how easy is it to put in a few extra stringers as i lost out on a second (balsa, cedar and redwood) custom that was going cheap, i can get the wood
tips tricks?
thanks
paul
The devil hates a coward, measure where you want the sticks to go, mark and snap a chalkline, cut on the line, run the surfaces on the jointer. For the wood, split on the bandsaw, run it through the planer, and with bar clamps, glue it up, easy as pie, yeah!
Jim didn’t mention his other method of glueing up the new sandwich of foam and stringers. He told me a while back about using old bicycle inner tubes to stretch around the board to squeeze the whole thing together instead of using clamps.
I made a an outside pond and waterfall with rubber liner (same stuff as the inner tubes). From some left over liner I cut 20ft. long x 2" wide strips and they worked great. If you don’t have a buddy at the bike shop you can buy the liner rubber at the “depot” in the garden center in whatever size you want. Thanks Jim for the idea! Enjoy the ride.
Believe it or not, 3M duct tape will clamp the shit out of anyting. Glued up a few stringer inserts this way. Though, you do need to have a very level edge on the areas abutting one another.
Drew
but the question is how to make a good cut. simply hacking along a line with a carpenter saw won’t make a nice straight cut.
I thought of the panel saw at the hardware store, that they use to cut 4x8 sheets of plywood.
I thought of some sort of “trolley” that the blank would ride on past/through a band saw.
I thought of planing the bottom flat (side to side) then clamping a guide for a circular saw…
how bout a router with a plywood factory edge guide…good for 8’ and under,that spiral cut out bit after initial cut at 2’‘depth can be extended deeper to theextent of the router capacity the first cut of 2’’ makes the surfae cutting redundant allowing for a pretty deep cut/// any cut greater can be rough cut with saw and still be sanded as the sawcut is much smaller kerf than the cut out bit…ambrose …and the bit cut is as clean and as vert as the bottom is flat and horizontal
Rip the board any way you like. Not that hard by hand if you take your time and keep the saw smooth and perpindicular to the board as you go. Bandsaw works with an outfeed roller table. Whatever way you like, You’ve got to run the sawn edges through the jointer to get a tight and correct joint / glueline.
If you don’t have access to a jointer you’re probably going to have to come up with some kind of temporary fence set-up to run a saw up against. If you’ve got a longboard with 3" thickness or more, most portable sawblades won’t go deep enough however. Could be more hassle than it’s worth unless you really want to fuss a bunch with it, so I’d suggest you take the ripped pieces to a cabinet shop or some place with a longbead jointer and pay them $20 to joint the edges. It’s worth it to get it done right.
You guys are technocrats! Talk about overkill. The handsaw’s fine, if as Jim stated you’ve got a joiner to tru-up your cuts. I don’t know about Clark and Walker, but more than likely they just rip the blank with a bandsaw and glue. Of course you can turn your half blank on edge and trace your rocker onto your stringer material befor glue-up. Then cut that out with a jig-saw. I bought a few blanks from the old Rogers Foam co. once, many (like 30) years ago and got to watch them glue up my blanks. Bandsaw and glue-up. Simple. I thought what they used for clamping was pretty unique and haven’t seen anyone use it since. They used a bander like you would use to band large cardboard cartons for shipping. They would slip cardboard strips under each band to protect the blank. When the blanks were set up they would just cut the bands. I have an old lifeguard board blank, complete with fiberglass mat shell, that is stringerless. I am going to do as Jim said; snap a chalk line. But I am going to use of all things a “rafter saw” to make a nice straight cut through that 6 inch thick 11 foot monster. McDing
I have a banding system, but I use it after the resin has set, band it up and use the clamps for more boards
i found a very very (like 6") long jig saw blade made by Festool (t top type blade) at Woodcraft, then i took two strait rips of 1/4 ply and clamped them to the blank to make a “track” for my jig saw. then i simply ran the jig saw down the “track” . make sure the tracks are good and tight to the saw. i did a dry run without the blade to make sure there was no play down the whole run. it worked pretty darn good. i am currently making some curved tracks to do some fancy stringers…
This is the same method Clark Foam is using to do their curved stringers.
Jim, are the curved stringers initially straight? are they under tension in the board?
I won’t answer for Jim or for Clark Foam, but if I were doing them, yes they are straight stringers compressed and clamped. A 1/8" or up to a 3/16" stringer if nice straight grained cedar, redwood, bass will bend that radius fine. If you want to go T-band or wider you’ll sandwich multiple thin ones to all flex into the curve together.
Note however, that if you get into stringers much wider than about 1/4" in a figure 8 running down the length of a board, you begin to deal with some geometry I won’t bore you with a long explanation, but if your stringer is wider than the width of the blade that cut the curves, you’ll end up with a wider distance between the cut planks where the curve arcs away from the nose to tail vertical line. Wish I could do one of Doc’s drawings, but if it matters at all to figure it out, take a piece of paper, draw one side of the long vertical figure 8 down the length of the paper, cut it out with scisors. Put the two pieces back together. Now very slowly pull them back apart about 1/8" equally at top and bottom of the paper. Notice that the gap between the two pieces of paper is not exactly the same width apart all through the figure 8.
I’m failing at the explanation (help Doc!), but suffice to say that with thin stringers and good adequate clamping pressure you’ll be fine, but just so that if some guy plans to go off and laminate a 1" wide stringer in there, he’s forwarned.
Jim, I don’t know if Noll was the first to do those figure 8s back in the early to mid 60s, but I remember wondering how the flip did he do that?! When did you do yur first ones? Here we go with that age old question… Is the crafting of surfboards art or science. Obviously both, but when it comes to these high-style aesthetics which started back in the “soul” days of surfing, I say it’s a lot of art. Enjoy the ride.
It’s nice to have another craftsman to be on the same page with me. When I do figue 8’s, I have to plane the thickness of the stringer out where it intersects the center stringer, otherwise the blank gets longer each time you cut through the center stick. The sticks sre easy to bend, the hard part is getting a really clean cut, so that you don’t have to spend an eternity cleaning up the lines. I would cut it on the bandsaw, but the distance from outside to the nearest curve is too big to get through the throat of the saw, you need at least a 20" saw, more ka-ching than I have. I have templates for the curves and draw them on both sides of the blank, with my handy assistant Larry, I put him on the other side of my 2 man saw and we each saw down the line, doesn’t take but a few minutes
Ah - took me a bit to figure out what you guys were thinking of and how it would be done… and while doing that I may have come up with a way to do it that’d make allowances for different thickness stringers and get the cut widths right every time.
Notice how the stringer thickness is different at the midpoint of the arc than it is close to the center? I used the same arc in the drawing, copied and pasted and set out further…but it’s become a different radius when ya do that. And you can only squish foam so much. To get it right, you need two cuts, one that’s the inside radius and one that’s the outside radius, two parallell arcs that are always distance ‘d’ apart-
Now, making two bandsaw cuts just right, let alone laying it out correctly…that’s gonna be a beeyotch. I wouldn’t want to try it on a regular basis. However…
howzabout something like this??
You have a sheet or piece of ply with the curves as slots - you could use a batten of a certain width* bent on top of the ply to scribe your curves to a consistent width. Stop the slots appropriately, as shown and maybe at the intersections too, or use a different pattern than I have shown for the stopped slots. Whittle your curves in the jig with a saber saw. It’d be nice if you used a batten made of the least bendy wood you were gonna use for the stringers, so more flexible woods would take the curve well and your least flexy wood would make it.
Then, you get cute. Use a plunge router with a collar of that certain width in the slot with a ( pretty doggoned long ) straight cutter the same width as your stringer material for that particular job ( notice that you could use different width cutters for different thicknesses of stringer, same collar every time - less bendy wood, thin stringer and cutter, very bendy wood, thicker stringer and cutter) . WHEEEEEEEERRRRR ( router sounds…) and you have a slot that’s the width of your stringer, centered on the curve and it should accept that stringer very nicely, as it has generated those two different radiuses you need all by itself. The stopped slots ( like a letter stencil ) are so you don’t have pieces of blank falling away in mid-cut and so your jig stays together - finish them with a keyhole saw or something similar, mebbe one of those small Japanese detail saws with a narrow blade and a very thin kerf, or mebbe a fretsaw. I’d probably go with something that was not full length so you could make it work for different length boards, or a one-sided jig that you could use like a template, adjusting it some to get your end intersections right for different lengths as you would with an outline template.
That seem like it might work, gents? Might be worthwhile if you had a lot of 'em to do, anyhow. You’d need to secure your blank to a flat table and move your jig ( on feet like one of those ouijia board gizmos or something similar) to get the cuts right, but I don’t think that’d be a real problem.
doc…
Doc,
You way out did yourself! You not only picked up on the geometry thing I was talking about, but you came up with a brilliant set of drawings to explain and pull off the process. I finally figured out how to make some serious money: Write a book with professor Jim’s surfboard crafting knowledge (and of course the knowledge of a few other Swaylocks pros) and your engineering and illustrations.
Your jig idea: Only thing to scratch our heads about is a smooth way to connect the slot where your stops are without having to use a handsaw and risk an otherwise perfect line. Ahh, idea: Instead of stops in your slot, just run a 4" wide x full jig width cleat board of ply across the whole jig at each end to permenantly hold it all together (glue and screw) and go ahead and run the slot all the way from end to end without stops. Maybe add another cleat or two along the middle area for rigidity, but those could be little short portables (screw on / screw off) as your router could pass on through.
The only other area to try to refine would be where the figure 8s cross eachother where there’s a chance the router could snub off track in that open intersection area. One idea for that possible pitfall would be to make the jig in two halves…guide the router around all the curves of the left side, change jigs to the other half and go around and through the intersections on that side. Hey, or just finish the left side and flip it over for the right side?
You’re the engineer so you can enhance those ideas, but I have fun when you get me going with these jig ideas. Good work!
Believe me, I’ve tried the router already, but with the bottom curvature, the route starts to be off vertical as you go farther towards the nose and tail and they no longer meet up. That is why I finally ended up on drawing the line on both sides and hand sawing it. The other problem I had was slowing down a 1/4" X 4" bit with a speed control and still have it cut without wobble. Amazingly, the foam really does offer quite a bit of resistance. The only place I have to compensate for stringer width is at the center stick itself, the foam is more than flexy enough to assorb the the slack. The other thing I had to overcome was, the foam wants to do a tectonic plate slide as you tighten the clamps, left slides back while right slides forward. I found I had to keep the clamps aligned to 90 degrees to the curved stringer. I also need to support the blank in more than 2 places, as the blank looses its backbone when cut in the “s” pattern. I did a figure 8 for Weber Surfboards, but when I unclamped the first side, it was an open gap on the bottom in the wide part of the arc, nose and tail. This was from the blank sagging in the center and opening the bottom curves while keeping it closed on the top. What a bitch! I had the choice of scrapping a hundred bucks or with a fine tooth saw sawing along the sides of the screwed up stringer, then cleaning the hardened resing off the blank side and trying again (the devil hates a coward)
Serious money…well, that definitely sounds good. You don’t want to know how little it pays, running a surf shop and being a clam pirate on the side.
I was thinking of the stops as something to keep the structure kinda rigid, so that the weight of the router and the jig itself didn’t especially deform it as you were cutting. If you went with a jig that’d do more than one of those semi-helical cuts then you could offset the stops so that you could move it up and take a quick pass to finish the cut. You’d almost have to have a dedicated table for this sort of thing.
A smooth way to connect at the vertices? Well, how about stealing a trick from your noseblock jig. Tack down some battens so that ( considering the flat sides of plunge routers ) you had fences that acted as tracks for the router to run between? Not unlike a railroad switch, if you get my drift there. Or, as you say, flip the jig ( prolly easiest ) and let her rip.
Thinking about it… the problem Jim’s describing, with the curve of the bottom throwing it off and stuff not matching up, I’d agree. You’d have to have something that was independant of the curve of the bottom:
Would you need a helluva long router bit? Yeah. And there’s other problems too. Solvable? Maybe.
For clamping something like that while gluing it up…hoo, baby. I can just visualise what happened with the Weber blank, having had some similar stuff happen to me while doing laminated wood curved both side to side and up and down, the wood just kept wanting to slide by as I took up on the clamps . Plus having it grow lengthways. I start thinking about doing it all on a curved Lauan ply surface, with weights on top and light bar clamps and angled blocks and stops at either end to keep it from growing too much or band clamping it and still a lot of bar clamps and blocks or gluing up curved stringer and those ovoid foam center sections first and then putting the sides on later, also a nightmare.
You know, I am Real Glad that my chances of doing one of these range from amazingly improbable to no bleeping way. Suddenly being a clam pirate sounds pretty good after all…
Just came in for lunch. This figure 8 stringer thing is getting some serious brain power investment. Reminds me of the Sundance and the Kid movie where they’re trying everything to get out of a jam…“You just keep thinkin Butch”.
I think in the final analysis Professor Jim is correct, as experience is the root of all perfection (something like that). Since you’ve already paid some dues by making the mistakes I would likely discover after making a high-tech jig, I’ve come up with the ultimate solution: When all tech fails, pull out the one big gun that’s always tried and true: The old fashion never out of date method of… just doing it by hand! There’s certainly a time and a place for a jig (the old day masters would love Doc), but I don’t think figure 8 stringers sound like they are the place or time. Besides, we’ve got to get off this post so Doc can put more attention to other ideas that needs graphics, engineering, and thought. Thanks for the input guys - good exchange of ideas. Now what was the original question in this post???
I started shaping a new model for Surfboards Hawaii today, it is the Model “J”. It is the Model “A”, but the stringers are the Triple “AAA” and the Model"A". Triple “AAA” meet at the tip of the center stick at the tail and the Model"A" are set at 5-3/4" apart at the tail. I used my semi-ugly temp as a guide, the center pair start at the stringer and go up to 84" where they take a turn and flair out to the rail. The second set start at the 5-3/4" point apart and follow the first set, double curved sticks 2-3/4" apart and they fall into the step deck, yeah!!! picture to come