17 replies to this topic

[justin1287]

I want to make ceramic handles for stainless steel tools and fire them together as one piece (cone 6).  Is there anything I should know before trying this?  Thanks

[joshur]

You would be much better off making the handles, then gluing the stainless in after firing, the most common types of stainless steel 304 and 316 loose their ability to resist oxidization at about 1650F along with other changes to their basic properties, in the end you will not have the stainless you started with. Heating most alloys to high temperatures, requires special atmospheres and other conditions, and usually also requires the metal to be refinished and reworked even if the proper procedures have been followed, just for fun put a piece of your favorite stainless in your next firing and see what it does.

[Tyler Miller]

I've got some experience with blacksmithing and heat treatment of low alloy and carbon steels.

 

To answer more fully I'd like to know what kinds of tools are you making and what type of steel are you using.  You might come across a number of problems with firing the steel and ceramic together.  The first problem is that if you're looking to make tools that require either hardness or toughness, firing the steel according to a ceramic schedule might ruin its performance.

 

Steel changes from a body-centred to face centred cubic structure above what is called "critical temperature" and rapidly quenching steel that is above critical temperature freezes the face-centred structure, making it hard.  The slow cooling rate of a kiln will make that steel soft.  There are air-quenching steels that may fit your bill, but I don't know much about them as they require very exacting heat treatment regimens.

 

On the other hand, cone 6 is nearly at welding temperature for most steels, and you'll be growing the "grain" of your steel to massive proportions.  This will sacrifice a lot of a steel's toughness.  Taking steel up to that high a temperature without some sort of grain refinement afterward is like trading in a corvette for a pinto.  Usually, to refine grain you'd heat the steel to a little above critical and let cool to room temp in open, still air, then very slightly above critical, and cool to room temp, and then a little under critical, and cool.

 

The other issue I see is that you may have to contend with the differing rates of expansion and contraction of the steel and ceramic, as well as the shrinkage rate of the ceramic.  This may take some doing, but I don't see it being impossible to overcome.

 

As Joshur says, making the pieces separately is much easier.

[Mark C.]

I want to make ceramic handles for stainless steel tools and fire them together as one piece (cone 6).  Is there anything I should know before trying this?  Thanks

What you should know is that you will not be happy with the result

In one of my cone 10 fires I left a pair of Klien electricans pliers in the flue and they where a chuck of slag

Your stainless 316 or 304 will not have any qualities left in them that you want. Make your handles consider shrinkage and fire them then glue them onto the S/S. with epoxy

Let us know how this turns out.

Mark

 

PS this has been brought up before here and we never got any feedback on what happened,

[Pres]

Interestingly enough, while taking grad work at Penn State, there was a student doing S&M sculptures for want of a better word. These life size female forms were embedded with nails sticking out of their torsos, barbed wire wrapped around them and other such metals used to "torture" the form. The fired result was often a surprise. First many of the nails did survive in some form. It seems the outsides remained, and the centers melted. In the barb wire some of the wire remained in places, and in other areas melted off leaving imprint of the wire-often metallicly shiney. In none of these cone 10 reduction pieces did I see any indication that there was a viable way of firing metal with clay for useful utilitarian objects.

[jrgpots]

[quote name="Norm Stuart" post="49421" timestamp="1388945415"]
 
...Put a copper, brass, or bronze rod in a kiln to cone 6 and there will be nothing left apart from green splotches on all of the ware, as the rod will splatter as it oxidizes....

Off the subject a bit, but.....
Norm, do have pic of the splatter? Does it look good on glazed ware? I have lots of bronze and brass scraps.

Jed


 

[justin1287]

Hmmm, looks like it may not work.  I was planning on getting these and wrapping clay around the middle for nice handles for pottery tools for myself.  http://www.ebay.com/...=item5402ff46cb

 

Any thoughts on other types of metals that may hold up to cone 6?  Titanium maybe?

[Tyler Miller]

Titanium would likely burn at cone 6.  It's very reactive and when it burns it's bad news.  Metal fires are scary and would probably mess up your kiln pretty badly.

 

I don't want to discourage you from the way you want to do things, but it would be really easy to make the kinds of tools you want from stainless with a hacksaw and files and make the handles separately.

 

 

Edit: MSDS for Titanium:  autoignition is 1200C for solid metal, under heading four.

[Tyler Miller]

Norm, I know from first hand experience it burns before it melts--as the MSDS sheet I linked shows.  When I was young I got my hands on some and tried to forge it.  Bright white light and sparks everywhere.  The high heat is relative, aluminum melts at 1220 F. Titanium withstands heat in relation to aircraft aluminum.  Titanium alloys and compounds are another matter entirely.

 

I apologize if I've caused any offence in correcting you, but please read the MSDS I posted.  The autoignition temp is indeed right around cone 6 (2192 F).

[MichaelP]

310 stainless steel should withstand Cone 6 just fine for your purposes (although Code 4 would be a bit safer). The difference in the thermal expansion is what should really worry you.

 

I agree that gluing metal to fired clay handles would be a correct approach.

[MudBug]

At cone 6, the metal I found out to be still stable and not melt is Molybdenum.

I was looking for metal to make some stilts with that wont melt at cone 6. 

Found that Molybbenum is the one to use which has a melting point of 4753 degrees F.

 

I am not an expert in these things. Just sharing the info I found during my research. I have not tried the Molybdenum rods yet. I am going to in spring!

 

http://www.ebay.com/...4553263?lpid=82

[Bob Coyle]

I have made ceramic pot handles that have a threaded nut  inserted into the ceramic handle. These were made with low fire clay at cone 05.  Of course the steel oxidized all to hell but the bolt did not split away from the ceramic after it cooled, and it threaded OK... it didn't crack the ceramic when I snugged it down. .  You might be able to get away with something at lower temperature, but I am sure you would have an extensive re-work on any metal you might have showing.

[Benzine]

 

Most people at our studio have a similar or identical set of tools. I paint the center of mine with bands of red nail polish so people remember where they borrowed it from. If you wanted to add a ceramic center it would have to be a two-part that you glue on.

 

All my classroom tools have a circular burn mark, the size of a peep hole plug.  Well, those with wood on them somewhere do.

[Mark C.]

Make your clay handles with slots for the tools and fill the gap after firing with thick epoxy. Then you have a strong piece of steel with fired clay handles.

M

[Mart]

Make yourself a 2 part "prototype" so you can be sure, those tools actually are improved if handle is thicker.
I am sure it will feel nice when you pick it up but because your fingers are further apart you will lose accuracy in your movement.
If you like to make those metal handles a bit softer, use heat-shrink tubing (used in electronics or by electricians).

[bny]

Molybdenum has a stellar melting point, but it looks very likely to oxidize. I have some Mo and might throw a sliver into the kiln with one of my 2225F firings some time to see what happens.

[jerisme73]

I just did a raku piece and used a stainless handle afixed with screws. I marked the holes when it was leather hard and attached after it was bisqued and then fired had no problems with it distorting or melting

[Babs]

I just did a raku piece and used a stainless handle afixed with screws. I marked the holes when it was leather hard and attached after it was bisqued and then fired had no problems with it distorting or melting

Amazed, what no shrinkage in the clay from leather hard to fired second time?  Better market that clay!