Login | Contact

Vancouver Island Pottery Supply

View Catalog

Normal Hours of Operation
Monday - Friday 9 - 4 pm

Information

Home

About

Map

Plainsman Products

Clays

Low Temperature Clays

Medium Temperature Clays

High Temperature Clays

Porcelains

Other Clays

Native Clays

Casting Slips

Materials

Dry Materials

Stains

Liquids

Encapsulated Stains

Glazes

Low Fire Glazes

Medium Fire Glazes

Liquid Brights

Underglazes

Spectrum 500 Underglazes

Crysanthos Underglazes

Spectrum RAC Underglaze Pens

Underglaze Tools

Enamelling

Enamelling Supplies

Enamelling Tools

Equipment

Kilns

Potter's Wheels

Slab Rollers

Hand Extruders

Pugmills

Scales

Banding Wheels

Air Brushes

Tools

Brushes

Throwing Tools

Trimming, Turning, Cutting Tools

Wood/Bamboo Tools

Wire and Wood Tools

Rollers/Stamps

Decorating Tools

Glazing Tools

Ribs & Scrapers

Ribbon/Wire Tools

Rasps

Knives, Needle Tools, Cutters

Sculpture Tools

Tool Kits

Unclassified

Accessories

Miscellaneous Accesories

Corks/Stoppers

Cork Pads

Oil Lamp Accessories

Dispenser Pumps

Teapot Handles

Bisque Tiles

Magazines

Sign up and get our Tech-Tip monthly email

You will get practical messages like those shown below.

Welcome

This is our new site as of Aug 25, 2020. It will help us to serve you better. PLEASE NOTE WE ARE IN THE PROCESS OF PUTTING VANCOUVER ISLAND PRICES IN OUR NEW CATALOG. We are configuring and adapting it in the coming weeks for better information and better functionality on smartphones. Stay tuned for more services to come via this site as well.

Click the links to the left to get information and pricing on our products. Click the "Plainsman Data Sheets" for details information on the use and Plainsman clay bodies and glazes. The blog below is intended to help you with all manner of technical issues in ceramic hobby production, these posts come every few days, so check back often.

Technical Tips Blog

Knowing about recipe limits would save you the work of testing this glaze

A recipe accompanied by fancy pictures that make it look credible

This is an example of a recipe being trafficked online that raises red flags just looking at it. The first red flag: There is no silica! That means this is a low fire glaze masquerading as middle temperature, so it is going to run during firing (run a lot). It will also mean poor durability. There is a ton of feldspar, that means a high level of sodium. Without low-expansion MgO to counterbalance it's high thermal expansion the glaze is likely going to craze badly. The mechanism of the crystallization is titanium over-supply, this has triple the maximum I would ever put in a glaze. The crystallization happens during cooling in the kiln (producing the visual effect being sought). But the the surface produced will cutlery mark and stain, probably very badly. Given the unbalanced chemistry this has, any colorant added will likely be leachable! I tested it and all my fears were realized. My slow-cool firing made the surface so dry it was very unpleasant to touch. Maybe this needs fast cooling. But who knows, there are no notes. This does not appear to belong on any functional ware, inside or outside. Someone noted that people use this to produce layering effects (see links). That begs documentation on how that wold work. Without gum would it lift and crawl as layers are added over it. Would you have to overlay every square inch? Would it still craze? All the how-to information needed to make it work are more important that the recipe itself.

Context: Trafficking in Glaze Recipes, Crystal Magic at cone6pots.com, Stephen Hill Pottery, Limit Recipe

Thursday 15th October 2020

G1916Q transparent on terra cotta body at cone 06, 05, 03

Three clear-glaze terra cotta mugs with rich red color

The body is Plainsman L215. We used the 04DSDH firing schedule. The glaze is inexpensive to make so we have a 2 gallon bucket. It has good dipping much like a stoneware glaze so it is easy to apply quickly and evenly. For most terra cottas, body strength increases dramatically by cone 03. However the most transparent and glassy glaze surface happens at cone 06. Terra cotta bodies need to be bisque fired fairly low (e.g. cone 06) to have enough porosity to work well with dipping glazes. After cone 06 they generate increasing amounts of gases (as various particle species decompose within), for this reason the glazes can have more micro-bubble clouding or tiny dimples in the surface. This glaze has 2% iron oxide added as a fining agent to remove the bubbles. That iron also reddens the color and variegates the surface somewhat. Even though the surface character at cone 03 is not a smooth, it has a natural charm, and the color is very rich. And that piece has stoneware durability and strength.

Context: G1916Q, Terra cotta

Thursday 15th October 2020

Add 2% iron oxide to a transparent glossy low temperature glaze to get better color, less clouding

Two brilliantly transparent glazed terra cotta mugs

Both pieces are the same clay body, Plansman L215. Both are fired to cone 03. Both are glazed using G1916Q recipe. The glaze on the piece on the left has 2% added iron oxide (and sieved to 80 mesh). Each grain of iron (which is refractory in this situation) acts to congregate the micro-bubbles so they can move through the glaze layer. Notice also how much richer the color is on that piece. The piece on the right does not have added iron oxide. It is not as red and not as transparent. Both of these mugs, by the way, are glazed on the bottom and were fired on stilts.

Context: Iron Oxide Red, G1916Q, Glaze Bubbles

Wednesday 7th October 2020

G1916Q on L215, L212, L210, L213, Buffstone at cone 03

Five fired test tile with a clear glaze

The G1916Q recipe uses common Ferro frits and fits most low fire bodies (except this with high talc). It is easier to tune its recipe to adjust thermal expansion adjustable than others we have published in the past. And it melts well down to cone 06. And we have a strategy to reduce clouding and micro-bubbling. These five test tiles were fired using the 04DSDH schedule (drop-and-hold) firing schedule. Results are flawless. All exited from the kiln without crazing. The L215, L213, L210 and L212 samples subsequently survived a 300F/Icewater test without crazing, but the Buffstone did not (it needs a higher thermal expansion glaze adjustment). The L213 would not likely survive a cold-to-hot test without shivering (it needs a lower thermal expansion adjustment).

Context: G1916Q

Wednesday 7th October 2020

The first of 15 "Fool-Proof Recipes" wrecked my kiln shelf!

A melt flow tester showing how a normal glazes runs when melting compared to this one

This is recommended in the booklet "15 Tried and True Cone 6 Glaze Recipes". This melt flow tester compares it with a typical cone 6 glossy, G2926B. This recipe is 90% Frit 3110 and 10% kaolin and their booklet recommends adding stains to it. But anyone knowing a little about this frit knows it would run off this flow tester even before bisque temperatures. It is crazy to recommend this. Even as a crackle. For cone 6 it needs to be diluted much more, not just with kaolin but also silica. I knew this would run but I underestimated its melt fluidity. I put a large tile below the tester to catch overrun, yet the melt ran off that and a big three-cm-wide blob melted through the kiln wash and so far into my zircon shelf I cannot chip it off! I cannot imagine how many people have tried this on vertical surfaces and had the same thing happen. The lesson: Use common sense when looking at recipes, then you don't even need waste time testing them. Even if their authors did not!

Context: Ferro Frit 3110, Trafficking in Glaze Recipes, Tried and True recipes. Really?, Trafficked online recipes waiting for a victim to try them!, Melt Fluidity, Limit Recipe

Wednesday 30th September 2020

Saint Rose Red being delivered. Look what it does at cone 10R!

Dump trucks delivering the bright red lump clay to the Plainsman plant

We get this clay from St. Rose, Manitoba. Four tandem loads arrived this week. Just seeing the pile inspires me to make more pieces! It is a red fireclay and it is highly unusual. St. Rose Red has issues. They at first seem to be problems, but in combination they give it magic powers! It fires with very heavy iron speckling. The iron pigmentation is so high that it burns almost black at cone 10R. It has low plasticity. It shivers glazes: The vase on this picture lasted an hour after kiln exit, it spontaneously fractured because of the outward pressure from the under-compression glaze on the inside. But, by combining St. Rose Red with our more vitreous clays, which are highly plastic, we can make H440 and H443. But guess what happens when feldspar is added? A mix of 45 St. Rose, 40 Ball clay and 15 feldspar produces a rustic metallic surface (like the cup shown). Such a body cannot be made from a low fire red clay (like RedArt), it would just warp and collapse in the kiln. It is the refractory character, heavy pigmentation, iron speckling and low plasticity of St. Rose that make metallic ware possible.

Context: Saint Rose Red, The stockpile of St. Rose Red fireclay at the Plainsman plant, Plainsman Red Fireclay (Fire-Red), Laguna B-Mix on Steroids: Wedge in some Plainsman Fire-Red!

Wednesday 16th September 2020

Polar Ice Porcelain with Body Stains - by Robert Barritz

Buttons of fired porcelain of many colors

Robert has done really valuable work in this research, what an amazing range of color! I am so grateful he shared this with the rest of us. Surfaces are unpolished and unglazed. All are fired to cone 6. Browns are missing, they can be made using iron oxide. For blacks, Mason 6600 is also effective. The blues require lower percentages than shown here, as low as 2% can be effective. Likewise with others, there is an optimal amount for each stain, beyond that, with increases in percentage the color intensity increase will drop significantly. There is another reason to keep stain percentages to a minimum: To reduce the impact on body maturity (and firing shrinkage). Blues, for example, can significantly heighten the degree of vitrification, even melting the porcelain. If you plan to marble different colors, keeping stain percentage as low as possible is even more important, unless you can do fired shrinkage compatibility testing, for example, the EBCT test. Need to develop your own white porcelain? See the link below.

Context: Mason 6027 Stain, Stain 6200, Mason 6255 Stain, Mason 6266 Stain, Frit VO 6200, Frit VO 6255, Mason 6363 Stain, Mason 6304 Violet Chrome Tin, Mason 6308 Stain, Mason 6306 Stain, Mason 6368 Copen Blue Stain, Stain 6388, Stain 6234, Stain 6219, Mason 6021 Red Stain, Spectrum 2276 Yellow Stain, Mason 6464 Yellow Stain, Mason 6485 Yellow Stain, Mason 6537 Grey Stain, Mason 6386 Blue Stain, Mason 6600 Black Stain, Stain 6121, Stain 6201, Stained Plainsman Polar Ice Porcelain - With Polishing (no glaze), Develop and maintain your own cone 6 porcelain recipe, Ceramic Stain

Monday 14th September 2020

Trafficked online recipes waiting for a victim to try them!

A pile of printed recipes to try, but few are likely to work

You found some recipes. Their photos looked great, you bought $500 of materials to try them, but none worked! Why? Consider these recipes. Many have 50+% feldspar/Cornwall/nepheline (with little dolomite or talc to counteract their high thermal expansion, they will craze). Many are high in Gerstley Borate (it will turn the slurry into a bucket of jelly, cause crawling). Others waste high percentages of expensive tin, lithium and cobalt in crappy base recipes. Metal carbonates in some encourage blistering. Some melt too much and run onto the kiln shelf. Some contain almost no clay (they will settle like a rock in the bucket). A better way? Find, or develop, fritted, stable base transparent glossy and matte base recipes that fit your body, have good slurry properties, resist leaching and cutlery marking. Identify the mechanisms (colorants, opacifiers and variegators) in a recipe you want to try and transplant these into your own base (or mix of bases). And use stains for color (instead of metal oxides).

Context: Trafficking in Glaze Recipes, Metal leaching from ceramic glazes: Lab report example, Tried and True recipes. Really?, The first of 15 "Fool-Proof Recipes" wrecked my kiln shelf!, Mechanism, Base Glaze, Limit Recipe, Glaze Recipes

Friday 11th September 2020

Mason stains in the G2934 matte base glaze at cone 6

Glazed porcelain tiles showing the range of color possible with stains

Stains can work surprisingly well in matte base glazes (provided they are not too matte). Stains perform differently in a matte host glaze. The glass is less transparent and so varying thickness do not produce as much variation is tint. Notice how low many of the stain percentages are: yet most of the colors are still bright. A good reason to minimize stain concentration is to avoid leaching. We tested 6600, 6350, 6300, 6021 and 6404 overnight in lemon juice, they passed without any visible changes. It is known that MgO mattes, like this one, are less prone to acid attack that CaO mattes. A down-side to this matte mechanism is that chrome-tin stains do not work (e.g. 6006), this is because this does not have the high CaO content needed in the host glaze to develop the color. The inclusion stains 6021 and 6027 work very well in this base. As do the 6450 yellow and 6364 blue. And the 6600 produces an incredible gunmetal black. The 6385 is an error, it should be purple (that being said, do not use it, it is ugly in this base).

Context: Mason 6021 Red Stain, G2934, Stain 6201, Stain 6134, Stain 6100, Stain 6006, Stain 6020, Stain 6666, Mason 6600 Black Stain, Stain 6500, Stains Mason, Mason 6027 Stain, Dipping Glaze, Ceramic Stain

Wednesday 9th September 2020

Mason stains in the G2926B base glaze at cone 6

19 glazed porcelain tiles showcasing Mason stain colors

Stains are a much better choice for coloring glazes than raw metal oxides. Other than the great colors they produce here, there are a number of things worth noticing. The percentages may be lower than what you think would be needed, stains are potent colorants. Staining a transparent glaze produces a transparent color, that means it is more intense where the glaze layer is thicker. This is often desirable in highlighting contours and designs. If you add an opacifier, like zircopax, the color will be less intense, producing a pastel shade the more you add. The chrome-tin maroon 6006 does not develop well in this base (alternatives are G2916F or G1214M ). The 6020 manganese alumina pink is also not developing here (it is a body stain). Caution is required with inclusion stains (like #6021), the bubbling here is not likely because it is over fired (it is rated to cone 8), adding 1-2% zircopax normally fixes this issue.

Context: Mason 6021 Red Stain, Stains Mason, G2926B, Concentrate on One Good Glaze, Stain 6404, Stain 6385, Stain 6450, Stain 6364, Stain 6300, Stain 6100, Frit VO 6134, Stain 6201, Stain 6134, Stain 6500, Stain 6006, Stain 6666, Mason 6600 Black Stain, Mason 6027 Stain, Base Glaze, Ceramic Stain, Colorant

Wednesday 9th September 2020

Vancouver Island Pottery Supply, 515 Stanford Avenue E, PARKSVILLE, BC V9P 1V6
Phone: 250-248-2314, FAX: 250-248-2318, Email: sales@vipotterysupply.com