Riser Questions

[Brett Leinmiller]

I'm planning my first build, a takedown recurve or longbow with a laminated riser.
It'll be around 60 inches and 50 to 55#.
Riser material may include Osage, walnut and similar hardwoods. I'd like to build the riser without phenolic or glass.

1. Smooth On EA40 or Titebond- is one preferable for riser construction and why?
How do I avoid a too thin glue joint?

2. What design technique will result in a stable, all wood riser? Quarter sawn wood?

3. What Is I-beam construction?

Thanks everyone

[mikkekeswick]

EA40 - No joint creep over time.
Quarter sawn is less subject to shrinkage.
I-beam technology sounds lie marketing!! As long as it's big enough to not flex at full draw it's fine.

[Crooked Stic]

Walnut is not a good choice for a takedown riser. You can use for accents with osage and be ok. You want the growth rings to be from to belly. Quarter sawen works ok to. Making sure you glue surfaces mate up well EA-40 is all you need. C-clamp your pieces together. You can crank down on them pretty hard and be fine.

[Brett Leinmiller]

Thanks guys. Crooked Stic, is walnut to soft? Just curious cuz I love working with this wood and the finish is always exciting, especially if I luck in to some burl.

[bamboo]

walnut is on the brittle side

[Troy D. Breeding]

I've used walnut for riser material several times. It will do the job if your design is right. Still advise putting a couple layers of glass on the back and even a strip or two in as accents. The one that I left the glass off the back developed a crack not long after I started shooting it.

The best walnut riser I built was made up just like Actionwood. A lot of work but solid as a rock, but I still put glass on the back.

[Roy from Pa]

Curly walnut with Osage I beam.

 

 

 

[Bowjunkie]

Prepare the gluing surfaces for Smooth On by roughing them with coarse grit paper, a hacksaw blade, or a toothing plane blade, etc. I use the latter after everything is ground to shape and perfectly mated.

[Brett Leinmiller]

What makes walnut brittle? Not questioning what you say, just learning.    

Troy, you mention a riser built like actionwood. I like the idea of making my own actionwood. What are the ideal minimum and maximum thicknesses we should target for our risers? How is actionwood used in limbs?

That's a beauty Roy. Is it finished or a current build? I'd love to see the finished bow.

[BigJim]

60-80 grit is plenty rough for gluing surfaces. The tree is what makes walnut a bit brittle, but when used properly it will make a great riser.

Most any wood riser is going to flex a little weather you can see/feel it or not doesn't mean it's not flexing.
Personally I seldom ever put glass "in" a riser unless it is the limb glass running through it as in a one/two piece bow. I would however suggest backing it with glass as this will reduce the flex and help to keep you from wearing it.
I beams are great if you need it to strengthen a lesser wood choice. I personally don't care for them as it just adds another color or glue line that detracts from the appearance...but again this is just my opinion.

I use lots of woods that people claim aren't good for bows due to how oily they are or brittle but never have any issues if they are used correctly. Too often moisture levels are the cause of failure and not the species of wood itself.

good luck, Bigjim

[Brett Leinmiller]

Thanks BigJim. What's your glass of choice. I read a post where you didn't care for phenolic due to the flex and sanding issues. Now I'm trying to research and sort out the difference between G10, Uni-Weft, and Core Tuff. I saw super glass mentioned in one of your posts, Is it one of these I mentioned? Thanks again to all, this is a great resource.

[BigJim]

For limbs, I prefer Uls clear and uniweft. In the riser I don't put any except in one or two piece bows where the glass runs through it.

I will back a riser with g10...Now I will vary from this as necessary as I have built entire risers out of  g10. I sell all this stuff on my web site also.

thanks, bigjim

[Brett Leinmiller]

Yes, I've been looking at your site. I see you mention Core Tuff just for color strip purposes?
What's the difference between uls and Uni-Weft? Thanks for taking time to answer my questions.

[mikkekeswick]

Brittleness only matter when you are bending it a lot. I've made black walnut selfbows and they shoot fine. It's all about learning the properties of your materials and then using them appropriately in your design.

[BigJim]

Uls is glas that has a non visible scrim and highly suggested any time you are going to drill holes in it as in 3 piece TD. It will help to keep glass from cracking between holes.
Uls is available in clear and colored glass.

Uniweft is only available in black, red and natural and has a visible horizontal weave to it and can be seen slightly on the edge when finished. The horizontal glass acts as a stiffener where as the scrim in uls doesn't affect the bow torsion at all.

BigJim