As my online Build-Along for the Sopwith Camel continues, I recently did some lamination work on the top wing, and thought it would make a good How To. This technique has been used for decades but to a new generation of RC model builders might be worth explaining in detail. Here’s how I did.
There’s nothing exotic about the technique. I use soft A-grade (often referred to as “Contest Grade”) balsa, good old TiteBond yellow wood glue and some Ammonia from the grocery store.
For the center trailing edge of the top wing, I needed 5 layers of 1/16-inch balsa and I cut strips using a straight edge. The strips are a little wider that the finished height of the wing ribs in that section of the wing.
Fill the kitchen sink with hot water and then pour in about half of the ammonia in, (that’s about 30 oz. of Ammonia to 2 gallons of water.) Open a window for proper ventilation. Place the strips in the solution and use a handy weight (like a hammer,) to hold the strips submerged for about 2 hours.
Remove the balsa strips from the sink and wipe with a towel to remove access water/ammonia. The strips will be nice and bendy at this point and I used an old engine cowling to do the first bend. Use some cloth pins and clamp the strips as shown here.
Don’t use any glue. This bend does not have to exact, it is just the first step. Now let the strips dry overnight.
Here you see the strips now have a “set” and are still very bendy and flexible. They are also still a little damp but not wet.
To form the proper shape for your model, use your plans and make a forming block to match. I used 3/4 inch pine and a plywood base board.
To prevent the glue from sticking, I cover the plywood base and the forming block with Great Planes Plans Protector clear material.
Now lather up the strips with glue and then stick them all together.
Start at the center and use nails to “clamp” the strips tightly around the form block. Don’t worry about access glue oozing out. Just wipe it away with a paper towel.
The important thing is to apply enough pressure with the nails to eliminate any gaps between the strips and between the strips and the forming block. When satisfied, place the whole thing in a warm area and let dry completely. Titebond dries quickly, but I usually leave it for about 2 days to make sure it is completely dried.
That’s it for now. To see how to work with laminated parts and incorporate them into a wing structutre, click the link: http://www.modelairplanenews.com/blog/2014/09/03/workshop-tips-working-with-laminated-parts/