Diy Anodizing...

[aeroHAWK]

I like your air manifolds. I just use an aquarium air pump with the stone bubbler.

I am considering switching over to using a pump for circulation rather than bubble aeration. I understand it can be more effective. Plus the bubbles make a little mist ab0ve the tank and it'd be nice to eliminate that.

What are you using for heaters? I use a hot plate for the sealer and submersible tank heaters for the other solutions.

I'm using these for heaters:

However, I am using a hot plate for the sealer.

Oh, I almost forgot... Those are REALLY NICE parts! You did a good job with the anodizing too.

 

[jbolt]

I am considering switching over to using a pump for circulation rather than bubble aeration. I understand it can be more effective. Plus the bubbles make a little mist ab0ve the tank and it'd be nice to eliminate that.


I'm using these for heaters:
View attachment 105427
However, I am using a hot plate for the sealer.

Oh, I almost forgot... Those are REALLY NICE parts! You did a good job with the anodizing too.

I do get some splashing with the bubbler. By pump do you mean to circulate the tank fluids?

Is that a water heater element? How are you controlling the temp? My tank heaters are some that Caswell sold years ago. They had a lot of problems with the heat controllers and finally discontinued them. I must have returned 5 or 6 before I got a good set.

Thanks on the parts. The declination drive was all done on my Smithy Granite 1324 3-in-1. Fun project

Jay

 

[aeroHAWK]

By pump do you mean to circulate the tank fluids?

Yes, I have some small submersible pumps on order. I'll make a manifold to expel the fluid throughout the tank. I'm also looking at being able to adjust the flow.

Is that a water heater element?

Yes. It is a small 1440 watt unit.

How are you controlling the temp?

I have a few choices. First, I have a couple simple microprocessor based temp controllers I built from a kit. I'll likely start with them. I could also make custom microprocessor based controllers. Or, somebody pointed me to some real nice controllers that are used by home-brewers. They're inexpensive on eBay, called STC-1000.

 

[aeroHAWK]

I have a lot of balls in the air right now. But I did have the opportunity to do more with my anodizing setup today. In my previous post, I mentioned that I was getting some submersible pumps to circulate the fluids in the tanks, in favor of using the air agitation I had been using. They sat on the shelf a few weeks, but I finally had an idea that solved a few issues.

One of the issues, I haven't been happy with my heater element setup. Mostly, I haven't really had a setup.

Since I am now going to use a pump with a manifold, I figured I could mount the heater element in a larger vertical pipe in the manifold. I could then pump the fluid into the top of the pipe and down around the heater and into the branches of the manifold.


You can see the pump is attached to the top of the standpipe. The outlet is inserted into a hole in the side of the pipe. The inlet is a short length of vinyl tube beneath the pump. I made the standpipe from PVC fittings.


I turned the fittings in the lathe and glued them together. One of the fittings has a female pipe thread that matches that of the heater element, one is a cap for the electrical connection. You can also see the pump in the foreground.
This is the pump and manifold in one of the tanks filled with water for testing.


I pointed the exit holes in the manifold in different directions in the hopes of creating a relatively random circulation. As it turns out, the pump isn't strong enough to squirt much of a 'jet' out the holes in the manifold, so it didn't matter where they were pointed.

It took a few minutes for me to figure out how to prime the pump (since it isn't submerged). The heater and pump worked well! There isn't much of a fluid stream exiting from the holes, but there is clearly some circulation. I believe it is sufficient for use in the degrease tank and also in the dye tanks.

I don't believe the circulation creates sufficient agitation for the anodizing tank, so I'll be looking into a different pump for that. I am quite pleased with this for use with the dye and degrease tanks!

 

[aeroHAWK]

After testing in the tank with plain water, I discovered that the holes in the manifold were too large, so I made new tubes with 1/8" holes rather than the 3/16" of the old tubes. I also experimented with the temperature controller. Years ago, I got an electronics kit for a simple temperature controller.


I connected it to the heater element and dropped the temp sensor into the tank. It worked so well, I replaced the water in the tank with the detergent solution of the degrease tank. Here you see the temp is 57.6 degrees C (136 F).


You can see the holes in the manifold are smaller. They create much better agitation than the larger ones. I am very happy with the agitation instead of the aeration (the old way I did it), since it doesn't create suds in the detergent like the air bubbles did.

With this new setup, it took less than 25 minutes to heat the solution from room temp, to 140 degrees F (60 C). The temp controller is a simple thermostat so it doesn't hold temp like a PID controller, but for this it's completely adequate. It easily held the nominal temperature within 3 degrees C, and with some tweaking, I know I can reduce that to 2 degrees if I need to.

I will also need to control the temperature of the dye tanks so I'll need more controllers. I found these on fleaBay for $3 each so a grabbed four (the above controller was $20 and I still needed to build it).

It looks like it has the same capability as the controller above for way less money....

I'll keep you posted....

 

[aeroHAWK]

I decided to see if I could get tighter temperature regulation from the controller. I had purchased "waterproof" temp sensors as shown here:


I didn't originally trust the heat shrink tubing to seal the liquid, so I slid the sensor into a vinyl tube that I had made a plug for. I potted the probe end of the tubing with silicone.


I suspected that all this potentially thermally insulating material was a big part of the issue with controlling the temperature more tightly. So I took the sensor out of the vinyl tube to see how it would work.

Well... guess what... IT WASN'T WATERPROOF! It lasted about 10 minutes and then it was giving squirrely results. I pulled it out of the solution and the stainless steel tube fell off the end!

I filled the stainless tube with "flowable" silicone, and reassembled the probe. It now seems to be waterproof for real this time.

With the sensor fixed, I can now control the temperature within less than one degree C.