Balsa, types/use

[Basil]

Hi, some time ago someone pointed me in the direction of a chart/page that specifies the types of and hardness etc for various uses ie spars, wing sheeting etc etc.But it has gone astray. Can some one point me in the direction of a suitable document as I need to order some timber for a new model. Thanks in advance.

Bas

[EarlyBird]

All About Balsawood (go-cl.se)

[EarlyBird]

 

[Basil]

Many thanks Early Bird this may have been it.

Thanks again Bas

[Basil]

Sorry to be such a pain, BUT, it seems when ordering the question of hardness arises. Soft, Medium, Hard. Early birds post high lights the cuts, so select a cut  first, how do you know what hardness  to select( Hardness reflects weight and strength I believe). Is it just the voice of experience, or is there a fairly simple rule for novice  persons like me.

Thanks again Bas

[Don Fry]

Basil. Big block wood, buy light. Sheet for D sections on the wings, light or medium, leading edges, ditto, everything else, medium.

Except, if it uses balsa for wing spars, hard. 
All the weight tables I’ve seen do the grades in weight ranges, and when you buy wood it comes within the weight range, and sometimes, because normality, it’s a batch off one tree, cut one after the other, they all weigh the same, just the batch is hardish medium, or softish medium, or medium medium. 
I'm making an assumption, you build airframes in the range 1 to 10 kilos. But it’s no big deal to worry about, medium is good.

And in fairness, if I need a balsa spar, a bit of hardish medium is fine. Just be sure, that if you say, need 2 sheets to do wing D section sheeting, stick them on the scales to make sure they are close in weight, so the behave as a pair. Ditto logerons.

[Basil]

Don, makes a bit more sense now. All seems more logical. Keep it light, that corresponds to what you have said. Harder is heavier/stronger influenced by grain type.

Thanks.

[kc]

If you order from Balsa Cabin then if you look under the 'Contest Grade' section you will find they also list C Grain sheet.   So you could get C grain or the lightweight Contest grade at extra cost.

It's always worth ordering a few extra sheets so you can select yourself.   Cheaper than paying for another lot of postage if you need some more for any reason.   Like everything it probably won't ever get cheaper!

 

Digital kitchen scales make it easy to select the lightest balsa.   Put a container on the scales so the balsa clears the worksurface and use the zero or 'Tare ' facility to remove container weight.  

Consider ordering spruce instead of hard balsa for wing spars in medium to large models. 

[Basil]

Kc, thanks for your input. What is 'Contest grade'.

Bas

 

[Don Fry]

I don’t own any contest grade. It’s a carefully selected wood, fine grain, light. Very nice stuff. Not cheap. Beloved by contest winning free flight types. Too posh for me. C grain is a cross grain cut sheet, used for ribs as it’s more bidirectional in its bendability. 
Didn’t know it is still available, so now I know. Next wood order to Balsa Cabin.

[Basil]

Thanks for the info.

Bas