Firing And Repairing Old Greenware

[Troika]

Hello everyone!  I am new to this forum and have what I hope is not a unique situation.

 

I recently purchased four unfinished Troika bisque wheel vases from a UK auction house last week.  Despite great packing with bubble wrap and Styrofoam peanuts, one of the vases was damaged in shipment.  i was a bit surprised that the bisque vase would be so damaged since the box didn't show any signs of impact.  The other three vases in the box were undamaged and the auction house is refunding one fourth of the hammer price as compensation for the damage.

 

When I compared one of the undamaged vases to an identical vase that has been glazed and fired, I immediately noticed the bisque vase was overall larger than its finished version.  I checked the other bisque vases to similar finished versions, and they were larger as well.  Then I examined the broken vase and discovered that the loose material easily crumbles and all vases can be scratched with no problem.

 

This leads me to conclude that I did not purchase bisque vases, but purchased greenware.  I have mixed feelings about this, as the unfired Troika greenware is more rare than the unfinished bisque. 

 

As a bit of history, Troika was active in Cornwall from 1963 to 1983 and produced lots of ceramics (mostly from slip) before closing its doors.  Some of the unfinished pieces and molds that weren't immediately tossed were stored in barns or attics for decades before being scrapped or sold.  It's possible that my vases were made while Troika was still in business, or were made by someone else later using the original molds.  Some fakes have appeared on the market, but these are easy to identify.  The fakes were made by creating molds of finished pieces, then decorating and firing them.  The results were lesser quality and smaller than the originals.

 

Regardless of the origin, will there be any issues with firing the greenware to produce bisque?  I do not want to finish the vases, but want to leave them in a state that will make them less fragile.

 

Is it possible to repair the broken vase to a condition that it can be fired with a reasonable chance of success of surviving the kiln?

 

What I don't know about ceramics will fill volumes, so I am relying on the experts to guide me.  As soon as I take photos of the items, I'll post images of the vases here.

 

Thank you in advance!

Mike

[Benzine]

You should be able to repair the piece. There are numerous recipes to make a greenware mender. A bsic recipe involves corn syrup, vinegar, paper pulp and clay powder from whatever the rest of the ware is made from. The last ingredient woukd be your hang up, unless you know what type of clay the wares are made from.

 

If you can figure that out, you should easily be able to repair and fire the wares.

[Troika]

Thanks, Benzine!  I read some of the other threads about repairing greenware and they all required material from the original pour.  Assuming my vase is original, the last opportunity to find the material was in 1983.

 

Will there be an issue firing the other three vases if they are so old?

[MatthewV]

I really doubt they are greenware.

Do the whole pieces making a light ring when pinged with a fingernail? Or a dull thud?

 

Repair really depend on how it was broken. In general, most people find it not worth the time and effort to repair -- it is faster to make a new one. I do not believe I could repair the cast piece to the original quality.

[Troika]

I really doubt they are greenware.

Do the whole pieces making a light ring when pinged with a fingernail? Or a dull thud?

 

Repair really depend on how it was broken. In general, most people find it not worth the time and effort to repair -- it is faster to make a new one. I do not believe I could repair the cast piece to the original quality.

The vases make a thud when pinged.  I compared the sound to completed vases, and the finished vases have more of a ring to them.

 

Unfortunately, making a new one is not possible as the Troika factory closed its doors 33 years ago and most of the molds were scrapped.  The damage is contained to one area, and there are several large pieces.  There is lots of dust in the bubble wrap where the broken pieces has been bounced around.  I'll post images of the pieces as soon as I can set up my camera.

 

I might sound a bit off base by trying to salvage this piece, but it does mean a lot to me and I certainly appreciate the comments.

[MatthewV]

Well, I guess they could be greenware! The surprise could be that only one broke :-)

 

OK-- I have been most successful with repair by putting the dry pieces back in place, using one drop of water on the crack at a time, and using a needle to scramble the joint. A smooth finish can be made with a rubber-tip brush. If there is enough thickness success is possible. This method fixes just the surface hopefully well enough to be glazed.

 

I have tried adding clay -- only makes the cracks worse.

I have tried vinegar water -- I don't like the smell and couldn't see much of a difference.

I have never tried to fix a thrown of cast piece.

[ayjay]

 

  There is lots of dust in the bubble wrap where the broken pieces has been bounced around. 

 

 

 

Mix some of that dust with a little water, you will either end up with clay, or gritty water.

 

If it's clay the pots are greenware etc etc

[Troika]

 

Mix some of that dust with a little water, you will either end up with clay, or gritty water.

 

If it's clay the pots are greenware etc etc

 

 

I'm doing this now.  It didn't help when my wife walked in and saw me leaning over the desk pushing some white powder into a spoon.

 

The white powder seems to have been turned to a gray paste, and the smaller chunks I added to it crumble easily and appear to be dissolving.  The paste is still a little gritty, but I'll let it rest for a while and see what happens.

[Troika]

Well, I guess they could be greenware! The surprise could be that only one broke :-)

 

OK-- I have been most successful with repair by putting the dry pieces back in place, using one drop of water on the crack at a time, and using a needle to scramble the joint. A smooth finish can be made with a rubber-tip brush. If there is enough thickness success is possible. This method fixes just the surface hopefully well enough to be glazed.

 

I have tried adding clay -- only makes the cracks worse.

I have tried vinegar water -- I don't like the smell and couldn't see much of a difference.

I have never tried to fix a thrown of cast piece.

I'm surprised only one broke as well.  The vase that broke was touching the base of the other vase, where the material is thicker.  The other two vases were bottom to bottom and there was another layer of bubble wrap around the smaller vase.

 

If these unique versions were still available, the broken vase would have already been in the trash.  I'll give it a reasonable attempt to fix, then it goes to the back of the storage shelf until I decide what to do with it.

[oldlady]

you have piqued my interest so i looked for Troika online.  found they started in 1963 and the company died in 1983.  your avatar is one of their pieces, isn't it?

 

what is it about the Troika pieces that attracts you?  how do you plan to finish the ones you have bought and what will you do with them?

[Troika]

you have piqued my interest so i looked for Troika online.  found they started in 1963 and the company died in 1983.  your avatar is one of their pieces, isn't it?

 

what is it about the Troika pieces that attracts you?  how do you plan to finish the ones you have bought and what will you do with them?

 

Thank you for asking!  Yes, my avatar is a Troika medium wheel vase, and is about 6.5 inches tall.  It was made from the same mold as one of the greenware vases that survived the shipping.

 

The first time I saw a piece of Troika on the UK show "Flog it!", I immediately liked it.  The unusual shapes, patterns, textures, and colors appealed to me.  The more I saw, the more I liked them.  Several years later, I was able to buy several vases and a lamp base from another UK auction house.  Now, I have well over 100 pieces of Troika, and am still looking for more.

 

The earlier pieces tend to be smooth, but after a few years, Troika started making the textured items for the Cornish tourists.  They are tactile and still useful.  I have several lamps around the house as primary lighting, and have several vases with dried flowers and and jardinieres with plants as decoration.  The rest are in display cases or displayed on shelves around the house.  Fortunately, my wife likes Troika almost as much as I do.

 

I won't be finishing these vases and planned on nothing more than preserving them.  Today I spoke with a Troika historian, and he doesn't recommend firing the greenware.  It has poor results and tends to disintegrate.  He has a few pieces of greenware as well and learned the hard way to not fire them.

[Benzine]

I don't know why firing them would cause them to disintegrate?  The only thing that should cause a greenware piece to come apart in such a way, would be moisture.  And in that case, it's usually only a lot of moisture in a small amount of time.  Like if you soaked bone dry greenware in water, or even wrapped it in sopping wet towels.

[Mark C.]

You will be far better drying them and bisque(low fire) firing them for storage than keeping them in a green(unfired ) state.

[MatthewV]

But keeping them greenware seems to be desirable from a collecting standpoint. With careful handling and prevention of water damage, there is little reason to fire them.

[Chilly]

How abut firing the one that is broken, then if it works out OK, you could glue it together, and also fire the others.

[Troika]

I don't know why firing them would cause them to disintegrate?  The only thing that should cause a greenware piece to come apart in such a way, would be moisture.  And in that case, it's usually only a lot of moisture in a small amount of time.  Like if you soaked bone dry greenware in water, or even wrapped it in sopping wet towels.

 

I don't know either, but I don't know much about ceramics.  I have to rely on experience with similar greenware from the same era.

 

But keeping them greenware seems to be desirable from a collecting standpoint. With careful handling and prevention of water damage, there is little reason to fire them.

 

I have mixed feelings about firing the vases.  I am confident that I can maintain them in their current state until its time to pass them on to the next custodian.  However, making some attempt to harden them will increase the potential that they will last longer.

 

 

You will be far better drying them and bisque(low fire) firing them for storage than keeping them in a green(unfired ) state.

 

How abut firing the one that is broken, then if it works out OK, you could glue it together, and also fire the others.

 

I think I will fire the broken vase as soon as I find an available kiln.  This will allow me to see how the old greenware reacts to the firing.  However, I don't know if the pieces will fit if they are fired separately.  I am concerned that they will distort in the heat.

[Troika]

I apologize for the delay, but here are some images of the greenware and a piece of finished Troika from the same mold for a side by side comparison.  Without having a finished example for comparison, i would not have been able to determine this had not been fired based on the size.