Use different gelcoat for other half of mould?

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Use different gelcoat for other half of mould?

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Timellis	Timellis posted 11 Years Ago HOT Topic Details
Group: Forum Members Posts: 14, Visits: 58	I am having finish issues on my pattern and mould when using Unimold gelcoat. The first time the part was finished in clear lacquer form Halfords. The part was easy leased and then waxed 8 times. When de-moulded the finish on the part had alligatored leaving a poor quality mould. The second time had 2k lacquer finish, again easy lease and wax with the same result. My question is can I use your epoxy tooling gelcoat for this half of my mould? (the first half has been repaired extensively from alligatoring) - I am looking at the "green stuff" you have. Also, what finish do you suggest for my part? Thanks in advance. Edited 11 Years Ago by Timellis
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Hanaldo	Hanaldo posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	So infusion or wet-lay? Is using PVA out of the question?
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Timellis	Timellis posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 14, Visits: 58	I am going to wet lay initially and try infusion at a later date. If I don't have the time to wait for 2k to fully cure what finish for the plug would you suggest. PVA is ok as the final product will be lacquered, blocked and polished. I believe I have followed all the Unimold instructions correctly - I have made a mould with the green gelcoat and epoxy clay kit in the past with no issues.
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wozza	wozza posted 11 Years Ago HOT Post Details
Group: Forum Members Posts: 688, Visits: 5.4K	If time is the issue and surface finish isn't critical then PVA as Hanaldo suggests. It will need to be spray applied. That way you can apply several coats creating a decent barrier layer between the plug and gelcoat. Epoxy Mould kits can be useful especially if working in a home environment as they dont give off any nasty fumes. The epoxy won't attack the plug like polyesters can but still generate heat during curing. Depending on what the plug is made from this heat can be sufficiently high to deform the plug. The same goes for polyester. Plastic trim parts for example or thin wood like some guitars. It's an expensive way to create larger moulds though compared to polyesters. In my opinion the less finishing work you have to do on the part the better. When sanding/flatting CF you always run the risk of sanding through the thin layer of resin into the cloth. Once that happens cosmetically the part is ruined. I prefer to spend the time on the plug/mould. There is something very satisfying about pulling a part from a mould that requires no more than a quick buff. It is also much more cost effective on multiple runs. Good luck with the project guitars are not easy things to make from composites especially acoustics. Carbon Copies Ltd Edited 11 Years Ago by wozza
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