Eagler's Nest
Airframes => Single Seaters => Topic started by: jrbirdman47 on April 04, 2020, 04:07:56 AM
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It has been noted that there isn't much in the way of building tips, videos, etc for the wings. I have seen YouTube videos for fuselage and tail, but not much for wings. I can't video, (And I'm almost finished building 4 wings), but I did take a lot of pictures while constructing the wings and will post them here as tips and techniques and invite y'all to do the same. It's a daunting task that can be intimidating and I hope this helps those who are starting their wing build.
The first pic: Remember to place a .8mm plywood shim under the front spar to allow the leading edge skin to butt flush against the rib on bottom.
Second pic: I clamped the front spar against a 1 X 2 stip on the edge of the bench to keep it rigid and straight. Photo shows the 1/8" plywood shim between the spar and edge strip, opposite the clamping cam, to account for the wing and strut attach pads.
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"Racking" the wing.
I didn't get a picture, but this is very important! First I used a carpenters square to draw a line vertically from the center of the wing attach fitting holes on both the forward and rear spars. (My thinking was that these two holes had to be perfectly aligned to mount a square wing) Then I used a sheet rock square with the short side against the forward spar and exactly on the lines on both spars to get everything square. ( I went through several squares at Lowes until I found one that really was square) Once this is done you can lock the spars down in place and begin glueing ribs to spars.
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Don't forget to apply downward force to the top of each rib to completely seat it before clamping/ glueing them. Some ribs may sit perfectly before applying glue, and then try to raise up in the slightest when lubricated by the epoxy. You should have about .8mm protruding above the spar to account for the thickness of the leading edge skin.
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Racking the wing, part 2:
First photo shows a piece of scrap 2 X 4 screwed to the bench behind the rear spar. With the wing spars and ribs in place, I applied moderate pressure forward to seat the ribs against the forward spar, then screwed the block in place. I did this in two places, about a third of the way down the spar each.
Second pic shows how the spar is clamped to the 2 X 4. I applied downward pressure to seat the spar in the ribs and then tightened the screw.
Note the liberal use of freezer paper under all glue joints to keep epoxy from glueing the wing to the bench. I highly recommend freezer paper!
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Aligning the rib trailing edge:
For most of the ribs, if the trailing edges aren't spaced at exactly 15 inches, it's no big deal. But for 3 places you should strive for the trailing edge of the rib to be exactly 90 degrees from the rear spar. Those being the end ribs, and the rib making up the inboard aileron well.
Start by jigging those ribs to 90 degrees from the back of the rear spar when you glue them to the rear spar. Once cured, they will likely have a slight "set" to one side or the other which you can fix when installing the wing trailing edge.
The end ribs should be straight for aesthetic reasons, and can easily be glued straight using a straight edge along the full length of the outside of the rib. But the ribs forming the aileron well will be what you base the aileron end ribs on, so if they are slightly angled, the aileron end ribs will be also.
What so important? Because you will drill the aileron hinge pin hole based 90 degrees to that rib and if it is off, the axis of the hinge pin will be off as well. Extend that axis line 6 1/2 feet, (The length of the aileron), and you can see how it will cause binding when moving the aileron.
To make a smooth, easy moving aileron you must drill both aileron pin holes exactly aligned to each other.
The photos show how I handled this. When preparing to glue the wing trailing edge on I again measured the rear spar to rib end angle and used a wood block screwed to the bench to nudge the rib into perfect alignment. Once the ribs were all where they should be, I glued the trailing edge in place.
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Now that you have those ribs perfectly plumb and square, you can jig the aileron end rib in place and drill the pin hole completely through using the aileron hinge block as a guide. In the picture, the right hand aileron, inboard rib is being drilled after clamping it to the wing rib with 1/2" spacers between them.
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Want to make that leading edge skin, (.8mm plywood), easy to bend around the leading edge ribs? I took all the plywood to be used and rolled it up and slid it into a 10" diameter cardboard concrete form as soon as I started on the wing. (A shipping tube could be used too, I just had one laying around). By the time I was ready to use the plywood it had taken the set and was easy to glue around the leading edge ribs.
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Nice. Thanks for this.. :emoji_u1f646:
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Starting the ailerons:
I jigged the aileron end ribs to the rib next door at the spacing I wanted first and prepared to drill the hinge pin hole. To ensure correct alignment I inserted a 3/8 tube, (What to do with the left over scrap from the tail?), into the hinge block and compared it to the rear spar for parallel both horizontally and vertically.
First picture shows looking horizontally toward the rear spar.
Second shows looking downward. The pencil line on the table is parallel to the rear spar.
Once I was satisfied, I drilled the hole through the rib which forms the aileron well using the hinge block for a guide.
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Glueing the aileron spar in:
I thought the aileron spar would center on the hinge/ hinge block. It did not, and doing so would have made the spar curve back toward the ends.
First picture shows 10.5 inches from trailing edge to the rear of the aileron spar where it attaches to the ribs.
Second picture shows that same 10.5 inches measured at the hinge block for proper spar placement.
Third picture shows actual spar placement on the hinge block. Note it is slightly forward of center.
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Making "False Ribs":
The lightest way I could think to help stiffen the leading edge skins, (Both aileron and wing), was to add styrofoam false ribs. Cutting them to shape was done using a hot wire stretched across the wood ribs. The wire can be purchased, but if you or the spouse has an old hair dryer, the wire inside those is perfect for such things, but trust me, you want to get permission to destroy said dryer first. Once you have the wire, build a frame of appropriate size. I built one with a 15 inch spacing for normal rib spacing, and an additional spreader for the outboard 19 inch spacing. Then just use a battery charger to heat the wire and run it across the wood ribs to shape the foam. I used the 2 amp setting and it works well. I also tried the little 12 volt batteries and had good results.
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Building the aileron well:
This is for those of you using the Iron Design plans to construct ribs:
I decided to use aluminum flashing to cover the aileron well and learned that it is very important to get the plywood as close to perfectly straight as possible. This was accomplished by marking the distance from the rear spar for top and bottom surfaces. As long as the plywood is at the mark your trailing edge will be plenty straight enough. Holding the plywood in place is tough, and this is one of the few places where I did use staples. I tried it without and..... Just nope. Clamping is difficult because the top and bottom surfaces are so far from parallel.
First pic shows trailing edge of plywood at the mark.
Second shows entire well assembly stapled/ clamped in place.
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Beautifully done.. thanks again. :emoji_u263a:
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What are the thoughts on installing the aileron diagonals with or without thin ply gussets? I am at that point building an XL wing with T88.
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Definitely with the gussets. They add considerable strength. Because the aileron is actuated from one end it has quite a twisting moment when deflected into the slipstream, so I figure every little bit helps.
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Do you have any pictures of your aileron diagonal gussets installed with the aileron LE ply?
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Hope this is what you're asking for:
First pic shows top of gusset in the foreground and bottom of the one behind it.
Second pic shows better detail of the underside.
I cut the 1/4" sticks to fit nearly precisely in the corner and add a small cleat under it glued to the spar and diagonal. This cleat gives you a surface to glue the gusset to since the nose skin occupies the spar cap. I used a disc sander to custom fit the cleats and diagonals because they angle slightly, so the beveled part that contacts the diagonal "leans" toward the inside a little. Don't think you have to go to such pains necessarily, I'm just wound tight that way.
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Nice cleat idea. Thanks for the pics.
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I'm nowhere *near* this far.. but looking ahead to get a feel for the complete job. How does everyone shape the trailing edge? I'm a machinist, not a woodworker..
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Table saw did the trick for me. Two cuts, one close then a fine cut right on the money.
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Being a machinist will help you believe it or not! I did a lot of my woodwork on the mill. My partner who is a machinist and building the other LEXL can quickly come up with jigs and ways to make parts because that's what he does with metal. He made steel templates for a lot of parts which allowed us to crank out precisely identical parts with a router. And really, any way you come up with to accomplish making a part is the right one. Pic shows the templates he made and the nose ribs/ template.
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We cut the trailing edges on a table saw. Used an 8 foot long spruce board thick enough to make two passes and get four 8 foot long pieces, (enough to complete both left and right wings) It doesn't need to be 13 feet long like the spar caps because it is cut at the inboard aileron rib anyway. I made them in two pieces and clamped them together in the middle during gluing as if it were a single piece trailing edge and it made a nice looking, straight trailing edge.
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First pic is of the bottom trailing edge gussets being glued on prior to fitting the trailing edge.
Second pic shows how the two trailing edges are clamped together during all this until the aileron is finished and you cut it out. (I just took the excess piece of trailing edge I cut off overhanging the wing tip and inverted it on the joint of the two trailing edges so it would form a parallel top and bottom for the clamps)
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Pictures really are worth a thousand words. :) Thanks again.
I'm trying to get Scott to send me .dxf files of the wing parts so I don't have to draw them. Unfortunately, my cnc mill is acting up. Probably a warranty problem.. I bought it in '85.. ::)
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Filling the aileron well:
Iron Design ribs with "K" blocks-
First I used a piece of aluminum flashing about 2 inches wide and bent the ends at such place as the flashing nested in the aileron well at a rib just perfectly, contacting the entire surface of the rear end of the rib and also the of the outside plywood forming the top and bottom of the well.
I then measured the distance between the two bends and added and inch so there'd be 1/2" hanging over top and bottom. I then used a straight edge and razor knife to cut the flashing to size. I found it easiest to make 3 pieces; an inboard piece, about 30" long, and outboard piece about 32" long and a piece to bridge those two in the middle about 15" long. (Your dimensions may vary) These sizes will work well with bench top bending brakes of 36" capacity.
NOTE: Remember to sand/ rough up the glue edges of the flashing BEFORE you bend it! (You only forget to do this once)
Bend the metal as far as the brake will allow. I had to bend it by hand a little more to get the angle right so that it would naturally lay flay on the plywood. It really takes about 130 degrees.
I installed by gluing the flashing to the rear end of the ribs first. (I used a LockTite brand glue that comes in a squeeze tube, no mixing. This stuff has a slightly elastic property I thought would handle vibration well. I think JB Weld would work great here too)
Once cured, I glued the short piece of flashing in the middle on top of the other two pieces. I used quick setting JB Weld for this part and it worked well.
Last I glued the top, and later, the bottom of the flashing to the plywood. For this I used Gorilla Glue because it expands and is kind of foamy and fills voids very well and is stickier than a politician's fingers.
If you use this don't forget to dampen the wood under the metal just before applying and use sparingly. The long nozzle on the bottle slides right under the metal and goes along it's length easily. I ran a bead about 3/16" wide and there was little mess. (My first try was a much bigger bead and resulted in a LOT of cleanup)
Also, save yourself a lot of sanding and cleanup by masking the metal to the edge and the plywood above that so that any glue that squishes out won't stick.
JB Weld can then be used to form a "fillet" where the pieces of flashing overlap and sanded smooth to make a nice, smooth transition for the fabric to rest on.
First pic is the template in place for final bending measurements
Second pic is flashing being glued to the ribs only.
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Glueing the upper and lower surfaces. I bought every clamp Lowes had. TWICE. I placed a long piece of aluminum or wood under the clamp handles to keep them at the correct angle.
JB Weld fillet after sanding.
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Needs more clamps.. :)
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Yeah, no lie! I think I have about 60 like those and 120 of the little tiny steel ones, not to mention all the squeeze clamps and bar clamps of many sizes. And there are still times where I can't do anything else because I've used all my clamps! I even had to make some clamps for specialty situations where nothing else would work. I really don't think you can have too many clamps. Except when I finish the last wing this week.......... Then I will have too many clamps.
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:emoji_u1f601: :emoji_u1f601:
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Hot wire foam cutter details:
As mentioned previously I made a hot wire styrofoam cutter using the wire from inside the wife's hair dryer. Pics below show one rig set up to cut 1" X 7.5" squares for the leading edge false ribs, sorta like a band saw would. You can stack several and cut a bunch in one pass. Second pic shows one made with a 17" opening to straddle two wood ribs at 15" spacing. Third pic is details of the build. Long through bolts allow clamping the battery charger directly to them. Para cord and a stick twisted below the frame allows for adjustment of tension. Too loose and you get poor cutting, too tight and you snap the wire.
Don't know why you couldn't use a rib as a template, fasten the foam to it and cut it like on a router table as well.
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Thanks again. This stuff is a gold mine of info.
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Tools:
Here's some of the tools that I found to be handiest and some indispensable:
Big ticket item: The big disc sander. Get the biggest/ highest power you can find. I see them on Craigslist all the time for decent prices. You will use this for final fitting almost every wing piece there is, as well as rough shaping your aluminum parts.
Next most used was the occilating saw/ sander. Never really used it to saw but holy cow can that thing sand! and get into small places too.
Indispensable: The fine cut hand saw. very fine cutting and cuts on the pull stroke. Used it constantly.
Occasional use, but sometimes was the only tool that would do the job: The mini version of above, a hobby saw.
And last, sturdy scissors of some kind. I used them to trim plywood, cut out gussets, etc. Very useful.
Drew blood with all of them except the occilating sander and scissors. Probably just not trying hard enough.
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More tools; Clamps
An assortment of what I used. Some more useful that others. The only one I would not recommend purchasing is the blue and yellow one at bottom right. Not much clamping strength and never really fit where I needed it to. Used the padded vice grip version at left instead. It ALWAYS worked. You will never have enough clamps.
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One more:
A big ticket item, but again, I see one on Craigslist for $75 right now: The scroll saw. I used it constantly for sticks, plywood, making jigs, etc.
Cheap and handy: Make yourself a glue rack like this. I got tired of flipping over bottles that were 1/3 full and waiting for the ever so slow glue to flow to the nozzle so I could squirt it out. This way the glue is ready when you are.
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Les uses these to hold the gussets in place when he's gluing the ribs
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Those are used along with staples. I didn't want to use staples, so I needed more clamping power. Also wanted to do both sides simultaneously to cut the build time down.Plus I was afraid I'd glue the clothespins to the gusset! :))
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I just ordered a bunch of them. I think I'll clamp them open and put a couple of coats of varnish and some paste wax where they clamp on the gussets. Maybe I won't glue them to the rib.. :grin:
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Those are used along with staples. I didn't want to use staples, so I needed more clamping power. Also wanted to do both sides simultaneously to cut the build time down.Plus I was afraid I'd glue the clothespins to the gusset! :))
JR this is where I saw it Les doesn't seem to be using the staples but as in all things I stand to be corrected. https://legaleagleflyingadventures.com/2020/04/04/my-rib-building-procedures/
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Sorry, Jon- My mistake. You wrote Les and my brain read "Leonard"! As with most everything Eagle, there are many ways to do things and the end result is what counts. That's the beauty of this forum!
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Today I began suffering from "empty nest" syndrome. (Sort of)
Nearly a year and a half ago a friend and I embarked on an adventure in building Legal Eagle XL's. Every day I have been home since then I started my day by going out to the shop and working to build the wings, piece by piece. Yesterday we finished the last one. This morning I went out to the shop and had nothing to do except start cleaning up, a considerable task in itself. It was kind of sad.
Pictured are the 4 wings, two in the racks above the garage door, (You get creative when you need to store stuff), and the last two on the work bench before storing them.
I have to admit that although I really love working with wood, I'm sort of over that now and I look forward to starting to work with aluminum and steel. Hopefully, in another year I'll be putt-putting around the area low and slow.
Whether you are sitting on plans and contemplating getting started, just beginning to cut wood, or deep into the wing portion of the project, I know it seems so very far in the future , but there really is a day where you are finished with the wings.
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JR "although I really love working with wood, I'm sort of over that now" . I had a good laugh when I read that line.
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It's a bittersweet moment when you finish an airplane project. Even something a simple as a Legal Eagle requires "thinking about it constantly." :)
You still have a fuselage to build, a powerplant to put together, covering, etc. Still *plenty* of things to enjoy before it's done. ;)
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All four wings finished and stored above the garage door. Just for curiosity's sake I weighed a wing before storing them and it came in at 31.8 pounds, finished, sealed, and ready to cover. (I did have protective "bumpers" installed on all the attach fittings, so it's probably closer to 31.5) The other wing likely weighs about 5.5 pounds more with the aluminum tank and tank mounting structure. Of course this was on the digital bathroom scale that routinely lies to me by overstating my weight by at least ten pounds every morning. ::)
Moving on to metal work!
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very well done, i cannot use hand drill, impossible to keep perpendicular, must use drill press or jig for horizontal drilling. I have used drill inside of pipe that was clamped(with collets).
great journalist!
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I'm an EAA tech counselor, and when asked what tools you *need* to build an airplane, I always say a drill press, band saw, and 12" disc sander.
The only tool I had when I was a kid was a Shopsmith. It got an airplane built, though.(with a *lot* of setups.)
For this woodwork on the LE, I bought an oscillating saw/sander. I'd call it necessary for all the sanding. I bought a 60 some dollar paper cutter for all the gussets. A trim router for scarfing and making the plywood parts may not be necessary, but is a great tool for that. I've always said that having the proper tool is normally about 2/3 of the job. ;)
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Why four wings? Are you building the first LE Biplane?
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LOL!!! No, building a pair of them! (But the thought has crossed my mind......)
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LOL!!! No, building a pair of them! (But the thought has crossed my mind......)
Bad idea. :)) :)) I'm already getting tired of making gussets, parts, and sanding. Two LEs would test your patience. Two LE biplanes would no doubt put me over the top. ;)
Just the same, looking at this project.. building the ribs is the biggest labor and time consumer. That's why I started there.
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You're right about the labor intensive part, and I did the ribs first as well for that reason. I estimated that I cut out over 1600 gussets, so if I never cut out another one, I'm good. I'm good on aluminum gussets too. Cut and fit tons of those for the tail feathers too. Just started on the fuselages and fortunately, not much in the way of gussets there!
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Many of you have already done, but using this base drawings of gussets, And knowing how many of each you need, you can lay out "like gussets in strips" So one cut gets you 2 or 4 or even more.. it takes a bit to get them laid out but once done...and a few blocks set up on your paper cutter, your off to the races.
I am pretty sure I cut all the gussets for one wing in less than 2 hours.. It was a larger paper cutter, (24") cut but the best part was almost NO waste. We always cut the largest first, down to the tiny ones to use up any scrape.
They were based off of the free pdf's
https://irondesigniowa.com/wp-content/uploads/2019/02/gussets-only.pdf (https://irondesigniowa.com/wp-content/uploads/2019/02/gussets-only.pdf)
Best of success.
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slight discrepancy on height of C1, gussets only says 3/4"/0.75, sheet 3 shows 1.1 inch, better to make them taller yes.
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slight discrepancy on height of C1, gussets only says 3/4"/0.75, sheet 3 shows 1.1 inch, better to make them taller yes.
yes, I would agree, and I still find it amazing after all these years, little discrepancies like this show up.. but certainly true, good eye.
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yes, I would agree, and I still find it amazing after all these years, little discrepancies like this show up.. but certainly true, good eye.
Actually, there are some big ones. :))
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I'm reviving this awesome thread with some questions. Approved Glues/Adhesives. I did a search and found a result but it went to a link to the Yahoo content which is no longer accessible.
I assume T-88 is an approved epoxy because T-88 is recommended in the LEXL plans, and I assume it can be used for all joints. Are there other approved epoxies?
I assume Titebond III is also an approved glue because I heard Leonard say it is a "really good glue" in a presentation he gave at Oshkosh this year. Are there any other 1 part glues that are approved? Since Titebond III requires close fitting joints, 100-150psi clamping pressure, and is not for use in structural or load bearing applications I assume its use is limited to gluing gussets on ribs. Are there any other approved applications of Titebond III or similar 1 part glues?
I'm happy to use these two products, just wondering if there are other approved options and making sure I understand where they can be applied.
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I think some use West systems epoxy. FWIW, I built everything that didn't have a long open time with Titebond 111. Sure, it says it's not water proof and not to be used for structural purposes, but like Leonard says, it's good glue. :) I wouldn't use it to glue the planking on a boat..(shrug)
It's hard to beat T88 for an all purpose adhesive, though.
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Actually, Titebond III is waterproof per the manufacturer's website. Titebond III webpage (http://"http://www.titebond.com/product/glues/e8d40b45-0ab3-49f7-8a9c-b53970f736af") If you select the Get Literature page there is more information especially on pages FF681 and FF1040.
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Titebond III Ultimate Wood Glue is not for continuous submersion or for use below the waterline.
Of course, if Bullet is below the waterline, I have bigger problems than whether the wings come apart.. :)