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Bob Coyle

Member Since 06 Jun 2013
Offline Last Active Yesterday, 10:59 AM

#61085 Glazing Textured Pottery

Posted by Bob Coyle on 18 June 2014 - 10:47 AM

Easiest way to get texture and interest is to just dip the pot in glaze, let it dry, and sponge off the high points so that some of the raw clay shows through. You can also accent the high points by sponging on slips and oxides. kind of dab them on after you sponge of the glaze. There are all sorts of combinations of slip, oxides and glazes that can be applied in sequence. Have some fun and experiment around.

#60407 Glaze Making/ Testing Again!

Posted by Bob Coyle on 09 June 2014 - 06:59 PM

The problem with glaze software is that it might get you close to what you are looking for but it probably won't get you there. You said you want six basic glazes but that is too many. start out very specific as to what your first glaze should look like and then pick an already existing glaze that (supposedly) gives you what you want at cone 6 Then, keep tweaking this glaze ONE COMPONENT AT A TIME as everyone has already stressed. till it starts to look like what you want. Make sure that you have plenty of each material you use. Don't buy 1/4 pound of rutile for your tests and then run out and have to buy from possibly a new batch for your production glazes. Variation in materials can negate all your hard earned progress.

When you get the first glaze to your satisfaction... move on to the next.


Every time you run a glaze test that doesn't work out... ask for help here or over on http://cone6pots.ning.com/   There is at least a thousand years of expertise in glaze development between these two sites.


Don't get discouraged. stay focused on specifics. there is no single answer as to how to develop a glaze. If you are really going to do this... WRITE EVERYTHING DOWN.


And what is really cool, is that sometimes you do an adjustment but it doesn't look like what you wanted in the first place but it is absolutely beautiful in it's own right.  Now you have another glaze that you can use.

#59906 Does Any One Else Miss This Nutcase?

Posted by Bob Coyle on 03 June 2014 - 02:17 PM

The problem I have with abstract art is that a whole lot of it is not very good, yet people insist that it have some meaning beyond what it looks like. Seems like most people think there is a statement behind Peter Voulkos abstract works but nobody seems to know what that is... but by golly there MUST be a meaning somewhere. People have said that they see great skill and mastery in Peter's later works. I am not sure what skill they are talking about, but I am willing to be educated.


Here are two of Peter's works. To me they look sloppy and careless, though I am sure that people will say no,no... they are spontaneous!


So what is the deeper meaning here, and ...truthfully now.. would you pay $5000 for them if  you saw them at a craft fare?

Attached Thumbnails

  • Voulkos dolls.jpg
  • peter-voulkos-untitled-sculptures-ceramic-2.jpg

#59220 Does Any One Else Miss This Nutcase?

Posted by Bob Coyle on 25 May 2014 - 12:03 PM

I came into doing ceramics rather late and never got to meet any of the more well known clay artists of the pre-millenial era. They all seem so "bigger than life" in the articles I have read about them. That said, I really don't much like the art that many of them ended up doing. I once watched a video of Peter Voulkos tearing off blobs of clay and stomping on it then slapping it together as art. Paul pretty much ended up doing the same. Big crappy, slabs slapped together and everyone saying...OOH...AHHH Abstract Expressionism!


I think a large part of art is technique, and I think a large number of people abandoned it to "get with the program". Probably Paul thought what he was doing was pretty funny... he seemed to have a wry sens of humor.

#58946 Raku Party - How Can We 'do It Up Right'?

Posted by Bob Coyle on 21 May 2014 - 10:19 AM

I used to host pit fire/raku get togethers when I lived in Santa Cruz CA. Most of the people had some experience in this so they were not likely to fall into the pit or try to remove their piece from the kiln with their bare hands.  My wife and I served home made chili and soft drinks. No beer or wine. Never had a problem, but I was not charging money and I knew most of the people that came. One woman had small kids but she was savy enough to keep them well away from the fire.


You better check what  your liability insurance covers... there are some real idiots out there but it sounds fun... hope you can pull it off.

#58823 Problems With Plasticity

Posted by Bob Coyle on 19 May 2014 - 01:48 PM


 If it fires okay, and you don't have access to other clay, mixing in ball clay isn't the worst thing in the world.

I have used inexpensive bagged fire clay as an additive instead of ball clay. The stuff I got was pretty full of crap so you might have to screen it to make sure you get out big chunks. The river bank clay I found required almost 50% addition to get a throwing body. If I coil built, I could have used much less. fired well at cone 5.

#58324 Carving Stamps - Any Tips?

Posted by Bob Coyle on 11 May 2014 - 10:55 AM

You can use Sculpty clay to carve on then bake it. It holds up pretty good and is not so much work as carving with a Dremel. I have also just used a hot melt gun to extrude a pattern onto a wood block. Not good for more intricate designs but you can make some nice patterns quick.


Another thing I have done is to impress a pattern into damp clay and then pour 5 min epoxy into the impression. It cures up and you have the original positive pattern. Just wash off the wet clay and you are ready to go. I used this technique with letter stamps to make whole words that were in perfect register so that I did not have to stamp each letter one at a time on every piece. Works great.

#57873 Reflections On The 2014 Spring Craft Fair (Tennessee)

Posted by Bob Coyle on 04 May 2014 - 01:40 PM

Good info Paul. Hope it plays out the same in the studio tour here in a couple of weeks.

#56176 More Clay, Wood And Metal Sculptures

Posted by Bob Coyle on 06 April 2014 - 07:57 PM

Yeah Tyler


Wire brushed it and then "tempered" :) the metal pieces  with a propane torch. The metal is attached to the wood behind with a 1/4" elbow and "floats" about a 1/4" in front of the clay piece... Looks a lot more 3D than the picture.

#56160 More Clay, Wood And Metal Sculptures

Posted by Bob Coyle on 06 April 2014 - 03:19 PM

Fired up the old forge and beat and hammered some bar stock into a curve. Attached it so it floats in front of a faux pit fired  micacious clay and wood.



Attached Thumbnails

  • metal1small.jpg

#56159 Hand-Built Baking Pans?

Posted by Bob Coyle on 06 April 2014 - 03:10 PM

I would get a chunk of 2" x 12" from a lumber yard (sometimes they have trim ends that they are throwing away. Cut it 9" x 13" and cut a bevel on all sides. /___\   This forms an inside mold that works great. I use them for my senior center beginning clay class. They release almost as well as plaster if you dust them with corn starch.

#55908 Mystery Chemicals

Posted by Bob Coyle on 01 April 2014 - 06:53 PM

Color might help. If they are white or grey they could be feldspar, frits, or clay. If they are colored they might be pigments.  Try a dropping a little into a few ounces of vinegar on each one. If it fizzes a lot and completely  goes into solution, then it is probably a carbonate of some sort. If not, it could be a frit or a feldspar.


get a piece of of nichrome ( old kiln element wire) or iron wire and dip it in the vinegar solution of the unknown.. put it in the flame of a propane torch. If it burns red you may have lithium or strontium.  If it burns green, you have copper or barium.  Most frits and feldspar's will show a yellow sodium color. potassium feldspar might show violet tones but might be obscured by the much stronger yellow sodium color.


Then follow Neils advice.


Also hope like hell that you don't use these unknowns and come up with a glaze that is a total knockout... you may not ever be able to reproduce it after you run out of whatever you used to make it.

#54899 Foil Saggar Results

Posted by Bob Coyle on 17 March 2014 - 05:32 PM

Wow Marcia! I'm impressed. That's a lot of torch firing. Maybe you need to graduate to a weed burner. :)

#54577 Vintage Materials

Posted by Bob Coyle on 13 March 2014 - 01:52 PM

Ruth... Those materials are pretty old...you better check the expiration date on the packages... they may not be good anymore :rolleyes:

#54494 Glaze Test Ga28-A Green Breaking Blue

Posted by Bob Coyle on 12 March 2014 - 10:38 AM



Interesting adjustment you made there by substituting additional Gerstley for the spodumene. You effectively changed out the lithium flux (from the spod) for twice the boron (from the additional Gerstley).

That is correct Dick. I didn't have any spod at the time and tried an adjustment with Li Carb and upping the ball clay. I had a ton of G borate so I tried that as a flux  instead and it worked out OK. I added extra TiO2 to opaque it more.


I am trying for a more antique look and the roughness is fine. Firing at cone 6 will smooth out the bumps but produces more gloss with some loss of the green break. The green break also depends on the clay body. Works on darker stoneware bodies.