I'm prepping my flat bow for a hickory backing.Do I need to make the back of my bow flat or can I leave the bumps from the stave in there.I would appreciate any help.Thank you.
I'm not an expert but I would say if you are going to do a hickory back you need to prepare the back of your bow as flat as possible.
That is what I was thinking.But I just wasn't sure.
Never done a hickory backing, but applying any backing is pretty much the same process. Make your belly blank gluing surface as flat as possible. Then score it or "rough it up" with a toothing plane or I use a fine tooth sawzall blade to make some little grooves in the surfaces to be glued. Urac 185 has worked well for me so far and it fills gaps nicely.
Good Luck!
Flat, flat, flatten the back if your gluing a flat backing on it.
if your bonding wood to wood with titebond or wood glue you want a flat smooth mating surface.
No toothing or rough surfaces
Why no toothing? Please explain.
I think your just asking for a dry glue joint if you don't at least use a heavy grit sand paper before gluing. I haven't noticed any ill effects from toothing when using Tite Bond glues or Urac, and haven't had one fail yet either.
I never tooth my TBIII surfaces either. The directions tell you to be sure the surfaces are clean and smooth, thats my reason. URAC always gets toothed.
TiteBond and other wood glues work best with smoother mating surfaces. You must remember that TiteBond III and other top-of-the-line wood glues are designed for modern cabinetry and the smooth surfaces and tight, void-free joinery associated with it. TB has NO void filling properties. Urac/epoxies are able to fill voids and will tolerate mating surfaces with slight architecture (i.e. toothing). Some even require this in order to grip and bond properly.
Here's some literature copied from the manufactures of TiteBond (www.titebond.com) and Urac 185 (www.nelsonpaint.com).
Regarding TiteBond:
"When working with woods that are high in tannic acid or are considered oily, wiping the joints with acetone before gluing them up ensures a good bond. Acetone clears the contaminants from the wood's pores on the bonding surface and dries quickly without leaving any residue. A good bonding surface can also be achieved by sanding or planing the wood just before gluing the joints."
Regarding Urac 185:
"Urac 185 is a modified urea formaldehyde liquid adhesive formulated to give craze resistant glue a line up to 0.02" thick. It may be used for gluing wooden structures where a thin glue line cannot be obtained because of inadequate pressure or irregularly contacting surfaces. Urac 185 is an ideal "gap filling" adhesive."
Hope that helps :)
Thank you everyone.That is a lot of good info.