Question about steam bending for an apprentice bowyer

[Pompano Joe]

Just curious, I'm in the tillering process and am still considering adding more reflex deflex to the bow(red oak self/board bow). Can this be done after it's been tillered ? Or has too much wood been removed from the limbs?

Also, how long do you steam the wood before bending? I've rigged up a large piece of pvc pipe that is taped off on both ends(after the bow is placed inside) and will stick the hose coming from a 67$ steam machine I got from Amazon

Thanks in advance,

Danny

[Pat B]

Yes, you can steam after tillering. I would suggest one limb at a time. You won't have enough time from the steam chamber to the caul before the wood cools to much to alter. Also, depending on what glue you used for the riser steam and the heat associated with it can cause a glue failure at the handle riser...and tip overlays if the same glue was used.
For a little bit of reflex dry heat might work and would be easier to control.
Can we see an unbraced pic too?

[Pompano Joe]

I appreciate the info. Man I never even would've thought about the glue melting under steam. I used tightbond 3. Would be cool to find out if steam, etc would weaken it. I'll try and get some pics of it unbraced

[Roy from Pa]

Titebond glue releases at 135 degrees.

[KenH]

Yep Titebond probably gonna come un-stuck if you steam that bow.  Heat gun will probably be better, unless you can figure a way to only steam the limbs and not the handle.   

[Roy from Pa]

I would leave it as is and make another one.

Chalk it up as a learning experience...

[Mad Max]

X2

[Pat B]

What Roy said. 

[Flem]

You could always steam the bow as you would like to and then glue the handle back on. It does not look like it is sculpted into the bow, so who cares if it comes off? I would continue tillering, steam it and re-glue the handle with some epoxy.

[Roy from Pa]

Not sure what you are looking for as far as the shape of the bow.

But in this picture all the bend now is happening just outside the ends of the riser and the rest of the limbs are flat.

The limbs look very thick also, how thick are they?

You want those outer limbs bending in a nice even arc "first", then work your way back into the end of the riser section with a very slight arc there. If the limbs bend too much into the riser, the riser will pop off.

And if the riser pops off, the bow could break there.

[attachment=1,msg2974952]

[Roy from Pa]

This the arc you want to shoot for.

Also is the bow sitting level in the tree cradle?

When I put a bow on the tree, I level the bow so the limb tips are level before ever pulling it.

[attachment=1,msg2974953]

[Mad Max]

Long strings lie
Long string to me means as short as you can get it.
Make it Nock to Nock long
 

[Roy from Pa]

Good point Mark, I forgot to mention that.

[Mad Max]

 

[Pompano Joe]

Thanks all for the info. A lot of great help on here for a newbie like me. So I steamed it and learned a pretty good lesson. The rawhide backing pealed up and needs to be removed. The handle and tip overlays are still in tact and the bow is now in the shaping jig.

[KenH]

Yep.  Backing should not have been on during tillering IMHO.  It does not affect the bending of the limbs.  That kind of backing -- rawhide, silk, snakeskin etc is primarily cosmetic and secondarily a preventer of splinters arising.  Has nothing to do with the draw weight/power of the bow.

[Flem]

You forgot to tell us that you glued rawhide onto it! That would have been good to know before giving any advice. In fact that was probably the most critical bit of information regarding whether or not to steam that you could have shared.

[Pat B]

Yeah, that would have been nice to know. You can clean up the rawhide and use it again.

[Pompano Joe]

Lesson learned. Many thanks

[Eric Krewson]

Make a tillering gizmo if you don't already have one.