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Massimiliano
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Hi, after the first not successful mold and part ( http://www.talkcomposites.com/Topic36543.aspx) I worked on the part to fix the issues in order to build a new mold. This time the part popped from the mold almost by itself but... something has happened to the tooling gelcoat! Please se pics. Last pic is the tooling gelcoat on the base glass, so I tend to exclude some interaction with the plug. Any ideas? 
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Warren (Staff)
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So your flange material was glass? It certainly wouldn't be a reaction to glass.
The gelcoat looks very very thin so it almost looks like the gel has lifted, either due to trapped air or possibly the coupling coat pulling it away from the mould surface. In thin sections like that, the gel probably isn't building up much heat compared to thicker sections. Normally you would get the alligatoring effect if the gel wasn't cured enough before double gelling or coupling coating but i think your gel is so thin it hasn't done that. Either that or you have managed to somehow trap a lot of air under the gel as you laid it.
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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Massimiliano
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Group: Forum Members
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+xSo your flange material was glass? It certainly wouldn't be a reaction to glass. The gelcoat looks very very thin so it almost looks like the gel has lifted, either due to trapped air or possibly the coupling coat pulling it away from the mould surface. In thin sections like that, the gel probably isn't building up much heat compared to thicker sections. Normally you would get the alligatoring effect if the gel wasn't cured enough before double gelling or coupling coating but i think your gel is so thin it hasn't done that. Either that or you have managed to somehow trap a lot of air under the gel as you laid it. Hello Warren, I don't think it is too thin, I would say rather the opposite... I applied the first coat with 1% catalizer and after 5 hours some "ponds" were still too tacky so left overnight. The second coat was applied 12 hours later this time catalized 2%. Coupling coat applied after 9 hours as the gelcoat seemed OK. Most of the part of the mold do not show any issue. Given the above, do you have other suggestions?
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Warren (Staff)
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Group: Administrators
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If you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better.
It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it.
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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Massimiliano
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Group: Forum Members
Posts: 167,
Visits: 1.1K
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+xIf you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better. It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it. Thanks... hope my third mold would be better :-) Do you have any suggestions on how to fix this mold?
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Massimiliano
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Group: Forum Members
Posts: 167,
Visits: 1.1K
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+x+xIf you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better. It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it. Thanks... hope my third mold would be better :-) Do you have any suggestions on how to fix this mold? Anyone has suggestion on how to fix this problem? Just apply new gelcoat? Is there any way to apply it the "flattest" possible?
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beliblisk
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Group: Forum Members
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+x+x+xIf you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better. It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it. Thanks... hope my third mold would be better :-) Do you have any suggestions on how to fix this mold? Anyone has suggestion on how to fix this problem? Just apply new gelcoat? Is there any way to apply it the "flattest" possible? I think the fastes way would be to redo whole mould from scratch. 1% catalysts seems way to low for gelcoat (i always go with 2%). Peehaps first layer didnt cure and then second layer pulled it a bit. If you were to try and fix it there will be a lot of sanding:/ Apply gelocat with spatula and cover it with flash tape so you will get relatively flat surface..... sand and do one more step if any low spots remain.
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Massimiliano
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Group: Forum Members
Posts: 167,
Visits: 1.1K
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+x+x+x+xIf you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better. It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it. Thanks... hope my third mold would be better :-) Do you have any suggestions on how to fix this mold? Anyone has suggestion on how to fix this problem? Just apply new gelcoat? Is there any way to apply it the "flattest" possible? I think the fastes way would be to redo whole mould from scratch. 1% catalysts seems way to low for gelcoat (i always go with 2%). Peehaps first layer didnt cure and then second layer pulled it a bit. If you were to try and fix it there will be a lot of sanding:/ Apply gelocat with spatula and cover it with flash tape so you will get relatively flat surface..... sand and do one more step if any low spots remain. Thank you... I will try on one damaged area and see how it will go... then decide to redo it for the third time..😒
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beliblisk
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Group: Forum Members
Posts: 53,
Visits: 2.8K
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+x+x+x+x+xIf you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better. It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it. Thanks... hope my third mold would be better :-) Do you have any suggestions on how to fix this mold? Anyone has suggestion on how to fix this problem? Just apply new gelcoat? Is there any way to apply it the "flattest" possible? I think the fastes way would be to redo whole mould from scratch. 1% catalysts seems way to low for gelcoat (i always go with 2%). Peehaps first layer didnt cure and then second layer pulled it a bit. If you were to try and fix it there will be a lot of sanding:/ Apply gelocat with spatula and cover it with flash tape so you will get relatively flat surface..... sand and do one more step if any low spots remain. Thank you... I will try on one damaged area and see how it will go... then decide to redo it for the third time..😒 You are welcome. I tend to take every failure as a learning process...... just keep it up and you will get there eventually 
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Massimiliano
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Group: Forum Members
Posts: 167,
Visits: 1.1K
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+x+x+x+x+x+xIf you look at your second attached image, you can see the strands of fibreglass heavily printing through the flat gelcoat to the right. That might be a side effect of the reaction you have had but looking to the left and edge of the mould it doesn't look much better. It might be pre-release from the surface in some way as the edge looks a bit like the gel has distorted a bit but that doesn't account for all of it. Thanks... hope my third mold would be better :-) Do you have any suggestions on how to fix this mold? Anyone has suggestion on how to fix this problem? Just apply new gelcoat? Is there any way to apply it the "flattest" possible? I think the fastes way would be to redo whole mould from scratch. 1% catalysts seems way to low for gelcoat (i always go with 2%). Peehaps first layer didnt cure and then second layer pulled it a bit. If you were to try and fix it there will be a lot of sanding:/ Apply gelocat with spatula and cover it with flash tape so you will get relatively flat surface..... sand and do one more step if any low spots remain. Thank you... I will try on one damaged area and see how it will go... then decide to redo it for the third time..😒 You are welcome. I tend to take every failure as a learning process...... just keep it up and you will get there eventually Yes you are right, first mold plug did not release properly as there were some slight undercuts. Also while applying the tooling resin I mixed too much in one pot so it started to gel before finishing to apply the various layer of mat 🤦♂️
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