Monday, 27 October 2014

Post 180 More new pots

These are the reamining 5 pots from my last firing; all with new glaze formulations from my last trial series.
The first two are from an oval mould with a slightly convex wall. The size is a useful intermediate scale.

Oval with rounded flange and lower rib      Pot No125     313 x 245 x 62

 Oval with squared flange          Pot No 128           321 x 257 x 60

The next three are also from the one (different) mould. They show how a slump mould can be used as a basis with different wall profiles to create slightly different pots.  In Post 172 I showed a new bowed wall rectangular shaped pot, with less bow in the walls and more squared corners. These are the first three pots of that shape. Pot 27 shown in that post while still drying is now shown here, below, glazed.

The first one a quite assertive model with squared flange and lower rib as well as quite sharpish corners.      Pot No 124        336 x  242 x  67  

 This one has the same tight corners but no lower rib. It's Pot 127 from Post 172.   
 Pot No 127       340 x  250 x  72

And then finally Pot No 123  with the more rounded corners.      Pot No 123      325 x  240 x  67

Three different pots with slightly different characters from the same mould; from the more formal to the more relaxed.

Wednesday, 22 October 2014

Post 179 New Shohin pots

After this year's show circuit I've been enthused to compete in more classes and so am working away to rapidly develop this season a few  potential shohins that have been on the 'back bench' for a while. I also have a few older trees that I've radically shortened (and posted about) and will work these into smaller pots too. So having something to put these trees into to show has been a motivator to make some stock and build the colour palette.  I'm happy to hang on to these pots especially the semis, no S47 and S48 which are very cute. I've got a couple of little benjamina 'shortys' looking very prospective for these.

The other motivator is a booking I have in a couple of weeks with one of our local Bonsai groups to do a pottery demonstration. I think a lot of people were very interested in and enjoyed the demo done by our Chinese pottery master friend at the Gold Coast conference. This will be an opportunity for a few more people to get a view of the process, albeit a little different, up quite 'close and personal'.

I've had a little warning of the slot and so the pots from this firing  will be useful to show first hand what the opportunities are and also to have something to sell if anyoine is inclined.

There were 16 pots in the last glaze firing - the 11 Shohins shown here as well as 5 mid sized oval and bowed wall rectangular pots. I posted a shot of the pots fresh from the bisque firing recently. The Shohins can be packed in and with the others being mid sized it was a productive glaze firing.

I was also keen to try out some of my 'new browns' from my recent Glaze trial 9. A number of them are here in this group along with a couple of new blues, also from that trial.

S41   Oval with square rim and lower rib    193 x 142 x 44

S42  Rounded rectangular with rounded rim and lower rib   175 x 130 x 52

S43  Oval with rounded rim and lower rib   175 x 130 x 52180 x 134 x 52

S44  Rectangular  165 x 115 x 50

S45  Oval  166 x 122 x 44

S46  Oval  175 x 132 x 55

S47  Square semi cascade   117 x 117 x 70

S48  Square semi cascade   117 x 117 x 70

Here's that little benjamina photoshopped into the pot. With the coming season's growth ahead I think a nice match.

 S49  Oval with textured walls   160 x 120 x 44
S50  Oval  178 x 127 x 46
S51 Rectangular    165 x 120 x 50

Monday, 20 October 2014

Post 178 Seasonal development - grow and cut

In south east Qld we are having perfect growing weather not to hot and not too cool, like goldilocks porridge, just right. This is very typical of our spring weather before the real heat and humidity strikes. Our trees have had a good run over the last 6 to 8 weeks and that time is pretty good for a grow and cut cycle here. We can get anywhere up to 4 or 5 of these cycles to build bulk and ramification.
I’ve got a couple of trees here today that I’ve just pruned for the next cycle. Both have had their tops restrained by tip pruning while the lower branches have been allowed to run.

The first one is a malus which I posted back in August when it was in its beautiful autumnal red. Today its before and after pruning photos. The wire will only need to be there for perhaps 4 or 5 weeks and in 6 or 8 weeks will look like the first photo again.

All that growth builds the trunk and primary branches developing taper and proportion. As you can see I’m happy to leave the top of the tree to be developed when it is the right time; that can always be done easily but if the lower branches aren’t developed now, then later is generally not an available option.

This one is a corky bark elm and has gotten pretty wild. Once again the top of the tree has been clipped to maintain the fine branches and the lower growth allowed to run. Building trunk mass over the years and keeping a tree in a presentable shape can be a slow process. 

And here it is after a good tidy up. Not too much wire in use and the foliage pads have had a good pinching to open them out and let the light in; ready to go again. If I was interested in further developing fine branches now would be a time for total defoliation. Leaving the leaves in place is more likely to result in new individual terminal growth, but that’s ok for a repetition of this cycle.
On my place I have a few big eucalypt trees and November is like another season here – we call it ‘bark’, because that’s when the trees shed their bark and generally make a real mess for a month. Well they’ve started and the first thing to get shed was a big paper wasp nest. I don’t know that I’ve seen one quite this big before and am very pleased I wasn’t around when it fell.


Monday, 13 October 2014

Post 177 Test tiles from glaze trial no 9

In my last glaze trial I continued my hunt for the 'perfect browns'. I started with a limited number of recipes that I liked from trial no 7 and then made a number of minor changes. Over previous trials the strategy has been  to bracket the inter-relationships between the colourants and then in this trial to test the fine detail. It is a valuable process and after a while you get to more deeply understand the colour impact of any one colourant and then the interactions between them.

 The base glazes I used have been described previously in Post 30 and Post 32. Those posts were over 2 years ago and this trial is testament to the value in finding a useful base and sticking with it.

 In each of the following pictures I have include the tile that was the starting point for the series - usually of 4 variations. The final picture is of a blue series where the same process was followed.
For the browns the colourants are generally combinations of Zinc and Chrome, Red IO and Yellow ochre and Cobalt. I haven't used Manganese. I find with my bases that it produces a muddy colour without much life. There is an interesting difference in the iron oxides. The RIO seems to impart an olive tone at low concentrations through to a yellow brown at higher, while the yellow ochre gives more of the red brown tones. So 4%YO and 1%RIO will be entirely different from 1%YO and 4%RIO.
I just added up all the recipes I've trialled to date and it comes to 622. That's 9 firings and 622 test tiles.I'm just starting to be able to predict an outcome, but always surprised at the result.


Now I've got 18 pots to glaze from the last bisque firing and will be using a number of these new formulations for the trial.

Wednesday, 8 October 2014

Post 176 Latest bisque firing

I powered up the furnace this week and now have some work in front of me.
The haul came to 18 pots.

You wouldn't know it but there is a mix of clays here or at least exact formulations. My supplier of the YG clay decided to change the coulourant from a yellow iron oxide to the red. While the raw clay has a different colour (pink rather than yellow) the bisque is the same and the finished vitrified ceramic should also be a similar buff colour. I'm hoping that the RIO colourant does not have the same fluxing effect and pot breakage that came with it in the RGH product when the formulation colourant changed there.

I have three of my new bowed wall rectangular pots, with varying degrees of rounded to sharp corners and three of a new oval with convex walls. There are also two nice little semi cascade pots in there and then a buch of new shohins. All the little loose pieces of clay in the pots are props to be used in the glaze firing. The depth of field effect in the photo is courtesy the gaussian blur filter in photoshop; neat.

In a couple of weeks I'm booked for a pot making demo at one of our local bonsai associations and was keen to be able to take a few pots along. I also wanted a pot I can show in the raw, bisque and finished state to show how it changes. I'm planning on making one of the ovals so will now be set for each stage.

The pots can to a degree be stacked in the bisque firing that is not possible in glaze firing so these pots probably represent two glaze firings coming up. My latest glaze test - number 9 in the series - has produced some nice new brown variants that I'm keen to try out.

Sunday, 5 October 2014

Post 175 Ficus air layering

Please have a look at the POSTSCRIPT at the bottom of this post, regarding the success of this technique.

In May I posted a story about some ficus I've been working on. They are mostly benjamina 'shortys' and the plan has been to turn them into heavy trunked shohin.

For this one, the root over rock, the grafted top has grown on really well considering the time of year the graft was set.
With spring now with us and things getting up some momentum it's time to air layer off the base. I want to take it off just at the level where the rock is visible to make use of the flaring in the trunk at that point.
Partly because if that position and partly to hedge my bets I'm going to do a drill and toothpick layer rather than take off a full strip of bark.

 Here I've marked the level I want to create new root growth.

 Here you can see I've gone around the tree and drilled closely spaced holes, in 
about 3 or 4 mm.

 Next comes the tooth  picks with root hormone on the end inserted in the holes. This shows the sort of nebari I'm aiming for.

 Then it's a matter of positioning the dam to hold the potting medium in place and filling it up.

Now comes the wait. Should be ready by Christmas I'm hoping.

POSTSCRIPT from February 2015.
I waited and waited and nothing happened as it should, so eventually just replaced the ring of toothpicks with the removal of a full ring of bark in the usual manner. This produced roots in about 6 weeks and I separated it soon after. I've tried this toothpick technique on other species and it didn't work well there either so would not suggest using it
 Have a look here to see how it was successfully layered.

Wednesday, 1 October 2014

Post 174 Glaze Trial number 9

I've been making a few pots lately and have a kiln load full and few more drying. While they are I've got onto another trial of glazes. Frankly I've been putting this off for some time and every time I think about it again I change my ideas a little on what to trial. Perhaps that's why it hasn't happened - just hadn't reached that point of commitment. Or mabee it's just that it's such a tedious task. Oh yes and the fact that keeper recipes are in the minority.

In my first posts on glaze testing back at Post 30 and Post 32 I provided the recipes for a number of the base glazes I use.
At Post 77 and Post 79 I covered some work on brown glazes. That was trial 7 and I see then that I missed posting anything on trial 8.

It all starts on the computer with recipes expressed in percentages which then have to be converted into actual weights to mix. I'm now doing individual glazes in 15 gram batches for trial so the percentages have to be converted to add up to 15 grams, without missing any components. Then you have to get down and do the weighing out.


I have a number of base glazes which I use and within each a number of favoured glazes. The objective of this trial is to take those favoured glazes and make minor variations to the recipes to create a number of ranges in tone. So that has made the preparation a little easier. For example if I have 6 glazes to be made from the same base I then mix up 6 * 15 grams of the base and then divide the mixed base between 6 containers for the colourants to be added. That takes a little precision but can be done accurately with a well calibrated 50ml plastic syringe.
On top of that plan there were a few other individual recipes that I wanted to try, as well as a number of overlays combinations.

As you can see from the cup array above I use small disposable 200ml plastic cups to mix and track the trial glazes.

 After all the precision weighing, mixing and combining comes the painting. Because I paint the glaze onto my pots I don't dip or pour to glaze the test tiles, so I paint the test tiles. You begin to see why it is quite a task. This trial came to 53 tiles and I know I can fit 60 in my little kiln.
In this shot you can also see my formulation spreadsheet. The only way I can keep track of what I'm doing as I weigh out is to cross off the material at each recipe. You can see on the spreadsheet the number of individual weighings this trial has taken, by the number of crossed out components.

 And here they are loaded in my little kiln. I've tracked the actual firing performance I use in my big kiln - which is just a little different from the controller schedule because the hotter it gets it is less able to maintain the same rising temperature rate. So the little kiln is programmed to replicate the actual firing achieved in the big one - a very important step for a trial using a different kiln.
Fingers crossed - let's hope more than a few will be keepers.

A couple of days later now and I've edited back into the same post. Here is the first shot of the result, whcih produced some very useful variations. More detail to come.

Post 173 Bandicoots and cockies

Bandicoots are famous or is that infamous for fereting around in people's lawns in springtime looking for something good to eat. I'm not sure that's the right word for it actually because they can be very active aerators. People say we are soooooooo lucky to have bandicoots but I'm not sure I share the sentiment.

The one in this area is probably the Northern Brown Bandicoot, sooo cute says my wife!

They've been visiting my place lately and have taken a shine to a particular patch of grass.

  This was the result of one night's hunt. Each hole can be up to 60mm across and anything up to 100mm deep. They've got little pointed noses and the holes they dig look  like they're just right to get those noses down there.

 I can only guess that they are going after beetle larvae that would hatch out later in summer. The little 'coots are nocturnal and elusive and I haven't seen one yet. Apparently they have a body length of about 400mm and tail about 170mm; about the shape of a big rat and the size of a small fox terrier. As long as they aerate the lawn that's fine. If they find the vegee patch the friendship might not last.

The other visitors who are on a good behaviour bond at the moment are a few sulphur crested cockatoos - cockies as they are known almost universally. These ones have found our feeder and we can hear them from the house, cracking the grain. I let them stay just a short time before 'moving them on'; can't have them enjoying it so much they bring their friends. These are big birds ( up to 500mm long) and they can be quite destructive to man made things, including buildings. They generally move around in quite large flocks. These ones seemed quite tame and one even said 'hello cockie' to me so they are well habituated to people. My reply, in the nicest possible way, 'yes hello to you too, now on your way'.