Search found 270 matches

by Lauri Levanto
Thu May 15, 2003 1:21 am
Forum: Techniques and Tools
Topic: Q: polishing curved surfaces?
Replies: 3
Views: 4737

Grinding and polishing

Thanks Brian, I had forgottn that.
It does not work in winter, when the roads are icy.

I have a Dremel, but have to find diamond pads for it.

-lauri
by Lauri Levanto
Wed May 14, 2003 2:11 am
Forum: Techniques and Tools
Topic: Q: polishing curved surfaces?
Replies: 3
Views: 4737

Q: polishing curved surfaces?

What kind of tools I need? In my kiln cast sculptures I have large surfaces that are slightly curved - convex nac concave. What are the proper tools for grinding and polishing? Just now I have nothing but two grades of diamond pad, 1000 grit wet'n'dry paper and a piece of chamoise to use with alumin...
by Lauri Levanto
Fri May 09, 2003 3:28 am
Forum: Techniques and Tools
Topic: New and boy do I ever need help! PLEASE!!!!
Replies: 21
Views: 20144

Polarisation question

I have tested flat pieces with polarized glasses.
Most of my work is 3D, however, and the
thickness variation seems to affect polarisation.

(Or have I annealed all my reliefs wrong?)

-lauri
by Lauri Levanto
Mon Apr 28, 2003 1:32 pm
Forum: Kiln Casting
Topic: Modeling wax recommendation
Replies: 12
Views: 20940

Removing Wax

I have no proper steaming rig, so I melt the vax (Candle vax or paraffin + beeswax) with a hot air gun. The mold absorb some vax, so when the mold is "empty" I squirt spoonful of acetone in it and burn the residue out. DEFINITELY outdoors!! If the mold is fairly open it burns out clean. In...
by Lauri Levanto
Thu Apr 24, 2003 1:26 pm
Forum: Kiln Casting
Topic: Casting multiples from the same mold?
Replies: 11
Views: 16398

Multiple casting of a ceramic mold

I have worked with ceramic molds, both for slumping and casting. I have used white low-fire clay with 25 percent of grogg. It needs kilnwash regularly, but have lasted over 20 castings w/o significant wearing. I have on web only one photo. It is a slumped float glass piece. http://www.netti.fi/~laur...
by Lauri Levanto
Wed Apr 23, 2003 1:23 pm
Forum: Kiln Casting
Topic: Raku clay slip vs plaster/silica
Replies: 25
Views: 43105

Thanks Charlie for the info on mixing. I didn't know you could let the wet components sit for that long without it going off. The calcining temperature is the point they heat crushed gypsum rock to make the plaster in the first place. That's the point that all of the bound water is driven off and y...
by Lauri Levanto
Fri Apr 18, 2003 6:26 am
Forum: Techniques and Tools
Topic: slumping molds
Replies: 3
Views: 5321

As a sculptor I make all my molds myself. The rest of the work is but clear glass :D Raku clay is sure good, it is designed to stand thermal shock. I have used low fire clay with 25 per cent of 0.2 mm chamotte (=grogg). It takes several firings. I kilnwash it when dry but before the first firing. An...
by Lauri Levanto
Fri Apr 18, 2003 6:16 am
Forum: Techniques and Tools
Topic: Pestle and mortar for crushing glass
Replies: 15
Views: 21952

Stainless inpurity.

I used to by my frit. Now I found a glass factory that produces crucible melt casts. I get their pilt (scrap class) very cheap. The pieces are 1-2 cm thick. Heating and throwing to water gives me pieces with small internal cracks. These are visible in a frit cast piece as spiderweb like structure of...
by Lauri Levanto
Thu Mar 13, 2003 2:47 am
Forum: Techniques and Tools
Topic: Separators - a comprehensive thread
Replies: 39
Views: 53089

To add confusion, when I make a mold for frit casting, the piece is first covered with a splash layer. If that layer is pure plaster, it cracks. Now I am testing with a 50/50 mixture of kilnwash and plaster. The first experiment worked fine. As Hugo mentioned, when kaolin is heated over 760 C it sta...
by Lauri Levanto
Wed Mar 12, 2003 4:33 am
Forum: Techniques and Tools
Topic: Question about fusing on/in bisque
Replies: 5
Views: 11855

I do almost all my work in frit casting in bisquit mold. MOst pieces are shallow reliefs, essentially flat. As Brad said some 800-840 C is a proper temperature, but ramp up slowly at two stages 570-600 C, the quarz inversion point at 573 C is quite a stress for a large flat mold. 650-700 C spend at ...