I’ve searched the archives and read all the articles on tailblocks and have a pretty good idea of how to do this, but I’m looking for the best way to get a square cut across the end of the blank. The board is a SIMSUP (Simmons inspired SUP) so the tail is pretty wide. It’s 1.5 lb EPS foam.
Specific questions:
What's the best way to set up a fence or guide for the saw without damaging the foam?
Should I use some sort of guide (say, a flexible wood batten) on the deck and the bottom?
What saw will work best: baack saw, Japan saw, something else?
Should I tape over the cut line and cut through the tape?
Is it best to cut from the deck side or bottom side?
Any other tips or advie are appreciated. Once the tail is off, I'll rough out the shape of the tail block on the bandsaw, get it close in shape with a low angle block plane, sander and sanding blocks, then glue it on with thickened epoxy. Once on, I'll tape off the blank and finish sand/shape the tail block.
You are right about the best way to finish it off. You’ve got that part correct. Pre shape to match cut-off, glue with epoxy and tape off. So you don’t need help there. As far as cutting the tail off; I use my shapers square to mark my cut-line. Lay it out on the stringer and make a straight cut across the tail. Even if you decide to mask off the board, do it at the line marked on the foam/stringer. If you mark it first using your shapers square the visible stringer is a good referance point. I have cut them off using a jig saw, but prefer to cut with a hand saw. Either a push/pull Japanese saw or a short tool box saw with the “shark” teeth like Stanley makes. I usually cut from the bottom because that is the flattest surface. Take your time and keep your saw vertical for a nice straight flush and flat cut. The foam cuts easily. The stringer will take a few quick strokes when you get to it. Use a couple of peices of masking tape to hold the new tailblock on when you glue it. Be careful finish sanding the tailblock, You’ll knock it off if you aren’t… A “biscuit” or dowel isn’t necessary if you are careful, The epoxy and glass job will hold it all together,
Just a personal preference... I'd cut the foam off to include the rounded off corners and shape those same corners on the wood replacement. Maybe you'd already planned it that way?
I use a hacksaw with blade installed backwards - so the teeth cut on the 'pull' stroke. A careful side view enables you to get the vertical angle right. It won't hurt anything if you have to go back with a sanding block or whatever to clean it up so it's perfectly square and plumb.
5-minute epoxy or hot glue work OK to attach the wood.
I mask off the foam to avoid stray glue getting spread around. Keep the 3M Rol-Lok disc positioned so it cuts towards the wood, not the foam when cleaning up/fine tuning. Pieces of resin and wood like to create dust and/or break off and discolor/gouge the foam otherwise.
I would glass the board first and then do the tail block as a repair.....Why?....Because you will never get all the wood dust out of the eps foam.......and.....
wood and epoxy resin don't always agree...I've had wierd stuff happen....so..... I choose to attack one problem at a time.
Cutting off the tail is the easy part. Hand saw and a nice sanding block......Make sure you have fun! I like the tail block!
Might be to late for it now, but I rough shape the board, then cut off the block. Use the cutoff to rough out your wood block, test fit, then go ahead and finish shape the block so it fits just inside the roughed blank. Lam it on, then finish shape the foam down to the wood block. I use a shaper’s square to strike a line, then cut if off to the line with a hand saw, then sand it perfectly flat with the hard side of a sanding block, focusing your pressure on the stringer, and eyeing the line on both sides to make sure it goes down in a straight line. The only thing I use tape for is to hold the block on to the blank.
…the easiest way is to square perfectly the tail then laminate all the board BUT do not let fiberglass wraps on the tail (rail) or let only 1 then glue the block and laminate.
Most my lams have colour in them so I usually do the lam then cut for the nose/tail blocks, rough shape the blocks, attach with 5min epoxy, fine tune then glass clear, blend in the glass and hot coat all in one. Very similar to classing on fins
I like to glue the unfinished block as you have in your picture to the board after i have “roughed’ out the board. Maybe have about an extra 1/8” on the top and get the bottom pretty flush before installing it. Before i star sanding. This way I am finishing the block and the board at the same time. I used to use a hard disk on my sander with some pretty coarse paper to get close than block plane etc to finish. Now I have a cool mini electric plane that I modified with a carbide wheel that works perfect, gotta have some “secrets”. I find it saves time and I am not having to fix the shape or change the block I get what I want with no extra steps,
I have a few different saws, those pull saws work OK. Whatever saw you use DO NOT LET THE HANDLE HIT THE FOAM. Cut from the bottom woks best.
HOT GLUE and EPS not good, melts the foam. I use Gorilla glue for all tail blocks now makes em look so perfect. I can attack em pretty heavy and rarely have one pop off.
As far as wood dust in blank I have an air compressor that blows the wood away. The blanks EPS or poly I use have a wood stringer so a tail block is no more problem than that.
Hey Ace, Which Gorilla glue do you use? Foamy or white/clear? I’ve used the white?clear for blank glue-ups. Works great. Used to use 5-min for tailblocks.
I use the “foamy” stuff. Fills any little nicks etc and has a nice wood like color. Have to use more tape and babysit it a little bit. Takes awhile to dry . Glue today finish tomorrow. Back when I had to finish today what i started today Hot glue was the stuff for poly.
Always mask the blank with wide tape to protect it while bonding and leave it on for shaping the block (a couple of layers).
On poly, I use a thick cabosil filler applied to both parts. Usually no need to clamp, just some tape for 15 min or so. For eps, gorilla or 5 min epoxy can be used. Gorilla glue must be clamped for 24 hrs, and the blank needs to be very rough so you can take out any clamp dents later.
A small grinder with a 3-4" disk for shaping, and a detail orbital sander for finishing as this gives more control. I use a long backsaw with no set on the teeth for a smooth cut, and go straight down from the deck. This is so that the stringer is always in the cut and the cut is straighter due the stiff blase of the saw. I've seen a Skil saw with a fine plywood blade also used, but you need a flat surface cut from.
For nose blocks, rough the outside curves on a band saw after dry fitting and sketching the curve. On those, it's easier to let the stringer pass between the blocks since it'll have to be pointed if you butt against it (angled blocks, not straight ones).
The hard part of shaping nose or tail blocks is the joint at the rail and keeping the foam even with the wood. Like when shaping multi-stringer blanks, you leave an allowance of wood and foam on the rail areas and whittle the wood using tiny planes and finish the joint by handsanding. Just stop your rail bands a couple of inches from the block to give a foam allowance.
Thanks for all the excellent advice. I cut the blank tonight using a backsaw (I liked the stiffer blade vs. the Japan saw) and it worked great. Just a bit of clean up with a long sanding block and it was ready to go. I roughed the block out on the band saw, and glued it on using epoxy thickened with cabosil, because that’s what I had. I’ll post some pictures when I get is shaped.
Kirk’s L41 SIMSUPs are the real deal. I was lucky enough to have extended test drives on all four flavors before deciding on this one (OS2), and I have to tell you that it’s the most fun I’ve had surfing in years. Performance on the face of the wave, section making speed and good stability make these boards a blast to ride, and super versatile. Putting my little custom touch on this board is just the icing on the cake, and I can’t wait to get it back from the glasser.
