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Building Tips and technical articles. => Building techniques => Topic started by: Jim Pollock on December 29, 2009, 02:04:06 PM
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Well now,
Here I am asking questions again......I know....What's new! The question is: Has anyone made a chart that indicates what the various types of glues weigh per ounce, or some other standard amount? If so, could you tell me where I can find it?
Thanks in advance,
Jim Pollock ???
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. . . So glue on preweighted sticks. . . .
. . .
I'll start this project tonight. H^^
I'd suggest the most meaningful method would be to start with equal volumes of each. Get the wet weight, then the cured / dried weight.
Now that I think about it, you'll probably do it your way! ;)
Larry Fulwider
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All I can say is that epoxy is a cure type adhesive, what ever you put on weight wise will still be the same. The other glues are drying type, what ever makes them a liquid will evaporate and be lighter. The CA's are a catalitic type that work with absence of air. Look at that one ounce bottle. It is only half full. An individual I know tried this with the first CA to come out. He would squeeze the bottle to get the air out and then put his finger over the hole. The last squeeze did it when he put his finger over the hole. It went off and got hot, very hot. He showed us where the blister pulled off of his finger. They way he told it, we were laughing so hard we about fell out of our chairs. To me CA is the lightest glue possible as I can build a complete plane with that one ounce bottle that is only half full.
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I think the answer to your question is not so simple.
Some materials, like very soft, light "contest balsa" might absorb more glue than harder balsa or plywood.
All glues may not have the equal strength-to-weight ratio. So with maybe a heavy glue, you could use disproportionately less of it.
The study mght uncover some heavy-but-weak glues that we would want to avoid entirely.
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And going on what Paul said, maybe a sheer test and a pull test to find out how much weight each glue joint can hold together before coming apart.
Thnaks,
Roger
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Hey Ty,
You could start a second career at this as there are enough variables to keep you busy for a few years, and by then there will be so many new adhesives on the market that you can start all over again! LL~
Bill
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Over thinking. :)
CA is the lightest.
Solvent based (including water) are middle.
Epoxy is the heaviest.
Simple. :)
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Like others have mentioned, there are a lot of variables.
For example, if you have nice tight fits, a simple application of thin CyA will fix that connection forever. Hard to imagine anything much lighter. On the other hand, if there are large gaps, then out comes the thick goopy CyA, and I bet that weighs a lot--comparatively speaking of course.
My guess is that for a normal quality fit, the glue, as long as you don't use epoxy for everything, isn't going to add a lot to the model. That job is probably given over to the finish!
Of course if you are gluing skins to foam, that does require you use a good technique to keep the weight in bounds.
There have been gluing strength measurements in most of the model mags. As far as I recall, almost all of our common glues are stronger than the balsa itself. So from that point of view, it probably doesn't matter which glue you choose.
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The CA's are a catalytic type that work with absence of air. Look at that one ounce bottle. It is only half full. An individual I know tried this with the first CA to come out. He would squeeze the bottle to get the air out and then put his finger over the hole. The last squeeze did it when he put his finger over the hole. It went off and got hot, very hot.
So, when you spray kicker (acetone) the fumes displace the oxygen and set off the CA?
Always wondered why I was getting half a bottle for full price. H^^
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Actually CA kick due to moisture or other chemicals. One reason they stick skin so well.
A simple blow (like trying to blow a smoke ring) kicks CA pretty well.
Liquid kickers are some chemical that reacts with the CA to cause it to kick. I have seen posts that a simple denatured alochol will work.
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>>One reason they stick skin so well.<<
Yea, have you ever noticed that CA will stick to your finger even when it will stick to nothing else?
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And I thought it was just me. LL~ LL~ LL~ LL~
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Like others have mentioned, there are a lot of variables.
For example, if you have nice tight fits, a simple application of thin CyA will fix that connection forever. Hard to imagine anything much lighter. On the other hand, if there are large gaps, then out comes the thick goopy CyA, and I bet that weighs a lot--comparatively speaking of course.
My guess is that for a normal quality fit, the glue, as long as you don't use epoxy for everything, isn't going to add a lot to the model. That job is probably given over to the finish!
Of course if you are gluing skins to foam, that does require you use a good technique to keep the weight in bounds.
There have been gluing strength measurements in most of the model mags. As far as I recall, almost all of our common glues are stronger than the balsa itself. So from that point of view, it probably doesn't matter which glue you choose.
Like others have mentioned, there are a lot of variables.
For example, if you have nice tight fits, a simple application of thin CyA will fix that connection forever. Hard to imagine anything much lighter. On the other hand, if there are large gaps, then out comes the thick goopy CyA, and I bet that weighs a lot--comparatively speaking of course.
My guess is that for a normal quality fit, the glue, as long as you don't use epoxy for everything, isn't going to add a lot to the model. That job is probably given over to the finish!
Of course if you are gluing skins to foam, that does require you use a good technique to keep the weight in bounds.
There have been gluing strength measurements in most of the model mags. As far as I recall, almost all of our common glues are stronger than the balsa itself. So from that point of view, it probably doesn't matter which glue you choose.
You got it exactly right Alan. How well the wood is cut determines how much glue and how much weight is added.
CyA is not as dense as epoxy, but it can add a lot of weight if the joints are not tight.
epoxies get a bad name because most people use waaay too much. It only takes enough to just wet the wood in the joint.
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Ty,
Please continue when you receive the new gram scale.
Thanks,
Jim Pollock
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Hmmmm. Lots of ifs, maybes, some times, etc here. So do I continue on or "fahgettaboutit." I have a very fine gram scale coming any day. Present scale only goes to 1 gram, but not tenths of a gram. D>K
Make bigger peices so you will know for sure there is a difference. LL~ LL~ LL~ LL~
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Hmmmm. Lots of ifs, maybes, some times, etc here. So do I continue on or "fahgettaboutit." I have a very fine gram scale coming any day. Present scale only goes to 1 gram, but not tenths of a gram. D>K
I used to reload my own ammo 10+ yrs ago and can tell you that your heat/ AC vent will play havoc with your readings. You need calm air, to zero it and get accurate readings.
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>>One reason they stick skin so well.<<
Yea, have you ever noticed that CA will stick to your finger even when it will stick to nothing else?
You know that one of the first uses of CA was as a battlefield suture?
It was DESIGNED to stick skin together.
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Not quite. It started out as a type of lens for fire control systems during WW2. When the labs techs went to take the lens apart, they couldn't. It was discovered this stuff would go solid in the absence of air. The use in Vietnam as a quick suture is of a slightly different formula, but basically the same stuff, but don't use the shop version on any wounds. D>K
How was it used as a lens?
OK< found this:
Cyanoacrylates were invented in 1942 by Dr. Harry Coover and Fred Joyner of Kodak Laboratories during experiments to make a special extra-clear plastic suitable for gun sights. Although not appropriate for the gun sights, they did find that cyanoacrylates would quickly glue together many materials with great strength.
So they were trying to make a lens plastic, but failed.
Yeah, the medical version comes from a medical supply place and costs even more than the hobby stuff.:) And I know of people who have sucessfully used hobby CA to surture wounds.
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WOW Ty,
Those results are completely unexpected by me. Heavy one is the 15 minute epoxy, but not by a whole lot
lightest is the Elmers. Also, who woulda thought that the other epoxies would have the same weight as other types of glues?
Thanks a lot Ty,
That was extremely informative!
Jim Pollock ;D
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Nice job, Ty! Thanks.
SK
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Ty,
Thanks for the all the work. Now, please do a "strength to weight" test---------the world is waiting!! D>K
Hope you are feeling fit.
Jim
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Ty,
Thanks, but I have seen you fly in the wind. n~ You do it about the same way I do, so I'll just do my own testing..... VD~
Jim
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Ty,
You need to check out kite flying with Shultzie since he's the kite master! :o
Jim Pollock D>K H^^
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Thanks, Ty. Cool project.
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Ty,
Thanks for the all the work. Now, please do a "strength to weight" test---------the world is waiting!! D>K
Hope you are feeling fit.
Jim
all the glues stick well enough to tear the wood, so the joints will all have the same strength.
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That's a simple answer, Phi.
Just wondering if the glues that penetrate the wood more than others would change anything ???
Cheers,
Jim
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Hey Ty,
I think I understand about the stuff you mentioned n~.
Actually, my comment about the strength to weight testing was a "gentle" tug on your chain :o, as was the comment to Phil about glue penetration. Some times I'm just bad VD~ VD~!
Cheers,
Jim
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Hi Ty,
Glad to see the old Chief doing a test! It surprises me to see te realtive numbers are not far off regardless of type of glue used. I think *Quantity* is the deciding factor. I have seen many examlpes of people using WAY too much glue than is necessary to get the job done.
And you point of "cleaning up the joints" is very valid. Getting all the excess out, glue, wood, whatever, is necessary, IMHO.
Thanks for taking the time!
Big Bear
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Ty,
I found some Duco Cement at Ace Hardware in Oxford, AL. It appears to have pretty identical consistency to Sigment Cement so I don't think that extrapolating it the same as Sigment would be far off from actuality.
Jim Pollock, Ole Duco finder - - LL~ LL~ LL~ H^^