eucalyptus for a bow

[Bill Tell]

I have a house with a eucalyptus wood floor and they left me like a whole box of extra boards.  Well I got to thinking that maybe I could make a backed bow out of one of them.

Does anyone know if this is a good wood to use for bows or anything about it?

[Pat B]

I'd say give it a try. I've never use eucalyptus but it would be worth trying.    Pat

[Bill Tell]

I have never built a bow befor so I thought I would try it on this wood since I don't really have to worry about messing it up.

[Pat B]

Some eucalyptus is soft but others are quite hard, from what I've heard. Try one with a simple cloth or brown paper backing and see how it goes.   Pat

[Bill Tell]

The stuff I have is very hard.  Looks like a red mahogany with a nice grain.   The one board I have the growth rings are perfect in the end.  I will have to go up to the fabric shop and pick out a nice white nylon.  I think that would end up being pretty clear wouldn't it?

[Pat B]

I think silk or linen would be better but none of them will be clear. Possible thin deer or goat rawhide would be as clear as you could get with a natural backing.  If the grain is good, you may not need a backing anyway. I would add a backing for insurance but that could be removed if the bow turns out well.

[Bill Tell]

Thanks I will try to find some silk or linen then.  You don't know me.....  I better go with the added insurance.    

[canid song]

i would advise backing aswel; i haven't used it for a bow yet [though i've thought about it many times] but i've worked with eucalyptus otherwise, though only invasive california species, and it's been pretty hard but brittle.

the thing about such wood is that there are so any eucalyptus species that they propbably demonstrate the entire range of wood properties between them.

[Glenn Newell]

Being a chippy I have worked with eucalyptus all of my life and I have made hundreds of selfbows out of many of the species of eucalyptus, most of them have been unbacked. Lots of eucalyptus species are very good for flooring, like spotted gum, red box and turpentine. The problem with the flooring you have is that it will be very dry and probably brittle so it might be safer to back it as has been suggested. Some species if eucalyptus makes fantastic selfbows and some don't, it's just a matter of trying it, and the correct limb design helps a lot as well.
The growth rings you see in the timber are just that, growth ring and not true grain as eucalyptus is even grained and you need to split it or use a grain detctor to find how the grain is running, but normally you can just plane the board flat and go from there for the back of the bow, you can sight the grain if you have a close look at it...Glenn...

[Bill Tell]

Glenn,

Wow some great info.  I love this place.

What type of limb design would you recommend?

I was figuring on a flat design with some pretty wide limbs.

[canid song]

flat and wide certainly seems best for brittle woods. less compression puts less tension per square inch, increasing the area instead.

[Glenn Newell]

Bill with the timber being so heavy I wouldn't go any wider than 1.5 inches, I make most of mine around the 1.25 inch mark and I like the holmegaard and Andaman Is. design bows and stretch them out to 66" long, I modify the dimensions to suit the timber but they work well. I like to round the belly and back a bit and round the edges as well, just seems to make a quicker shooting bow and takes less set as well.
 
I have posted this photo before but the bow is grey ironbark and it is 1.5 inches wide, this bow has only ever taken half on inch of set, going any wider has it's down side as the limbs can become too thin fron back to belly...Glenn...

[Bill Tell]

Glenn thanks for all of the advice.  I am fired up now.  Nice pic too.