{"id":863,"date":"2025-01-16T11:11:00","date_gmt":"2025-01-16T11:11:00","guid":{"rendered":"https:\/\/bethanhemus.art\/?p=863"},"modified":"2025-09-24T12:41:32","modified_gmt":"2025-09-24T12:41:32","slug":"creating-glass-investment-molds-and-the-lost-wax-process","status":"publish","type":"post","link":"https:\/\/bethanhemus.art\/?p=863","title":{"rendered":"Creating glass investment molds and the lost-wax process"},"content":{"rendered":"
I have never worked with glass, beyond smashing the odd jar, so I am looking forward to learning some new skills during this project.<\/div>\n
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I was lent an enormous block of Type B modeling wax in the shape of a heart. It was quite hard to work with until broken down into smaller pieces. Fitting really.<\/div>\n

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I am sculpting a positive castle model in this wax, which I will then cast to create a negative investment mould. An investment mold is a container for solid glass pellets to be poured into and then melted in a kiln, using a specific investment powder. The powder is made up of plaster and a refractory material mix; the latter being some form of quartz, usually silica. When combined, the two powders support each other and are therefore able to retain their structural integrity at glass-casting firing temperatures; around 900\u2070C.  <\/div>\n
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After melting the wax out with steam, also known as a burn-out process, I will cast the investment mold using glass pellets, also known as frit.<\/div>\n
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After experimenting with lots of detail and design elements, I settled for a primitive abstract form. <\/div>\n
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I am not trying to depict a specific castle, I am trying to evoke the qualities and concept of a castle, so this is an acceptable choice. It is also pleasing to mine eye. That’s an Alan Partridge quote.<\/div>\n
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I attached a cardboard tube to act as a glass reservoir in the base. The frit takes up more volume solid than it does liquid so this mechanism will feed a steady supply of glass into castle mold as it melts.<\/div>\n
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I glued the cardboard tube to the bottom of a disposable container and then sunk it in an equal parts mix of luke warm water, plaster, quartz and molochite. <\/div>\n
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The castle piece started floating as I submerged it, so I held it in place with a piece of pasta until the plaster mix was set enough to remove it and plug the hole using my finger.<\/div>\n
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After the mold had set for a few days I removed it from it’s plastic tub and peeled out the cardboard tubing, setting it to one side to dry further. <\/div>\n
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Next up: extracting the wax using a second hand steamer. What could possibly go wrong?!<\/div>\n<\/div>\n<\/div>\n
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I have never worked with glass, beyond smashing the odd jar, so I am looking forward to learning some new skills during this project. I was lent an enormous block of Type B modeling wax in the shape of a heart. It was quite hard to work with until broken down into smaller pieces. Fitting […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-863","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/bethanhemus.art\/index.php?rest_route=\/wp\/v2\/posts\/863","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bethanhemus.art\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bethanhemus.art\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bethanhemus.art\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bethanhemus.art\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=863"}],"version-history":[{"count":1,"href":"https:\/\/bethanhemus.art\/index.php?rest_route=\/wp\/v2\/posts\/863\/revisions"}],"predecessor-version":[{"id":864,"href":"https:\/\/bethanhemus.art\/index.php?rest_route=\/wp\/v2\/posts\/863\/revisions\/864"}],"wp:attachment":[{"href":"https:\/\/bethanhemus.art\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bethanhemus.art\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bethanhemus.art\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}