Storing balsa wood

I have a couple of top notch kits that I may not be able to get to anytime soon and want to store them so that the wood stays straight.

http://www.clstunt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=7296&forum=DCForumID1

http://www.clstunt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=7742&forum=DCForumID1#6

Cy

Which sounds a little bit to me like 'molding' the balsa into a straight position. In other words, binding it into straight bundles as it's waiting to be use has the same--if considerably subtler--effect as wrapping soaking wet balsa round a form you want it to maintain.

I don't know how much water is in balsa when you get it from the supplier or how much comes out while you store it, so I don't know how strong the effect would be of the balsa assuming a shape while drying out.

I have seen wood in the hobby shop that is free standing vertical that has remarkable warpage.

Which leads me to one of those thought experiments.

We all know that soaking wood and then forcing it into a postion and letting it dry can get it to assume a shape. There is also the notion that you can build stress and twistage into a ship by adding wood that later dries or whatever. Ed Southwick in his article about how to build the Skylark makes the remark that you want to cover the bottom of the fuselage with the cross grain balsa BEFORE you attach the stab, because the act of gluing that wood on will twist any alignment you have in place between the stab and the wing.

So it occurred to me that if one had a lot of jig to hold everything in place, why not soak (or at least wet) all the compontents of a wing, stab, whatever, jig them up into position and let them dry out. One might tack a few critical joints together to establish corners and what not if the jig needs it. But all the parts are in place wet and then allowed to dry out and essentially 'settle' into the configuration you want them in. Then there are no stresses in the framework to relieve themselves out as twisted control surfaces.

I realize this sounds rather Gary Weaverish, but I'll risk that just to get some thoughts on the notion.

This is, of course, the kind of idea you have in Arizona, where the only thing we have to say in defense of the climate is that 'It's a Dry Heat."

This evolved from the construction of my most recent wing a Super Chief, where I build up the ribs, spars and LE/TE sticks on a jig. When it came time to sheet the leading edge back to the spar, I soaked my sheeting and taped it in place on the structure to date, which--still being held by the jig--I used as a form to pre bend the leading edge sheeting into shape for gluing in place. It was not a super accurate form job like you might get putting the LE over a foam buck. But it served to preset the sheets in relation to the ribs so that I did not have do deal with much resistance when it came time to pry them back, still hinged by tape at the spar, lay down my glue in a hurry and simply bend them back into the position they had dried in and tape them back down to attach them.

Then I began to think about the curved sides of the fueslage, the warped sticks I've seen in kits and at the hobby shop and the tales of balsa twisting under finishing as some 'build-in stress' relieved itself during finishing.

So why not 'mold' every part a little by wetting it, assembing the structure in a jig and let the whole shebang dry to a crisp before tacking it all together with CA?

Just a thought while I wait for the 'monsoons' to actually produce some rain...

Cy

Ron B.
F4Fguy

Little by little ,you're learning ,grasshopper............
but,forget the CA and double glue with aliphatic or, better yet,Ambroid.If you pre glue and let it dry before final assembly,it won't shrink and cause the dreaded "skeletons".

Ron B.

P.S. WARNING!!! Hobby shop balsa is pre-warped by a special process designed especially for RC,it is not intended for the use of real modelers.Unauthorized use may lead to weight addiction and subsequent inability to fly a coherent pattern.Please report any such use to the proper authorities.

Ah, so.

>but,forget the CA and double glue with aliphatic or, better
>yet, Ambroid.

Double glue.

I've always heard that glue you put on the outside of the joint is just weight you are adding to the airframe, with no gain.

>If you pre glue and let it dry before final
>assembly,it won't shrink and cause the dreaded "skeletons".

So the complete procedure might be:

Soak the wood.

Jig in place and let dry.

Dissassemble dry, formed jigged parts

Pre glue all joint areas with a thin coat of glue to seep into the wood and provide a base.

Reassemble on jig and confirm alignment.

Glue during reassembly?

What, big grasshopper are the dreaded "Skeletons"?

Cy

>>If you pre glue and let it dry before final
>>assembly,it won't shrink and cause the dreaded "skeletons".
>
>So the complete procedure might be:
>
>Soak the wood.
>
>Jig in place and let dry.
>
>Dissassemble dry, formed jigged parts
>
>Pre glue all joint areas with a thin coat of glue to seep
>into the wood and provide a base.
>
>Reassemble on jig and confirm alignment.
>
>Glue during reassembly?

In truth there is strength.

>What, big grasshopper are the dreaded "Skeletons"?

See the wisdom in ripples and waves in Post#9779.

Ron B.
F4Fguy
Follow the Tao.

There is very little that has not been discussed on the site over its short life--other than the Builder of the Model Rule, which no one seems to want to talk about.

There's a bit of a trick to running the search engine, though, and I'm not sure how it performs on a slow connection. I find it times out on me the first time. I suspect, however, that it caches some of the search code or criteria and will often return a good string of links if you are persistent. I often just expect the first search to time out, relaunch it when it does and then glean through the results for the best. I figure if I take the time to do the search once and place the results in a post, then that much time spent will be multiplied by all who follow for a while who want to know the same thing.

This is such a fantastic repository of wisdom that someone ought to sit down and generate a section of static threads (i.e. threads you can't add on) that contain links to the best of a series of searches on specific issues that seem to keep cropping up and leave them lying round as a sort of Best Practices FAQ on the varous subjects.

How much castor in the fuel for my old engine?

How to pitch/balance a prop?

How to use PolySpan?

The best of Al Rabe.

Etc.

Anyway, you are welcome.

Now there is a page that serves as a menu on storage of balsa for the next guys to read.

Cy

So don't suffer the learning curve. Embrace it. (So to speak.)

There's material in the archives that should get you though a half dozen mistakes by just reading, down to the point where you can probably do reasonably well on your own.

I'd not do the tips or compound surfaces like noses and cowls with it. But otherwise, slathered on shiny side up with several floated layers of thinned dope after having been shrunk properly with a heat gun--the stuff is close to bullet proof.

Learning curves just ahead:

My learning curve

Application Methods

Critique

Shiny side Up!

Rigidity

Fuzzies

With Brodak dope

Cy.

I can't help you with the kits, but if you have any really nice 4 - 6lb wood there is one very good way to deal with it:

1) Bring it to my shop.

2) Place it on the shelf with my wood.

3) Go home.

I find this method quite satisfactory.