Laser Peltier cooling system Part 2.
There are a lot of ways of doing this and this was how I did it. If I was to do it again, somethings I would do differently.
The tank and outer shell plus two cans of insulating foam are needed. I’ll try to post pictures in order below.
I put blocks of 5/8” wood to allow the foam to expand at the bottom in between the shell and red tank . You need to Drill 1/2 “ holes about every six inches up and down the sides and in the bottom no matter what you make your shell out of. I didn’t drill enough and had some problems with bulging from the foam expanding. I fit checked the tank before hand and built a top for the shell with clearance for foam and tubes. The top will be screwed on.
The red tank inside the shell needed holes drilled in the top and a square cut in it. I drilled the holes before I set it in foam and washed chips out from the inside but had to do more holes after the foam had set. So I made sure to wash them out later. The square is for a float switch. This I will be hooked up to a a warning light to let me if I’m low on water. I added a vent hole also that can also be used to add algaecide without taking the lid off. The plumbing outsidewill have some tee’s in it so that I can pump water out or add to it without removing the tank from under the stand.
The foam needs to be applied in layers otherwise it will not setup. The bottom first (3/4 “ thick max) position the red tank and put a heavy weight on it to keep in place. Wait at least an hour or overnight is even better. BTW- I Put a couple of 2 x 2’s under the shell so that the excess foam could easily come out the ½” holes in the bottom.
A trick that worked for me with the spray foam was I flushed the nozzle out with acetone in between layers to avoid clogging of the can. With each layer be sure to put no more than 1 inch of foam or it will not cure correctly. Again wait at least an hour or more between those layers.
Do not over fill the wet foam and do not cover the foam/ shell with anything ( I found out the hard way). It will slow and prevent the “set”. Misting a little water on each layer is suppose to help.
I was limited to 13.5 inches height to fit under my stand so the cover I built out of wood was to fit. Holes are drilled in the edge of the cover to allow for the coolant lines and electrical wire from the float.
However you set up your shell, once the foam has set and dried completely any excess can be shaved off with a long serrated bread knife (Don’t tell the wife I used it). The foam that flowed out the ½ inch holes was cut or busted off.
The ½ Poly tubing I used came with a curve from being coiled so I had to heat it up with a heat gun at about 275F to get the curve out then quenched in water to hold the shape. It turns kind of clear when its ready to be bent. Afterwards I heated in the 90 degree angles so that I could come out the side. Next I used a old solder gun tip to mold a groove in them to help hold the silicone tubing on when it was tie wrapped.
Next in part 3 the Peltier and wiring.
