Tag: Glue

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A couple days’ work

Saturday: Ripped the CW37 parts down to the proper 1/4″ thickness. These are the strips with one beveled edge that go in the top and bottom of the aileron bay. The parts I got are 1/2″ thick, which won’t work anywhere. Ripped them all down to 1/4″ so I don’t have to do that again for the other two wings. With them cut to the right thickness, I cut one to length and glued it into the bottom of the aileron bay.

Then I discovered (or confirmed) that I’m an idiot… there were a couple of missing aileron pieces that I found in the bottom of the parts crate. Had I installed them in the first place, the little triangular braces would not have been needed. It’s no big deal; I was able to slot the nose skin support spar and get them glued in.

Today: Got the nose skin plywood glued onto the front of the wing. I think there are now about 70 or more clamps on the wing. I had planned to glue the top aileron nose skin in place, but that’s going to take some more work. I see no way to get that ply to stay attached all the way around without some sort of clamping jig. Stu and I figured out a good arrangement, but I’ll need to get some MDF, ply, or pine scrap to cut them out of. I need seven sets of clamping blocks for the nose and trailing edge, then I can use bar clamps to hold everything in place.

I also found that a few batches of glue I mixed up over the past week or two were probably not the greatest. My T88 had started getting cloudy — a sign that the resin is starting to crystallize. Some of my test pieces failed at the glue joint, albeit with a lot of force required, instead of the wood failing before the joint. I’m not really concerned about this. All of the affected glue was used for either the wing walk or adding corner blocking and gussets to the wingtip bow. The wing walk pieces are fully supported and there will be no bending, twisting, or pulling loads applied. The glue is strong, just not AS strong as what I’ve used everywhere else.

I have since tossed the syringe of clouded resin, warmed the rest of my resin supply until it’s crystal clear, and verified that test pieces now all break well into the wood rather than at the glue line. I’ve tried spruce to spruce, which tore apart well into the wood, and spruce to plywood which ripped the plywood apart.

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On a roll!

Today I did some work with the razor plane and a new sanding block to get the aileron spar and other bits to their final dimensions. I got the top side geodetic braces cut and glued in place on the aileron. Then I glued the lower aileron nose skin in place – the aileron now has, I think, the maximum possible number of clamps on it.

With that done, I got the blocking sanded down on the wingtip bow supports, and cut and glued the top gussets in place. Only eight clamps there, but I think it’s still feeling the love.

And if you’re a Star Trek: Voyager fan, this makes Seven of Nine days in September that I’ve worked on the plane.

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Wing walk skins down

Today I went through more epoxy than I have since gluing the spar caps. After some sanding and test fitting, I pre-glued the wing wall structure and the two plywood skins. Then Stu helped me clamp the edges down, and pinned down any spots that weren’t firmly in place.

As planned, I used some scrap lumber to make clamping bars. I used strips of geodetic material between them and the skins to ensure good pressure and clamped everything together with bar clamps.

With some epoxy left over, I glued the nose spar onto the aileron and did a little more corner blocking on the wingtip bow supports. With all that clamped, pinned, and taped in place it was time for lunch!

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Aileron end plates, blocking, tip supports

This morning I woke up early and couldn’t get back to sleep, so I headed over to get a little work done. I glued and clamped the aileron end plates (CW34) in place, along with the corner blocking for them. I also did a little work shaving off some of the excess plywood and corner blocking on the wingtip bow. I’ll probably just have to switch to some low-grit sandpaper to get that job done. I’d really like to get the plywood gussets cut and glued in — oh, wait, there’s more bracing for the wingtip bows to be done…

This afternoon I figured that after 8 hours or so it was safe to move on. I made another trip over and cut and installed the CW40 plywood stiffeners for the aileron and each end of the aileron bay. Then I cut and glued in supports for the wingtip bow. All of this is just the bottom side — since the wing is upside down. I’ll do the top side once I flip the wing back over, which will likely be tomorrow.

Getting two work sessions per day in could really speed things up. I think I’ll try and do more of that. I’m not thrilled with the fact that I seem to be averaging only three days a week working on this — I need to get a fire lit under things, figuratively speaking.

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Aileron spar and parts fitting

Today I got the aileron spar web cut and glued in, along with the top pieces of 1/4″ spar cap. I couldn’t get to the bottom side to clamp those pieces without some significant effort, so I left those for the next session. I also got the CW32 pieces cut and sanded to fit between the rib caps. I trimmed and clamped the CW36 and CW34 pieces in place to locate the aileron torque tube, then marked the CW32 pieces for the holes that will need to be drilled for the torque tube.

The wingtip is nice and solidly in place, so now I just need to sand the blocking and trailing edge flush so I can start installing the gussets and additional bracing.

This time around I plan to NOT screw up the same way I did the first aileron, by assuming that the holes in ANY of the parts are drilled in the proper place. As I did before, I’ll index everything off of the CW34 parts, using those to locate the torque tube, and drill or sand everything else to match them. And of course I’ve already 3D printed a pair of torque tube bearing blocks for this wing. The final parts will be milled out of UHMW or something similar, not 3D printed, but these are great for getting all the holes located without the risk of messing up a flight part.

The more I use it, the more I like my little razor plane. This thing was bought back in the 70s, I think, by my father for use on R/C airplanes that we (mostly he) built in our basement, usually from scratch. It’s a plastic body with a blade that resembled a heavy duty, oversized razor blade. The key thing I found was to use light passes, and hold the plane at an angle to the wood. It’s quite effective for shaving down spruce, plywood, and even the odd bit of end grain. It’s usually quicker than sanding.

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Bottom geodetic and false spars

Yesterday I got the rest of the compression member gussets glued in, then cut and glued in all but two of the bottom geodetic braces. Those two I couldn’t get in because of a clamp holding a gusset in place. I also got about a quarter or so of the geodetic intersections glued and clamped before running out of epoxy.

Today I finished up the geodetic members, and had enough glue left to install the false spars on the front of the ribs. I think I may have actually used all of the spring clamps I had over there… in fact I know I did, because today I took over another dozen I’d gotten for Christmas a couple years back, that had been sitting in a gift bag in the basement. I think there were a couple left today, but certainly less than a dozen.

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Top geodetic glued in

Yesterday I went over and cut all of the geodetic braces for the top of the wing. Unfortunately, I’d neglected to take over any epoxy – and I’d finished up the last pair of syringes earlier in the week. I remedied that today.

My strategy of using the geodetic braces to shim the rib cap to spar cap joint worked a treat, as the Brits say. It saved me time and trouble. Most were a close fit, and a couple pieces needed sanding to slip in snugly.

I thought I was going to use a record number of clamps, but then I remembered the wingtip bow laminations. Still, it looked like a lot of clamps.

Everything glued and clamped in place. Joints that aren’t clamped are a snug fit and don’t need it.
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Compression members in (lower left wing)

Over the past few days, I have gotten the rest of the ribs glued to the rear spar. I’ve left them unattached to the top of the main spar, as I’m planning to just run the geodetic braces between the rib cap and spar rather than use a separate shim between the cap and spar.

Today I got all four of the compression member assembles cut, fitted, and glued in place, and glued plywood gussets on some of the joints. I ran out of time before I could get the remainder of the gussets cut and glued in.

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Aileron progress

It’s been an on-and-off couple of weeks. I’ve had a persistent cold/bronchitis that has kept me away from the shop for days at a time. On days I do feel like working, I’ve got a house cleanup project that’s been sucking time as well.

This evening I got over to have a look at the aileron. I’m not thrilled with the plywood, to be perfectly honest, but I believe it will be OK. I re-glued a couple of the geodetic braces and glued down a couple of corners of the thin plywood that were loos and/or slightly de-laminating. I think the fabric would probably have been sufficient, but I want to make things as close to perfect as practical. I’ve got a list of things to do differently on the next three ailerons.

I got a few corner blocks installed to make sure the plywood stiffeners don’t flex or bow. The pans don’t call for them, but I’ll feel better knowing they’re there. I also got the ends of the aileron nose plywood trimmed and sanded flush with the ends of the aileron. There’s one more round of gluing to do, then I can use a router to put a radius on the lower front edge and it will be done. I did check the aileron travel; 22 degrees up and down will not be a problem.

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Aileron and wingtip 12/2

Today we got the ends of the wingtip bows trimmed to length, and the wingtip supports trimmed to fit. I want to get the bows routed or sanded to their final shape before gluing them in, so that’s going g to need to wait a bit. I did cut the corner blocks for both ends.

The CW36 aileron bay end plates aren’t as bad as I thought, and the holes can be modified as needed, so I glued them in place. I also cut and glued in the remaining aileron spar stiffeners and the plywood piece that will hold the bracket for the aileron connecting rod. I think that’s everything I feel comfortable doing before getting the torque type in place. I also need to stop at Lowe’s Aviation Department to pick up a little chunk of 1” PVC pipe. The Celebrity uses 3/8” slices of plastic pipe to keep the ailerons centered in the aileron bays.

I was pretty chuffed. I estimated it would take about 8 cc of glue for everything I wanted to glue today… so I mixed up 8 cc, and ended up with almost nothing left over.