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Water tight seal with high voltage?


#1

Hi everyone,
My name is Tito Jankowski, I am working on a DIYbio project to create a gel electrophoresis kit for new biologists. A good friend from high school, Scott Torborg, recommended this site to me. I’m interested in knowing if voltage will break down a watertight acrylic seal.

On a very simple level, we want to make a rectangular box, about 10"x6"x4", with no top, using laser cut acrylic pieces which we glue together. For the gel electrophoresis experiment, we fill the box with a liquid buffer and run a voltage across the buffer. We run between 100-600 volts through the buffer for about 1 hour for each experiment.

I’ve been told that at these voltages, microscopic flaws from the laser cut will propogate and compromise water tightness. Is this true? Any thoughts on this issue?

Here’s a link showing instructions for building a DIY gel electrophoresis box:
learn.genetics.utah.edu/content/ … elchamber/

Thank you,
Tito Jankowski


#2

Hello,

A big issue is that laser-cut acrylic will not have precise 90-degree edges: they will be slanted a bit, because the beam cuts something like a cone out of your material. To make a box, you’ll need to use enough glue to fill in the cracks. You can’t just use the acrylic bonding agent mentioned in your link; instead you’ll need something thick, like silicone aquarium sealant.

We don’t really know, but we have never heard of this kind of crack propagation, and we think that if you can get the box sealed well enough there shouldn’t be any problems. The voltage is across the entire length of the gel box, so the electric fields won’t be very high anywhere except right near the electrodes.

This sounds like an interesting project - good luck!
-Paul


#3

Thanks for the tips, Paul. I appreciate your quick response and I’ll look into aquarium sealant.

I did a bit more research on the cracking issue - turns out it’s not related to voltage, but happens with all laser cut acrylic according to people on another forum. The people in this thread found that cracks in laser cut plastic happen even without gluing, and are accelerated by solvents. I included one of the relevant posts below. Does this issue sound familiar to you?

Thanks, Paul!
Tito

[quote]Hi everyone!
I’ve been laser-cutting acrylic parts for a year now, mostly for sign letters. Up to now, I used double-sided tape for putting together my work.

Recently, I was asked to make acrylic displays to protect some collector items, basically boxes with an open bottom. I laser-cut the parts in 1/8’’ acrylic and used methylene chloride (a solvent) to glue them. To my surprise, all the smooth, laser-cut edges would immediately crack in contact with the solvent.

After research, I learned that laser-cut acrylic edges are brittle and under a big mechanical stress, and will crack with solvents or alcohol… unlike routed or sawed edges. Wow, this is a big drawback no one told me about!

So now, I am looking for a bubble-free, clear glue that will do a nice job without cracking the laser-cutparts… I was thinking about trying Weld-On #16 glue. Anyone as any advice?

Thanks!
Fred[/quote]