My first Ano - Am I color blind?

[ken_the_stp]

After studding for quite some time I did my first ano today.

I have 2 problems:
The Yellow 4a dose not look yellow.
I can rub a little dye onto a paper towel and it is sticky kinda, takes finger prints and i can scratch it with me finger nails

I Think the problem was in the sealing as far as the stickiness ect.. goes.

but the color i am not so sure about. the dye that took to the AL looks the same color as the dye I mixed up an orange color. Could caswell have messed up my dye or did i mess up?

here is everything i did you ppl can tell me what you think:

first i sanded off the urethane and finish off some al flashing that i got from lows.

(I used normal tap water for rinse)
i etched the cathode in lye.
desmuted the cathode with caswells desmut
rinsed the cathode
Put it in a 3 gal bucket with diluted battery acid(64 flOZ with one gallon wall mart distilled water)

put the test pice in the lye for a good long time came out spotty black.
rinsed the test pice
put the test pice in desmut for about 15 mins desmut was about 80F
came out nice a shinny
rinsed the test pice
put test pice in bath.

test pice has about 4sur inches surface area.
set my bench supply to 20 volts and 0.22 amps CC
anoed for 45 mins
the voltage read on the supply started at 5.4 volts and went down to 5.1 when I removed test pice from bath
rinsed the test pice
placed in dye for 30 mins.
dye was aprox 81F
placed in near boiling water
water started a mild boil timed 30 mins from that point
turned heat down a bit.
came back to it 20 mins later and water was steaming a bubbling a little but not boiling
turned heat back up
came to a mild boil

[acidrain]

OK, a couple of things...
I calced you surface area, etc. and found you are ano'ing at 8 amps per sq. ft.
Your run time of 45 minutes was for a .5mil ano build. For yellow, this is fine.
Your acid/water mix is too strong. This will lead to desolution at the lower CD's.
You didn't say what the acid bath temp was. This is very important... ano'ing at over 70F bath temp will also cause desolution.
Did you pass water break test? After you etch and de-smut, you should also de-grease and check for water break.
The dye temp is way too low... 140F for 15min is normal. Shortened dye times for lighter color.
Boiling in distilled water is OK to seal... I use the high temp nickel acetate sealer.
Be sure to mix all your solutions and rinse with distilled water. This is imprtant. You can get a RO setup and make your own for about $80. It is well worth it as distilled water from the grocery store runs about $1 per gallon.
I think the acid temp and strength are your biggest issues... the chalky surface is desolution me thinks.

[ken_the_stp]

ok i guess you could call that chalky. So that is was dissolution looks like.

0.5 mill and 8-per sqr foot was what i was going for on that run.

from hear on out I am gona go 5.5 amps per sqr feet due to the limits of my supply and the runs i intend to do with this tank.

As far as temp goes i don't think it was an issue. standing water in that room was about 60F and i wasn't pumping all that much wattage into it. I could drop one of those HDPE ice gel pac things in there to make it nice and cool

as far as acid concentration goes i see 1:3 as being the golden number. that was what I was going for but i seemed to have messed it up.

how dose 64 flOZ of bat acid and 1.5 gals of water sound?

water did not beed on the prepped surface so I am fine there.


Now i hope someone can answer this one. Dose caswells A4 Yellow Look orange when mixed with water. I am really worried now that they shipped me the wrong dye.

[sage]

The color you get in the dyeing process is dependant on almost every other factor in the anodizing process. I'd say the color in the picture is probably within the capabilities of the yellow dye but you left it in too long which resulted in dark yellow to orange.
You'll need to get the dye up to between 120-140 F dip the part and check the color - maybe as much as every few seconds until it is the shade you desired. I wouldn't say you can dye for a fixed time and get fixed results.

I've also found that stripping previously ano'd aluminum affects the parameters of the anodizing i.e two pieces in the same bath same size one stripped one factory aluminum draw different currents and therefore the ano layer comes our different and therefore the color if you process them together. Quite a pain actually - one that I'm currently having trouble with and may need guidance on.

Sage

[ken_the_stp]

ok i'll just put the dye on the stove and get it up to temp as i have no idea how long it would take the submergible fish heater to get up to that temp.

now as far as acid concentration goes would 64 flOZ of acid and 192 flOZ of water be fine for 5.5 APSF That would leave the AL in the bath for 65 mins.

Is it even posable to get a good ano to come out if it is in the bath for 65 mins or should i go for a higher current density.

[sage]

The acid concentration should be 3 parts distilled water to one part battery acid , You quoted 64 and 192 so it sounds like you have that right.
Also sounds like you haven't seen the 720 rule calculator yet else you'd be able to get the time and curent down right away.
Here is a link to it.

http://ndhsubmersiblescience.com/ano/720rule.html

I think you said you had 4 sq inches. If you plug that into the calculator with 1mil and 6A/Sq ft you should be anodizing at 0.17 amps for 120 minutes.

Just pay attention to all the details of time and temperature in the whole process and you should be ok. Don't guess at stuff.

Sage

[ken_the_stp]

PLEASE RTFP before submitting a reply.

acidrain help me out here .
As mentioned in this thread I am trying to set up a tank to anodize parts with a larger surface area than the test part.
I am running the test part at the APSF that the actual parts will run will have to be at

I am going for 0.5 mil's of ano
I am testing for a run that will be 73 sqr inches
my CC power supply can't go higher than 2 amps
I will need to ano at 3.9 amps per square foot to achieve this(correction from earlier posts as I thought I had 3 to work with)
I will need to leave the AL in the bath for 92.31 mins


my questions are:
Is it posable to get a good ano with the AL submerged for that long
what acid Concentration should i use( is 1:3 good or should i go lower).
should i abandon trying to ano at 3.9 APSF and build myself a denser power supply.

[cameraman]

Is it posable to get a good ano with the AL submerged for that long
I regularly do runs for 112 minutes and have gone as high as 160 minutes. Yes, it's entirely possible.

what acid Concentration should i use( is 1:3 good or should i go lower).
1:3

should i abandon trying to ano at 3.9 APSF and build myself a denser power supply.
I've anodized down to 3 amps/ft² with no trouble. Depending on what you want out of your color you may be happier at higher current densities. It's not imperative, but if you've got the fundage you'll probably be glad that you did it.

[acidrain]

OK, yes you have your acid ratio correct... add an additional 64 oz. of water to what you already have.
You can ano below 4.5 amps/sq. ft., but it will be in the tank an awfully long time. I would step up to a bigger PS myself. It will make a stronger, more dense pore structure if you do.
You can heat the dye on the stove, or in the microwave if the dye batch is small. I use a double boiler system... I keep the dyes in 2 gal buckets, and simply place the entire bucket in a large canning pot with about 4 inches of boiling water in it. Get yourself a digital thermometer (less than $10 at a lot of places). You'll need it for all the steps.
I don't know if I asked this yet... do you have good agitation?
Besides monitoring the temp of the ano bath, you have to have good agitation so that the bubbles are knocked off, but more imortant, so that the thin layer of acid next to the part remains at the lower temp. as well.
Finally, I suspect the dye is fine, but you'll need to keep at the test pieces to know for sure. The color of the dye can be decieving, but as I recall, the yellow dyes look really yellow in the bucket. Somebody else here got the wrong color, but I can't recall what the color was.

[sage]

PLEASE RTFP before submitting a reply..

>> If that remark was genuine and directed at me then you're way off base. In all previous posts there was no indication that you were trying to anodize outside the "standard" parameters. You didn't mention that until just after I made my post. Up until then, according to all the parameters you were quoting you had almost everything wrong in your process - which is fine, we help a lot of people try to get it right here. That's what this forum is all about.

Sorry if I missed something along the way.

I'm outa here !!



Sage