2nd run at a board bow

[Double Acre]

Welcome to the forums Double Acre!

If your board is bending away from the belly, that's called reflex. Bending towards the belly is deflex.

Personally if the reflex in one limb is so slight that it's hard to even get a picture of it, I would just leave it. Bending the other one to match it probably opens up more room for error than letting it work itself out during tiller. It will develop some string follow anyway, and might even out like that.

Looking forward to seeing this bow shape up!

Thank you for the welcome!

I layed the bow on its back on a flat surface and managed to get a couple of pics.  Upon further inspection, it appears one limb is about 1/4" in deflex while the other limb is about a heavy 1/8th" of reflex.  The reflex picture is approximately at mid-limb.

[JW_Halverson]

The reflex and deflex is piddly and beneath your attention.  The tillering process will likely change all that anyway. 

Start your next step!

[Double Acre]

The reflex and deflex is piddly and beneath your attention.  The tillering process will likely change all that anyway. 

Start your next step!

Very well... WE RIDE!!

[JW_Halverson]

I believe Wagner's "Ride of the Valkyries" would be appropriate music now!

[Double Acre]

Latest update:

I cut some nocks in the bow.  I used a 3/16 chainsaw file, which now after the fact may have been a smidge on the large size?
 


I then cut a piece of cord and fastened it to the nocks.  I tried to make the cord snug with the board but i wasn't working out ... it is a tad loose.
I then put together this little tree and zero'd the weight on the scale so that it read 0 when the tree and bow were sitting on it. Never mind how loose the cord is in this picture.. I snugged it up a bit more before I pulled on it.



So for the first pull, I pulled downward slowly until the scale read around 23lbs and marked the string location at 15".  My "target" weight for this would be ~50lbs.  For the sake of getting a picture, I put a small screw at the 15" mark, attached the string and snapped the pic as fast as I could.



I can see the limbs are still really stiff, as most of the bending was happening closer to the tips.  At this point, I am thinking if I am going to back this thing, I should do it before I round off the edges and tiller anymore?

[dirthas]

I've done two backed board bows, and on both I backed before I started tillering at all. The backing will likely change the tiller, so no sense in doing all that work and letting it all go to waste IMO.

[Double Acre]

I've done two backed board bows, and on both I backed before I started tillering at all. The backing will likely change the tiller, so no sense in doing all that work and letting it all go to waste IMO.

What backing material did you use?

[Double Acre]

I decided to use linen to back this bow before I move any further.  I picked up a yard of 100% linen from the craft store, so I figure I have enough to do multiple layers or a couple bows.

Any tips on linen backing?  Should I back the full length of the bow from nock to nock?  One or two layers?

I will be using tb3 glue

Thanks

DA

[loon]

Nice going. I have a very similar board, though the grain might not be as good.
Good luck

[mikekeswick]

The grain looks good to me. There is no need to back it. Try to get a full sized picture up of the tiller.

[George Tsoukalas]

Don't force it. Try to get 10" of string movement and your target weight. Makes sure the bend is good. Look at the red  oak build along on my site. Jawge

[Double Acre]

I went ahead and backed this other bow with 2 layers of linen.  One of the reasons was because of this edge run out show here



The rest of these pics are just some others from the process.



One of the things that I did, was I glued the strips down before rounding the edges on the back.  I recall reading that it was easier to get edge coverage when you do it that way.  What I ran into, was now I am not sure if I can round the edges on the back without destroying the backing? 

I will try and get some pics of the tiller process.  I'll start by trying to get the 10" of string movement Jawge mentioned.

DA

[Knoll]

2 layers may be excessive. I've not used more than one. More weight will require more energy, which will make bit less energy avail to throw the arrow. But likely not the end of the world.

Now that backing is glued down, you're not going to do harm to it as ya round edges. Be sure to make your rasping strokes from back of bow to belly. That'll further insure ya won't lift edge of backing from limb. My 2 cents.

Good luck!

[burtonridr]

Lookin good, shouldn't have a problem with that one breaking

[Springbuck]

The reflex and deflex is piddly and beneath your attention.

I agree.  I love starting with a straight, symmetrical stave, but that is not enough to go through the complicated steps of heating or steaming, and will likely resolve itself.

You are doing things right.  I often go two layers on linen backs, but that, of course, depends on how thick the cloth is, etc..  I like to lay down a Titebond III sizing coat on the wood, let it get tacky, then almost saturate the cloth and lay it down, pressing it in with my hands or a roller.  You are fine to trim or round the edges as you are doing.

The issue with two layers is it takes a lot more glue to hold down cloth to cloth, so the proportional weight rises.  Also,if you used any glue with water in it, which is most wood glues and hideglue, give the stave a few days to lose that water before flexing it much.  You want the glue good and dry, and you want the wood good and dry.