Jump to content
BenC

Hello from a new potter & process question

Recommended Posts

Hello all,

I am a very new potter, I have currently only made one piece but I'm very interested in mixed materials ceramics and metal/wood for bowls and cups, I was wondering if it was possible to turn per fired ceramics on something like a wood lathe at very slow speeds? I was hoping someone on here migh of experimented with this workflow and be able/willing to share their experinces?

My thoughts currently are as follows:

Throw the clay body, wait for it to dry to possibly just a little beyond leather dry, then turning to slightly larger than the required diameter on lathe, allowing for shrinkage in the firing.

Looking forward to sharing my adventures with all of you.

Ben Crowe

Share this post


Link to post
Share on other sites

I don't think you'd ever get it to stay on the lathe. You can't chuck it up like a piece of wood. You can trim things on the pottery wheel, though, which is similar to wood turning. If you're looking to join wood or metal elements to clay pieces after firing, it's best to fit the wood and metal to the clay. Clay shrinkage is not precise enough for fitting things together.

Share this post


Link to post
Share on other sites

My question would be, what exactly are you trying to accomplish?

If you've already thrown the body, then it has already had most of the forming and shaping done.  As @neilestrick stated, some trimming can be done, after throwing.  For many potters, that is part of the process; throw, cut off the wheel/ bat, let dry, invert, trim and cut a foot, then finish.

The wheel IS the lathe, of the pottery world, used for both forming and removing excess material.  

Share this post


Link to post
Share on other sites

I'm gonna go ahead and say it again just for reinforcements sake.  The pottery wheel is a lathe.  My dad does wood turning and it's all about reducing a block into a vessel.  Pottery is the opposite, you're not reducing but moving the clay where you want it.  If you need to reduce to fine tune, you can do it at leather hard on the wheel.  

I don't think clay could take the force of a wood turning lathe without being destroyed almost instantly anyway.

Share this post


Link to post
Share on other sites

Neil nailed it! Getting the jaws on a wood lathe to grasp the clay, without damaging the clay vessel/foot of the vessel, will not happen. Likewise, if you could get it locked into the jaws, without damaging the clay, once you start applying pressure with a gouge, it will likely break loose its hold in the jaws. As well, most wood turning takes place at RPM speeds which are much higher than a potters wheel operates at; if you could get it secured in the jaws, once you start building RPM's and working on it, it would likely come flying out at you, which is not good. 2# of anything flying at you at fast speeds is gonna hurt, even if its a "soft" material vs a chunk of wood.

A potters wheel is a lathe, just on a vertical axis vs horizontal on a wood/metal lathe.

There are materials in the studio ceramics world which are turned on lathes though; plaster can be poured to your desired general shape/size and refined on your lathe. If you do go to turn plaster on your lathe, keep in mind one thing; plaster is loaded with water (especially if its newly poured plaster), and it will leave serious rust marks all over your nice lathe if you let them dry on it. If you do turn plaster, do it on a junky lathe, or use compressed air to clean up afterwards. You'll also want to use the tailstock quill to secure your work piece, and not just a set of jaws at the headstock. Keep your RPM's relatively low, and dont be too aggressive with your cuts; plaster, while more durable than clay, is not nearly as strong as wood, and could break loose if worked too aggressively....essentially the quill will work itself a larger oblong hole.  Also, treat any dust generated by turning plaster with the same caution you would wood dust; heard first hand story of two mold making brothers who BOTH had to have their impacted nasal cavities (filled with plaster dust) drilled out because they never wore masks/respirators while making molds...granted this was powdered plaster, but turning plaster makes a lot of dust, which you dont want to breath.

Out of a purely technical query, it might be possible to turn something like air dry clay, or a polymer clay on a wood lathe; the agents/resins which "harden/cure" the clay might make it durable enough to turn, but soft enough that you can cut it with your gouges and not ruin either the tools or workpiece. However, you cant fire those clays in a regular ceramic kiln to any temperature which would make it durable for any real use or to apply a glaze, so really a null point, but technically, it might be possible.

You could easily enough join a turned piece of wood, to a thrown/trimmed/fired ceramic object. Use calipers to measure your ceramic piece's connection area, and work the wood piece to fit. I would NOT recommend joining fired ceramic and wood together, and then turning the wood piece down to match profile of ceramic portion. Not only would you be in the same predicament (above) as unfired/leather hard clay (not locking securely in the jaws; jaws would likely crack fired clay, as the pressure from the tailstock would too), but if the clay breaks apart, you now have SHARP flying shrapnel.....sounds kind of like a scene from a "slasher movie".

It is likely that your ceramic object, even if you take great care to throw it perfectly centered, trim it perfectly centered, and handle/fire it very carefully, that it will warp to be slightly out of round, especially in comparison to an stable material like a piece of turned wood, so you may have to do some hand carving/sanding for your profiles to match perfectly. Also, the wood is going to expand/contract over time, whereas the clay will not; a rigid adhesive (even a really high quality one) may not keep them from breaking apart over time(might even be that the wood expanding would crack the ceramic); might be best to use a flexible adhesive like a silicone, and make the connection between the two more than just a flat surface (more surface area, more bonding area...something like a keyed connection). Of course when the wood swells, the profiles will not longer match, but there is not a whole lot you could do, other than to vacuum a resin into the pores of the wood, so there is no room left for water to swell.

Share this post


Link to post
Share on other sites

Turning on lathe no dust protection. Ridiculous.

Local woodturner now dead lungs full of wood dust...

Are we really that ininformed!

Read up on silicosis or however it is spelled. 

For goodness sake!!!!!!!!

Share this post


Link to post
Share on other sites
1 minute ago, Babs said:

Turning on lathe no dust protection. Ridiculous.

Local woodturner now dead lungs full of wood dust...

Are we really that ininformed!

Read up on silicosis or however it is spelled. 

For goodness sake!!!!!!!!

Babs, are you referencing the video that shawnhar posted? I surely dont wear a respirator when I trim pots, and Ive never met anyone who does. Im not concerned about silicosis unless the clay/silica is dried and making itself airborne.

Turning wood presents way more concerns than just silicosis, or inhaling wood fibers/dust; many woods contain oils which cause allergic reactions in many a folks, and a lot of imported hardwoods contain poisonous oils which can kill. All the woodturners I know at the very least have very good ventilation/exhaust systems in place, most use a respirator, and a few use fully hooded oxygen masks in combination with their exhaust systems. Granted there are those who do nothing to protect themselves, and I consider them to be in the same mindset as those who dry mix glazes without any protection; short lived and foolish.

Why so many !!!!! ?

Share this post


Link to post
Share on other sites

Cranky this morning I guess.

Seems a lot if posts lately of people with no experience acquiring kilns etc and asking for help. Fine but it leaves me feeling a bit weird re giving any advice as a little knowledge can be more dangerous than none in some circumstances.

That's all

I refrained from any exclamations at all.

Regaining my equilibrium.

At what stage of dryness, not a great word there, do clay particles stay in atmosphere?

Just asking. 

Namaste

Share this post


Link to post
Share on other sites
20 minutes ago, Babs said:

as a little knowledge can be more dangerous than none in some circumstances.

Agreed wholeheartedly!

I consider clay scraps that can be "crunched" into pieces to be dry enough for the silica to become free and airborne. Dust on my floor is the place where I fastidiously try to keep clean; trimming scraps are cleaned up immediately before they get walked over, and a sponge is used at the end of every throwing session to wipe up slop spills before they dry. Wet mop thoroughly once per week; wiped dry with towels which are laundered. Table tops are wet sponged daily; new studio I wont have any canvas; just nice wood tops.

Activity from simply walking across a dust laden floor is enough to cause particles to become air borne, and can linger for easily 6-10 hours depending on the atmosphere. I run my air filtration unit whenever I am in the studio; run it on low when Im just working, on high whenever any dust creating activities are going on (i.e. sanding pots, pounding clay on canvas table, cleaning up scraps from floors, etc). Bill Pentz is a woodworker who has done a lot of studies on dust in the studio. His daughter is a ceramics professor at a CA college so while clay isnt his media of choice he is very knowledgeable. His site is full of good information regarding the hazards of dust which all should read through; he specifically discusses how particles become airborne, and how long they become airborne. He uses a meter to test the air quality, which is much better than "....sure is dusty in here...".

Share this post


Link to post
Share on other sites
1 hour ago, Hulk said:

Thanks for postin' that vid Shawn!

Mechanized sgraffito, wow

It's actually more of an "Inlay" technique, than sgraffito.  The latter would be carving through a colored slip or underglaze, to expose the clay body color.  The former, is carving first, applying a slip or underglaze into the carved areas, then removing said colorant, from the high spots, leaving only the recessed areas colored.  

Share this post


Link to post
Share on other sites
5 minutes ago, Benzine said:

It's actually more of an "Inlay" technique, than sgraffito.  The latter would be carving through a colored slip or underglaze, to expose the clay body color.  The former, is carving first, applying a slip or underglaze into the carved areas, then removing said colorant, from the high spots, leaving only the recessed areas colored.  

Skip to the 13 minute mark, pretty certain it's sgraffito

Share this post


Link to post
Share on other sites
2 minutes ago, liambesaw said:

Skip to the 13 minute mark, pretty certain it's sgraffito

I watched the whole video, mainly because watching other potters (Or  trades people) work, is like video crack to me, but I still think that is considered inlay. 

It would be sgraffito, if he applied the slip first, then carved through, to the clay body.

Share this post


Link to post
Share on other sites
2 minutes ago, Benzine said:

I watched the whole video, mainly because watching other potters (Or  trades people) work, is like video crack to me, but I still think that is considered inlay. 

It would be sgraffito, if he applied the slip first, then carved through, to the clay body.

It looks like he's carving through white slip into a buff body, maybe it's just lighting? 

Share this post


Link to post
Share on other sites
3 minutes ago, liambesaw said:

It looks like he's carving through white slip into a buff body, maybe it's just lighting? 

Could be, If that's the case, then he's doing both sgrafitto and inlay.  

Regardless, it's an interesting process, with some amazing results.  It's crazy to think, that the person, who's work he was replicating created a similar machine, hundreds of years ago.  Like Pre-Industrial Revolution!

Share this post


Link to post
Share on other sites

When I trim wet to leather hard, I don't worry. When I trim a completely dry pot.  .. . I'm cowardly and wear a full respirator, not a rubber band mask. Thank fully I don't have to do that often. I even go outside afterwards to dust off still wearing the respirator. Yes I do think about silicosis, but you can't keep it all away, and there are limits, but why be completely stupid!

 

 

best,

Pres  

Share this post


Link to post
Share on other sites
45 minutes ago, liambesaw said:

It's very cool, but the look is very target/Walmart, probably belongs in industrial process.  Would never have thought something that perfect was made by a person

Unfortunately, that's the problem isn't it?  We have these mass, mass produced wares, that sell for cheap, and people have a tough time understanding, why ceramic artists sell those for more.

It's kind of like marble countertops.  I am not a fan, at all, and I blame it on the faux marble sinks, that were everywhere in the '70s and '80s.  In both cases, a cheaper process copied the look of something higher end.  But because it was cheaper, people started to associate that look, with being a lesser product.

Share this post


Link to post
Share on other sites

Lotta machining and machine adjustments for a limited-production studio. This guy loves precision! In the Wedgewood factory, I can see it, but he'd have to sell a lot of pots to pay a machinist to fabricate that, must have built it himself. (Okay, I watched without listening) Looks like the leather belt on Granny's treadle sewing machine. 

I do really like the basketweave teapot.

Are these slipcast? Guessing yes.

Edited by Rae Reich

Share this post


Link to post
Share on other sites

In my crankiness i didn't explaining viewing the video was no info re danger of dust and yes that's ok in the wide world.....drive down dusty roads all the time , full body load being added to all the time

However in a forum i feel unwise to show video without a mention as new to game folk may think ok to do this technique with clay at any stage of dryness and face it , it is tempting

I now wear protection doung normal farm woek like driving stock..should have watched more cowboy movies but couldnt stand the Indian slaughter and gun content

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.