Problem with wax additive in polyester topcoat

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Problem with wax additive in polyester topcoat

Author	Message
mingo_poppy	mingo_poppy posted 9 Years Ago HOT Topic Details
Group: Forum Members Posts: 3, Visits: 16	Hello all, I have used the wax gelcoat additive (https://www.easycomposites.co.uk/solution-mw-wax-gelcoat-additive) in the top layer of a polyester-covered table. It looked fine when I mixed and poured it, but now that it has cured it has a weird, patchy, greasy-looking surface. It's still transparent but less clear and the shine has gone off it. It feels alright to the touch, though, and definitely isn't tacky. What have I done wrong here? I used about 2% wax additive but may not have measured it that accurately... I plan to sand off the top layer and redo it but I'm keen to avoid the same problem happening again. I want a smooth, high-gloss finish on the final pour. Thank you in advance. Edited 9 Years Ago by mingo_poppy
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Dravis	Dravis posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	You are not going to get a "perfect" surface using a gelcoat for a table-top -- even when adding wax-additive .. A Polyester Gelcoat is simply not made for the purpose. I would suggest sanding down the layer you have already added, then polish it and let it cure for a very long time. live with the polished surface as it is for at least a month or more .. Then sand down and apply a dedicated "table top" Resin - Like EC's "Glasscast" https://www.easycomposites.co.uk/glasscast-clear-epoxy-surface-coating-resin "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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Fasta	Fasta posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	You did nothing wrong, the cloudy wax surface finish you have is normal. Fastacraft Facebook page
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mingo_poppy	mingo_poppy posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 3, Visits: 16	Hello all, I have finally got round to following up on this project. I have sanded down the polyester layer which turned cloudy, and bought the epoxy resin that was suggested as a topcoat. My polyester is now (naturally) matte, rather than shiny, because I have sanded it. My question is: If I place the epoxy resin on top of the matte polyester, will my eventual finish be clear? Or will I still be able to see the matte polyester surface underneath the epoxy? If necessary, I can do another layer of polyester before the epoxy - so that the final polyester surface is shiny - but I would rather not if I can avoid it. Many thanks to those who have taken the time to help with this.
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Dravis	Dravis posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	Hi, No need to do anything but add the epoxy on top! It will "fill in " the matte surface of the polyester - making the whole thing clear. In essence, the "matte" surface on the polyester consists of a myriad of tiny scratches from the sanding, these will fill out with clear epoxy.. If you tried to polish the polyester, the epoxy will not bind to it, and would definitely delaminate very quickly.. Also remember to degrease the surface very thoroughly!! "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-) Edited 9 Years Ago by Dravis
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mingo_poppy	mingo_poppy posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 3, Visits: 16	Hi Dravis, Thanks for such a quick and helpful answer. It's good to hear that the sanded surface is actually beneficial! I'll have a go and will make sure to degrease first.
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