Baking dish to bonsai pot?

[Smoke]

I think with the right tree this one may be pretty cool.....

 

[Poink88]

How about this $8.00 - 3" deep x 13" long oval baking dish?

View attachment 29976

 

[Vance Wood]

How about this $8.00 - 3" deep x 13" long oval baking dish?

View attachment 29976

Usually pots with glazed interiors tend to get too hot during the summer. Posts glazed on the outside tend to not be too good for conifer bonsai. There is really nothing particularly bad about this idea other than the likelihood of failure. I don't think you will be able to find the right kind of pot other than stoneware, porcelain pots, as pointed out previously, have glazed interiors and stone ware is probably not fired to high enough temperatures to with stand winter temperatures.

 

[Vance Wood]

I think with the right tree this one may be pretty cool.....

That would make for a great meat loafsai.

 

[RichKid]

Usually pots with glazed interiors tend to get too hot during the summer. Posts glazed on the outside tend to not be too good for conifer bonsai. There is really nothing particularly bad about this idea other than the likelihood of failure. I don't think you will be able to find the right kind of pot other than stoneware, porcelain pots, as pointed out previously, have glazed interiors and stone ware is probably not fired to high enough temperatures to with stand winter temperatures.

So the inside glazed is a no no? All the pots I was planning on trying to use have the insides glazed. I was wondering if this would be a problem. The only con I came across was that the roots would have a hard time gripping the slippery surface. Never heard anyone mention heat retention. Is there anyone who has come across solid research on the subject?

 

[Dav4]

How about this $8.00 - 3" deep x 13" long oval baking dish?

View attachment 29976

...baked ziti?...

 

[Vance Wood]

So the inside glazed is a no no? All the pots I was planning on trying to use have the insides glazed. I was wondering if this would be a problem. The only con I came across was that the roots would have a hard time gripping the slippery surface. Never heard anyone mention heat retention. Is there anyone who has come across solid research on the subject?

I just remembered something (call the presses Vance remembered something!), I have used glazed pots for Maples and Hornbeams and I have found that glazed pots do not stand up to winter conditions here in Michigan very long. First the glaze will crack and water will seep into the cracks, freeze and crack the pot further.

After examining the debris of some of these pots I discovered that the substance under the glaze, the unglazed body of the pot, is much softer than the body of an unglazed pot and once exposed to the elements will crumble into dust in short order.

So here is my point. Unless the pans you choose are fired at a very high temperature, over 2,000 degrees, they will not hold up in the areas where you have had to drill through to make drain holes.

 

[RichKid]

I just remembered something (call the presses Vance remembered something!), I have used glazed pots for Maples and Hornbeams and I have found that glazed pots do not stand up to winter conditions here in Michigan very long. First the glaze will crack and water will seep into the cracks, freeze and crack the pot further.

After examining the debris of some of these pots I discovered that the substance under the glaze, the unglazed body of the pot, is much softer than the body of an unglazed pot and once exposed to the elements will crumble into dust in short order.

So here is my point. Unless the pans you choose are fired at a very high temperature, over 2,000 degrees, they will not hold up in the areas where you have had to drill through to make drain holes.

At the risk of sounding like an idiot, is there any way to tell how high a temp they were fired at? The dishes I have are mostly collected from friends and family who were getting rid of them. I'm not the original owner.

 

[Poink88]

At the risk of sounding like an idiot, is there any way to tell how high a temp they were fired at? The dishes I have are mostly collected from friends and family who were getting rid of them. I'm not the original owner.

Not sure how true or reliable but I was told the "ping" test. Just flick on the pot and listen to the sound. If it is a high pitched resonating sound, it is supposed to be high fired. If it is a dull sound, it is likely porous/low fired.

Any one else heard this? True or False?

 

[Paradox]

For interim pots between training pot and finished tree pot, I found some heavy plastic round "saucers" that are used for drainage under larger pots at the local garden center. The ones I have are 16-18 inch diameter for larger trees and cost about $4 each. I can make holes in the bottom easy enough and they are a nice dark green color so should look bad while I try to find the right finished pot.

 

[Vance Wood]

At the risk of sounding like an idiot, is there any way to tell how high a temp they were fired at? The dishes I have are mostly collected from friends and family who were getting rid of them. I'm not the original owner.

Probably not. Even if you knew the manufacturer and could get in touch with them it is questionable as to whether they would give you the information you have requested. The bottom line is this, in my mind: As long as you are not looking to use these dishes as a final home for any of your trees go ahead and use them. Just don't expect anything more than three or four years use out of any of them.

 

[rockm]

"After examining the debris of some of these pots I discovered that the substance under the glaze, the unglazed body of the pot, is much softer than the body of an unglazed pot and once exposed to the elements will crumble into dust in short order."

This is true for only some pots. It greatly depends on the glaze and the underlying clay. I've used glazed pots for many years. I've had some that spalled (lost their glazes), most don't. Glazed pots are fired and the clay underneath is too. Softer clays on cheaper pots will crumble.I've found chinese pots that are made with an engobe process in which a different colored clay slip is applied to a softer clay underneath. These pots tend to deteriorate quickly in feezing weather.

The thing to understand here is that Stoneware is fired at extremely high temps, terra cotta and earthenware at lower temps. Most quality bonsai pots (glazed and unglazed) are stoneware, from the better Western potters to Tokoname and now China.

As a rough guide, earthenwares are normally fired at temperatures in the range of about 1,000°C (1,830 °F) to 1,200 °C (2,190 °F); stonewares at between about 1,100 °C (2,010 °F) to 1,300 °C (2,370 °F); and porcelains at between about 1,200 °C (2,190 °F) to 1,400 °C (2,550 °F).

The higher the firing, the more resistant to freezing the clay becomes. The high firing melts the clay so its becomes impervious to water. Lower fired clay like earthenware and terra cotta allows water to penetrate the surface, which, in cold weather, freezes and breaks down the clay by expanding inside it.

It's not hard to really tell stoneware from earthenware. Stoneware is essentially glass. It doesn't leave dusty residue on your fingers, like terra cotta or earthenware. It also, as pointed out, rings clearly when tapped. Lower fired vessels tend to go "clunk" when tapped with your fingernail.

Baking dishes are porcelain, which is basically glass. They are high fired and will probably stand up to the weather with no problem.

 

[Poink88]

Usually pots with glazed interiors tend to get too hot during the summer. Posts glazed on the outside tend to not be too good for conifer bonsai. There is really nothing particularly bad about this idea other than the likelihood of failure. I don't think you will be able to find the right kind of pot other than stoneware, porcelain pots, as pointed out previously, have glazed interiors and stone ware is probably not fired to high enough temperatures to with stand winter temperatures.

Based on Rockm's post below (which is very consistent of what I've read), why would inside glazing matter if high fired pots basically turns into glass anyway? Or are conifers better off on lower fired porous pots so they can "breath" better?

The thing to understand here is that Stoneware is fired at extremely high temps, terra cotta and earthenware at lower temps. Most quality bonsai pots (glazed and unglazed) are stoneware, from the better Western potters to Tokoname and now China.

As a rough guide, earthenwares are normally fired at temperatures in the range of about 1,000°C (1,830 °F) to 1,200 °C (2,190 °F); stonewares at between about 1,100 °C (2,010 °F) to 1,300 °C (2,370 °F); and porcelains at between about 1,200 °C (2,190 °F) to 1,400 °C (2,550 °F).

The higher the firing, the more resistant to freezing the clay becomes. The high firing melts the clay so its becomes impervious to water. Lower fired clay like earthenware and terra cotta allows water to penetrate the surface, which, in cold weather, freezes and breaks down the clay by expanding inside it.

It's not hard to really tell stoneware from earthenware. Stoneware is essentially glass. It doesn't leave dusty residue on your fingers, like terra cotta or earthenware. It also, as pointed out, rings clearly when tapped. Lower fired vessels tend to go "clunk" when tapped with your fingernail.

Baking dishes are porcelain, which is basically glass. They are high fired and will probably stand up to the weather with no problem.

Thanks!

I noticed some are labelled as porcelain and others as stoneware ceramic.

 

[Poink88]

Good luck drilling them out...

Thanks. The diamond coring bit won't have any problems going through these. At work, we've used them on concrete, through rebar and even 1/2" stainless steel bolts w/o a problem.

 

[rockm]

"we've used them on concrete, through rebar and even 1/2" stainless steel bolts w/o a problem"

Yeah, but those materials aren't glass. You might consider a tile bit.

 

[Poink88]

"we've used them on concrete, through rebar and even 1/2" stainless steel bolts w/o a problem"

Yeah, but those materials aren't glass. You might consider a tile bit.

These go through tiles as well...same abrasive material is used...diamond.

 

[rockm]

I don't think it's a question of the cutting material. I think the issue would be the surface area the core bits cover.

I've only drilled pots with single bits, not the core bits you're using, though.

 

[KennedyMarx]

I dunno about baking dishes but I have a ceramic bowl that I drilled a drainage hole into and it looks pretty good as a bonsai pot.



Not the best picture but you get the idea. Pardon the scraggly looking boxwood.

 

[Poink88]

I don't think it's a question of the cutting material. I think the issue would be the surface area the core bits cover.

I've only drilled pots with single bits, not the core bits you're using, though.

You lost me there. Coring bit has minimal area actually since you are only cutting around the hole (perimeter)...leaving the center untouched.

Believe me on this, no better tool to drill big holes on ceramics/glass/tiles/concrete/rocks is commercially available.

In my 20+ years in construction, this has always been the tool used in drilling tiles (for pipe penetration). In our case, a diamond bit would be ideal for the anchor holes...thankfully I have those too.

 

[GrimLore]

This started out as a inexpensive bonsai pot thread and ended up a Tim The Toolman thread. Please explain Dario as you started it

Note: Levity