De-smut question

[borgen]

Hi all,

Well, i am finally preparing for my first tests on stock alu pipe to see if i can get any result before i move on to other parts.
Going through my chemicals i discovered i am missing the de-smut stuff.
I bought my kits through speeddemon and these kits are not the same as the caswell kits so de-smut was not included.
Can i skip the de-smut step before anodizing or can i use an alternative chemical ?
(I got SD degreaser, SDKlene 175 and 416 and Pickle4)

I will follow the manual and the good advice in this forum to the letter in order to eliminate as many potential mess-up factors as possible.
I will also take note of Voltage over anodizing time.

Tnx.

Danny

[Fibergeek]

Desmutting is only required if there is smut to be removed after etching. You can avoid the need if (for now) you stick to barstock, preferably 6061 or 6063. This is the common hardware store Al barstock sold in the US, and I would think also in the UK.

Desmutting is commonly used when anodizing most Al castings, and some extrusions.

Many anodizers (myself included) like a quick desmut and rinse step immediately before anodizing, on all alloys that are not highly polished. This promotes a very even anodize texture by producing a super clean surface. This is not an acceptable substitute for all the normal cleaning and deoxidizing procedures.

[PhilM]

Danny you are from tthee uk? I ordered my caswell dye from speed demon.

Just had my first attemp this evening, was rubbish due to not having any anodise/oxide stripper, ie was just anodised with no prep. I need to find some uk based stripper stuff, im sure there is a chemical we can buy readily for the job.

[Fibergeek]

Old fashioned sodium hydroxide (lye) in a weakish solution with warm (NOT HOT) water will work. Watch the action on your part carefully, it can be unpredictable. Watch out for the noxious fumes this also produces.

[PhilM]

What sort of streength soloution mate?10%, 30%?

Thanks fibregeek, you are a god-send!

[Fibergeek]

Start with 10% and work your way up to get faster removal if you need it. Be prepared to experiment, this is not as predictable as commercial concoctions, but it should be available to you.

[borgen]

Another quick question:

I have polished 10 pieces alu tube diam. 30 mm length 100 mm to play around with.
When i do the amp calc according to the 720 rule must i also take the inside of the tube into consideration or do the math for outside exposed area only.
Just wondering if inside will be effective anodized and if this area should be taken into consideration when determining amps..

tnx in advance for helping this beginner.

Danny

[PhilM]

Danny, if you still need Caustic Soloution (Sodium Hydroxide/Lye), I found some today in Wilkinsons, called Kleen Off - Caustic Soda by Jeyes.....in the chemical section (drain cleaners etc)

HTH

[borgen]

Phil,

I got plenty anodise/chrome stripper so i'll be ok.
I am from Holland btw.

Rgds, Danny

[M_D]

Regarding the calculation on the 30mm diameter x 100mm long tubes, I would figure 100% the surface area of the inside as well as the outside. But, there are cases where you may want or need to drop some of the interior surface area. Once tubes and holes get beyond a certain depth/diameter ratio the anodizing begins to slow down, and eventually it almost ceases.

I can't give any exact guidlines though. But for instance, if you were anodizing a 10 meter coil of 7mm tube, I would only count 30-40 mm of the inside. I could be wrong, but based on other stuff that is my gut feeling.

[borgen]

M_D,

Thanks for reply.

I'll adjust area to include inside area also and give it a try.

Rgds, Danny