A little progress XL H-58

[jrbirdman47]

I never sanded the Birch plywood, and when it came time to remove a few gussets I can attest that they were STUCK! Only way to remove them was with a router or sand them off. 

That being said......... Just don't glue them on where they'll have to be taken off! I found it easier to designate each rib a position on the wing and build it accordingly. Some need partial gussets, like where the compression strips and mounting hardware go. Some have plywood attached where a gusset would normally go. Think about each rib being built and save some trouble.

[Chuck in Indiana]

Thanks, I've been looking at that. I think there are only 4 "normal" ribs on each wing. I've used most aircraft glues except resorcinol.. and was a little skeptical about the titebond III. I've been using T88 since the 90s..but..I hate it. It's messy and wasteful. At any rate, I tested the Titebond III. First, no sanding, light glue pressure, and 12 hours time. It pulled wood fibers, (the main thing) but I could peel the parts apart. Next was the same with 24 hours drying time. Same scenario. I realize that the gussets are loaded in shear, and would have been fine.
The last test was with both the spruce and the ply sanded, and I destroyed it trying to get it apart. I'll post a picture if the cleaning lady  hasn't pitched them.

[Kamcoman77]

Here is a Word file containing some notes I wrote on rib building for a friend. They are based on using the IronDesign LLC wing ribs. There may be some errors, but it helped my friend when he was planning each rib build.

[Chuck in Indiana]

Thanks, Keith.. that's awesome.

[Chuck in Indiana]

 
Pulled off the Delrin pressure plates this morning.. the glue stuck to them a little. Thought, "Uh oh." Had my tack puller at the ready in case I'd glued it to the jig, but it just lifted out. Note to self.. paste wax on the Delrin, too.

I found my glue test pieces. The first is no sanding, 12 hours drying time. The second is the same with 24 hours drying time. What I did was put the cap strip in the vise, hold the plywood with duckbills, and try to peel the ply off. I got it done with both, but they pulled wood fibers.. the acid test.
The one on the right was with sanded cap strip and plywood. Trying to peel it broke the ply. Took a chisel, lifted up the back, put a square piece of steel against the edge and gave it a few whacks. It's not coming loose. 
I'm *not* being alarmist here. If you built your ribs without sanding, they'll be fine. I just remembered from where I built a Baby Great Lakes in the 60s that used mahogany gussets that they didn't need to be sanded. It was considered "good practice" to sand birch.

[jrbirdman47]

Beautiful rib! You're using T-88, right? That's what I used, (Without sanding), and there was no way to remove them without destroying the wood. Believe me, I tried. But after cutting out 700 of the buggers by hand, the last thing I was gonna do was sand them. 

Very nice work! Keep us all posted.

[Chuck in Indiana]

Beautiful rib! You're using T-88, right? That's what I used, (Without sanding), and there was no way to remove them without destroying the wood. Believe me, I tried. But after cutting out 700 of the buggers by hand, the last thing I was gonna do was sand them. 

Very nice work! Keep us all posted.

Thanks! I'm trying to do as nice a job as you did. 
No, I'm using Titebond III. It's by far the easiest I've ever used.. and apparently strong enough.
I started this project for *something to do* during the enforced staycation. I mentioned before, that I'm a machinist.. not a woodworker, so I've been buying woodworking tools for this job. One was this:
https://www.amazon.com/Rockwell-RK5132K-Sonicrafter-Oscillating-Accessories/dp/B01HD4EOTS/ref=pd_rhf_ee_p_img_1?_encoding=UTF8&psc=1&refRID=DP02FFHV080V7TVGZ1E1
It makes *really* short work of sanding those gussets.. and.. it gives me something to do. 

[Kamcoman77]

Beautiful rib! Did you decide not to put the last vertical in? IronDesigns did not show it on his drawing but Leonard did. A lot of guys are going back and adding the vertical to make the aileron a little stronger.

[jrbirdman47]

My plans didn't show that last vertical either and I didn't notice until the wing was essentially finished. I posted about it and it was discussed here:

https://www.eaglersnest.com/forum/index.php?topic=2062.0

My fix was to glue a 3/4" wide piece of 1/8" plywood across the cap strips at that location. My non-engineering brain thinks it is of comparable strength and weight.

[Chuck in Indiana]

Hmmm. I *was* going to build the wing like the Iron design drawing.. but you guys have convinced me to go ahead and put that little piece in there. What's a few more sticks and gussets?

[jrbirdman47]

Chuck, my only real concern was that shrinking the fabric in that area might cause it to collapse slightly, however, some in the discussion held that it wouldn't do that either. I was looking for a cheap and easy way to peace of mind that did not include making more gussets to augment the hundreds of thousands it seemed I had already made for 4 wings, and that's why the plywood addition.

[Chuck in Indiana]

Well my thought was, "I've seen lots of ailerons of that size without it." Just the same, if everyone is putting them in, I will, too.(shrug)

[Chuck in Indiana]

3 7/8 ounces.

[Chuck in Indiana]

Chuck, my only real concern was that shrinking the fabric in that area might cause it to collapse slightly, however, some in the discussion held that it wouldn't do that either. I was looking for a cheap and easy way to peace of mind that did not include making more gussets to augment the hundreds of thousands it seemed I had already made for 4 wings, and that's why the plywood addition.

As the NFL says, "Upon further review.."  I drug out my Pietenpol drawings, and the last vertical member in Bernie's rib is 11 3/4 from the trailing edge. As far as I know, they don't have a problem.. and are a real speed demon, to boot. 

[rfeenstra]

Chuck, tell me about that Sparton radio in the background.  Is it original or a repo?  If it's original, is it for sale?