notenoughtime

I crashed my GP super decathlon and destroyed half a wing. I was wondering how you can replace the leading edge of the wing. I can't seem to find the right LE material to match and the plane is out of production I think. I thought about running the ribs all the way to the front of the wing (I can get the right curve this way) and using a thin piece of ply along the leading edge for reinforcement (inserted into the front edge of the ribs). Then I was going to sheet the whole leading edge to get the right curve. Any thoughts or help would be appreciated.

CP140

I finished my second (tree ate the first) 4*40 not that long ago. The leading edge for it is a square balsa stick which fits into notches in the leading edges of the ribs. You then have to sand the balsa stick to give it a rounded surface. Not too difficult... just a bit of a pain.... I've also resorted to this to replace a chunk of the leading edge on a LT40 ARF. I cut new "half" ribs(from the spar forward), notched them and then glued them to the still sound portions of the ribs. Insert a balsa stick in the notches and sand to something sort of round. Would something like that work?

Tired Old Man

My Feedback: (1)

If you still have pieces of the original leading edge, then you have a pretty good idea of what the shape, depth, and thickness should be. It is not uncommon to have to shape your own leading edges, especially if you are a scratch builder. You may need to laminate two pieces of wood together and sand them to shape, but it's not that much work. Just make sure everything is straight.

Dsegal

The secret is to buy a MasterAirscrew razor plane (about $5). You will not easily create a leading edge by sanding. Use the plane and then sand with a long sanding block for final shape. One of the greatest tools ever.

MinnFlyer

My Feedback: (4)

I would also go with a rectangular block and sand to shape. It's really not as hard as it sounds.

notenoughtime

Thanks for the advice, I don't know what I'll use yet but it gives me some ideas. Probably have to sand the le to match.

Dsegal

> I would also go with a rectangular block and sand to shape. It's really not as hard as it sounds <

I would argue that it takes very littlle muscle effort to draw a plane along the leading edge vs. a lot of energy needed to grind away wood with a sanding block. And a big factor is that the shavings from a plane can be picked up easily and dropped into the wastebasket while a sanding project spreads dust all over the worktable which is a pain to clean up.

pete913

I'd buy a little Stanley modeling plane and get it close , then sand it. I think these planes are still available, although mine is probably about 20 yrs old. Try one and you'll never use a razor plane again.

CafeenMan

I have a great razor plane that I don't think you can buy any more, but razor planes are wonderful things. Sureform planes work well as long as you quit soon enough because they will leave some deep gouges. In other words, you can't plane as close with one as you can a razor plane.

Never sand when you carve (or plane). If you must sand, start out with 80 grit to take off the bulk of the wood quickly.

BTW - somebody makes a leading edge sander but I can't remember who. I would never buy one of these because it will be the wrong shape for every airplane you ever build.

MinnFlyer

My Feedback: (4)

Geeze guys don't be so literal!

I meant CARVE and sand to shape.

Flypaper 2

I use a Little David plane bought back in the 60s. Uses industrial razor blades. If you come across a used one, grab it, as they're not made anymore as far as I know.

stuk_at_work

My Feedback: (111)

In addition to the planing and sanding steps described in earlier posts, a trick I also use is to lay a 1-2 inch piece of masking tape along the length of the leading edge sheeting "just" behind the leading edge that needs shaping. This helps prevent gouging the sheeting if I make a less than accurate pass with the sander.

Once the leading edge is pretty close, I use the "shoe-shine" method to smooth the whole thing out. Starting with a sheet of 150 grit sandpaper with one end held in each hand and your wing held in place (probably with your knees!) loosely roll the sheet up and down the length of the wing as if shining a pair of shoes. After a couple of passes with the 150 grit, start again with 220 grit, and keep going until you are satisfied. BTW, the protective tape is not needed for these steps.