Here was one method being used by John Newton and Fred Anderson, documented by Fred several years ago, again, on the speed forum:
I got some [aluminum] last week for $12US at Ace Hardware in Southern California and went to John Newton’s and we made two nice "D" wings. This is a new brand product, 12"x10' rolled and taped into a 4"x12" tube and shrink wrapped... [It is] .0092" thick and a little harder than other brands. It bends and works well.
The label reads:
Aluminum Flashing
12"x10" ECON made in U.S.A.
#68-312
Amerimax Home Products
Lancaster, PA 17603
barcode# 49821 68312
John Newton is using a Locktite glue these days that squeezes out and is then catalyzed with an aerosol spray. Let me know if you need the product code.
The process is kind of like making your first burrito...The first one is real messy and a little crooked and you have to clean yourself up afterward; but it feels good when you are done...
General Procedure:
1. Get (2) 2"X4"x4' alum blocks and screw folding flat lengthwise with a 4' piano hinge
2. Cut the aluminum skin blank oversize about an inch on the TE planform
3. Open the huge blocks, place flush lengthwise to the front edge on top of your bench
4. Place your blank on top w/ proposed leading edge radius over hinge line
5. Put a 48"x2-3" x 1/8" thick steel rule on top
6. Locate its inner edge line 1/16" back of proposed LE radius
7. Clamp one block side, skin and steel rule to the bench with multiple C clamps
Do not rush the following process......
8. Bend up other block 120 degrees on first bend
9. Check the radius on LE now, then bend a little more
10. Unclamp the rule if you have to and move back steel rule, repeat gently…. Repeat gently, bending smoothly. Repeat gently, check that radius.... In order to achieve a smooth radius, you will find a way, leave it a little large at first
Finally, you will have a taco shell wing when you squeeze the trailing edges together. The leading edge radius now should be what you want when you finish. The wing will appear way [too] thick in section, like a Piper Cub, but do not flatten it yet....
11. Turn the clamp bars around and put the overcut trailing edge flash between the bars
12. Clamp the bars gently at first and press the taco into the clamp a little at a time.
13. Measure your overall chord now and massage the wing to its final dimensions. Do not ever tighten the clamps at all until you first sight down the leading edge. The leading edge will for sure, always, have some sort of bow in it, be careful here.
14. Straighten the leading edge, you can add tip wash-in here if you like, which is cool
15. Clamp it all tight, check it again real good. Get a carpet knife or utility blade (the grey kind with the blades that snap off new). Slice the aluminum flush with the blocks for your "Fresh New Trailing Edge" look. Open the blocks, throw away the scrap. [Then] clamp the "new taco" TE back in 1/4" and check for straightness.
16. Get a sharp felt tip and mark each skin surface where it touches the blocks.
17. Take it apart and then practice putting to the marks straight and clamping fluidly.
18. Take it apart again and practice clamping it straight again.
19. Practice again, it’s got to go together smooth and fast.
20. Open up the TE and sand the inside of the blank where the spar and TE glue is going. Take a walk, come back and put on some gloves and a mask
21. Apply your weird, probably toxic, glue in a controlled bead on both sides
22. Take a deep breath and assemble the whole mess and clamp it
23. Take a last look at the LE, but be quick
24. Take the catalyst and spray it down the inside of the wing
25. Make sure it's all straight, but it's too late to fix now...
26. Go to your nearest Mexican Food Cafe for 8 hours and celebrate.
Remember, the skin is still kinda plump looking? If you want to put in a spar, all you have to do is glue both sides and stick it in, then press it between boards.
The biggest problem I have had is saying 'Bueno' to a senorita at the cafe, and when I got home two days later the blocks were stuck for good...waddamesss....