Newbie Q's

[Nearly-There]

Hi All

I've just anodised my first few items and have had success and failure at the same time. I'm thinking my success maybe down to luck but I'm unsure. I'm using a constant current power supply, worked out my surface area then used the 720 calculator to work out the amps and thickness required.
I set the part in the tank then set the amps on my power supply, I notice the voltage drops over time.
Q- Is this is normal as I have built up a thickness?

I then decided to place 4 parts in the tank. I worked out the individual surface area then multiplied this by the number of parts going in the tank.I noticed only one part had small bubbles coming from it so turned the power supply off, took the parts out and checked my connections. I placed them back in knowing I probably had some coating already. Again only one showed bubbles again I checked my connections and put them back in the tank.
Only one part still showed bubbles so I left them this time. By the time I took them out they had been in the tank for 1 1/2 hours at 3amps. All parts were going to be coloured 2 red 2 blue. The 2 blue came out really good although they were not in the dye as long as my 1st attempt as more anodise had been grown. The red- well here lies the problem one came out an interesting shade of pink and the other darker than a good red wine. I had noted which
part had shown bubbles in the ano tank, this is the one which turned out darker, it also has a very rough finish. Although this doesn't show in the picture very well. The bad red part is the small circular one sitting on top of red another part which I previously anodised

Q- Why did 1 part grow very little, 2 parts be ok and 1 part grow too much an
Is this problem just bad connections?

Parts placed in sealer, first thing I notice is a chalky residue on the fume balls,
I assume this is sealer evaporating with the water ?
When I remove the part it dries very quickly because of the heat, this leaves a chalky residue on the part and looks dull. I wash it with distilled water and unless I spray it straight away with WD40 the dull chalky finish stays. Please see pics, the red parts are two different parts anodised at different times.

Q- I am not washing this enough, why does this happen?

All of my tanks and solutions are new and I have been very careful not to contaminate any of them by making sure all parts are very well rinsed before the next stage. I have made sure my parts are away from the plates, that I have good agitation in Ano and Dye tanks.
Ano tank is heated to 68 degrees although this rises slightly during the process. My acid ratio is correct.
I was supplied an airstone to aggitate the water, not a good idea it fell apart after sitting in the Ano tank for 2 days, the solution in the Ano tank has since been replaced but after the above parts were anodised. Parts are held with welding rod, clamped through the tank bar.

Having said this I am really happy with the good parts, they are of a better colour than we have ever had done by our anodising shop they even feel different due to better sealing.

I know this is a massive post but I though it best I give a little background to my issues.
Any advice will be greatly appreciated.

[Nearly-There]

Some more pics:
Blue parts, these didn't come out dull it's just the photo.
Red- This is what the parts look like if I don't spray loads of WD40 on them, the darker edges are from the WD40 which I sprayed on the topside which can be seen above.

[Nearly-There]

This is the circular part before anodise, again polishing is something I am fairly new to.

[acidrain]

The bubbles aren't really an indication of anodizing... sometimes they bubble, and sometimes not.
You need agitation...yeah, the air stone is a joke... make a PVC pipe that goes across the bottom of the tank with a small hole drilled at the part locations. Bigger bubbles are better.
As for the parts turning out differently, you might of lost connection. A good way to tell if something is/has gone wrong is to make careful notes. I've anodized hundreds if not thousands of parts, and I always do this. I use a dry erase board with a chart and just fill in the blanks. Basically, make a chart that keeps track of time, tank temperature, amps and volts. If you see the volts suddenly jump, or start out too high, that is an indication of lost connection. The result will be the three parts with good connection will take dye very well, but might have dissolution from over-anodizing.
When sealing, always pull the parts out and immediately dunk in water. Don't let the sealer dry on the parts as you know what happens.
It sounds like you have a good grasp of the process. The only thing I would suggest is to try going with titanium wire, You can make some inside and outside clamps that hold really well for not much more that a couple of runs of disposable aluminum wire. 3' x 1/16in type I, II Ti welding rod is about $3 each. 1/8in is about $3 per foot.

[Nearly-There]

Thanks for the response. Being new to this I had set myself up with check sheets so I didn't forget something I made notes on everything. I think I need to perfect the connections.

We came across another issue today which I hope you can shed some light on.
We tried to anodize a new part with a section of weld around the diameter , all including the weld had been polished to a mirror finish so no weld could be seen. After being in the desmutt we noticed the mirror finish had turned a bit "milky", the mirror finish had gone. The item is a circle with a few holes protruding from the outer edge. I used 2 of these to hold the part so I had 2 rods connecting to the tank bar. Half way through the anodize time I noticed patches of discoloration around the protruding holes including the holes which were not held. My air bubbles were directly below the part.
After closer inspection these areas are now brass colour They follow the same pattern on both sides of the circle. The weld now shows and it looks really bad.

Any ideas ??

Thanks

[acidrain]

Probably didn't get all the prep chemicals out of the holes before ano.
Try this:
Prep and polish your parts normally (strip, rinse, de-smut, rinse, dry, polish).
Use lacquer thinner to get every bit of buffing compound off. Pay special attention to the holes. Use a toothbrush and small bottle brush if possible (the drug store sell really tiny ones for washing measuring syringes).
Degrease in your heated SP degreaser for only a few seconds, and immediately dunk in your rinse tank. Check for water break, and repeat if necessary. Once they pass WB, spray rinse the parts and especially the holes.
BTW, there is a good chance the welds will not look the same as the surrounding areas unless they were done using the same alloy filler rod.