Degreasing buffed part and other noob questions

[lhaddix]

I'm about to try to anodize some 6061 parts that I've buffed
with Tripoli.

They are obviously 'waxed' from the buffing compound. There is
no visible residue, but water beads on them like a freshly waxed car.

Should I go straight into degreaser, or scrub them down in acetone or
lacquer thinner first?

Also I strongly suspect SP degreaser is TSP. I considered trying acetone
followed by TSP, but if TSP is the same as SP degreaser there wouldn't
be much point.

Also the LCD manual shows the caustic etch step with anodize stripper
in one spot, but not in others. The same for acid neutralization with
baking soda before dye. Should I do these steps?

I've got an RO-DI filter system with a 50gal tank and a pump fed garden
hose nozzle. I can probably do a really good rinse between steps so I was
considering skipping the acid neutralization.

I'm worried the caustic etch will kill my buffed surface completely, but if it
improves the process I can lose a little shine.

I've also noticed the manual calls for both 4.5A/ft2 and 3.0A/ft2 in
different places. Which would you reccomend for a first try at LCD?

I've got a PC interfaced voltmeter with graph output. Whatever the current
I will go till I can see PAR has occured.

Is there any difference at all between GP plates and Al sheet for the cathode?

I'm doing a fairly large total surface area and wondered if I would be better
off nearly lining the bucket wall with sheet Al.

Thanks
Landrum

[acidrain]

I degrease with lacquer thinner first, then heated degreaser. Only dunk the part long enough to pass the water break test.

I don't know about Caswells degreaser being TSP (I doubt it), but it does dull the part, so only degrease long enough to pas WB.

Etching the part is only done when the aluminum is old and dirty. Forget about doing that if your parts are well prepared.

Neutralizing the acid after ano is something that has proven to cause problems. As long as you rinse well, you don't need it. Spray rinse first, then dunk, then spray again just before going into the dye tank. Pay special attention to the holes, nooks and crannies where acid might be trapped.

I wouldn't go lower than 4.5 CD.
6 amps per square foot works well, and is easy to calculate. That's what I suggest.

Forget about anodizing to PAR... use the 720 rule calculator. For 6 amps CD, you'll get a full 1 mil in two hours, .75mil in 1-1/2 hours, and .5 in 1 hour. Ano to 1 mil for black and dark colors, .75 for medium colors, and .5 for clear, gold, copper.

Lead cathode will last longer, but makes the bath a hazardous waste. A large cathode is better than too small.

[lhaddix]

Thanks,
That was concise and answered my questions exactly.

Do you see any problem with doing 336 sq. in. at 14A
in a 4 gallon ano tank with 2 x GP plates. I've got 12 heatsinks
I've milled and want to run them in one batch for uniformity.
How much will this heat the tank?

Would the results be better if I did several batches?

I noticed one of the sticky topics shows the proper PH
for various color dyes.

What do you use to titrate it up and down?

Landrum

[Z]

to raise the ph in dyes use sodium hydroxide
to lower the ph use acetic acid.

[stevepelle91]

Originally Posted by Z

to raise the ph in dyes use sodium hydroxide
to lower the ph use acetic acid.

I'm no expert but Sodium Hydroxide is what you use to strip anno off aluminum, even a small amount would ruin your entire run and you would have to start over again.

[lhaddix]

I was wondering about clear ammonia (ammonium hydroxide ) to
raise PH, but I have no idea if it is compatable with the process.
Even better would be a buffer solution mixed with the dye when it
was packaged.

I don't think I care too much since I'm just getting started.

I do wonder how much putting a couple of hundred watts into 4 gals of
electrolyte for 90mins will raise the temp.

Just in case I got out an old water chiller I have meant for a medical laser.
It can run down to 4C. I found a Titanium coil made out of 12' of
8mm tubing on Ebay from some guy in Riga Latvia for only 40 bucks.

(should cost $300-$600, but I've always heard Ti is cheap and plentiful
in the former soviet union.)

I'll pump 4C water through that and see what sort of cooling I can get.
If it can keep up with the heat input then I might rig up either a 3 way solenoid
or 2x 2 way to shunt the flow past the coil or force it through and drive that with
a Ranco temp controller to get thermostat controlled cooling.
I've used the same chiller to water cool a CCD camera dissapating 40W
to a constant 4C hopefully it can do even more. If it can't overcome the input
I'll just run it open loop to delay the inevitable.

Check out the Ranco controller
It's what hobby plating tanks crave.
RANCO ETC-111000 Microprocessor Temperature Control: RANC1 Climate Doctors
These are pretty cool for the price.

I've got that engineer disease that makes me want to resort to massive
overkill, this is combined with a love for anything colorful or shiny.
Somebody kill me.

[radmaximus]

I use regular old amonia for adjusting ph with no problems, and muratic acid for lowering the ph. Both are cheap and easy to find.

Rad

[acidrain]

Your cooling idea is great!
Nothing better than cheap AND overkill in my book.

[destroyer125]

Originally Posted by lhaddix

Just in case I got out an old water chiller I have meant for a medical laser.
It can run down to 4C. I found a Titanium coil made out of 12' of
8mm tubing on Ebay from some guy in Riga Latvia for only 40 bucks.

(should cost $300-$600, but I've always heard Ti is cheap and plentiful
in the former soviet union.)

Ive seen that guy selling Ti on ebay. I was somewhat skeptical about ordering from him due to shipping though.

Originally Posted by lhaddix

Even better would be a buffer solution mixed with the dye when it
was packaged.

US Specialties does, Caswell doesnt

[Z]

Originally Posted by stevepelle91

I'm no expert but Sodium Hydroxide is what you use to strip anno off aluminum, even a small amount would ruin your entire run and you would have to start over again.

Sodium Hydroxide won't cause any problems...unless of course you add way to much. I've been using Sodium hydroxide for 3 years now and I'm still using the same black dye solution.