Elastic Launched Glider B

[NewSciolyer]

Looks like Guru and FF have replaced their wooden fuselages in exchange for carbon fiber rods.

[Nathanfrommars]

Is there any possible to remove super glue and rebuild some parts? I tried the super glue remover but ending up destroying the part because the connection part is thin. What do you do if some part are glued but you need to disconnect it? Is that possible? Or just build another one? Thanks.

[bjt4888]

Nathan,

It depends. What parts are you referring to.

Also, a good practice to consider is to use just as much glue as needed and not more. If your joint is setup with minimal gap, then very little glue is needed. We apply glue with a double pin that places very small drops. You can use thinned duco cement for some joints and duco joints can be easily separated using acetone (recommend that acetone is used by an adult only and that material handling specs are followed).

Good job asking questions. Keep building and testing.

Brian T

[Nathanfrommars]

Nathan,

It depends. What parts are you referring to.

Also, a good practice to consider is to use just as much glue as needed and not more. If your joint is setup with minimal gap, then very little glue is needed. We apply glue with a double pin that places very small drops. You can use thinned duco cement for some joints and duco joints can be easily separated using acetone (recommend that acetone is used by an adult only and that material handling specs are followed).

Good job asking questions. Keep building and testing.

Brian T

Thank you, Brian. I just bought the green tube Duco cement. Is that the thinned Duco cement you mentioned? Or do I need to thin it? How? Thanks.

Nathan

[jander14indoor]

Right cement, but not thinned as you buy it. Testor's balsa cement also works. I thin mine with dope thinner, acetone will also work. I have a couple of small bottles with needle applicators. I fill them 1/4 to 1/3 full with cement from the tube, then add the thinner. Then it takes a while to mix. Shaking isn't so useful as constant turn over.
Be careful with ventilation and handling. Both are nasty stuff to breath and both are easily absorbed through the skin. Outdoors or a proper chemistry vent hood. Chemical resistant gloves. Splash proof safety goggles.

Jeff Anderson
Livonia, MI

[bjt4888]

Nathan,

Sorry to not answer your question today. I’ve been prepping for a team of high school students that are building Wright Stuff airplanes in my shop this weekend.

I can send you an answer tomorrow.

Brian T

[Nathanfrommars]

Right cement, but not thinned as you buy it. Testor's balsa cement also works. I thin mine with dope thinner, acetone will also work. I have a couple of small bottles with needle applicators. I fill them 1/4 to 1/3 full with cement from the tube, then add the thinner. Then it takes a while to mix. Shaking isn't so useful as constant turn over.
Be careful with ventilation and handling. Both are nasty stuff to breath and both are easily absorbed through the skin. Outdoors or a proper chemistry vent hood. Chemical resistant gloves. Splash proof safety goggles.

Jeff Anderson
Livonia, MI

Jeff,

What brand of dope thinner do you use?

Thanks,

Nathan

[bjt4888]

Nathan,

Needle applicator bottles like this:

https://www.amazon.com/bottles-stainles ... op?ie=UTF8

Acetone works fine to thin, but follow Jeff’s instructions for handling. After I add thinner, I stir with a length of thin basswood or a bamboo skewer. Yes, the skewer that you can get in the grocery store for cooking kabobs.

Sometimes the plastic collar on these bottles and the attach point for the metal is loosened by the acetone. When this happens, I pull the metal tube partially out and put one small drop of medium viscosity super glue into the gap and push the tube back in to its seat. Holds fine. To keep the tube from clogging with dried glue, I slide a piece of wire all the way in so that it projects into the bottle about 1/4” and pokes through the rubber cap. For an 18 gauge needle (strangely enough, they seem to measure gauge by the outside diameter of the tube), a 1/32” wire should fit well. Last two maintenance items. If the bottle sits for awhile after using, a drop of partially dried glue will settle on the inner tip of the wire. Unscrew the cap and wipe this drop off the wire before pulling the wire out of the tube. If you forget to do this, you will pull this partially dried glue into the tube and plug the tube. You can fix by running the wire in and out a few times and passing a drop of acetone through the tube. Thinner glue will thicken over the course of a day or so. Add a little acetone to thin to the correct consistency again.

My team uses thinned duco for the fin to stab joint and the stab to fuselage joint only. We use CA on every thing else except foam. Apply CA in very small amounts with a double pin applicator. We use Weldbond for the foam to balsa joint (again, very small amounts of glue applied with the edge of a toothpick). Glider national record holder, Kurt Krempertz put me onto the Weldbond; works great; longish working time and dries somewhat flexible and holds foam to wood as tight as epoxy.

Brian T

[jander14indoor]

What he said!
Dope thinner, whatever brand the hobby shop carries typically.
Around me it has usually been Sig dopes available. https://sigmfg.com/
I've never used their dope, but the company has a good reputation, Brodak sells dope to hobbiests. https://brodak.com/finishing-products/d ... -dope.html
Note, dope comes in two major varieties, Nitrate and Butyrate. The thinners are sold separately, and it is relevant to dope finishes, but I'm not sure its relevant to the balsa cements we use.

KEY, the balsa cements we are discussing, Duco, Testors, etc. are a VERY different adhesive system than Cyanoacrylates (superglue or CA), Epoxies, Urethanes and PVA glues. Each of those is essentially one way. Yes you can dissolve some of them, but they aren't the same after and cannot really be reused. These balsa cements are basically a plastic that is sticky when dissolved with the right solvent, drys quickly, hardening and retains a high adhesion to a range of surfaces. Key for this purpose, it can be redissolved and re-used/re-adherred essentially infinitely with the proper solvents.

Oh, and the bottles I use are similar to those, but with a metal cap that doesn't have the issue of loosening the tube. Where I got them from is out of business, but a little quick googling for precision oil applicator found this example among others https://www.classicshaving.com/products ... applicator
Still needs that wire to prevent clogging that tiny nozzle.

Jeff Anderson
Livonia, MI

[Nathanfrommars]

Brian and Jeff,

Thank you for all the details about how to use the balsa cement. I may go for Acetone for thinner first. The dope things sounds not that easy to manage to me.

Thanks,

Nathan