I'd like to try infusion epoxy. What would you suggest?

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#1

I’ve been using PE and VE resins for infusing my carbon fiber parts. They need to be strong and good looking. So what would you guys suggest? This is what I need…

+It needs to be thin for infusion.
+Have a high heat distortion temperature. The reson being because these will be going on the interior and exterior of cars. I hate print through, its extremely annoying.
+can be post cured (if I have to) out side of the mold with out it changing shape or distorting on me since the molds I have now wont last under 180F and above.
+Can be sprayed with 2k urethane clear
+Does not have a million hour pot life. I like my pot life to be around 10 - 15 min.
+Can be purchased at 1 - 5 gallon kits since the production is low to medium.

As much as I love polyester and vinyl ester I hate having to shave away the hairy edges of the parts due to the carbon fiber not absorbing the resin too well.

I have about 5 gal of PE infusion, and 1 gal of VE infusion left, but I’m willing to eat the cost and switch if I can find something that works well for automotive parts.

Please help! I tried looking around and its most likely me, but I couldn’t find any resin systems that has everything I need.

#2

For what I read of it, I would suggest VE resin. What issue do you have with protruding fibers? VE (and UP) should penetrate the fiber easily. Epoxy will be no different.

#3

I was going to suggest VE too. Epoxy sometimes will warp when post cured, however I am SURE there are slow cycles you can use that will minimize that. In your hairy carbon issue, sometimes the carbon is sized for ONLY epoxy…so when you trim the part, it doesn’t bond as well as it should to the VE resin.
I’m guessing you want a room temp cure system?

#4

I used to feel the same way about VER leaving the carbon unsaturated after cure. I switched to Composites One VER and experienced less of this issue with their blend. I however am not using their infusion specific VER.

I use Huntsman Infusion resin 8604 but i do not know what the tech sheets say about post cure as i have never post cured. It has a pot life of about 25-30 minutes and that lessens with more mixed volume of the epoxy. If i mix up 30oz the cup would harden in less than 20 minutes. But the infused part does require a minimum of 8 to 10 hours under vacuum pressure for initial curing. 24 hours to demold.

Let me know what infusion resin you end up going with. I’m not adverse to changing if i find something that works well.

Possibly leaving your lay ups under full vacuum for at least 5 hours will cure the problem with the fibers not saturating?

#5

Maybe, but I don’t seee how leaving it under vacuum will help since I see as the part dries, it looks like its desaturated. Maybe I’m adding too much heat right away? Usually after infusion I go straight to heat lamps and bump it up to 100F.

Can you post cure polyester and vinyl ester?

#6

I mean if at all possible, I’d like to be able to post cure epoxy at no higher than 100 for now because of what I have to work with. But I’d like to get my HTD up to at least 200 on all my parts. Can anybody help?

John

#7

I would just look up various resin companies and look at the tech specs for each to get the desired resin.

The RENinfusion 8604 epoxy has a tg of 175f.

The only epoxy resin i have seen that has a high tg without post cure is Resin Services HTR212/386-99 It is not an infusion resin.

Any infusion epoxy, i believe, you are going to have to post cure to get a tg higher than 200f.

This is why so many automotive body panels ( carbon fiber ) use vinyl ester. It has a tg of 230 - 245f.

#8

Does vinyl ester have to be cured? Or can I just put direct heat over the part immediate after infusing. Like 100F?

I also spoke today to one of the lab techs at Resin Services. He said that they are in the works of manufacturing an HTR212 infusion epoxy with similar heat distortion temps of 200 - 375 with out post cure.

He recommended me to post cure to reach a HDT of 375, but said that I didn’t have to. So he confused me as well… If anybody knows more information about this please do tell.

#9

Any new news on the HTR212 infusion epoxy mentioned above?

#10

For the time being: About all high-Tg epoxy resins that have a slowerr-than-10-minutes cure need postcure to reach these values. Sorry for that, it is the nature of the beast…