Perimeter stringer build

I've been talking with some of the woodworkers about splicing together two pieces of basswood in order to form a length long enough to make a perimeter stringer.

This is what I am starting with for the blank:

What I want to achieve with the construction is a few things.

1) Stiffer rails to help prevent rail twist off
2) Tie the fin boxes into something more solid than the foam
3) Stiffen up the tail under the rear foot.

The process that intend to follow is to CUT the blank at the line where the stringer will "reside".

Next, smooth that cut up as much as possible and epoxy the spliced basswood stringers on to the core. Then apply some epoxy to the off cuts and bag the whole mess.

Finally, after everything is cured, I will cut the FINAL outline and shape the board as usual.

The one thing I may do different is from the intersection of the stringers at the tail to the end of the tail to resemble this treatment.

Jeff you are doing some crazy stuff. keep it up and great board how does it ride?

Hey Bob - yeah, I'm the wild man of CPA's on the west coast I'm sorry if I was misleading the picture above of the finished board isn't mine - it's a Wiley Perimeter Stringer. Here is a picture of the top - the art work is incredible - I really like the "frame" of the stringers.

This board had perimeter stringers - my fin setup proved to be "stupid" but in hard bottom turns the board would unload after the turn and it felt like it would shoot the board up and forward. Interesting concept.

The GFX on that board in the middle are sick.

cool Jeff - will be excited to see how that glues up. as always - takin' it to the next level.

Jeff CPA? (California Party Animal)
Couldn't be accountant. Anyways still some awesome boards and great creativity

(Message edited by konaking on March 21, 2008)

(Message edited by konaking on March 21, 2008)

very cool jeff..ive been messin with alotta diff stringer set ups too.i have been trying to source just the perfect boards with the grain going with the stringer stead of against it.from what i can tell,the added stiffness increases speed and pop.old timer told me,proper grain usage could add twice as much strength.anyways,you have your hands full with this one.cant wait to see it.

I wish that I could airbrush like that second picture, Blair - that is a skill I just can't master.

Thanks Matt! This one 'bout made me pull the rest of my hair out! So 5 strands The bend in the wood made it REALLY hard to get everything lined up.

Thanks Bob - when I was first certified we had such crazy names for the CPA designation - Can't Possibly Add Cut Paste and Assemble (before computers!!!!!!!!) some of the others can't be typed in mixed company (we have engineers present )

Billy - wow! That makes sense, I wish that I knew more about wood in general, but I swear I'd rather stab my eyes out than work with the stuff Lots of info from the old craftsmen that I'd like to assimilate. It sounds like you are building your own blanks? Are they available on your site? I'd like to hear more when you get a second.

Let me crop and I'll post up the glue up

I didn't want to mess with the intersection of the stringers at the tail - it looks sweet, but just getting the bend in there was hard enough, I can image what it would be like with the intersection and fitting the little piece in between.

So, I just used the jigsaw and cut the "inside" out. I lightly sanded everything to smooth it out, but also to reduce some of the material that will now be filled with the stringer material.

The center:

This is the the offcut - it's basically one piece, except for the entry at the front.

After sanding and smoothing all cut surfaces, I mixed up some epoxy and lightly painted all surfaces - both the foam and the stringer material. I have a rockerbed for this blank, and that is what I am bagging to to maintain the bottom rocker.

I painted the inside of the offcut first and set it on he rockerbed. Then the center section was painted and assembled. Finally the stringer pieces were painted with epoxy and I worked them into the gap between the two sections of foam.

From there I slid the "blank" and the rockerbed into the bag and pulled the vacuum.

In the bag:

The wood wanted to straighten out and it made the center piece push forward. As the vacuum was being pulled and the bag started to get tight I basically pushed and shoved everything until the bag pulled it snug. This process would have been better with 6 hands

Out of the bag! I didn't get the stringer fully seated on the right side rail so I've got a slight gap between the bottom and the stringer - but other than that it should be fine as I start to shape it.

Jeff, I just love all the different construction ideas to try. You are absolutely fearless.

Jeff, is your email working. I know, I know you’re busy, something about taxes. I got a bounce back from an email that I sent.

Ed

Hey Ed,

Yeah...failure is my middle name Success comes last

We've been up in the snow...err, I mean slush. Doing a little snowboarding. I just responded. Thank you sir.

While I have you...maybe you know of a formula for the perimeter stringer thing. When you run a stringer down the middle it's easy to trace the blank half on the wood and cut that. However, like planking a wooden boat, when the stringers curve inward, they "rise" off of a horizontal plane. You can't just trace a side view of the rocker, it actually has to be less.

My garage way of doing this was to "smoosh" (that's a technical term let me know if you need that defined ) butcher paper over the area on the cut inside piece - then I just cut along the crinkle or the "smoosh" line. Using that paper to trace onto the basswood. There has to be a more accurate way. Knower of all things engineer, what can you suggested?

To make a smooth line I would make a template. When you cut the template it won't be smooth. Use sand paper or a planer to smooth out the edge of the template. Then use the template as a guide for a router. Think about how Verner used a straight edge as a guide for the router for the V struts.

Does that make sense?

I wouldn’t cut the board all the way through, I’d cut a groove a lot like Verner did. Maybe even go the next step and make a carbon fiber stringer like Vernon did for the V struts.

That's an interesting concept - I can make a masonite template and route the cut...then slip the stringer material into the slot and mark it to cut the bottom rocker.

There is a company that makes boards with carbon composite perimeter rails - I believe they are wood with a thin piece of carbon that runs the length and a 5# density foam outer rail.

I think the wood, rather than the coremat that Vernor uses would be a better choice.

yeah jeff, i have hAD TO step it up alot since the outsourcing skills of my competitors has hit an all time high with the quads and carbon and dingh proof this and dingh proof that.long story short,my new triple stringer designs are my way of separating my skills from the mass producers.i've seen the airs your kid busts,he and riders of his level would benefit the most from this latest innovation

Triple stringer? One down the middle and two out towards the rails, Billy?

Hey Ed, Bessell surfboards is the guy I was thinking about. He had an interview done on surfshot - it's AWFUL commentary, very inaccurate they call EPS foam EXTRUDED and the like, but they do vaguely describe his "reflex" methodology. There is an ad over there also, for what Bessell calls a 50/50. In the ad, working from the inside out it's:

1) EPS core
2) Wood perimeter stringer
3) Carbon tape (it's TINY and doesn't extend to the deck or bottom surface
4) XPS foam rails.

At the snow yesterday...pardon, at the SLUSH yesterday I noticed a number of snowboards with a clear topsheet and manufacturers are running just a few pieces of carbon tape the length of the board. Typically it's between the centerline and the rails widthwise. It runs lengthwise between the curves UP to the nose and tail. I think that the tape is just 1" wide.

The way that Bessell is building his..."I THINK" is trimming the carbon tape to the desired dimensions and then laminating the rail foam and carbon tape to the semi shaped blank.

I am struggling with a flu, so that may be my biggest problem, but can anyone figure this picture out?

It's an attachment to a hot wire that is used to cut a blank down for perimeter stringers. Is the flat table in the background used to hold the hotwire in place and the blank pushed against the hotwire? If so, how? Or is that 70 pound hotwire somehow held perfectly straight as it is pulled against the blank?

Any input so that I don't have to strain my fevered brain would be appreciated.

Jeff,
Looks to me that the blank slides up against the silver bar on the left and the blank is held flat against the flat piece at the top making a square cut however thick the bar allows on the right which looks like it is adjustable for perimeter thickness. How that for a run on sentence .

Thanks Dennis and excellent display of run-on sentence skills. Ok, I "think" that makes sense...at least the pushing the blank through...and the hotwire bow is somehow affixed to a table - no doubt that white table top with the slot cut into it.

Any idea how the contraption would affix to the table?

Not sure it needs to be fixed to a table. I could see this device working best with the blue part attached parallel to the floor or table top. The blank would just ride along the silver bar and flat against the flat plate. Looks simple.

There isn't much resistance when hotwiring the foam, but enough that it would cause the bow to fall or lean during the cut unless it was supported. I'm thinking it would take two hands to push the blank through the hot wire being held against the "bolt" AND that flat surface. Maybe I'm just too sick to grasp it, but I think the bow would have to be fixed to prevent it from leaning as the blank is pushed through - no?

Yes the hotwire would have to be secured to floor, table or such. After that
i think it would be fairly straight forward.

Deep in the darkest part of the Amazon jungle there grows a special tree. This is the unique and exceptionally rare basswood tree TALLER than 48 inches!

60" basswood - 1/8 x 4" I'll betcha you're jealous!

They look artificially grown, are you sure they are real?

Artifically grown?! Like farmed basswood or are you saying it's pergo?