Double the wood, half the weight!!!????

emilyshangg
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Double the wood, half the weight!!!????

Postby emilyshangg » Thu Mar 01, 2018 8:39 pm

Yoooo Anyone know where to buy the ULTRA LIGHT wood?
Before you ask, yes I have tried SIG, National, Specialized, Amazon, and I'm checking out f1d.biz.
But somehow, those that are winning have wayyyy more wood on their tower than I do, and are half the weight. What the phlorque am I missing?
I'm just about to plant my own balsa tree and harvest my own sticks so... any other ideas? ANYthing would help!! Thanks!

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Re: Double the wood, half the weight!!!????

Postby Crtomir » Thu Mar 01, 2018 9:57 pm

Specialized Balsa http://www.specializedbalsa.com/ has really light wood. You can select the density range you want. This is from their website for balsa sticks:

•Extra Light Balsa at (6 or less pounds per cubic foot) is 100% extra.
•Light Balsa at (6-10 pounds per cubic foot) is 100% extra.
•Medium Balsa at (10-14 pounds per cubic foot) is 100% extra.
•Heavy Balsa at (14-19 pounds per cubic foot) is 100% extra.
•Extra Heavy Balsa at (19+ pounds per cubic foot) is 100% extra.


What you want is probably "Light Balsa" unless you are trying to build one of those towers that jus barely holds the loading block and bucket.

Unfortunately Specialized Balsa did not have enough Light Balsa to fill my order, so they gave me a good deal on "Discolored" wood. I gotta say, that the I can hardly tell the difference. However, the density range is not so narrow, so I have some really light pieces (0.8g) and some heavy pieces (1.7g-2g) for 1/8" x 1/8" x 36" sticks.

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Re: Double the wood, half the weight!!!????

Postby retired1 » Fri Mar 02, 2018 12:26 am

What are you looking for? sheets or sticks? I might have some that I can spare.

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Re: Double the wood, half the weight!!!????

Postby cool hand luke » Fri Mar 02, 2018 12:43 am

do you have a pic of your tower and the competitions? The SUPER light balsa from specialized is very very challenging to work with. I don't think it would be worth attempting. how much do your towers weigh? what about glue, how much of your weight is glue?

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Re: Double the wood, half the weight!!!????

Postby DarthBuilder » Fri Mar 02, 2018 1:23 am

To add to Luke’s post, it literally breaks in your fingers if you basically touch it.
New Trier 19’

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Re: Double the wood, half the weight!!!????

Postby dholdgreve » Fri Mar 02, 2018 1:50 pm

The key is in finding sticks that are both very light and very stiff... Then add to this, very straight. These are very rare... You may need to go through a hundred pieces just to find 2 or 3 that meet this criteria. This is just for the columns... We will order several ultra light sticks, then cut them into 12" lengths, then weigh them and test for strength to choose the columns we want to use.

You can lose any advantage by not being just as picky with the bracing. We cut our own from light weight sheets of 1/32" balsa

Finally, CA glue is very heavy... I've seen it make as much as 1.5 gram difference from an experienced builder and one just starting out, using the exact same density material, same design... The only difference is the amount of glue used.
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Re: Double the wood, half the weight!!!????

Postby emilyshangg » Fri Mar 02, 2018 4:16 pm

retired1 wrote:What are you looking for? sheets or sticks? I might have some that I can spare.


Thanks, no I have wood right now, and it's decent. I've just seen much better wood that is much lighter and wondered if there was another store I was missing out on.

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Re: Double the wood, half the weight!!!????

Postby emilyshangg » Fri Mar 02, 2018 4:16 pm

cool hand luke wrote:do you have a pic of your tower and the competitions? The SUPER light balsa from specialized is very very challenging to work with. I don't think it would be worth attempting. how much do your towers weigh? what about glue, how much of your weight is glue?


I already do make my towers from specialized wood and it's fine. I'm just looking for alternative options.

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Re: Double the wood, half the weight!!!????

Postby emilyshangg » Fri Mar 02, 2018 4:18 pm

dholdgreve wrote:The key is in finding sticks that are both very light and very stiff... Then add to this, very straight. These are very rare... You may need to go through a hundred pieces just to find 2 or 3 that meet this criteria. This is just for the columns... We will order several ultra light sticks, then cut them into 12" lengths, then weigh them and test for strength to choose the columns we want to use.

You can lose any advantage by not being just as picky with the bracing. We cut our own from light weight sheets of 1/32" balsa

Finally, CA glue is very heavy... I've seen it make as much as 1.5 gram difference from an experienced builder and one just starting out, using the exact same density material, same design... The only difference is the amount of glue used.


That being said, any glue ideas? Looking to try new brands.
Y'all cut your own pieces? How do you do that accurately?
Thanks for the advice and response!

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Re: Double the wood, half the weight!!!????

Postby dholdgreve » Fri Mar 02, 2018 8:24 pm

emilyshangg wrote:
dholdgreve wrote:The key is in finding sticks that are both very light and very stiff... Then add to this, very straight. These are very rare... You may need to go through a hundred pieces just to find 2 or 3 that meet this criteria. This is just for the columns... We will order several ultra light sticks, then cut them into 12" lengths, then weigh them and test for strength to choose the columns we want to use.

You can lose any advantage by not being just as picky with the bracing. We cut our own from light weight sheets of 1/32" balsa

Finally, CA glue is very heavy... I've seen it make as much as 1.5 gram difference from an experienced builder and one just starting out, using the exact same density material, same design... The only difference is the amount of glue used.


That being said, any glue ideas? Looking to try new brands.
Y'all cut your own pieces? How do you do that accurately?
Thanks for the advice and response!


The brand of glue is not that important... We use Jet, but any medium viscosity C/A glue will do... it is the amount that is so critical. Go to a Hobby Store and ask for micro-tip adapters. That will cut your glue use by up to 80%.
We buy our balsa columns in sticks, already cut, in random densities to start the season (to save money), figure what works and doesn't work and where the best trade-off is. As has been said numerous times on this forum, as the column density and weight comes down, the bracing quantity goes up. So it is up to you to figure out what that perfect balance is.
Yes, for the bracing, we buy 4" x 1/32" x 36" sheets of balsa, and strip it ourselves, so we can make adjustments infinitely in width. If we wanted to try bracing that was 5/128" wide x 1/32" thick, we could.
Dan Holdgreve
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Dedicated to the Memory of Len Joeris
"For the betterment of Science"

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Re: Double the wood, half the weight!!!????

Postby dholdgreve » Fri Mar 02, 2018 8:34 pm

Oh ya, and stay away from the accelerator if at all possible. Most will evaporate, but not all of it. what remains will add weight to your structure. And by all means, try not to remove or reglue any pieces or joints. This will double the weight of glue on that joint.

OK, I know this is really a purist, elitist thing to say... but try not to build when it is single digits outside unless your facility happens to have a humidifier. C/A glue is catalyzed by moisture in the air... when it is really cold outside, the air can't hold very much moisture. This translates to very low humidity inside as well (something less than 15%)... When the humidity gets this low it takes much longer for the C/A to set up unless you hit it with accelerator, which can add weight. Instead of using the accelerator, try heavy breathing (seriously!) on the joint. the moisture in your breath will be closer to 85% humidity because it is being exhaled at a balmy 98.6 degrees... nearly tropical! I think you'll find hat your glue will set just as fast as when accelerator is used, with no residual weight gain (of the tower, that is)
Dan Holdgreve
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Dedicated to the Memory of Len Joeris
"For the betterment of Science"

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Re: Double the wood, half the weight!!!????

Postby JonB » Fri Mar 02, 2018 8:49 pm

dholdgreve wrote:Oh ya, and stay away from the accelerator if at all possible. Most will evaporate, but not all of it. what remains will add weight to your structure. And by all means, try not to remove or reglue any pieces or joints. This will double the weight of glue on that joint.

OK, I know this is really a purist, elitist thing to say... but try not to build when it is single digits outside unless your facility happens to have a humidifier. C/A glue is catalyzed by moisture in the air... when it is really cold outside, the air can't hold very much moisture. This translates to very low humidity inside as well (something less than 15%)... When the humidity gets this low it takes much longer for the C/A to set up unless you hit it with accelerator, which can add weight. Instead of using the accelerator, try heavy breathing (seriously!) on the joint. the moisture in your breath will be closer to 85% humidity because it is being exhaled at a balmy 98.6 degrees... nearly tropical! I think you'll find hat your glue will set just as fast as when accelerator is used, with no residual weight gain (of the tower, that is)



This is an great observation that I never thought of being that we are in Florida. We live in ~80% humidity at all times so the glue always dries quickly.

Also, if your hobby shop does not have micro-tip adapters, go ask your bio (or biotech) teacher for micropipette tips. They probably have a large bag of disposable, non-sterile tips that work REALLY well for CA (depending on size of the tip).


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