Friday, 1 August 2014

Post 162 Bonsai Table construction #2

My universal carpentry tool is a little 8 inch bandsaw. I'd be lost without it, a real workhorse. The downside is that when I need precision every cut has to be finished off in another way and when you are doing mitres precision is first, second and third priority. Number two tool is a table mounted router. It's the finishing and precision tool, wonderfully versatile even if it is a bit scary.

The first job is 'close to final cuts' into manageable pieces to further mark out and cut again.

Here you can see the table top sections and the undercarriage, legs and rails. The four pieces of the table top are cut from wide boards and with mitres this wide there is no room for error. Opposite sides must be exactly the same length and the 45 degree edges must be nothing but 45 and straight and square and flat. I have routed a ledge in the opening in the middle to house another closing piece of timber. I used biscuits to join these pieces and pulled them together with a strap clamp; what a fantastic tool for that job. The legs are going to be a fiddle as I'm laminating them up from a number of board sections. Not sure how this is going to go.

 Here I am getting into assembly. The old shoe laces are really useful, don't laugh.
As I do so I realise I've allowed impatience to triumph again and am going to have to wrestle with those legs all interconnected when it would have been better to finish their construction and sanding individually. Arrrrrhhhhhhh!

This is the joint at the top corner of each leg. The timber is mitred on the front and side and top.

Here are the front and back undercarriage assemblies. Another valuable tool I have is a spindle sander. It cuts material off quickly and neatly when wanted and does a fantastic job on curves.

Thursday, 31 July 2014

Post 161 Bonsai Table construction #1

It’s heading into exhibition season here and in particular the BCI conference in August. I have a couple of trees (and pots) listed for the exhibition and so need them presented at the right height.
I made three tables back in March for the Redlands NativeBonsai Exhibition but now need another one with a large table top.
Getting the tree at the right height is critical to the whole look and feel and the conference tables are going to be the standard 750 height so the new table will need to be about 330 high. I posted some research I did on this a while ago on Post 139.
In March I made the tables with pine and while it was relatively low cost and easy, the timber remains fairly soft and easily damaged. I’m actually doing a job on the larger one right now to inlay new table top corners of a harder timber. Just little triangular pieces of timber cut at 45 degrees to give that exposed point a little more durability.

This is the insert prior to painting
So this time I’m biting the bullet and going for a harder timber and having a shot at a more interesting design.

My normal design process is the back of the envelope to start, with the basic shape and dimensions. Here then are the working plans for the project. I like the look of the double miter often used in higher quality tables and thought I should give it a go.

That said the proportions have to be right and I do like to mock up a template or model at full size to eyeball the design and make the adjustments when they are easy to do. A light cardboard sheet is ideal and enables a front and side view. 

My woodworking equipment is a bit of a limitation and so I try to use commercially available material in standard board sizes. This influences the design a bit too. Flat and straight pieces of timber are essential to reducing the size of the job so I’m very picky at the local hardware shop. I'd love a good table saw but my pottery/woodwork shop would need a second floor.
The timber I’ve chosen this time is American Red Oak, from Masters, nice grain.


It looks, feels and works like Tasmanian Oak which I’ve worked on before. It is a hard timber which keeps a good edge and has an attractive grain. Tasmanian Oak is of course eucalypt timber (any one of three varieties apparently) as we don’t have oaks. But the Red Oak really is oak.


$120 doesn’t go far buying timber these days and this is what I have to show for it; better make a good job of it.

Wednesday, 30 July 2014

Post 160 New Pots - another firing

I had a request to make a rectangular pot 'like Pot No 38' which I made in February 2013 . It had a length of about 360mm and was 79mm high.

The requested pot was just a bit longer and a bit higher, but with the same glaze colouring and effect. Well easier said than done when the colouration is principally achieved by the different depth of application of the glaze to give the patinated mottled look. I keep careful records of glaze recipes I use on which pot but as to the detail of how I apply them well that's a different matter.
I'm not keen on making rectangular pots because of the risk of deformation which is less likely and less apparent where the walls have some curvature. The making of a rectangular pot is best accomplished by using slab formed clay which has dried flat to a point of inflexibility and is only moved by board flipping. By doing this the only memory the clay has is of being flat and straight. The drier the clay of course the higher the risk of joint failure and the more care needs to be taken. Also the thickness of the clay on the corners needs to be uniform and consistent with the walls so that there is little differential contraction at the corner to promote bowing. All this takes more time and carries greater risk which is why all makers charge more for rectangular pots than other shapes.

Despite all that I've done pretty well on the colour match. One wall has a little bow but that is one of those wabi-sabi atefacts of a hand made pot and will be invisible to the eye in use.
 Pot No 122 Rectangular at 373mm x 281mm x 85mm

 Post 153 in June was about glaze crawling on a large oval pot. The next pot, Pot No 121, is its replacement in a slightly different glaze formulation, still a high gloss dark blue.

 Pot No 121 Oval at 470mm x 342mm x 88mm

 Pot No 121 overview

 Pot No 121 Glaze detail

The next one, Pot No 111 is a nice little oval pot in a pale blue glaze.

  Pot No 111 Oval at 273mm x 205mm x 53mm

I made the next two pots to eventually contain a couple of my ceramic tanuki/sergent trees. Because the ceramic tanukis have fairly substiantial base diameters I wanted pots that have a complementary depth. The first one is one of my compound shapes. The glaze has an antique base overglazed with beige. I though it might be darker but this is a fine match for the colour of the 'deadwood'.
  Pot No 115 Compound at 270mm x 197mm x 79mm

 Pot No 115  Overview

 Pot No 114 is a rectangular pot fired with a mottled mid brown glaze.

   Pot No 114 Compound at 245mm x 185mm x 78mm

And the last one for this firing is a Shohin, Pot S38. It is a bowed wall rectangular pot with a rounded flange and lower wall rib. The glaze is the same dual combo as Pot No 115.
Shohin S38 at 176mm x 133mm x 53mm