TECHNO TIP A Potter's Nightmare Imagine unpacking a bunch of pots while gelling ready to sell them al your bopecst yearly show and noticing that they wre crazed. Quickly you check each one and they all show signs of the problem, Some poiters would ignore this, others would panic, The latter reaction might be mest appropri: because this 15 a serous issue. Cruzed functional ware is substandard no miter how you slice mt. [would never get pel a Testaurant inspector becouse of hy- sienic questions, Purhermorecrazing can cul ware sirenglh up to 400%. [ve seen cone 1D erased iron ware that con be tom upart casily with bare hands. Crazed ware eventually failson repeated thermal shock, especilly on non-vitrecuss stoneware bod - ies that become waterlogged. Crazing happens because the thermal ex- pansion of the glaze is too high, Body and glite are attached so there is trouble if they do nat expand and contract together as the prece is heated and cooled, A matching glinciseand tot lhe body. A good bodhy- glaze expansion match has a pretty wide lolerance for chunges in process and ma- terials. If vou find one crased piece, there is a good chance that all your ware will eventually craze. Imagine realizing that every thing you have made for the past 5 years has or will craze. Yikes! [fa glaze shows sums of not fitting, then fining or application acrobatics or other band-aid appraaches to suppress the prob- lem don't work, You have ta bite the bullet. Usually the glaze has to be adjusted ta lower its expansion bo fix it Or you have ta switch toa higher expansion body For mare information: http. digiialline com/education glare! crazed. him. Tony Hansen The Jiformation in tits erticle has been prepared by Tony Hansen with the gener- cus sypoor! of Plannsman Clays Limited 16 Alberta. Greenbarn in the Fraser Valley and fiend Pottery Warehouse on Van- conver are affiliates. EXHIBITIONS Jume 10-July 30 The Tradition of Wondfired Ceramics, GalleryalCepertey House, 63a Deer Lake Ave, Burnaby, 4.205 7332 July 6-August | Mary Fox Treasured Versely, Portfolio Gallery, 863 West Hast- ings, Vancouver, 604.801.6978 Mary Fos Vewe! earthenware, undergkaze., crawl glaze, hit: 36.8 cm Serving Western Canaaian Potters for the past 30 years CNL POTTERS SUPPLY On Vancouver Island see our newest dealer The Pottery Warehouse in Nanaimo 250.716.9966 « Clays + Materials « Underglazes « Stains « Glazes * Tools « Equipment * Wheels « Magazines Monday-Friday 9-5 Saturdays 9-1 $548 - 192 Street, Surrey, B.C. V4aN GA9 Phone: 604-888-3411 Fax: 604-388-4247 E-mail: greenbarn@be.sympaticoe.ca Intemet wew.greanbarn.com Juli Auge 200%) Potters Guild af Brinsh Columbta