my bbo glue lines

[don s]

here's a few pics of the bbo i'm working on now. also, a couple pics of the home made scraper i use to prep the boo and osage surfaces for glue up. it's shape is convex instead of flat. the boo and osage surfaces will be slightly concave. the result is some pretty good glue lines. does anyone else use a convex scraper? btw, this boo was given to me by JamesV. thank you james. don      

[don s]

[don s]

[don s]

the scraper is a piece of an old hacksaw blade. it's 4 inches long. 1 3/4 inches wide and the thickness is .088. i ground an angle on one side and i burnished a hook on the other side. it works well. don

[JamesV]

Don, looks like you are comming along great with your bow. It should be a fine shooter. glad the boo is working for you, can't wait to see the finished bow!

My bow building is at a standstill for now. I am located just above Vicksburg, Ms and the river is predicted to crest here tuesday. If the backwater levee holds I might be alright but if not I will have 7-10 feet of water in my house and shop. We have moved most everything out to hi-ground and hoping for the best.

James.............

[Aznboi3644]

both surfaces are concave? so leaving a small gap in the middle along the limbs?

[don s]

james, i don't know how some people can deal with flood waters,tornados,hurricanes or earthquakes. if the worse that i have to deal with is lake effect snow and fridged temps, thats fine with me. i'll say a prayer for you and yours.
anzboi3644, yes. both surfaces end up concave with a very small gap between the two that ends up filled with glue. titebond III in this case. the gap is so small and the bow is clamped down so much during glue up,that the gap is not as much or as bad as you would think. don  

[Bowjunkie]

I do it too. I do it with a toothing plane whose blade I've sharpened on a very slight convex curve... ala "Hunting the Bamboo Backed Bow". It makes for slightly concave boo and osage gluing surfaces. The boo flattens out upon clamping, while still leaving perfect glue lines down all sides of the bow.

[don s]

bowjunkie, yes, thats where i learned it also. i don't have a toothing plane and although i've used urac and like the results. i prefer the easier to use TBII and TBIII glues. so, for anyone who struggles with less than perfect glue lines and your at a loss as to what you can do. try using a convex scraper or toothing plane. i'll bet it solves your problem. don

[Roy from Pa]

Don in the picture above, is that the bamboo you have the clamps snugged down on?

[don s]

roy, yes. that is the boo clamped down on the osage. i have it on a length of 2x4 with blocks at the end to glue in some reflex.  don

[Roy from Pa]

Ok that's what I thought Don. Little tip here, you should be padding the back of the boo with something so that the clamps do not indent it, that can cause failures on down the road, trust me, I learned that the hard way.

[soopernate]

Have you ever glued one up like that and then sawed across to look inside?  With two concave surfaces trying to meet and using TB2 or TB3 which is not a gap filling glue I know your glue lines on the edges are going to look good but worry about voids in the center.  I also second the use of something to keep the C clamps from damaging the outter fibers (aka POWER FIBERS) of the boo.  Good practice to preserve the backs integrity.

[don s]

thanks roy, i'll do that the next bow. so far i've been lucky i guess.
soopernate, the void between the two surfaces is not like you are imagining. as bowjunkie states in his post, the boo does flatten out somewhat when clamped but the curved scraper does not concave the boo like you are thinking it does.this is a pic of the boo just before glue up.you can't even see the concave shape it's so slight.i scrape the full length of the boo, including the tips. check out dean torges "hunting the bamboo backed bow". don

[hova]

i considered this back when i glued up my handle on my 51" . no matter how much i sanded , i just couldnt get a clean line. thought about something like this , but disregarded due to the concerns everyone has expressed.


as lon as the arc is slight , it shouldnt be an issue though...


-=hov