Silly Q on home made chiller, improving cameraman's design

[Tim Wiltse]

I beg to differ! I have been using pieces of 6061 aluminum as my cathodes for a couple of years now. They are thin, maybe 1/16" plates. When I first started using them I would take them out after each days run to clean them off etc. I haven't taken them out of my acid in over a year I think and they are more than fine still! I do wonder alittle about the disolved aluminum in my acid mix but so far no problem. Also lead is a very "dirty" material and you have to worry about impurities in it getting into your mix. Again aluminum is heads and tails better to use than lead. As for the pump. I don't know what model pump he is using but there are many pumps of this type that area mag drive pumps, they have no steel shaft turning the rotor itself. Making them acid safe. Pumps that are acid safe use a ceramic shaft that is acid safe. They cost alittle more but it's all what you want out of what you spend.

LAter,
Tim

[acidrain]

Well, we've had the lead vs. aluminum cathode debate before, so let's not go there...
I used those pumps quite a bit when I first started out. They are typically ceramic shafts, so are safe in acid. The problem will come after a couple months in the acid... the plastic will become brittle, and crack at the impeller. For sure it will go out right when you need it the most, so either have a spare on hand, or go with a HC (high corrosive) rated little giant. I picked up a monster (220v) HC Little Giant for ~$50 on ebay.
Why don't you go the other direction? Use chilled clean water inside pipes ran in the acid tank. That would keep down the apparatus placed inside the tank.
As long as you use metal pipe as the heat exchanger, I think it would work fine.
BTW, This is how I heat my tank (with PVC as shown). It just wont work with cooling (with PVC).
Got any friends with TIG or MIG welders?

[Tim Wiltse]

That's the thing. It's a mute point if the pump in this setup can handle acid or not. All the thing is pumping will be water.

LAter,
Tim

[schema]

Originally Posted by Tim Wiltse

That's the thing. It's a mute point if the pump in this setup can handle acid or not. All the thing is pumping will be water.

LAter,
Tim

bingo, i never planned on circulating the acid, just cold water through the pipes, thus cooling the acid.

I'm going to rebuild an aluminum set up this week. I won't bother taking calculations on the PVC set up, but I will on the aluminum one. Later in the game I might tear apart a small fridge and see if I can make this thing a "set it and forget it" , instead of dumping ice in the water all the time.

I'll keep ya guys posted

[snipescastle2]

Just an idea fella's, you know those water fountains you see or use in most buildings now days? you could probably find one of those and circulate a water source via small pump to continually pump water (now chilled water) through your system, these units are mostly 110V and I would bet you can find a cheap unit at most auctions or even salvage yards. this would make a real cheap chiller considering you would only be cooling the water-vs. acid.
Good luck hunting!
Ben

[snipescastle2]

Hey Guys, here is a picture of what I am describing. There is a fitting on the back of these coolers for a fresh water supply line. If you have a small submersible pump in a tank and plumb the water from the tank pump to the cooler, then using another fitting where the fountain button/valve would normally be located to the coil in your anodizing tank. These units have 115V input and also have a thermostat installed, they run at a maximum 50 degrees F outlet Temp, the thermostat should allow the temps to be warmer. should make a stable cooling water chiller! Look for a school auction or flea market and see if you can find one there. Most plumbing supply stores may know where to buy these used.
Good Luck!
Ben

[acidrain]

That is a great idea.
I think any chilling device will work as long as the tubing is able to transfer the heat efficiently.
I can tell you none of these ideas will work with plastic tubing (been there, done that ).
A thought I had is if you used aluminum tubing (yeah, I know it will be eaten... but not for a long time) and threaded the ends using a pipe threader (had some done for free at Home Depot once ), you could use elbows and couplers available here: http://www.metalsalesusa.com/fitt.htm
and easily make heat transfer manifold. Only the parts in the tank, and at the chiller need to be metal... you could plumb it to and from with PVC.

[snipescastle2]

Thanks! I knew the 22 years I served in the Navy meant something! I used to do maintenance to hundreds of these drinking fountains, I know them inside and out. Once I get moved into my new place, I'm setting up shop and going to buy some titanium tubing or a coil made of it to run in the tank for the heat transfer. probably going to run 20 gallon cooler size tank to start with.
I picked up several large lead strips that were counter weights for something where I work to use for cathodes, and I even found a step plate made of 6061 T6 aluminum for a cathode, at least I can see which performs better.
I mostly plan to anodize aluminum Pop rivets (many of them) but also larger pieces and if there is enough interest, maybe step up to even larger pieces later.
Have a good one!
Ben