Wood Parts

[Fernando]

Can I use another kind of wood for the longerons and triangle parts? Do I have to use only Birch Plywood? I coudn´t get any birch in my country!

[Kent Ashton]

I think any dry, straight hardwood would be OK. Birch plywood is nice because it's made of thin (1/16"?) laminates , relatively dense, and not prone to warping but not absolutely necessary, IMHO.

 

Que pais, amigo?

[Big Steve]

I built my Longerons out of select douglas fir. It is stronger than the spruce called out in the plans but 20% heavier I sacrificed a couple of ounces so that I did not have to pay $100 shipping There is an article on the net that talks about different woods and there use in aviation. Do a Google search. STeve build on

[rickh]

Do you have mahogany (Swietenia macrophylla)? That should work for the longerons.

 

Is there a boat builder near? They often have high quality plywood. The plywood needs to be water proof glue, take heat (~100C), free of internal voids (knot holes), and relatively strong. Baltic Birch may be an option too, it's typically imported from Finland and Russia.

 

Rick

[Cozy1200]

I used Australian Hoop Pine as it is an approved substitute for Spruce. It was available locally and cost about $30. It was marginally heavier, something like a few percent.

[goatherder]

+1 on the Doug Fir Longerons and also the plywood. Like mentioned above, clear mahogany should work for the longerons as long as the grain is straight for the length of the wood. I wouldn't use anything with the grain running at an angle or swirly grained wood of any type, and I'd avoid the heavier varieties (like Jatoba).

 

I used "Loyds-of-London grade" okoume 6mm plywood for the firewall and also the instrument panel, F22 and F28. This plywood is used extensively in boat building. Boats take a bashing.

 

Yes its heavier than the plans material, but after all the holes are cut out of the bulkheads its not MUCH heavier, and it was available across town. (unlike that silly red foam stuff)

[Fernando]

I think any dry, straight hardwood would be OK. Birch plywood is nice because it's made of thin (1/16"?) laminates , relatively dense, and not prone to warping but not absolutely necessary, IMHO.

 

Que pais, amigo?

ARGENTINA: Maradona(god), tango, gardel y hermosas mujeres!

[Fernando]

Do I have to make a Load Test on the longerons to make sure that they are strong enough? How can I know that the longerons are really good ones?, becouse wood use to be inestable on its shapes and sometimes the wood hides invisibles failures...

[Spodman]

On the cozybuilders email list Nat is quoted as saying the longeron material is not terribly important, it is a core to put bolts through and screw stuff to. for the removable fus top the plans say you can use clear pine for the required doubler, (crivens!). Hoop pine for me.

[Fernando]

On the cozybuilders email list Nat is quoted as saying the longeron material is not terribly important, it is a core to put bolts through and screw stuff to. for the removable fus top the plans say you can use clear pine for the required doubler, (crivens!). Hoop pine for me.

Oh! Thanks that was a hopefull and helpfull answer, there´s a lot of pines here!