberider rocker template. I reduced it 15% throughout for Rincon and later 7.5% for all-rounders. Grandpa Board started life as a twin fin, and stayed that way for at least a half dozen seasons - epoxy over 55 psi compressive strength extruded styrene lasts nearly forever. The 5' 11" will use a 6' 4" tuberider rocker with 2" cut off the tail and 3" off the nose -small wave twin-fin fishy boards need rockers that are a wee bit straigher in the tail.
If we keep talking about it; I'm sure it will shape itself.
A couple of historical corrections are necessary:
The Lis Fish was first designed as a kneeboard. It was one of the first high-performace surfboards and is intended to be riden as such. Go find some videos of David Nuuhiwa riding a fish in '71 or so and you'll see somebody ripping, not cruising. Shortly following that development came the Clyde Beatty Jr. Rocket Fish that measured about 6' 6" x 21" x 3". Clyde liked having some foam under his chest - he told me so. Clyde was the first to toe in the single side foil fins. Every now and then I hear some kid in the lineup saying that he discoverd this thing called a Rocket Fish and then goes on to proclaim its the greatest summer board he has ever ridden.
Back to shaping
You might consider a small re-shape to your present board to see if the tracking 'feature' can be fixed. If it were my board, I'd try making it into a winged swallow, a little bit like the Channel Islands Twin Fin template, which is a wee bit like an MR Twin. I've done a number of re-shapes over the years. It's easier and cheaper than making a new board. I also learn more that way. I start with a Dremel cutting wheel...
Your template looks to have a wee bit too much curve at the wide point, and that makes your tails too straight in the hips. It looks like you need to push out the hips a fair bit - about half the width of your lap. That could be much of the source of your tracking 'feature.' I'm presently doing a re-shape on a board that had the opposite problem - too much curve in the hips that made it wildly loose and incapable of tracking down the line - t'was a silly experiment that I had to try.
I'd also suggest Futures boxes in your future and try various fins in the 18 to 20 square inch area range. I don't know how much area your fins have, but modern production keel fins have about 25 square inches, and that's way too big for a Lis.
I crunched some numbers off of my last surviving 90's era twin, and your fin placement looks to be about right.
I think it is possible to keep the Lis Fish look while making a board capable of very dynamic performance: add about a 2 degree bump in the template just forward of the fins, sand progressive rocker in the last foot to add about 1/4 - 3/8", maybe even sand progressive spiral vee in the last 1/3 of the board that's about 1-1.5 degrees per side at the swallow tip. Each alone isn't obvious, but they'll synergize together to liven up the board. But it'll still look and ride like a Lis Fish. Use modern thin rails too.
I'll just add the 'tracking' problem is reduced by fast, hollow waves. All my fish were dogs in soft mushy surf. Mike
Well I got out to the shaping shed tonight, actually went in to do a few touch ups on a shortboard I'm finishing but it wasn't quite dry. The shed roof took a battering with a run of 6 storms this month so no pics today
I made a flip template off my original board, heck I like it, I'm just trying to improve it so I stuck with what I new. Once I did the template I put a small hip at the back of the fin, 6 inches up, a few degrees as suggested and blended it in. I'm not a fan of this angular hips you see on some boards. Cut the blank down to 5'6. As I said before i had this thought in my head about moving the wife point under my front foot for total Controll. I've pulled the nose in to 16 1/4" Tail is at 16 5/8" and the tips are reduced to 11" with the hip.
After cutting out the outline it looked pretty good and allready felt nice under the arm (isn't that what people did before volume!)
I placed the wide point of 20 7/8" at 2.5" ahead of centre. I originally planned to go a touch more narrow but wanted to compensate the length and foil.
New blades in the planer, started to work the rocker in and skim the bottom, I'll aim for 2.5" thickness. I plan to keep the nose rocker and tail as my original but increase the V, and add a single concave through the 1/3rd mark
Pics and progress to come. Tha ks for all the advice so far
Had half hour In the bay so cleaned up the outline with my thread tool
I liked your green board and I like this shape. If you put a quad or Speedialer type split keel on that it should turn out to be pretty lively.
Interesting page with a lot of helpful info and good looking boards but I’m still left with some questions. I’m shaping a 5,6 x 21x 2 ½’’ twin fin at the moment and already made some progress. It is an old school looking fish but want to give it a bit more performance. I want to surf it a bit more vertical and in the pocket because we don’t have long rides here in the Netherlands. Thereby I was thinking to have around 33L in the board considering I’m around 154lbs. The board has a nose rocker of 3'' and 1.5 tail rocker. I have the feeling the tail area is maybe a bit to thick for te preformance i want, wondering what you guys think of it.... I’m almost done shaping and thinking about the fin placement I want to go with.I came up with the following numbers for fin placement and wondering what you guys think of it: Toe in 3/16’’ off rail: 1 ¼’’ and not sure about the distance from tail. A lot of people throw numbers and not sure what I need to take(somewhere between 8 and 10 ½’’ )?! The bottom contours are flat on the nose to single and ending in a double concave. Still doubting if these contours are deep enough because it’s the first surfboard I shape and they are pretty shallow. Sorry for the amount of questions but I’m eager to learn!!!
Personally I think your outline looks OK but your butt crack seems a bit shallow Rule of thumb seems to be half the width of your tail, Ie 12" tip to tip would have a 6"deep crack
Tail looks pretty thick but have you measured it 12" up???
Looking at the racks in surf shops at the moment the modern fish seem to be really foiled out through the tail. Think my original board on this thread was about 1.5"