Uni-Mould curing issue

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Uni-Mould curing issue

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Legoman	Legoman posted 5 Years Ago Post Details
Group: Forum Members Posts: 29, Visits: 622	+x noahark - 9/17/2019 10:20:39 PM +x Legoman - 9/17/2019 8:02:00 PM As you can see there are different colours on the cured mould surface. Probably I failed with lamination and got some air under the last layer...any idea? What tool & resin did you use to wet it out? Any heat applied in the process? What type of fiberglass mat was used? What ambient temperature did it cure at? Does it really matter if the other side is clean? Just like Uni-Mould system. Vinyl gelcoat, 2x100g CSM coupling coat with vinyl resin after that 4x450 CSM with polyester tooling resin. Ambient temp was arround 17-20 Celsius. I used brush to apply the reinforcements. Non of any heat applied... What you mean exactly on the other side?
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Legoman	Legoman posted 5 Years Ago HOT Post Details
Group: Forum Members Posts: 29, Visits: 622	+x MarkMK - 9/19/2019 1:27:09 PM I'm sure it would be fine proceeding in that way but, ideally, you need to get 3-4 layers of the heavier CSM on at the same time so that the build-up of the tooling resin can reach its usual curing temperature. Less resin applied would likely lead to patches similar to what you've seen rather than limit them I wouldn't worry at all regarding the slightly different colour of the cured resin, as long as your surface gel coat is sound and everything has cured hard I've seen similar patches many times on different moulds and as Hanaldo said, it's likely that some patches cured at slightly different temperatures or that some parts of the resin were richer in the filler element of the product which you can sometimes see accumulated at the bottom of the can if not thoroughly mixed before use Yep thanks Mark! Everything is fine. I paid more attention on the other side and it is cosmeticly much better. Anyway the chemists told me only 2 layers is not recommended. If the laminating is too thin sometimes the resin cant reach its prescribed curing temerature and can shrink...which is no good. At all! Here is the other side:
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Legoman	Legoman posted 5 Years Ago Post Details
Group: Forum Members Posts: 29, Visits: 622	+x Warren (Staff) - 9/19/2019 2:45:48 PM If you are worried, do a postcure of the mould and it should force the resin to an even cure by the time the postcure is complete. Thx Warren. By the way I do always post cure to avoid the "print through" effect on the gelcoat after the infusion process. Anybody else noticed this issue already?
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Warren (Staff)	Warren (Staff) posted 5 Years Ago ANSWER Post Details
Group: Administrators Posts: 2.5K, Visits: 8K	If you are worried, do a postcure of the mould and it should force the resin to an even cure by the time the postcure is complete. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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MarkMK	MarkMK posted 5 Years Ago ANSWER Post Details
Group: Forum Members Posts: 338, Visits: 2K	I'm sure it would be fine proceeding in that way but, ideally, you need to get 3-4 layers of the heavier CSM on at the same time so that the build-up of the tooling resin can reach its usual curing temperature. Less resin applied would likely lead to patches similar to what you've seen rather than limit them I wouldn't worry at all regarding the slightly different colour of the cured resin, as long as your surface gel coat is sound and everything has cured hard I've seen similar patches many times on different moulds and as Hanaldo said, it's likely that some patches cured at slightly different temperatures or that some parts of the resin were richer in the filler element of the product which you can sometimes see accumulated at the bottom of the can if not thoroughly mixed before use
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Legoman	Legoman posted 5 Years Ago HOT Post Details
Group: Forum Members Posts: 29, Visits: 622	+x Hanaldo - 9/18/2019 4:43:56 AM It's just the cure indication in the resin. Different parts of the part may have been thicker and got hotter, or some were maybe catalyzed a bit higher. Or did the resin in the lower layers start to cure before you finished laminating? In this case some areas may not have reached full cure temperature. In any case, it shouldn't be any concern as long as the resin isn't sticky. Yep, you are probably right! It is fully cured everywhere it was just weird to me...anyway next time I will apply 2 layers and next day just sand it back and apply the other ones (you think it can work?) to avoid the curing danger. Unfortunately it takes a lot of time to apply all of the 4 layers in "one go", 'cause of the comlplex shape. And I am not a pro!
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Hanaldo	Hanaldo posted 5 Years Ago ANSWER Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	It's just the cure indication in the resin. Different parts of the part may have been thicker and got hotter, or some were maybe catalyzed a bit higher. Or did the resin in the lower layers start to cure before you finished laminating? In this case some areas may not have reached full cure temperature. In any case, it shouldn't be any concern as long as the resin isn't sticky.
	Reply Like 3
noahark	noahark posted 5 Years Ago HOT Post Details
Group: Forum Members Posts: 5, Visits: 40	+x Legoman - 9/17/2019 8:02:00 PM As you can see there are different colours on the cured mould surface. Probably I failed with lamination and got some air under the last layer...any idea? What tool & resin did you use to wet it out? Any heat applied in the process? What type of fiberglass mat was used? What ambient temperature did it cure at? Does it really matter if the other side is clean? Edited 5 Years Ago by noahark
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Legoman	Legoman posted 5 Years Ago Topic Details
Group: Forum Members Posts: 29, Visits: 622	As you can see there are different colours on the cured mould surface. Probably I failed with lamination and got some air under the last layer...any idea?
	Reply Like 1