Wings

[Brock]

Finally ran out of chores to chase on the fuslage, for now, so had no choice but to switch gears from metal to wood.  Felt good to cut a few bits of wood.  Cut once measure thrice, or is that the other way around.

[Kamcoman77]

Looking good!

[Brock]

The spar-cap tapers were easier than I thought they would be.  Cut a wedge from a 2x4, taped it to the spar-web and ran it through the table saw.  First glue tomorrow.

[Brock]

Glued up the second front spar today.  Just like Isotopes, I had to add a bit (1/8th inch) to my filler block.

Tomorrow I am going to try out the scarfing sled which was setup, today, with a Hitachi router.  This Scarfing will be a first for me.  Hope to scarf all four spar webs in one go.  There is a lot of surface area in common between the spar-caps and spar-web.  I'm begining to think it might be better to glue it with TitebondIII instead of T-88.

[Kamcoman77]

I made a scarfing jig and tried a router as my 1st choice. Either the bit wasn't sharp enough or the router speed was too slow, but the thin plywood edge at the end was torn quite a bit. I added a steel strip at the end of the jig and switched to a belt sander. Worked great. If the router works for you, it will be a lot faster. I just wasn't happy with my test scarf using my router.

[Brock]

Using the Scarf Sled for the first time was not as difficult as I had feared.  After figuring out how it is supposed to work I made a few slight mods.  First was to put a board across the top and make some wedges to hold the plywood. I also screwed a hold down 1/4" peice to keep the end of the ply from lifting.  Finally used several 1/4 slivers to guide the router sled.  I'd remove 1/4 inch after each cut this way the router was better guided and not free to go all over the place.  After the first scarf the following 7 went smoothly.

The result seemed good enough, to me, to glue.  So I glued up (t-88) the two front spar-webs.  Look forward to seeing what I have tomorrow.

[Brock]

Glue day.  Like much of this build I've learned along each step.  I started by sanding the glue joints with 120 grit then layed the web on the bench and traced the glue locations onto the web.  I put a few stapples through the web into the bench.  Mixed up 55mm of T88 then eventually another 40mm and applied it to the web with a shortenend acid brush.  Took 25-30 minutes.  Good thing working time is 45 minutes.  Now that the assembly is safely weighted and becoming strong I took time to do more research on T88.  Something I didn't know to do before hand.  What I learned is the technique of applying glue to both surfaces.  I'm not sure if I would have had time to do that without a second pair of hands.  Still thinking about this.

[Kamcoman77]

Yes, the best practice with epoxy is an even, thin coat on both glue surfaces, then check quickly for any dry spots, and apply extra, if needed. That's why I had a buddy help me by spreading the epoxy on the web while I spread it on the spar. We got an extremely even bond that way with no chance of any dry spots. I don't think I could have done as nice a layup without help. If you got a nice, even squeeze out of epoxy, you are good to go! Congratulations on your progress.