More SO Bridge Building Tips

An L-beam is more efficient than a square the same width. It is not going to hold as much, but it is going to be more efficient. An L-beam is also more efficient than a square with the same mass of wood. Of course, you have to count in the glue weight for an L-beam.Balsa, for some reason it seems, needs to be thick but low-density for pieces in compression. For tension, you have to worry about the face of the wood tearing. That is a weak spot for Balsa wood. You need a good glue that seeps into the wood to help correct this.

I don’t use CA glue, or any other super glue. I have had lots of trouble with normal super glue sticking. I do know that CA is a whole lot better than regular super glue though. However, there are no stores around where I live that sell CA glue. It is fairly expensive to order it over the internet.

I am currently using a glue called Weld Bond. It looks a lot like Elmer’s white glue, but dries completely clear and not just transparent. It is also a lot stronger. I glued several nickels together, and cannot get them apart. I had to throw them away. It actually dries pretty quickly, less than 10 minutes to get mostly hard.The only thing is, if you mess up, as in glue something in the wrong spot and have to pull it off (you realize you mess up right away), the glue has already dried enough that you won’t get a good joint anymore. You have to sand off the old glue and try again.

2 thoughts on “More SO Bridge Building Tips”

  1. Another nice thing about making L beams is since you are using long thing pieces you have more surface area for gluing. Also to give a comparison if you have a 1/4″ x 1/4″ chunk of balsa and a L beam made from two 1/2″ by 1/16″ beams the L beam is almost 10 times as strong in compression but has the same mass not taking into account the glue.

  2. Thick pieces have a higher area moment of inertia, which lets them resist buckling better.
    I don’t see what the difference between CA glue and superglue is. CA is cyanoacrylate and so is superglue, if I’m not mistaken?


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