Resin Recommendation required for complete novice

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Resin Recommendation required for complete novice

Author	Message
FingerPickinRic	F FingerPickinRic posted 4 Years Ago HOT Topic Details
F Group: Forum Members Posts: 3, Visits: 5	Hi all, I am undertaking an R&D project to reinforce a curved wood surface with Kevlar. It will need a resin surface of some sort that can withstand regular strikes against a metal edge. The kevlar will be reasonable secure against the surface, but the resin will need to both bond and seal the surface. The clarity of the finish is not critical and ideally, the surface should be machinable or at least able to be smoothed with sandpaper or varying grit. In terms of application, I was hoping not to have to cast, but i'm not sure as to what finish can be achieved with a brush. I can't give too many specifics due to IP, sorry. All ideas greatly appreciated. Thanks in advance, Ric
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Hanaldo	Hanaldo posted 4 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Its hard to recommend anything without knowing the application. Based off your description, I would say what you are looking for does not exist, and you will have to compromise somewhere or look to redesign. Resins are not great at taking regular impacts from a metal edge, but then it also depends on how hard those impacts are. Resins made for laminating reinforcement like Kevlar are typically quite brittle, and wont last long taking regular impacts. Polyurethane rubbers are likely to be the most resilient, but they would need to be cast and do not have fantastic bonding properties, so no good for your Kevlar. A flexible epoxy like Ex's EF80 might be the most suitable, but it still isnt going to take impacts superbly well - it is flexible rather than soft.
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FingerPickinRic	F FingerPickinRic posted 4 Years Ago HOT Post Details
F Group: Forum Members Posts: 3, Visits: 5	+x Hanaldo - 4/6/2020 9:38:55 AM Its hard to recommend anything without knowing the application. Based off your description, I would say what you are looking for does not exist, and you will have to compromise somewhere or look to redesign. Resins are not great at taking regular impacts from a metal edge, but then it also depends on how hard those impacts are. Resins made for laminating reinforcement like Kevlar are typically quite brittle, and wont last long taking regular impacts. Polyurethane rubbers are likely to be the most resilient, but they would need to be cast and do not have fantastic bonding properties, so no good for your Kevlar. A flexible epoxy like Ex's EF80 might be the most suitable, but it still isnt going to take impacts superbly well - it is flexible rather than soft. Thanks @Hanaldo, I think I was slowly coming to a similar conclusion. I will try EF80 first as this may offer what I need. The application has a somwhat throwaway aspect and the main purpose of the kevlar is to prolong the life of the wood. The hope is to try and make a cost effective compromise between durability and replacement time. Ric
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Hanaldo	Hanaldo posted 4 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Regular laminating may do the job in that case. The Kevlar itself will give very good impact protection, so if the idea is to protect the wood underneath and the outer surface isnt so important then it may work, depending on how thick your Kevlar layer is. Really I think you will only get your answer by testing, you'll just have to try some stuff out and see how it goes.
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Warren (Staff)	Warren (Staff) posted 4 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	To meet your requirements of sandability and impact resistance, I would almost certainly say a rigid laminating resin such as our EL2 Epoxy Laminating Resin You will be able to coat the surface a couple of times if necessary to get a smoother finish and it can be sanded once cured. Although epoxy in its own right isn't great at load spreading from a narrow impact, it is quite a hard material and combined with the kevlar underneath, it should absorb some of the energy before it gets to the wood. Over time this is likely to be destructive to the resin surface and hence would loose efficiency over time but it should extend the life of your wooden part. Obviously the more layers of material, the more energy it would absorb. The resin would also be suitable to bond the kevlar onto the wood surface as well killing 2 birds with one stone so to speak. How effective it is would depend on testing to see if the extra lifespan is worth the extra cost and time adding the composite laminate? Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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FingerPickinRic	F FingerPickinRic posted 4 Years Ago HOT Post Details
F Group: Forum Members Posts: 3, Visits: 5	+x Warren (Staff) - 4/6/2020 2:29:11 PM To meet your requirements of sandability and impact resistance, I would almost certainly say a rigid laminating resin such as our EL2 Epoxy Laminating Resin You will be able to coat the surface a couple of times if necessary to get a smoother finish and it can be sanded once cured. Although epoxy in its own right isn't great at load spreading from a narrow impact, it is quite a hard material and combined with the kevlar underneath, it should absorb some of the energy before it gets to the wood. Over time this is likely to be destructive to the resin surface and hence would loose efficiency over time but it should extend the life of your wooden part. Obviously the more layers of material, the more energy it would absorb. The resin would also be suitable to bond the kevlar onto the wood surface as well killing 2 birds with one stone so to speak. How effective it is would depend on testing to see if the extra lifespan is worth the extra cost and time adding the composite laminate? Thanks @Warren (Staff), EL2 would certainly be the cheaper option. I shall make that my first port of call. I don't intend to use a particularly thich top coat of epoxy, so the hope is that most of the forces wil be transferrede into the kevlar.
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