Workshop Tips — Laminating Balsa Parts

Sep 02, 2014 4 Comments by

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.

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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.

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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.

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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.

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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.

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Don’t use any glue. This bend does not have to exact, it is just the first step. Now let the strips dry overnight.

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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.

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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.

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To prevent the glue from sticking, I cover the plywood base and the forming block with Great Planes Plans Protector clear material.

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Now lather up the strips with glue and then stick them all together.

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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.

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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/

 

 

Featured News, Gerry Yarrish, How-tos

About the author

Senior Technical Editor About Me: I have a lifelong passion for all things scale, and I love to design, build and fly scale RC airplanes. With 20 plus years as part of the Air Age family of magazines, I love producing Model Airplane News and Electric Flight.

4 Responses to “Workshop Tips — Laminating Balsa Parts”

  1. Dave Artz says:

    I used the same lamination process when building my Grumman Goose. Instead of wood glue, which is slow to dry, I wicked super thin CA into the layer joints with them all stacked and held in place. Much faster and seems to be just as strong.

  2. Rick Alba says:

    Great tips on laminating.

  3. Tony says:

    Instead of nails, you can also use several rubber bands

  4. JOHN ARCHIBALD says:

    STEAM FROM A KETTLE WORKS VERY WELL AND IS QUICKER IT IS SILL BEST TO USE SOME AMMONIA IN THE PROCESS BUT YOU DON’T HAVE TO LEAVE THEM IN FOR SO LONG AND I HAVE EVEN FORMED PLYWOOD THIS WAY WITH STEAM AND AMMONIA (NH4)

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