Bill,

Please go to the Classic Pattern forum and look up the thread "A few ideas to chew on". The latest ideas discuss one way to make built up balsa wings. This set of ideas deal with a wing that will look more like a foam cored wing, with minimal to no bay sag.

I don't know how the Park wings are made but I would bet that he uses 1/16" balsa sheeting and a minimum of ribs. That works great for plastic film covers since they hide all the surface flaws.

If one wants to "glass n' paint" these wings, it might be a stretch. The rib spacing just won't provide enough support for the sheeting and you will get what Dean Pappas calls the "starving dawg" look. The spacing I use in that build and the sheeting thickness I opted for, produces panels that truly resemble foam cored panels

If you decide to make one from scratch, it's quite a bit of work but it is also very satisfying to see your creation come in at 75 to 100 grams lighter than the foam cored counterpart per panel. And that's all "glass n' paint" because I absolutely abhor plastic film. One thing I wanted to do in that build was to use carbon tissue on the inside of the sheeting. I thought I had the tissue on hand but didn't. One thing certain, carbon inside and silkspan on the outside makes for an extremely effective composite (very light but very strong). And poking holes in the sheeting when you grab a bit awkwardly becomes much harder

Putting it on the outside you have a choice of either filling all of the holes of the tissue which kinda defeats lightness or you can cover the tissue as I have done on my new panels with another layer of paper tissue. Paper tissue, either silkspan or Esaki Jap tissue are much tighter and require a minimum of filling. Light silkspan is the lightest but is also tuff to work with. Medium silkspan has good handling and adds strength.

There are several ways these coverings may be applied. I use nitrate usually but have used MinWax oil based urethane which is slightly heavier and even used the water based acrylic once before on a foam job, as Portlandflyer is here. I like the Lacquer idea he is using to seal. I would use it to bed the covering directly onto the wood....

We can take it off line and chat directly if you decide to proceed