Attaching wood handles to functional pottery

[MichaelP]

How do you attach wood handles to functional pottery, especially when the joint will be subjected to high heat?

Here is an example, ceramic coffee pot ( cezve ) that is put on a gas stove to prepare Turkish coffee.

[neilestrick]

I wouldn't trust an adhesive to hold up to the heat, as they tend to soften when heated. I would leave a hole in the attachment area of the pot to run a wooden peg through to lock in the handle.

[MichaelP]

Thank you Neil. That's what I thought too,  but this pot and some other similar pottery served us for about 25 years without any problem.  The pot handle just loosened , but I don't see any obvious signs of adhesive there.   At least, nothing similar to epoxy.  Yet I'm sure it wasn't a simple friction that held it there.

There are some high heat epoxies available now IIRC, but I'm not sure I can really trust them.

So cross pin is one good option.  What else?

 

[Mark C.]

I would trust the high heat epoxies-thats a clay pots so really its low heat anyway.

[MichaelP]

I checked on easily obtainable high temp adhesives, and it looks like the original J-B Weld Epoxy should work. It withstands 600F (continuous exposure).

[Mark C.]

I used JB wield today-Its my go to epoxy .

The regular is slow set and a bit stronger than the fast set.

Good choice.

[Bill Kielb]

Hmmm, the handle on that pot has no burn marks so hats off to it never getting exposed to 400  - 500 degrees! Having said that if you simply warm liquids then it is unlikely to exceed 212 degrees until all the  liquid boils off. (Remember the boil water in the paper cup science experiment) And finally there are many high temperature adhesives including epoxy and immediate cure UV stuff good to over 2000 degrees. ( even some food grade stuff for top dollar)

last a wood or brass  pin is a nice mechanical assurance as is a decorative removable Stainless steel pin or even  finish with wire wrap for a one of a kind look. The wire wrap only needs to keep the handled from retracting out of the hole so easy to come up with a wrap that retains the handle along its longitudinal axis. Look at some wire wrapped glass ornaments and you will see the concept.

just a few thoughts

[MichaelP]

Thank you guys.  Please keep the hints and ideas coming.

[Russ]

Perhaps a high heat silicone from an auto supply store? Remember the silicone oven mitts one could buy. I doubt the coffee pot would get over 212f  as long as it had water in it. If one is letting it boil dry then one definitely has far greater problems than just a wooden handle scorching! Just sayin

[MichaelP]

It will definitely go well above the water boiling temperature because the attachment point is offset and subject to high heat of the nearby flame.

P.S. The walls of the pot will stay cooler, of course, but considering the very low thermal conductivity of ceramics, the outside surface of the body at and near the bottom (near the flame) will also be overheated.  Very much unlike copper pots or the above mentioned thin paper.

As for the tapered connection alone, IMO,  it will not work reliably for this particular application.  The surfaces are not smooth enough to provide friction along the entire conical surface. The frequent heating cycles will dry and shrink the wood in a short order.  Initially, even though we cannot apply much compression force, the taper will work.  But I don't think it will last. The tapers,  indeed,  work well in my lathes, drill presses and milling machine  where there is ground metal-to-metal contact, and when there are no lateral forces.

[neilestrick]

3 hours ago, RonSa said:

I would guess that the tip of wooden handle has a taper that matches the ceramic pot's post. If so its just a friction fit and the handle has dried and shrunk to a point where it no longer has a snug fit into the pot.

A taper like this is called a Morse Taper and its used on drill press to hold chucks and on lathes to hold various tools called centers and/or chucks. Quite strong and reliable.  I've made a few from wood for some custom tool work with success.

Also tuning pegs on violins and such.

[neilestrick]

I've been thinking about this a lot for the last few days, and personally, I'd never trust any adhesive long term, especially in a high heat situation where you're gluing together two very different materials. I spend some time on a banjo forum, too, and one of the rules for wooden instrument builders is to use a glue that can be undone in the future so repairs can be made. Epoxy is commonly used to attach fretboards to necks, because it doesn't creep like some other adhesives, but can still be undone. The way to remove a fretboard is with heat. The other issue with using an adhesive is that if the handle does come loose, which is will do over time as the wood dries out, re-gluing it can be difficult because adhesives don't stick well to old adhesives. My goal would be to not have to make a new handle in the future.

If you were to do this, I would do a tapered fit, and pin it with a wooden peg. The peg could even become a decorative element. If the wood shrinks up and the handle becomes loose, just drill out the peg, fill the hole in the handle with a piece of dowel rod, then re-drill and re-peg it. With the tapered fit, you wouldn't have to make any changes to the attachment area of the handle, just push it in a little further.

[MichaelP]

The cross pin is the most reliable approach, of course.  The handle will become loose with time, but, at least, it won't suddenly disconnect.

When I was daydreaming, I was also thinking about a threaded connection plus a "set screw" (pin) or adhesive, but this would be a major undertaking considering clay shrinkage, etc.  Bayonet connection augmented with a spring, pins or adhesive  came to my mind too...

[Bill Kielb]

10 hours ago, MichaelP said:

It will definitely go well above the water boiling temperature because the attachment point is offset and subject to high heat of the nearby flame.

P.S. The walls of the pot will stay cooler, of course, but considering the very low thermal conductivity of ceramics, the outside surface of the body at and near the bottom (near the flame) will also be overheated.  Very much unlike copper pots or the above mentioned thin paper.

As for the tapered connection alone, IMO,  it will not work reliably for this particular application.  The surfaces are not smooth enough to provide friction along the entire conical surface. The frequent heating cycles will dry and shrink the wood in a short order.  Initially, even though we cannot apply much compression force, the taper will work.  But I don't think it will last. The tapers,  indeed,  work well in my lathes, drill presses and milling machine  where there is ground metal-to-metal contact, and when there are no lateral forces.

Ceramic body, not a good thermal insulator and pretty conductive with respect to heat actually, It is possible he could start his handle on fire though as the pot needs to be tended and set on the burner with some precision. I still compliment him on years of use and not scorching the handle. With natural gas peek flame temperature should be about 2000 degrees but I suspect it diminishes greatly as the distance from it increases. Finally this tapered connection appears to have lasted for many years and now is only loose. My thought would be any mechanical attachment that keeps the thing in the bore will make it last many more. 

[liambesaw]

Turkish coffee is cooked in hot sand so I don't think it would have come into contact with gas flames.  I think a high heat adhesive would be fine, or shimming the handle if there's an actual shimmable gap.

[Bill Kielb]

Just now, liambesaw said:

Turkish coffee is cooked in hot sand so I don't think it would have come into contact with gas flames.  I think a high heat adhesive would be fine, or shimming the handle if there's an actual shimmable gap.

Interesting. Never been on a burner I guess. Looks like this handle lasted a long time, so anything reasonable is likely to allow it to last a lot longer. Adhesive, shims, sound great to try.

[liambesaw]

5 minutes ago, Bill Kielb said:

Interesting. Never been on a burner I guess. Looks like this handle lasted a long time, so anything reasonable is likely to allow it to last a lot longer. Adhesive, shims, sound great to try.

People do all sorts of things with their pots, I don't think ceramic is even a good choice for something like this.  It's usually done in very thin metal cups so the heat transfers really quickly from sand to coffee, and the Turkish coffee is flash boiled, then poured, flashed again and poured, its really something else to watch.  Seems like it would be difficult to flash boil in a ceramic vessel. Don't know, not Turkish, I only drink their coffee.

[MichaelP]

Copper pot in a sand is the gold standard, of course.  But ceramic or metal ones on a gas stove produce a reasonable alternative outside of Turkey.

[Bill Kielb]

2 minutes ago, MichaelP said:

Copper pot in a sand is the gold standard, of course.  But ceramic or metal ones on a gas stove produce a reasonable alternative outside of Turkey.

Thanks!

However it is being used  it doesn’t seem to get hot enough to burn the handle. I hope he tightens the handle, sounds like there are many ways for him to do it effectively.