[Clayart] alum wheel head pitting/story

[mel jacobson via Clayart]

i was laughing to myself this morning...`american craft` is running
a lovely story on Warren Mackenzie.

he is pictured..but, as we all do, i was looking
behind him..at his 60 year old leach wheels..a kicker as
most of you know. dirty, old, crusty, used every day.
`i wonder if he cares if his wheel head might pit?`
he just makes pots on it every day..from last count
by donovan, he makes several thousand a year..he is
91. and knowing warren, he does not even see pits / not aware
of them.

our wheels, kilns, tools are just that ...tools...they wear, get
tired, pit and rust...but, in most cases they just keep on
going.

it is like i laughed with arnold on the phone the other day...
`do you sell stainless steel polish for kilns???`
`yes, we do.`
the answer is why???????????????????...kilns get crusty.
i have never polished one in my life. they are not living
room furniture...they are tools. when they wear out,
\you buy a new one. the inside bricks flake, break off
and the story is...`so what???????` they work just fine
with chips in the brick. the bricks in my stoneware kiln
are turning 55 this year. they look 55. but, the kiln
\is perfect. i just sprayed another thin coat of itc top
coat...nice. bright white inside...looks nice. but, the reason
i did it was to increase the K factor. it worked as advertised.

think of going to a garage sale and you see a 75 year old
hammer. grease from years of being worked with someone's
hand. it is a thing of beauty. i have several...i cannot leave
them on a table. they have to be protected. (my daughter said i have
at least 35 hammers.) old tools.
beauty. real tools, used by someone. it is like a thousand
year old pot. the stories they can tell.

i just cannot wash my wheel. i should, maybe even polish it*.
but, i would think it would be like beating up a kitten....`leave
it alone...it likes clay all over it...it is camo.`
love to all.
mel
* i do wax and polish my `old` simplicity lawn tractor. bright orange.
starts right up every time. i have a neighbor that has had, and
ruined three garden tractors since i purchased mine. it is actual
abuse. makes me shutter. but, some people just don't know or
care...throw it out. sad. it is a critical philosophical question of
the ages. the `mind body problem` is not nearly as complex.
`i think, therefor i destroy tools`. man, complex.

from: minnetonka, mn
website:http://www.melpots.com
new book: http://www.21stcenturykilns.com
http://www.melpots.com/clayart.html

MAILMAN_MIMEDEFANG WRAP
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[Hank Murrow via Clayart]

On Nov 20, 2014, at 10:24 AM, mel jacobson via Clayart <cla...@lists.clayartworld.com> wrote:

> `do you sell stainless steel polish for kilns???`
> `yes, we do.`
> the answer is why???????????????????...kilns get crusty.
> i have never polished one in my life.

Just between you and me, I don't polish or obsessively clean my wheels, and as you have seen, my stainless steel lifting kiln is dusty most of the time. However, I do maintain a supply of stainless cleaner/oil/polish, which when heated beyond 240F will turn brown and indicate a 'thin spot' in the fiber lining which will soon need stuffing. So every once in a while I clean up the shell and spray on the polish, and count on the oil to reveal to me when the kiln needs maintenance.

I don't do this for my stainless-clad electric.

Cheers Mel!

Hank

PS: Wish you could see George Kokis' work in this show.

To view additional works in this exhibition, please visit: http://www.wlotus.com/BrothersInClay.html

[John Post via Clayart]

I have a pad of stoneware clay on my wheelhead that keeps the bats from sliding around.
As long as I keep a bat on it it stays moist. Sometimes I add a little water to it.
Of course this corrodes/pits the beautiful aluminium (British pronunciation) wheelhead.

The wheel head on my Brent is in mint condition. Shiny new.
I don't like it as much as my Bailey.
The Bailey is a fine wheel, it's just a personal preference thing.

My Bailey wheel is ultra-quiet and dirty like a pig right now.
If I switch from brown to white clay, I take the wheel outside and blast the one piece splash clean with a hose.

Never be afraid to use your tools or open 'em up.
My 74 year old dad has never found the perfect wood carving knife - he always tweaks them to meet his needs.
You can see my dad's thinking in all of the changes he's made to those knives.

johnpost

http://www.johnpost.us/

[Taylor Hendrix via Clayart]

I'm willing to bet that Warren's wheel head is steel.

I have had zero problem with my Whispers sitting in clay gunk for months;
however, if I allow moist clay to stay on the aluminum wheel head, I have a
crust form at the edge of the clay which I find to be annoying. In my neck
of the woods, if you allow certain things to remain in contact with
aluminum, you will lose the integrity of the aluminum to corrosion. I've
posted a picture of one of our aluminum parking signs (fastened with
stainless steel bolts) after only a few months exposure to the elements.

On my flickr photostream
https://www.flickr.com/photos/wirerabbit/15650938108/

I found that sign in the parking lot several meters away from it's post
after a 20kt day.

Taylor, in Rockport TX

[don jung via Clayart]

Is it because of the stoneware clay or simply because it's moist that
corrosion occurs? Someone also mentioned steel/iron bat pins, but with a
clay pad, you likely don't use bat pins so is there another source of metal
like the shaft that contributes to the corrosion? I'm thinking
about aluminum pugmills where moist stoneware won't cause
corrosion but porcelain will.
Along the same lines, how would connecting some zinc weights under or
around the edge work... like they do to aluminum boats?

cheers,
Don

[Paul Watkins via Clayart]

__________
Paul Watkins
www.redshedstudio.com

[MGordon via Clayart]

Taylor I can't open this , my browser is toooo old!! But maybe
electrolysis is the cause of the degradation. I also think that the old
aluminum wheel heads were a softer compound than the newer ones. My
wheel heads are probably the cleanest part of my wheels! Except my
wooden kick wheel's table top that gets a lot of water, once a year it
gets cleaned & a new coat of sealer!.Mike Gordon

[L TURNER via Clayart]

My speculation on why aluminum wheel heads corrodes when left dirty with
porcelain:

Porcelain, especially cone 6 types, contains significant neph-sy as part of
the feldspar recipe component. Feldspars, especially the sodium and
potassium versions -- and particularly neph-sy, leach alkali salts. Alkali
is a strong corrodent for aluminum. The reaction produces an aluminum gel
that dries to a rock hard mess.
What is happening to your wheel head is the same thing that happens to the
pug mills constructed with aluminum parts.

Stoneware recipes tend to not leach as much alkali as porcelains.
Steel does not react with the alkali to produce the aluminum gel, and is
less likely to be corroded by the soluble salts from porcelain.

Bat pins are a favorite place for small bits of slip to hide, keeping the
pins greased and clean is a good idea.

How fast the aluminum corrodes depends on the alloy chosen for the wheel
head. I have seen the pitting at bat pins wheels with steel bolts and
stainless bolts, so I doubt that the pin choice is made more on pin nut
corrosion. SS bolt/nuts hardly ever get fused by rust.

Regards,
Lou Turner
The Woodlands, TX

[jonathan byler via Clayart]

our bat pins wear out due to abrasion from the grog in the clay getting rubbed between the holes on the bats and the pins. I replace them with new stainless steel "pins" from time to time when people start to notice that they are worn and the bats are loose.

I'm 99% certain that the reason the porcelain is causing more corrosion is probably due to more soluble alkali in the clay body than stoneware. The wet corrosion, and the alkali in wet clays with alkaline bodies is going to cause it to happen even faster. no worries with a steel wheel head, alkalies, actually protect steel from rusting in many cases. this is why rebar in concrete holds up so well, the concrete is alkaline and protects the rebar from rusting (so long as you don't add liquid road salt).

jb

[Steve Mills via Clayart]

Warren is 14 years my senior, and I got my Woodleys Leach Wheel in '67. It had a cast iron wheelhead which was lovely to throw on. It still has the same head only I had to have it re-surfaced I threw grooves in it over the years. If I could put cast iron on my Whisper I would. Much nicer to throw on

Steve M

Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod

[Vince Pitelka via Clayart]

Jonathan Byler wrote:
"I'm 99% certain that the reason the porcelain is causing more corrosion is probably due to more soluble alkali in the clay body than stoneware. The wet corrosion, and the alkali in wet clays with alkaline bodies is going to cause it to happen even faster."

Hi Jon -
This is an interesting subject, and maybe Ron Roy will weigh in with an opinion. The reality is that if the alkalinity was in solution, the clay would be deflocculated and unworkable. That's obviously not the case with most porcelain claybodies, and yet the sodium seems to interact with the aluminum, causing corrosion, but without having gone into water solution. I do not know the chemistry of that, but maybe someone else on the list does.
- Vince

Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpit...@dtccom.net
http://iweb.tntech.edu/wpitelka/

[via Clayart]

Hi Vince,

Most porcelains are to some extent subject to some deflocculation - it
depend on the spar used and the PH of the water used in mixing.

It is most certainly true for cone 6 porcelains which are fluxed with
Neph Sy. I don't want to start up with the definition of porcelains -
just think of them as a type of clay body for this discussion.

So there can be some tendency towards deflocculation and some attempt
to counter that tendency is needed. Epsom salts is one way and there
are other solutions (remedies) in use. Perhaps someone can do some
research and find out what flocculators are being used and if there
might be some connection with the problem of aluminum corrosion.

Are Epsom salts ever used in clay bodies in the UK for instance? If
not what is is used?

RR

Ron Roy
ron...@ca.inter.net

[Ivor Lewis via Clayart]

Dear Vince, Ron, Michael, Jon.

Aluminium Wheel-head Corrosion. Elementary Chemistry

Aluminium alloys have differing responses to corrosion forces. However the
hydroxide Al(2OH)3 is amphoteric, that is, it can behave as an acid or a
base. Aluminium (M) is insoluble in Water. Aluminium oxide, in the form of
Ruby and Sapphire is insoluble in water.
Anodisation is an electrochemical is a way of preventing aluminium and its
alloys corroding.
Speculating, unprotected metallic Aluminium is soluble in weak or dilute
acid. Dissolved Carbon dioxide, a weak acid, is implicated in the reactions
Carbonic acid forms when CO2 dissolves in water. This substance has never
been isolated

Regards to you all
Ivor.

Ivor Lewis, South Australia

[John Mcclure via Clayart]

Hi,

The wet environment of the potters wheel sets up a wonderful little world
of galvanic corrosion and it does not take very many free ions to allow the
cell to establish itself. We just have a simple battery with the aluminum
wheel head paired with stainless steel bat pins. Stainless steel and
aluminum are far apart or have a greater potential for corrosion. But of
course we don't want the rusting bat pins, so we pick passivated stainless
and our poor wheel head is the sacrificial anode. A possible solution is
to find zinc plated pins which have a lower potential on the galvanic scale
then aluminum and the pins would be the anode until the zinc was depleted.
Or is there a market for stainless steel wheel heads?

John McClure

[Hank Murrow via Clayart]

On Nov 23, 2014, at 6:57 AM, John Mcclure via Clayart <cla...@lists.clayartworld.com> wrote:

> Hi,
>
> The wet environment of the potters wheel sets up a wonderful little world
> of galvanic corrosion and it does not take very many free ions to allow the
> cell to establish itself. We just have a simple battery with the aluminum
> wheel head paired with stainless steel bat pins. Stainless steel and
> aluminum are far apart or have a greater potential for corrosion. But of
> course we don't want the rusting bat pins, so we pick passivated stainless
> and our poor wheel head is the sacrificial anode. A possible solution is
> to find zinc plated pins which have a lower potential on the galvanic scale
> then aluminum and the pins would be the anode until the zinc was depleted.
> Or is there a market for stainless steel wheel heads?

Dear John;

A student who went on from Anderson Ranch to Alfred U. in the 70's cast silicon-bronze wheelheads for himself and me. I have an old 'growler' variable brush motor wheel that has that 70# bronze wheelhead mounted. I keep a pad of clay on it for attaching bats and when it dries out the colors on the bronze are spectacular!

Cheers, Hank in Eugene

PS: That student was Cory Levins, and Ian Currie published his glaze "Cory's Weird" in his book "Revealing Glazes".

[pdp1 via Clayart]

Once clean and dry, or beginning when new, and renewing every now and then -
I expect one could apply any of various 'space age' Hydrophobic Aerosols or
other Solutions to the usual stainless 1/4-20-Bat-Pins and to the
Cast-Aluminum-Wheel-Head, thereby preventing any water/moisture from
encouraging Galvanic corrosion conditions.

-----Original Message-----
From: Hank Murrow via Clayart
Sent: Sunday, November 23, 2014 11:39 AM
To: John Mcclure ; Clayart international pottery discussion forum
Subject: Re: [Clayart] alum wheel head pitting/story

Dear John;

Cheers, Hank in Eugene

MAILMAN_MIMEDEFANG

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[Steve Mills via Clayart]

The answer with a cast iron Head, is to clean and dry it after use (sponge and squeegee with my thumb), and spray with WD40 if leaving it longer than two days.
Never rusted, ever!

Steve M

Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod