raverys12

I'm in the process of building the Mike Hurley 300 extra as featured in AMA Mag. I was wondering if anyone has tryed using obeche sheeting on this size plane for the wings. I have a few sailplanes that have this sheeting and it holds up to some pretty tought antics. I also was wondering where to get the sheeting if it makes sense to use it. I'm sure one would be able to vacuum bag it with little problem. Also, what thickness would be appropriate for a plane this size ????? Your help will be appreciated.

Goggles

My Feedback: (4)

Superior Balsa use to carry this stuff but I don't know of any one else.
If you find a place, let me know.

v-snap

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I have sheeted a few large planes with obeechi. The biggest being a 101" AT-6 built to race..It wasn't that difficult and the only problems I had was the thinner airfoil where it mated with the wing saddle on the fuse. Used silicone on the wingsaddle to refit.

Looks good when done. No seems to worry about.

v-snap

raverys12

Thanks for the reply, do you recall where you obtained the Obeche Sheeting? This seems to be the problem now. I found some from a supplier locally, but it is 1/16 of an inch thick. It seems like the material on some of my purchased wing for a sailplane measures about .030 thick. Thanks again.

torque-roll-RCU

I have located some 60"x60" sheets of 1/64 3 ply birch plywood that looks like it would work. I'm not sure how many sheets you would need to do all the surfaces, perhaps 2. They sell for $45.00 each.

raverys12

I was thinking of that, using birch ply that is. Not sure about the weight, but my guess is that it is very close to the obechi, considering the thickness difference. The real question would be the weight per cubic foot difference compared to balsa or obechi. Obechi is also considered a hardwood, much the same as birch. I would think birch would be a bit easier to work as well. Obechi has a tendency to split rather easily. The other thing is shipping. Where would this be coming from? Thanks for the reply. Also, have you ever tried it?

v-snap

My Feedback: (18)

I can not remember where I got the obeechi (?) from it has been about 7 years ago.. It actually was easy to use. IF it split than tape was added to the back side prior to sheeting then removed following the cure.
I am sure the 1/64th ply will work but will be quite a bit heavier than the obechi(?).

The only thing is remember to keep it over solid surfaces. Any hollow areas will cause the obeechi to eventually split and crack.

raverys12

Thanks for the info. I measured the obechi I have on a sailplane and it was .030 thick. 1/64 inch birch woutd be .015 thick. Not sure like I said, the weight might be close. We'll have to see how it measures up. I guess I'll have to try a few experiments to evaluate the diff. materials. Thanks again.

torque-roll-RCU

I'm planning on picking some ply up and using it on a sample piece of foam. One thing for sure, you woun't have to worry about "surface dings" in the plywood. The 1/64 plywood can be rolled and sent out is a tube. I wish they made it in 4x8 sheets.

raverys12

Thanks Torque: I have another place that I can also call. They had obechi in 1/16 x 4 x 8 sheets. I know that would be to heavy to use. I'll keep you posted on my findings monday. Thanks again.

torque-roll-RCU

What was the material that covered the rear turtle deck on the Goldberg "Ultimate" it molded really nice over 3 or 4 formers. It was hollow and covered well and held up great!!!!!!!!

raverys12

Not sure! I have one still in the box up in the garage. I'll have to take a look.

raverys12

Well guys I finally got a few samples of some thin plywood from an outfit that I located. One was 4 mm (.015) the other was 8 mm (.030) respectfully. Let me tell you the stuff looks super. I'm sure the 4 mm will work instead of obechi with no problems. It contours very well. I'm going to try and order out some full sheets and experiment on one of my other foam wing I have cut. Those wings are 95 inches total and runs a quadra 42. Take care, Bob.