Liquid PU casting resin over epoxy tooling gel coat for composite mould?

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Liquid PU casting resin over epoxy tooling gel coat for composite mould?

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Faberge	Faberge posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 3, Visits: 5	Can I pour liquid polyurethane casting resin directly over an epoxy tooling gel coat as a much faster way to make a split composite mould than by building up layers of fibreglass and resin as normal? It is a small mould so cost is not an issue. Tags Mould making
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Abmod	Abmod posted 10 Years Ago HOT Post Details
Group: Awaiting Activation Posts: 2, Visits: 31	Good question . I believe there is a special epoxy product that you pour over your pattern . Maximum depth to pour is around 70 mm , maybe due to exotherming . I assume you wait a certain time and then pour some more to cover your whole pattern . A small part should be no problem , a big one wll be heavy and expensive I assume Casting polyester resins have been used for smaller parts Also a mould that will only be used for a few parts is " plaster of Paris " , heavy and britle . To avoid wasting of resin and keeping the weight down you can probably put some polystyrene blocks in between pours . I'm still investigating myself , but for a bigger product between 1-2 m long and 400 mm wide and about 100 mm deep .
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Faberge	Faberge posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 3, Visits: 5	Many thanks for taking the time to respond. You are correct about exotherm problems - see my reply to Warren. If you are interested there is a detailed thread about what they call "DIY Corian Moulds" on RCGROUPS.COM. See below. http://www.rcgroups.com/forums/showthread.php?t=2165394
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Abmod	Abmod posted 10 Years Ago HOT Post Details
Group: Awaiting Activation Posts: 2, Visits: 31	I believe there is a pourable Epoxy made by Devcon We are trying to avoid the traditional multiple layers of glass here . I've had great success with resin and sand , ratio of 1 / 5 , very similar to concrete . A bigger mould I just made came out great , super strong and rigid , but heavy . Next one I will fill same space with foam , it will be poured in 2-3 stages to avoid build up .
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