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Titebond II drying really slowly

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BDB

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I'm building the modular fin can for my Binder Design Terrordactyl. I decided to use Titebond II because its strong, light, cheap and no one will see it once it's inserted into the airframe.

I applied the first set of fillets (~3/8" wide) nearly 24 hrs ago and let them sit at room temp. Since then they have dried somewhat, but they're still gooey. At this rate they won't be completely dry for 2-3 days. Is something screwed up?

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lcorinth

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I'm building the modular fin can for my Binder Design Terrordactyl. I decided to use Titebond II because its strong, light, cheap and no one will see it once it's inserted into the airframe.

I applied the first set of fillets (~3/8" wide) nearly 24 hrs ago and let them sit at room temp. Since then they have dried somewhat, but they're still gooey. At this rate they won't be completely dry for 2-3 days. Is something screwed up?

View attachment 305532
Funny you should bring this up. I use Titebond II for my LPR and MPR builds, and for gluing, it dries pretty quickly. But I'm doing a test to see how much of the glue's weight is just water, so I measured out 10 grams of glue into a cup, and I'm letting it dry completely. Once it's dry, I plan to weigh it again and see how much mass it lost.

This started two days ago. It's still pretty gooey.

With the amount it looks like you've got in those fillets, it might take a few days, I'm guessing.
 

dhbarr

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That's normal for a fat line of TB2 at relatively high humidity and/or low temperature.
 

rharshberger

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I'm building the modular fin can for my Binder Design Terrordactyl. I decided to use Titebond II because its strong, light, cheap and no one will see it once it's inserted into the airframe.

I applied the first set of fillets (~3/8" wide) nearly 24 hrs ago and let them sit at room temp. Since then they have dried somewhat, but they're still gooey. At this rate they won't be completely dry for 2-3 days. Is something screwed up?

View attachment 305532
Those are pretty beefy beads/fillets, as Titebond (any type) dries the surface skins over slowing drying time greatly on thick fillets. Did you remove the glassine from the mmt, if not that creates another barrier to slow down drying.
 

BDB

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Those are pretty beefy beads/fillets, as Titebond (any type) dries the surface skins over slowing drying time greatly on thick fillets. Did you remove the glassine from the mmt, if not that creates another barrier to slow down drying.
I peeled the glassine on the MMT, and I definitely have a skin on the surface of the fillets.

Based on my LPR/MPR builds I had hoped that these would be dry in an hour so I could finish the fillets in one night. Patience is a virtue.
 

rharshberger

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I peeled the glassine on the MMT, and I definitely have a skin on the surface of the fillets.

Based on my LPR/MPR builds I had hoped that these would be dry in an hour so I could finish the fillets in one night. Patience is a virtue.
Looks like you are in for a wait, sorry. I usually build up thin layers over several days.
 

scsager

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When wood glue penetrates the materials being joined, it makes a very strong joint. There is little additional strength added using wood glue for a thick fillet.

You can add substantial strength to the joint by using less glue AND adding SURFACE AREA. The addition of a 1/4 x 1/4 inch strip of basswood where the fillet is, makes a crazy-strong joint.

Woodworkers call this a "glue-block".

http://www.hobbylinc.com/htm/rmx/rmx887451.htm
 

Rex R

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or a 3/16" dowel, or even bamboo skewers.
Rex
 

BDB

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Thanks. I like the glue block idea. It reminds me of the fin pocket method for internal fillets. I seriously considered doing that on this build.
 

Kallahan11

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Titebond's outer layer will dry and create a thin layer that prevents the rest of the glue from drying. I would scrape the fillets off and make them much thinner, it may take days to dry, or even never dry thoroughly.
 

tightwad

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Besides using the block method, I have papered joints for strength and I even have used light weight cloth to reinforce the joint. Yes, it is old school, but it works and I really do not care how it looks if it is hidden from view. I have used these methods on RC planes and boats with great results back in the 60's. You could also use light weight fiberglass for strengthening joints.
 

BDB

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What would I do without you guys?! (Build crappy rockets.)

I used a plastic knife to dig out the two sets of fillets that I had already laid. Even the ones that were two days old were not completely dry. I then used 1/4" square dowel to create glue blocks. Thanks!

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BDB

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Things are going much faster now. I just applied a second set of fillets after 4 hrs. The first ones aren't completely dry, but tacky enough to rotate the fin can.

I ran out of square dowel, so I used 1/4" round dowel for this most recent set. It works much better because it fits more snugly into the groove.
 

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