european hornbeam

[sapling bowyer]

Hello guys! I have recently found that we have lots of good saplings of european hornbeam around. I have heard that this hornbeam   
is better in compression than it is in tension and bad news is that I can not cut wood large enough so that it has no crown. I can only cut saplings like 3 inch diameter with high crown. Can trapping the bow do any good? I'm also not aiming at anything above 45 pounds. Would heat treating the back do any help? I do not want to back this bow and I'm afraid of decrowning because I can run it.  Anybody help? Also looking forward for some tips.

[ajooter]

a crowned stave is already essentially trapped so no trapping required.  I don't think it is ever wise to heat treat the back of a bow.  a 3" sapling should easily yield the draw weight you are looking for without any fussing.

[wizardgoat]

if there's lots around just make some bows and see how the wood is as a self bow.
Make the bow a little bit long until you figure out the wood

[Del the cat]

Best to keep the back untouched, but if it is too highly crowned you may need to decrown it.
I think you are confusing trapping and decrowning.
I have used European Hornbeam, its hard stuff.
Del

[sapling bowyer]

By trapping, I mean making the belly narrower than the back so that compression does not over power tension. If I am right. Does hornbeam check?

[Dakota Kid]

I'm pretty sure trapping refers to the back of the bow, which means the back would be narrower than the belly. It would give it more of a crowned shape if it was flat to begin with.

[sapling bowyer]

Well than I plan on reverse trapping if that helps with equalizing the compression and tension forces. Anybody know how hornbeam behaves when drying fast?

[Pat B]

Trapping can go either way. Wider back for weaker back, wider belly for weaker belly.

[mullet]

Sounds like you already know the answer to your question.

[joachimM]

Hornbeam checks rather badly in my experience. Debark, reduce to rough dimensions, seal on all sides with wood glue (water soluble so you can wash it off afterwards) clamp the limbs to a board so it wont warp, store dry and wait a few weeks.

Trapping can be done on back or belly, generally done on the back hence the confusion.
Such rounded bows are sweet shooters but tend to be a bit slower as they are heavy (mass) for their draw weight: all the mass is concentrated in the neutral plane.

Try multiple ones. I would decrown one on the back and back it with wathever you can: sinew, sisal, bamboo, hickory, maple, ...
Joachim

[bambule]

I've build some bows out of european hornbeam. Most of them fail on the back cause the wood is so strong in compression that the back can't handle it.
Only long, narrow and leightweighted bows (~ 30#).
Backing with Hickory, Bamboo or Silk is good option for surviving.
Only two of the bows with a natural back didn't broke.

Good Luck for you

Greetz
Cord

[Springbuck]

If you can't get a wide stave, get a long one.  If you can't get a long one, get more % wood moving: make a bendy handle, whip tiller it a little,  etc...   The point is to decrease the strain felt on the highest part of the crown.  Standard rules apply.  I don't know the wood species, so reverse trapping might help, but so might a narrow design with a flat or slight rounded belly.  I had heard European hornbeam was pretty strong, so I'm surprised to hear it's tension-poor.

[bambule]

@Springbuck:
I don't think that European Hornbeam is poor in tension - it's only very strong in compression which makes it feel like weak in tension. I also don't know if the failures are really a reason of weak tension or maybe of a failure in the back. Cause of the wiggely surface you can't see it. I had success with bows which look like each others...
European Hornbeam is one of the strongest woods in Europe - with an sg about .97. It's used for axe handles and other tools.

[sapling bowyer]

Thanks everyone! I will start once I find a decent piece

[Springbuck]

 Thanks, Bambule.  That was kind of the impression I had about the strength and density.