Woods that won't bend

[bubby]

Hamish i've never had any differences between kiln dry and stack dry lumber

[gfugal]

So I'm posting several pictures. The first shows my new form and a scrap piece around the same thickness that I tried. You can't see it but it splintered up before It could make the full bend. I boiled it for 30 minutes. The second picture shows a curve of a bowl with a radius of 3 inches which happens to be around the same radius on my caul in the third picture. In the fourth you see that the furniture I used in the past to recurve has a much greater radius and thus a more gentle bend. This may be the source of my problem. I might be expecting too much from the wood and should go back to a more gentle bend. Or maybe I'm just too slow and it cools off before I can get it far enough without breaking it. as you can see in the first picture my setup is not the best and is really difficult to clamp down a large bow especially when it's hot and you need pretty much two hands to work the clamp.

[DC]

I tried a few tight bends (2" radius) with Ocean Spray the other day and broke all of them. I tried everything I could think of. Strap, no strap, boiled , steamed, in a bag. I was trying to bend 1/2" material like you and it just wouldn't go. I didn't try pre-soaking or green wood. What did work was kerfing it. Kerfing is ripping the 1/2" and bending it and then inserting a thin piece into the kerf. I think some woods(and pieces of wood) just bend better than others. I think you might want to try a larger radius. You are doing the right thing by trying test strips though. I hate it when the second recurve on a bow breaks. Actually it ain't so great when the first one breaks either

[gutpile]

boiling for curves is way better...need to be quick on the bend though...make sure you use a metal band also to prevent splinter on belly...gut

[gutpile]

that is a rough form too...not much of a bend either...I suggest you put a c clamp at point of form to lock down wood .just enough to slide in wood and metal band...gut

[DC]

Here's what I was using. I deliberately used a sharp bend to see what I could do. I couldn't do nuthin"   I have a wedge that I drive in the loop to hold the bow and strap in place. I was steaming the wood with the strap already clamped to it so setup took less time.

[scp]

It would be easier to bend if you keep the tip longer and start bending several inches below the tip. After boiling for an hour, 4 to 6 inch diameter bend would not be too difficult.

[DesertDisciple]

As has been mentioned, red oak will bend but you need to heat it thoroughly. I havent had much success with the tent over pot method so I started using long bags fixed to a makeshift spout on the pot, then rubber banded to the bow. You have to get it on the form quick and doing it in the bags let me keep the heat going while bending.

That being said, ive never bent red oak without getting a little delamination on the belly. Make the tips thicker so you have room to remove the splinters and dont move the stave side to side once clamps are on. Boiling might work just as well

[Selfbowman]

Mesquite

[gfugal]

Ok I have some updates on bending the red oak. I made a new form with a radius of 5 1/4 inch radius (the largest plate I had). The form was designed with 4 inches of reflex. However, as you can see in the last picture it lost an inch and is only about 3 inches reflexed now. I rounded the edges boiled it for an hour. I did the same for the second but took it out of the form after an hour and a half. Is that why it lost an inch or is that going to happen no matter what. The second sie splintered up on the belly. I hope I didn't destroy the whole thing. It splinters down maybe 1/8 of an inch. I was wondering if I filled it with glue and file it down if it would still work.

[mspink]

Kiln dried or air dried oak will steam bend.

[Springbuck]

  I don't see dimensions, but to my eye, I still think you are bending wood that is too thick.  MUCH better attempt, though!  Form looks awesome.

  Yes, leave the wood in the form until it is completely cool, and some would suggest until it is completely dry.  Once curved, I often return them to the form and do my heat treating with them in the full curve like that.  3" is a hell of a lot of reflex for SOME bow designs, actually. depending on the style of bow.  Big, sharp recurves require wide limbs below them, and sometimes even a bit of deflex.   Which leads me to the next thought........

I think that bow looks way too narrow for a red oak board bow, and a little narrow for anything with that big a recurve, unless another design compensation is made.

When making a recurve like that, I get the bow to floor tiller or even strung dimensions, then add the recurves.  Tiller will change, but stiffnes just went up, and you proved the wood cn take some bend.

That cracked belly on the recurve is rerpairable with some simple thinning and some overlays.  Hardest part is working them flat enough to match the overlay while glueing.

And, BTW, I PM'd you about getting some staves and bow wood into your hands, so check that.

[Hamish]

Oak is a good bending wood, but if it has been kiln dried its ability to plasticise will diminish, meaning you won't be able get as tight a radius bend without failure. Not saying it can't be done, just that you are better off using air dried wood, preferably around 15-20% moisture content, ie still a bit green.
 Kiln drying supposedly permanently changes the nature of the wood cells. Check out any text book specifically on wood, you will find they all recommend against using kiln dried wood for steam bending. My own personal experience steam bending kiln dried beech confirmed  to me that it was not worth doing again. It didn't keep the bend well and developed checks. I haven't had the same expience with air dried woods.

[gfugal]

  I don't see dimensions, but to my eye, I still think you are bending wood that is too thick.  MUCH better attempt, though!  Form looks awesome.

  Yes, leave the wood in the form until it is completely cool, and some would suggest until it is completely dry.  Once curved, I often return them to the form and do my heat treating with them in the full curve like that.  3" is a hell of a lot of reflex for SOME bow designs, actually. depending on the style of bow.  Big, sharp recurves require wide limbs below them, and sometimes even a bit of deflex.   Which leads me to the next thought........

I think that bow looks way too narrow for a red oak board bow, and a little narrow for anything with that big a recurve, unless another design compensation is made.

When making a recurve like that, I get the bow to floor tiller or even strung dimensions, then add the recurves.  Tiller will change, but stiffnes just went up, and you proved the wood cn take some bend.

That cracked belly on the recurve is rerpairable with some simple thinning and some overlays.  Hardest part is working them flat enough to match the overlay while glueing.

And, BTW, I PM'd you about getting some staves and bow wood into your hands, so check that.

Sorry I didn't post the dimensions other than the width and thickness of the tips. I think I said it was a little over 1/2 inch thick and 3/4 inch wide at the tips. The bow its self is a modified pyramid and is actually quite wide I think. It's two inches thick right past the handle at the fades and stays that way for maybe 12 or so inches then starts narrowing to the 3/4 an inch at the tips. Once I finish with the backing I'm doing I'll post a picture of a top view profile.

I sanded the crack down about 1/8 and inch but it still slightly shows although not bad. I filled it with super glue and am hoping it won't cause any problems.  I also put Horn Overlays on it which helped increase the length of the bow by an inch. It was 64 inches long with a 5-inch handle extended into the fades for 8 inches basically non-working. I'm planning on getting it to a 30-inch draw for safety but shooting it at 28 inches. I wanting it to be around 60-70 lbs.

I'll see if I can also post a picture of the crack, and see what you guys think. I don't think it will be an issue so if I don't have to overlay the belly that would be good. I could see myself messing that up royally.