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Laminating balsa

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Will Hinton:
I would use finishing resin.  Spread it on then try to scrape it off, using the remaining film as your adhesive.  Weight it down good and then let it cure  and you should have a piece of very, yes, very stiff 1/8.
However, I agree with just procuring some "real" 1/8 and saving the 1/16 for another time. S?P

Ken Culbertson:
I am building Endgame IV entirely out of 1/16.  I have done quite a bit of laminating using cross grained 1/16 and also .3mm CF sheet.  I have found that slow cure CA spread on like you would finishing resin really works and sets up for use in about 30 seconds.  Really strong on the CF.  Probably heavier than scraped resin but not enough to really matter.

Ken

Dave Hull:
I would agree with Colin's method. I have laminated a number of pieces with excellent results. I'm not sure about creating entire sheets of 1/8" that way, but I don't doubt it can be done.

For example, I laminated a LE and TE set for a mid-sized I-beamer. The TE was 3/8" by 1/2" laminated from 3 pieces of 1/8". That results in two gluelines. The resulting TE stock was a bit over 43" so that I could trim it down for this elliptical wing.

The weight of the glued-up blank (no shaping or sanding) after fully drying was 20.0 grams; the prepared wood prior to glue-up was 19.1 grams. With proper control of the glue thinning the weight gain of this method is negligible. But don't expect to slather on full-strength Titebond, then add enough clamping pressure to balsa to achieve a proper glueline, and thus keep weight growth under control. That is not a viable method. You will crush the balsa trying to get there.*

As far as the warping, I clamped the TE to a piece of aluminum angle and let it fully dry. It is straight. Better than a single piece with one caveat--you will be sanding a glueline. With the thinned glue, this isn't near the "rubbery" experience you might be expecting. I didn't have a problem with it.

My suggestion would be to try a sample or two. Tune your methods up. See if you are happy with it.

Dave


*--there are also a lot of guys who will tell you that you can't use Titebond to glue plywood doublers to a profile fuselage. That it never dries. That the gooey mess will allow the fuselage to "let go" under engine vibration. That's nonsense. The issue is that there was extreme excess of glue used, that it was not thinned, so no reasonable amount of clamping was going to allow squeeze-out, and the moisture migration was going to take a long time. And by then, these guys might already have paint on it so where is that water going to go? When gluing things together, the methods make a huge difference in the results.

Dave_Trible:

--- Quote from: Will Hinton on March 30, 2024, 02:47:49 PM ---I would use finishing resin.  Spread it on then try to scrape it off, using the remaining film as your adhesive.  Weight it down good and then let it cure  and you should have a piece of very, yes, very stiff 1/8.
However, I agree with just procuring some "real" 1/8 and saving the 1/16 for another time. S?P

--- End quote ---
+1.....I usually use laminating resin I have to mold props since it's very thin and spreads easily.   However any good slow set epoxy spread to nearly dry then the pieces weighted down flat overnight.   The bigger problem with any glue that requires air to cure is that sheet lams do not allow air in.  I can remember stripping off plywood doublers from a profile to replace oil soaked motor mounts.  The airplane was several years old.  The glue-in this case model cement-Ambroid_ was still wet if more than 1/2" in from the edge.   Without air the cement OR white glues are just as if you left them in the bottle.   Using resins that do not require air to set is the way to go.

Dave

Tim Wescott:

--- Quote from: Dave_Trible on April 02, 2024, 10:21:23 AM ---+1.....I usually use laminating resin I have to mold props since it's very thin and spreads easily.   However any good slow set epoxy spread to nearly dry then the pieces weighted down flat overnight.   The bigger problem with any glue that requires air to cure is that sheet lams do not allow air in.  I can remember stripping off plywood doublers from a profile to replace oil soaked motor mounts.  The airplane was several years old.  The glue-in this case model cement-Ambroid_ was still wet if more than 1/2" in from the edge.   Without air the cement OR white glues are just as if you left them in the bottle.   Using resins that do not require air to set is the way to go.

Dave

--- End quote ---

Ambroid and yellow glues will dry just fine as long as you give them time.  I've laminated 1/2" thick fuselage blanks from 1/4" wood using Titebond II.  Get it glued up Sunday night, let it stay under weights for a week, build the plane as I get time -- everything works fine.

But I am by no means a fast, production-line builder.  I'd give a fuselage like that a month to fully dry before I sealed the solvent in with dope.  For me, that just happens naturally -- if you're blessed with the abilty to build faster, be sure to plan ahead.

For 1/8 laminated out of 1/16, I'd use Ambroid and let it dry for a week.  Or, maybe I'd use finishing resin.

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