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FiXeL 08-10-2012 08:57 AM

So... I did some anodising...

Not everything turned out good... Still more to learn i have... :old:

Spider! 08-10-2012 09:24 AM


Do you have a current limiting supply? That really does make things easier. Most of the rest is learning how to handle the parts consistently (and cleanly) with your setup.

FiXeL 08-10-2012 12:59 PM

Yes, i have a current limiting supply that cost me way more than i wanted, but atleast it can go up to 60 amps, way more than i will need. Weird thing it does not allow me to set the voltage as indicated in the 720 rule calculator.. Also i've invested in titanium wire for the fixtures, and they work very well. Cleanlyness is key, and that's no problem so far. Watching all those youtube vids really payed off:

When you think it's clean, clean it some more. After that? clean some more, and to be absolutely safe... clean some more. :ROTFL: (some guy that anodised his own made fountain pens)

I've done 3 runs so far, and these parts are out of the junk box, besides my mini maglite... Had it for 15 years, so it could use a fresh anno.

Spider! 08-10-2012 01:48 PM

After reading some more on the Caswell LCD manual, I bought a little chinese 5A lab supply with current and voltage limiting. After using my bath a few times, I found the required voltage to be relatively low (sometimes under 10 volts) for low current runs (3-4 A/sq ft.). I haven't noticed the need to limit the voltage yet, but I can see how limiting the voltage in a 12 A/sq. ft. (average) run could make a difference.

I've been working around 6A/sq. ft for about 2 hours, which fits the 720 rule but is longer than what I think the Caswell manual describes. It seems a bit contradictory in places. The dye penetration has been much better with the lower current densities, compared to running 13 volts for a time to match whatever current I would get.

FiXeL 08-10-2012 02:19 PM

Ok nice, a fellow anodiser! The thing with my power supply is, that it either switches to constant voltage, or constant current. For the mini maglite i was aiming for atleast 12 volts, and 2A, but i only anodised for 60 minutes, so the layer could be on the thin side. I don't have the caswell manual, but one from a german supplier that is a bit weird... But i found caswell europe short after, so that is where i get my suplies from now.

The second run should have been run at 7,8A according to the 720 rule, but i did it at 10A - 12,1V for 72 minutes, and it turned out ok. With the maglite, i could set the power supply to constant voltage, but with the second batch it switched to constant current...

If i were to set the amps to the 720 rule, i would end up using like 8 volts... isn't that a little less? Or is amps more important than voltage?

Hobbes 08-10-2012 02:37 PM

I don't know if it was a mistake, but that gas-thru grip on the left actually looks pretty cool :thumbup:

Spider! 08-10-2012 02:52 PM

Yeah, prefer current control over voltage. I had a constant current run that ran from 6.5 to 8.8 volts on the meter. I think the ratio of cathode area to anode (part) surface may alter the voltage some. I've messed around with my acid concentrations and couldn't find a big distinction as much as new acid needs more voltage (which matched up with the idea of "breaking in a tank").

Caswell says lower current densities get larger pore sizes, but with a softer layer (fewer pores would be weaker). I used to try to track my current on a constant voltage setup, and I would exceed 12 A/sqft pretty often. It always puzzled me that some Rit dyes would work and others wouldn't. Apparently, the pore size was too small for some of the pigments.

I had to study my new supply a bit. The translated chinese instructions were not too clear. It has a current limit knob and a voltage limit knob. They both operate full time and the two LEDs tell you which limit you are hitting. I usually just crank the voltage limit well above the initial voltage and set the current for the density I need. It has been a big improvement on coloring and you can watch the voltage swing up and back down.

I've done a few splashes, but I think this winter (when it is not hot) I will try using my old airbrush for some sort of effect, if it beats an old toothbrush splatter.

ranger steve 08-10-2012 04:01 PM

Looks good. The green to silver fade turned out well.

FiXeL 08-11-2012 06:49 AM

Thanks guys! My first fade ever, and i was amazed at the result!

@ Spider!: Interesting... I thought the voltage had to be at least above 12 volts to anodise. I'll try to do a run today on lower voltage, to see if that makes much difference. I did notice that during anodising the voltage drops slightly, but this is due to the anodised layer being built up.

I had some dye differences with different parts... In the picture, the J&J barrel tip and the parts on the bottom right were dyed with the same color.. Only the barrel tip is made from 6061, and the parts are 5754.. 5754 took alot of color in... Also the red heatsink was done separatly because it reacted a little funny to the lye... It stripped in moments, and created white flocks on the solution. I think it's a lower grade aluminum, and therefore did not catch the color well. (the original part was also not very colorfull)
I haven't used Rit dye yet.. (also not sure where to get it in the netherlands) I did get some powder dye from my german supplier, but i'm only ordering caswell dye from now on.

I do the same on my power supply, only difference is that with smaller batches, it automatically switches to constant voltage, because not enough amps are drawn. With larger batches it is the same like you describe.

I have always been curious on how splashes were made, what kind of masking medium do you use? I do have caswell masking laquer, but this stuff i kind of hard to remove.

Btw, this is my power supply (and air pump):

And my tank:

It's a 9.2 gallon (35 liters) cooler that i've modified a little. The insulation was removed, and hose barbs from a computer watercooling kit were added in the sides so i can run tap water trough it for cooling. The air line was made from 12mm PVC (about 0,5") and kathodes are 3mm alu tear plate. The Anode is made from 904L stainless steel. (one of the benefits of being a machinist at a machine factory)

For security i have the whole setup in a black tub, if for whatever reason it springs a leak. All of this is also in a wooden crate with a ventilation built in:

Oh, and if you ever have a sulphuric acid spill, use this to neutralise the acid:

My battery acid supplier came with this great tip!

Spider! 08-11-2012 09:50 AM

I'm sure the Caswell dyes are much better than Rit. I have the Caswell black because the Rit black was being difficult with my constant voltage setup. The Rit dyes are just cheap ($4) to try a color out or do a single part. The Rit yellows and colors with yellow in them seem to go bad after use. I try to stick to the liquid dyes, but there are a few odd colors that I could only find in powder. I could get the Caswell kit and mix a color, but it's a bit expensive if you're just checking out a color.

You can mask with anything that survives the process. I've used rubber cement for splashes because it is viscous and makes nice runs and drips. Some of it comes off in my steamer, but I cleaned it up with mineral spirits or lacquer thinner (?).

I've masked the inside of regulators with furniture lacquer prior to stripping and it held up all the way through the process. That came off with lacquer thinner for sure. :rolleyes:

That's a nice tank setup you have. I keep mine in the garage, so ventilation is no problem, but cooling is difficult. I had a circulating ice bath on the outside for a while, but I gave that up for ice bottles directly in the tank.

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