Super Big Bertha construction tips?

[BEC]

Two words - cheap headlamp! One of the best non-intuitive tools in the rocket shop, especially as I get older and need mucho light to do detailed up close work.

I have one of these by my workbench. It is often the flashlight in the mouth when doing this sort of thing (fillets or some repairs from the top). Much easier in a SBB than an Alpha.




I was using the other one of these to make sure I got the bores of several of my recorders evenly oiled yesterday.... but I wasn't trying to spread oil and light it at the same time, so I didn't need to hold that one in my mouth.

Isn't Tacky Glue grabbier than something like Elmer's Glue-All? Less moisture, thicker consistency quicker drying (and, presumably, grabbing). It might still be slow-grabbing compared to TBII, I suppose.

No, it's not. That its thicker does seem to suggest that, but after searching for a glue that I could use for group builds of regular Alphas (without getting the motor mounts stuck in the wrong spot), regular Alleene's, not the fast or the clear, did the job. Now when I do builds, especially for the Museum of Flight's programs, that's what I insist they get. And the Alphas hold together just fine.

Alleene's Tacky is one of four or five water-soluble glues that I have where I build rockets. Regular Elmers, TBII, TB thick and quick, and one like Pacer Forumula 560 (which is a substitute for the long-gone Wilhold RC-56) are the others.

You can still use Bernard’s three step technique - it’s the traditional way we’ve done it and, even though it can be a bit messy, works well. I use PVA glue (Elmer’s, TB, Aileen’s) rather than epoxy - the bonds are stronger than the materials being joined and it’s much easier to clean up with cotton swabs/paper towel on a stick than epoxy. But epoxy or polyurethane glues work fine too, do some trial runs on some scrap tubes and see which works best for you.

Yeah, it's messy. But paper towels and water are all one needs to clean it up. No alcohol like for epoxy. I have no idea what you could clean up polyurethane glue with.

 

[samb]

...

Yeah, it's messy. But paper towels and water are all one needs to clean it up. No alcohol like for epoxy. I have no idea what you could clean up polyurethane glue with.

Scraping and sanding is the only way I've found. When used on motor mounts and couplers (internal) I haven't had a big cleanup issue. Does Aleene's shrink like Elmer's and other PVA based glue? You can sometimes see a nice little "pucker" or wasp waist on thin LPR body tubes where the centering ring joint is caused by that shrinking effect. Ask me how I know.