Cutting a stringerless blank for a tapered stringer

Qustom

New Member
Jun 18, 2013
24
23
USA California
I've got a 9'0" board mostly shaped out of a stringerless blank and I have fabricated a tapered stringer out of cherry wood that is about ready to go in. I'm looking for some tips on how to accurately cut the blank in preparation for gluing it all up. I have left the hips a bit wide and extra thickness in the deck in anticipation of any damage that may occur while doing this. I understand that this is usually done before the blank is shaped, but because of how much foam I removed to get the shape I wanted and how beefy the stringer is at the tail, I did not want to do all that shaping with the stringer in place.

So... I am looking for tips on how to:

1. Get really clean, straight cuts in the foam
2. Support the foam sufficiently while cutting it
3. Jigging up the whole thing for gluing

Thanks!
Vince

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JMJackFish

Well-Known Member
Jul 5, 2016
1,013
1,593
USA North Carolina
What is the foam - Poly or EPS? I hot wire EPS quite a bit. Clean up your cuts making sure they are straight and clean. Glue up the stringer, clamp and mow to rocker/blank. Alternate your clamps and keep them pretty close together. Your glue choice is also important. The TiteBond2 is like white diamonds when you are mowing - be careful. Blow the foam/glue bits all the time off the stringer anytime you touch it.
 
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Qustom

New Member
Jun 18, 2013
24
23
USA California
What is the foam - Poly or EPS? I hot wire EPS quite a bit. Clean up your cuts making sure they are straight and clean. Glue up the stringer, clamp and mow to rocker/blank. Alternate your clamps and keep them pretty close together. Your glue choice is also important. The TiteBond is like white diamonds when you are mowing - be careful. Blow the foam/glue bits all the time off the stringer anytime you touch it.
Thanks for the tips. The blank is poly. I have used Gorilla Glue with success in the past. I assume you meant TiteBond III?
 

SharkB8

Well-Known Member
Sep 21, 2011
1,253
1,093
USA Virginia
Don’t cut the taper in the blank. Clamp a thin piece of trim board and use a circular saw. It works like a guide. Center the cut. I like gorilla glue but have use lam resin. It also leaves little bits that will scratch the foam. Re-outline and proceed.
 

shapewright

Well-Known Member
Aug 6, 2006
1,104
1,721
USA California
Thanks for the tips. The blank is poly. I have used Gorilla Glue with success in the past. I assume you meant TiteBond III?
I snap a line or draw, split on my band saw and run across my jointer.
Gorilla glue with white pigment in it, it is not light stabilized and browns out in the sun.
I use bicycle inner tune strips on pre shaped foam, clamps cut into it too much
 

Qustom

New Member
Jun 18, 2013
24
23
USA California
Don’t cut the taper in the blank. Clamp a thin piece of trim board and use a circular saw. It works like a guide. Center the cut. I like gorilla glue but have use lam resin. It also leaves little bits that will scratch the foam. Re-outline and proceed.

Too late on that, the taper has been cut. It was part of my plan to use the piece of tapered foam as a template for finishing the top and bottom contours of the stringer, and it looks like this will work great. I will stick it down to the wood with light duty double sided tape and fog it with spray paint to create my guide lines. I can get the stringer really close to the final shape that way, and once laminated in there should be only minor tweaks needed after that. Another bonus of doing this is that it's now really clear that I need to thin the board down a bit about 3' back. It has a slight step deck but it's still a bit fat right behind it.

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I snap a line or draw, split on my band saw and run across my jointer.
Gorilla glue with white pigment in it, it is not light stabilized and browns out in the sun.
I use bicycle inner tune strips on pre shaped foam, clamps cut into it too much

I have seen that too with GG and I am thinking I will use some type of epoxy instead or maybe the TightBond II. That's a great tip about the inner tube strips. I've got a bike shop nearby that will probably have lots of dead ones to donate to the cause.
 
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shapewright

Well-Known Member
Aug 6, 2006
1,104
1,721
USA California
D
Too late on that, the taper has been cut. It was part of my plan to use the piece of tapered foam as a template for finishing the top and bottom contours of the stringer, and it looks like this will work great. I will stick it down to the wood with light duty double sided tape and fog it with spray paint to create my guide lines. I can get the stringer really close to the final shape that way, and once laminated in there should be only minor tweaks needed after that. Another bonus of doing this is that it's now really clear that I need to thin the board down a bit about 3' back. It has a slight step deck but it's still a bit fat right behind it.

View attachment 33785



I have seen that too with GG and I am thinking I will use some type of epoxy instead or maybe the TightBond II. That's a great tip about the inner tube strips. I've got a bike shop nearby that will probably have lots of dead ones to donate to the cause.
Don’t use tight bond on poly foam, once the squeeze out drys along top and bottom, it is like putting the cap back on the bottle. The foam is NOT porous and it remains wet inside and when you start working in it, it will come apart
 




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