Anodizing ...

littlejohngael · Post by **littlejohngael** » Thu Sep 11, 2003 2:51 pm

Okay, so I've seen the anodized Howard whistles, and I've seen the anodized Overtons (and am loving the looks of the green one), so my question is simply: How hard is this to do?

Would I fry myself or burn my house down if I tried it myself?

All the best,

Little John

Tony · Post by **Tony** » Thu Sep 11, 2003 3:03 pm

It might be cheaper to send it out to a shop to do the work.
Here are some links to explain the process:
http://www.alphametal.com/anodizing.htm
http://www.focuser.com/atm/anodize/anodize99.html

LeeMarsh · Post by **LeeMarsh** » Thu Sep 11, 2003 4:41 pm

LittleJohn,
Sending out whistles, you might want to make sure the service you use will anodize only the outside of the tube. Anodizing the the inside or blade or windway may change the pitch and timbre greatly. My understanding is that changing the bore, the windway's attack on the blade, or the depth of the finger holes can have an impact on the tones pitch.

Good luck and let us know how it works out.

Brigitte · Post by **Brigitte** » Thu Sep 11, 2003 5:20 pm

Hello John,
some things I have learned about anodising over the last few years so maybe it is useful for you. First nope, doing it yourself I think you should not consider, quite a bit of chemicals (acids) involved and it has to be quite a deep pot to dip in a complete whistle. I think the "cooking" temperature is over 90 degrees. Beforehand you would need to give it the right wash which I do not know what it is. The Overtons afterwards get coated with Teflon and I still do not know what the material's state is when it goes over the whistles.

The toneholes may not be the biggest problems and the lining of the tube is REALLY thin so it may not noticably change pitch, but the windway gets coated as well so you should be able to do the right things afterwards to voice the instrument again.

Also to consider is the age of the instrument. Although with aluminium there is not really oxidation for the eye to see even after many years but when it comes down to anodising if you are unlucky you may have faulty bits on the instrument where the anodising does not grip, so tubing older than 6 months is not recommendable anymore. A whistle which is meant to be anodised here also will not see one drop of oil during the making process of the instrument.

Hope this is helpful information
Brigitte

Bloomfield · Post by **Bloomfield** » Thu Sep 11, 2003 5:37 pm

Brigitte wrote:Hello John,
some things I have learned about anodising over the last few years so maybe it is useful for you. First nope, doing it yourself I think you should not consider, quite a bit of chemicals (acids) involved and it has to be quite a deep pot to dip in a complete whistle. I think the "cooking" temperature is over 90 degrees. ...

That would be about 195° Fahrenheit, I think.

glauber · Post by **glauber** » Thu Sep 11, 2003 8:34 pm

Bloomfield wrote:
Brigitte wrote:I think the "cooking" temperature is over 90 degrees. ...
That would be about 195° Fahrenheit, I think.

More like 364° Kelvin.

Brigitte · Post by **Brigitte** » Fri Sep 12, 2003 2:48 am

glauber wrote:
Bloomfield wrote:
Brigitte wrote:I think the "cooking" temperature is over 90 degrees. ...
That would be about 195° Fahrenheit, I think.
More like 364° Kelvin.

You both are probably right although I have no idea about translation of Celsius into Fahrenheit oder Kelvin. Celsius makes so much more sense to me from 0 to 100 liquid and below 0 freezing and above 100 steam... feels easier than freezing temperature in Fahrenheit is still plus 32....

When I read now what I wrote about 1 or 2 o'clock last night, I think I should have tried to explain better but it was so late so I hope my message made the point. I was still up because I tried to bid for this little old whistle on ebay, but ending was around 4 in the morning it was too much time to go for me. At 2.15h I gave up and of course got overbid 2 minutes before the ending so I did not get it

Thought it looked nice and In Tune

Friday, weekend is coming.... have a nice one!
Brigitte

Tak_the_whistler · Post by **Tak_the_whistler** » Fri Sep 12, 2003 5:25 am

slightly OT....!?

I'd love to have my Overtons anodized....wooden look....but it's a bit expensive fae me....and too late for the process....

dkehoe · Post by **dkehoe** » Fri Sep 12, 2003 6:27 am

Here's the deal on anodizing. First, it really only works well on aluminum, though a few other metal can be anodized. First step is to clean the surface, and some anodizers will use a caustic dip on aluminum to give it a satin-like finish (if you want a bright finish, skip this step). The aluminum is then rinsed and put into a concentrated sulfuric acid bath. A voltage is applied to the aluminum, making the aluminum the positiive electrode (anode). The voltage is not high, usually around 14-18 volts, but the bigger the peice, the higher the amps. There are specs on the desired amps/sq in to be used (which escape me at the moment). Oxygen is attracted to the aluminum, leaving a layer of aluminum oxide. This layer is composed of hexagonal columns that are hollow (kind of like Giant's Causway in Ireland). After a certain amount of time determined by the amperage and temperature, the aluminum is removed and rinsed in distilled water. The oxide layer is very absorbant. The aluminum is put in a dye bath and absorbs the dye. The pores have to then be sealed, and this is done by boiling the aluminum in water. Usually a lanolin or other oil is wiped on the finished surface.

Can this be done at home? There are a few webistes that talk about anodizing small bit of aluminum, and one could probably do a high D whistle, but if your talking about a low D whistle, that's a lot of amps, and finding a REALLY BIG DC power supply is a problem (and expensive). I had a whistle I made anodized and it cost me the anodizer's minimum charge of $35. Not such a bad deal, and I'm sure they did a much better job.

Dave

littlejohngael · Post by **littlejohngael** » Fri Sep 12, 2003 6:34 am

glauber wrote:
Bloomfield wrote:
Brigitte wrote:I think the "cooking" temperature is over 90 degrees. ...
That would be about 195° Fahrenheit, I think.
More like 364° Kelvin.

More like WAAAAAAY too hot for me to do in my kitchen with two children under the age of six running circles around me with plastic swords yelling, "Ride for ruin and the world's ending!". (Note to prospective parents: You might think twice about letting small children watch the trailer to Return of the King. ... Oooooh yeah. My life runs at a mile-a-minute ...)

And much thanks to all of you for the replies. My tube's at least 11 months old -- got it in January -- and who knows how long it was around before being born into my little world. I'll follow the links posted (much obliged Tony!) if for no other reason than to have a bit of knowledge on the subject for future pursuits.

All the best,

Little John

Tony · Post by **Tony** » Fri Sep 12, 2003 6:49 am

Brigitte,
is there a difference in tuning before and after anodizing?? there should be some coating of the surface inside the tube and around the toneholes. Is this significant enough to require adjustment to allow for the anodizing?

dkehoe · Post by **dkehoe** » Fri Sep 12, 2003 8:35 am

Folks, were talking an oxide layer that is maybe 50 thousanths of an inch thick here. In addition, that layer comes from the base aluminum, so the actual dimentional change to the aluminum is maybe 20 thousanths. The effect on tuning, tone, fipple behavior, etc. is negligible at best.

Dave