Any assistance would help

[Balsa Pilot]

Greetings all!

Has anyone any ideas on how to build a laminated wings trailing edge out of (3) stringers (1/16th X 1/16th). How do you shape and glue this together, and is the kind of glue really important-I was going to use carpenters glue?? The leading edge is only 2 stringers so I can see that being not overly difficult, but three stingers lamination may pose some problems. The problem with this wings trailing edge is that it is curved like that of a spitfire( actually its an Aichi Type 99 Val).
Any assistance would be greatly appreciated.

Best regards to ALL, Henry

[tom arnold]

It is messy but certainly doable. You didn't say how big the wing was but I would guess it is around 20-24"? I would lay down a piece of stretch wrap over the plan (it is waterproof) and pin down the inside stringer first dry. Then taking a brush and slopping a very slightly diluted wood glue all along the length, shove the two remaining stringers in place and pin them tightly together. Wipe up as much as you can and let dry overnight and then build the rest of the wing ahead of it.

A problem may arise if the trailing end of the rib is greater in height than 1/16" where it butts up to the laminated trailing edge. In that case you would need to make your laminations 3/32 X 1/16 or 1/8 X 1/16 or whatever height you need to make a smooth transition from rib to trailing edge. Needless to say, you need to sand the trailing edge very carefully to shape with sanding sticks or sanding blocks with the wing held firmly to the very edge of the workbench. With an elliptical wing you sort of have to work your way around the curved edge in sections and smooth out later. A Val, huh? Great and please post some pics of it.

[Bill Gaylord]

If you can get pins to hold the stringers in place and form the boundary curve, then a bit of glue can be applied from the top, laminating them together. The idea is not to push the pins through the stringers, but only use them to create the boundary. One good thing about thin CA is that it pretty much instantly locks the seams in place. The CA could be used just in spots, with more sandable glue used for the majority of the length. I'd be tempted to just fabricate the TE from sheet stock in several lengths, so that the grain runs as straight as possible for each length. Use fairly long splices to join them, for strength.

[Chris A.]

I once tried ammonia soaking 1/16th stringers for a built up trailing edge for a Spitfire. The strips became very flexible so I used a lot of pins to make sort of a fence to hold the curve until the strip dried. The idea was to see if the shape held once it was dry. So-so results (the curve didn't "lock in") and maybe not worth the odor. It was close to the needed curve so I miht try it again. The Ross book on flying models had some ideas for laminating.

[Bill Gaylord]

I'd be interested in seeing the build, once started. If I remember correctly, the Balsa Pilot had pretty good success with the P47 as a giant scale rubber flyer. Not something you see often. I cheated and electric powered the model for r/c. Nice flyer, but probably a lot more difficult with rubber power.

[Balsa Pilot]

Thanks guys, for the input. There was a thought of using sheet stock and putting them together for the trailing EDGE, but my stubborn side said, " Wait a minute, let's try it by the plans", and its a new method and more experience so what the heck, lets give it a try! I've never used CA adhesives so I think in this case I'll try the wood glue lightly diluted, and formed to shape with pins. That makes perfect sense by brushing the glue to a preset stringer and bonding them together.
I have been confused previously with a person using the same name-I've never built a P-47 yet.
Granted the results coming off my worktable aren't too bad, but I don't think I live up to that kind of praise.
This is the first time for an aircraft of this complexity with risers under the leading edge(also laminated) and several terms i've had to research to understand. All in good fun and good modelling. If you want to get better you have to try.
The Val has a 30" w/s, and both leading and trailing edges are elliptical, and therefore laminated. Currently the fuselage is drying with tail feathers just being started.
I'll be in Arizona for a week, and upon return will post some pics of the existing squadron, the attempt, along with pics of the complete aircraft and test glides. The glides wont be til spring as the snow is about three feet right now. C'mon spring!!

Thanks to all again, and happy building.

Henry

[davidchoate]

Make a template from some 1/8" or 1/4" art foam board. I think the 1/16 square will be a concern. Use 1/8"x 1/16" strips. Soak them in water. A tube shaped container with a lid is best. Like a "pipe Bomb" made from PVC. I used Elmers and Titebond wood glue, but am on an alphetic resin kick lately. I did this twice, and learned that no matter how hard You Try, ther will be indentations from the pins, but amazingly the stuff wraps around the form like a Ramen Noodle. Dont be afraid of the Glue. It's sandable, and wipeable off of excess with water. Making it wider is good caus the laminations will or may shift. You can then use the extra 1/16" of wood to sand it smooth. I may try using a stripo or pieces of a thin flat material that will not stick to wood glue to prevent pin marks, but when it is done, You, My Friend will have the lightest, and strongest tail possible. If I got it on MY 1st try. Anyone can. I usually end up having to make 2 or 3 tails at least using the usual method. If I get time I will post the pics. If I can find them in the millions of unnamed files in My Laptop. RC Groups. Pat Tritle. Any of His build threads. It's like his trademark." Bowing" He calls iot.

[davidchoate]

My apologies. Just go and look at M Fw-190 Thread. I was so proud I "accidentally" inserted pictures of My 1st lamination. Shows the patterns and all.

[NcGunny]

I soak in windex and boil my water..once boiling drop in your pieces for a bit then lay up your laminations. Also I use other pieces of wood to keep from having the pin indents. Dont believe the old wives tail about windex turning the wood blue..never yet had anyone provide me proof of actual Windex dying wood blue. I have bent cowlings out of sheet balsa and basswood without a stain in sight. Also sometimes as it dries I will resoak the area that has a tight curve with Windex to loosen up the grain even more. Mainly I use bits of square stock styrene,small washers, etc as a shim between the pins and wood.

[Balsa Pilot]

If anyone looks, thanks for all the input.

First I pinned the line of the curve on the plan so as to be ready for the wood, then,soaked the stock, (3 X 3/32nds square) for the trailing edges, in hot water, and then carpenter's
( very slight dilution) glued and placing them on the line of pins, and pinning them as a curved unit in place. Next I used flat top pins to hold all down on the board as flat as I could get them. All dries overnite into a rock solid yet very light unit which is as easy to work with as can be. Then discover I used the wrong wood (read one thing, did another), so headed to the local hobby shop to start again. At the end of the day it was way easier than I thought. Lessons learned!

Thanks again to all

[davidchoate]

I told You it was not as hard as it appeared ! You're life is forever changed .! Now You can make a light strong tail whenever You need too. Like a Tail heavy Guillows Zero 404. All You need is a template.