Removing fins from a BT on purpose

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wscarvie

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Hi all,

I was *this* close, my friends. My Orbital Transport, a kit which I wanted SO badly as a child, had the booster finished and waiting for paint. It was sitting atop my fleet box, when a LARGE box from an adjacent pile slid off and into the fleet box.

On the positive side, the OT Booster broke the fall and nothing else was damaged.

On the negative side, the tube has a serious kink in it now. Bad enough that I don't think the tube can be salvaged.

I'd love to save the balsa fins. Especially the big main wing assemblies.

Can anyone recommend a way to remove balsa fins from a bare Estes BT, that have been attached with Elmers Carpenter's glue?

Thanks (he said, hopefully).
 

wscarvie

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P.S. I no longer store ANYTHING near my Fleet box. Too many hours of work in there to take that chance a second time.
 

jflis

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Here are some choices that i've used many times:

1) If the crinkle in the tube is above this fin assembly, I would consider cutting the tube just above the main fin then use a stage coupler and a replacement length of body tube. With careful sanding and elmers fill-n-finish, you should be able to hide the tube seam very easily.

2) use your razor knife to lightly score the body tube along the fin root on each side of the fin. Then begin to work the fin back and forth, weakening the fin root connection. Score a little more if needed. What you are trying to do here is pull the fin and a layer of body tube away from the tube while leaving the actual glue joint and filet intact.

hope this helps!

jim
 

n3tjm

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Originally posted by wscarvie

Can anyone recommend a way to remove balsa fins from a bare Estes BT, that have been attached with Elmers Carpenter's glue?
Fly the model on a D13... oh wait... that is a bad idea...

Nevermind ;):D
 

jflis

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Originally posted by n3tjm
Fly the model on a D13... oh wait... that is a bad idea...

Nevermind ;):D
LOL this *joke* will make far more sense after i post the pix of Doug's Praetor on a D13.... :p

jim
 

vjp

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Will -

What Jim said - if the kink is in front of the area where the
wings/fins are glued on, cut a new piece of BT and replace the bad portion.

To make a thin coupler, just take a short length of BT-50, remove a 1/8" slit, lengthwise, then use as a coupler. Since it's thin, it won't interfere with your recovery wadding or chute.
 

sandman

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OK...let's be real now!:D

Cut the tube with an Exacto as close to the fins as possible. You might have to cut outside the filets.

Now sand the root edge to remome most of the body tube from the fin. It may be difficult to get it all off but, work at it.

Carefully trim as much of the filet off as possible. A Dremel with a sanding drum would work nice but be careful!

sandman
 

wscarvie

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Hi Jim,

First of all, thanks very much!

Originally posted by jflis
1) If the crinkle in the tube is above this fin assembly, I would consider cutting the tube just above the main fin then use a stage coupler and a replacement length of body tube. With careful sanding and elmers fill-n-finish, you should be able to hide the tube seam very easily.
I'll have to look at it again. I think the damage is right where the forward edges of the main wings join the body. At a minimum, I'll need to get the forward canards off the body tube...then again, these are easily re-fabricated.

2) use your razor knife to lightly score the body tube along the fin root on each side of the fin. Then begin to work the fin back and forth, weakening the fin root connection. Score a little more if needed. What you are trying to do here is pull the fin and a layer of body tube away from the tube while leaving the actual glue joint and filet intact.
OK, I'm with you, but then what? Should I sand the remaining layer of body tube off the fin root and then proceed as normal? Or attempt to glue the layer of body tube directly to the new body tube and fillet over the whole mess?

Thanks very much, Jim.
 

wscarvie

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Originally posted by sandman
...Now sand the root edge to remome most of the body tube from the fin. It may be difficult to get it all off but, work at it. Carefully trim as much of the filet off as possible. A Dremel with a sanding drum would work nice but be careful!
Whoops! Looks like sandman answered my followup question before I even asked it.

So, I take it the goal is to just take it in stages, getting the fins back to their original state slowly. Then re-attach as normal. Makes sense to me.

Thanks, sandman.

Oh, and Doug, thanks for the laugh! :D
 

scadaman29325

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Isn't Elmers water soluble?

Maybe just rub a little water on the joint and wipe as necessary?
 

wscarvie

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Originally posted by scadaman29325
Isn't Elmers water soluble?

Maybe just rub a little water on the joint and wipe as necessary?
Elmers White Glue certainly is soluble. I'm not sure about Carpenter's Glue. I do know it's a totally different beast (some sort of resin). Anyone know for sure?

Thanks.
 

jflis

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heck, given enough time, *any*thing is water soluable... :)

I wouldn't recommend water. Enough water to loosen the glue would ruin the balsawood of the fin.

jim
 
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