Hatz Biplane Association

OK, I have all my jigs completed, and I am ready to start knocking out ribs. I have been looking at Wicks (seems to have a better reputation on their wood quality).

Well, I was looking at the plywood... 1/4" Birch.... only they don't have all Birch plywood... they have Birch and Popular, and Birch and Basswood?!?!? So three questions:

1) are one of these two better than the other?
2) Do I need all Birch?
2) What the heck is basswood?!!?

The specs are all the same, except the weight:
Birch/Poplar(4' x 8') 30 lb
Birch/Basswood (4' x 8') 27 lb

The same is true of the Mahogany gusset material. I was wanting to use 1/16" Mahogany, but they don't have 1/16" Mahogany... they have "Lauan Mahogany" (a cheaper grade), and Mahogany and Poplar 1/16" 3 ply... am I total looking at this all wrong?!

Also I am looking at buying about

600' 1/4 x 1/4 spruce.
3 pieces of 1/4" birch plywood 2' x 4'
3 pieces of 1/16 mahogany plywood 2' x 4'

I think that will give men plenty of "oops" room.

Any thoughts and help would be greatly appreciated!

Tre'

Hi,
I used Finnish birch plywood for some bulkheads, center section bottom, and wherever I wanted additional strength over the certified material. The thickness is metric and it may come with both "interior" glue and waterproof. You know which you want. I tested what I bought by boiling some pieces in water for a while, which had no effect. There are several sources for this product across the country. The equivalent to 1/4" has 13 plies and is awfully rigid.
The birch ply sold at hobby shops is all birch, so it is made, you just have to keep looking for a source. The mahog I have use has had a poplar core. We use the mahog because it glues better than birch. When using birch, you should scuff the surface being glued with fine sandpaper.
Al

From what I've read, basswood is more of a filler wood. Has very little strength. OK to use it for non structural applications. I used birch ply and sanded surfaces before gluing. I used the Finnish birch for stringer bulkheads and instrument panels. It's metric and has "footballs" in it. These are places that had knots or defects removed and replaced with good wood. Makes a football shape about 3" long. I just laid out the items to be cut out in a way that the footballs were nearer the center of the piece because the strength is needed around the edges more than the middle. And I didn't use any football pieces where they would show. I purchased my Finnish ply at a local cabinet makers supply house for about $25 per 3' X 5' panel. My gussets are mahog.

I emailed Wicks... a lot of people on this and other boards real seem to think Wick's know their stuff.... but I still don't know if I like it or not.

If your plans call for birch plywood then the birch poplar would be the correct way to go.

Keith Gibbs

To be perfectly honest I was really hoping for more info than this!!!

I am now thinking maybe I should just go with Aircraft Spruce... they have all birch ply?!?!?!

Any experts out there!? I'll even take an "expert"... at least they could get me started.

I am by no means an expert and tried to learn through experience and by taking other builders of different forums advise. I stayed away from using any poplar core material. I only used two suppliers and those were Aircraft Spruce and Anderson International Trading for plywood.

http://www.aitwood.com/StoreFront.Asp?W ... Desc=Ultra Thin Finland Birch Plywood

Anderson sells sheets in 60" lengths that can be ripped for shipping. Although they only sell in metric it was no issue at all and their Birch plywood has always been very high quality with no defects.

I ordered all 1/16" mahogany gusset material from Aircraft Spruce. I found that Wicks 1/4" cap strip spruce to be the best quality and more uniform in square and size then Aircraft Spruce so I ordered all the cap strip material from Wicks.

Hope this may help some but I too discovered the best way to learn is to ask many questions and then decide based on the overall best information gathered and then do my own testing to make a final decision.