Primitive Archer

Main Discussion Area => Bows => Topic started by: Dweena on May 16, 2015, 11:35:16 am

Title: Questions about how to finish bow
Post by: Dweena on May 16, 2015, 11:35:16 am
Hi, I'm a newbie!
 
I've been pursuing target archery since December of last year. I've been shooting a commercial recurve bow, but I am very interested in shooting barebow.

I got myself a vintage longbow, which unexpectedly blew up in my face on about the 80th draw. That made me sad, because I was really enjoying shooting that thing. So I ordered a very basic longbow from Philip Silva (which turned out to come from rudderbows.com). I had to order a custom one because I am only able to draw about 20 - 22 lbs, which was way below the lowest draw weight they had in stock.

That arrived, and I started shooting it; but the hand shock was such that I started getting tendonitis in my bow hand. Even though I added a padded wrap, it was still hurting me, so I set it aside for the time being.

I am now in the middle of tillering my first bow. I decided to try to make a board bow, found a pretty good red oak board at the hardware store, and just jumped in. I backed it with linen, added extra wood to the grip so it would give less hand shock...all seemed not bad, until I got to the tillering - surprise, surprise!

I built a tillering tree and made a (crude) tillering gizmo. I'm in the long string tillering stage right now and I don't know if I'll ever be able to shave this thing down to a reasonable draw weight for myself. With the long string I can draw it, but I don't imagine that once I get the bowstring on it, that I'll be able to.

My question: how do I figure out what draw weight the bow is currently at? I see people attaching scales of some kind to the string? How is that done? I looked for more detail on George's website but couldn't find the detail I wanted about how he is actually using the scale.
I'm attaching a picture of where I was at with it last night, 18" with the long string:
(http://i57.tinypic.com/2dtyop4.jpg)

I would welcome feedback on how to get this down to around 22lb draw weight, and also anything you see in the tiller shown here.
Thanks,
Dweena
Title: Re: Questions about how to finish bow
Post by: bubby on May 16, 2015, 01:10:04 pm
Dweena congrats on starting your bow although you would probably get more help in the bow section.
First off you need to shorten the string so that it is at a couple inches brace height then post a pic of it at brace, also needed are the dimensions of the bow length and layout and I'll help you out
Title: Re: Questions about how to finish bow
Post by: aaron on May 16, 2015, 01:46:50 pm
Yes, first shorten that long string as much as possible.
next, get a bathroom scale. Put your tillering tree right on the scale and pull down on the string until the scale reads 20. Never pull the bow past 20 lbs. Re-read that last sentence. Just continue tillering until you can get a short string on it. Your tiller looks fine so far. Please post dimentions, a picture of the back, and a closeup side view of the handle. What tools do you have?
Title: Re: Questions about how to finish bow
Post by: aaron on May 16, 2015, 01:51:02 pm
Also, you can reduce the handshock in the other bow by narrowing the tips. If you start another thread on it, we can help. On a 20 lb bow, the tips are often no bigger than a pencil
Title: Re: Questions about how to finish bow
Post by: Dweena on May 16, 2015, 03:42:32 pm
OK, I will shorten that long string and post new pics of it with a couple inches brace height.

The bow is 68" in length, and is a pyramid board bow. Here is a pic of the belly to give you an idea of the outline.
(http://i59.tinypic.com/ezgwba.jpg)

At this point the board thickness right past the handle fade is .5", and at the tips it is .25".
The limbs are 2" at the widest point, handle is about 6" if you include the 'shoulders' of the pyramids.

And I think I get what you're saying Aaron - but, would it be best to put the tillering tree & bow on the scale first, zero it out, then see how far the string goes to make 20 lb?

Should I ask the admin to move this to Bows?  I promise that's the last question for now!
Title: Re: Questions about how to finish bow
Post by: Dweena on May 16, 2015, 03:46:03 pm
Oh, also - the tools I have are: table saw, bandsaw, farrier rasp, surform rasp, chisels, sandpaper, clamps, drills, the usual - the thing I wish I had but don't is a belt sander
Title: Re: Questions about how to finish bow
Post by: bubby on May 16, 2015, 04:35:35 pm
You need to start narrowing the width, side tillering
Title: Re: Questions about how to finish bow
Post by: DC on May 16, 2015, 04:36:58 pm
Questions are what keeps this place going. Never stop asking.
Title: Re: Questions about how to finish bow
Post by: aaron on May 16, 2015, 04:56:58 pm
Yes, zero the scale with everything on it
Can you post a side view of the handle and fades?
Title: Re: Questions about how to finish bow
Post by: Dweena on May 16, 2015, 05:45:20 pm
Ugh, I hate posting these - it looks so wonky. But here you go, hope these help:
(http://i57.tinypic.com/1q4jdz.jpg)
(http://i59.tinypic.com/ncjaef.jpg)
(http://i60.tinypic.com/29ln69l.jpg)
(http://i58.tinypic.com/2yv46e9.jpg)

The darker wood on the handle is Koa.
I don't have a half round file, and I haven't been able to get the rough marks out yet...it looks rough, and is rough, I guess ;D.
Title: Re: Questions about how to finish bow
Post by: Dweena on May 16, 2015, 05:48:04 pm
So, side tillering - need to take material off the edges, then? This will reduce the draw weight?
That seems like it might not be too hard. I still need to put the shorter string on this and use the scale. Probably tomorrow - I'm supposed to be getting ready to have people over :P
Title: Re: Questions about how to finish bow
Post by: aaron on May 16, 2015, 05:50:16 pm
Ok, thanks. The fades are a bit abrupt.Next time extend the fades a little, and make the belly surface of the fade more concave. To remove those tool marks, wrap rough sand paper around something round.
Title: Re: Questions about how to finish bow
Post by: aaron on May 16, 2015, 05:52:42 pm
Yes, side tillering is removal from the edges, making it narrower.
Title: Re: Questions about how to finish bow
Post by: bubby on May 16, 2015, 05:53:20 pm
That looks thicker than 1/4" thick if it is you can still remove belly wood you need to get a more curved transition at the fades
Title: Re: Questions about how to finish bow
Post by: Dweena on May 17, 2015, 01:21:42 pm
OK, sounds like the fade from built-up handle to limb should be concave, rather than convex, which is what it's like now -  I think I can do something about that.

The limb thickness is 1/2" right past the fade, so I can still remove belly wood, especially on the lower half of the limbs.

I wish now that I hadn't backed it already - will the linen be a problem when I go to rasping the edges to make it narrower? How would you approach that - would you just mark a line to the inside of the current edge, and rasp down to that?

I'm guessing that I will want to narrow the limbs mostly on the lower half - the top half of the limbs is already pretty slender. So just establish a new angle that eventually joins the existing line of the upper limb, maybe. Should I be working in 1/8" increments to do that, or is that too much?

I strung the bow with a shorter string, enough to give it about a 2" brace height:

(http://i60.tinypic.com/2w7pvtj.jpg)
(http://i57.tinypic.com/t6z5sl.jpg)

And I weighed the tillering tree with bow on it, made note of weight, then  pulled until the scale read 20. However, I think that counts as 14.5 pounds, because the tree/bow weighed 6.4 pounds. I didn't feel I could safely pull it further than that, so I stopped there. This was at 18" draw as given on the tillering tree.
(http://i60.tinypic.com/2yum3ac.jpg)

(edited to add) My draw length is about 26.5, so I have a way to go to get where I can use this bow.
Title: Re: Questions about how to finish bow
Post by: bubby on May 17, 2015, 02:13:15 pm
If your thickness is half an inch you don't have to narrow, you originally posted it was 1/4" thick and not 1/2" it's a little stiff inner third, take a six inch board or straight edge pull the bow to about 12" and run it along the bellywhen you start to get a gap make a mark when the gap closes make a mark, don't remove wood between the marks but do remove from either side, does that make sense?
Title: Re: Questions about how to finish bow
Post by: aaron on May 17, 2015, 04:24:23 pm
Go really slow now. You probably have less than one sixteenth of an inch to remove from the thickness.
Title: Re: Questions about how to finish bow
Post by: aaron on May 17, 2015, 04:32:36 pm
I think the tiller is pretty good, but as bubby said, the inner third looks stiff, so remove wood from there, except the first inch or so next to the handle fades. Right where your glued on handle ends is a place you dont want any bend, so leave that part alone.
Title: Re: Questions about how to finish bow
Post by: Dweena on May 17, 2015, 04:38:25 pm
There seems like there is a twist on one of the limbs, it becomes more obvious when drawn to the 18" length. Hmmmm. I definitely will be going slowly now...I'll let you know how it goes, thanks so much for the thoughts!
Title: Re: Questions about how to finish bow
Post by: aaron on May 17, 2015, 08:06:47 pm
Dont worry much about the twist, but do check that one edge is not thicker than the other. Measure the "SIDES" of the limb to see that they are the same.
Title: Re: Questions about how to finish bow
Post by: Dweena on May 20, 2015, 09:17:57 am
I've done a bit more work on this now, and even done some shooting at half-draw. At this point I have the bow at 20lb @ 25" draw length, and here is what it looks with the bowstring on:
(http://i62.tinypic.com/29yjmt3.jpg)
(http://i62.tinypic.com/294o4cz.jpg)

And here is how it looks on the tillering tree at that draw length:
(http://i61.tinypic.com/110yux4.jpg)

I am still having a twist in the right limb as you look at it here, it's not severe, but.
The left limb looks like a more even curve, but stiffer than the other.
I would welcome your input, as I'm at a very delicate stage with this bow!
I'm excited that it had held up so far.



Title: Re: Questions about how to finish bow
Post by: aaron on May 20, 2015, 09:40:56 am
look great to me. congrats! Don't let it sit on the tiller tree drawn for longer than absolutely needed to get a photo. Better yet, draw by hand and get a friend to snap the pic. .
Title: Re: Questions about how to finish bow
Post by: Dweena on May 20, 2015, 10:14:03 am
Thanks Aaron! The bow shoots straight and sweet so far, just done some blank bale shooting but getting good groups at half draw at about 12 yards.

I definitely hurry it off the tillering tree as soon as I can get a good picture...probably have it on there less than half a minute all told. Still, that is a long time to linger at full draw, much much more time than it will get in normal use. I have not yet pulled this to my full draw length of 26.5 - 27", and I intend to tiller it past that to 28 just to be careful. I'm aiming for something like 23 - 24lb at 28", hoping that will make it approx 20lb at 27". Does that sound right?
Title: Re: Questions about how to finish bow
Post by: aaron on May 20, 2015, 10:35:00 am
yes, 24 @ 28 will be about 20 @ 27. At this point , I would sand it, round off any sharp corners, and shoot about 100 arrows. After that, check the weight and tiller and make final adjustments if needed. Don't put a final finish on it for about a month in case the tiller changes.
Title: Re: Questions about how to finish bow
Post by: Dweena on May 20, 2015, 10:46:48 am
So sounds like you think it's OK to start pulling this to my full draw of 26.5 - 27". That's pretty exciting! :D
I already have sanded it and rounded edges, so it's ready to start those 100 arrows.
I so appreciate the feedback - I've been enjoying this project for sure.
-Dweena
Title: Re: Questions about how to finish bow
Post by: bushboy on May 21, 2015, 06:15:28 pm
Maybe try plumbers sand cloth.120 grit, comes in a roll and sand like shining a shoe.great for rounding edges and handles.make sure all sharp edges are nicely rounded is key.i use this sandcloth on all of my bows,boards or staves.never used it with linen so i'm not sure?