Disappointing MyCarta result

Hankins

Hankins

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Dec 7, 2008
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Disappointing MyCarta result Because I have way to much time on my hands and love experimenting...
Making some MyCarta using Clearcast 7000 and keeps curing relatively soft. Imprint from a fingernail stays.
Maybe clueless on my part as I am probably asking the material to do that which is not designed to do
Suggestions on which epoxy to use that will dry Clear and HARD Has a low viscosity, slow cure and high shore value?
Followed all the instructions etc so the method should not be an issue.
 
Hankins said:
Disappointing MyCarta result Because I have way to much time on my hands and love experimenting...
Making some MyCarta using Clearcast 7000 and keeps curing relatively soft. Imprint from a fingernail stays.
Maybe clueless on my part as I am probably asking the material to do that which is not designed to do
Suggestions on which epoxy to use that will dry Clear and HARD Has a low viscosity, slow cure and high shore value?
Followed all the instructions etc so the method should not be an issue.
Click to expand...

You need something like this , for laminating carbon fiber ........................ https://www.r-g.de/art/104100AP

 
Are u mixing it right and curing it in right conditions? Also, some of mine homemade stuff cured hard only after a full week cause I was doing it in basement with low temp and high humidity.

Also, check if your epoxy expired.
 
Actually with more research answered my own question thanks for your help
 
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The epoxy ordered has a Shore hardness rating of 65 which is about the durometer rating of a contact wheel. Press into a contact wheel and you can make a fingernail impression.
Got it because the price was half of the 85 shore rated epoxy. Wanted to get closer to Micarta hardness so I will bite the bullet and buy the better stuff.
There is a 90shore rated epoxy out there but that is even more pricy for experiments!
 
You might also want to check the heat rating on them. A lot of heat is generated with grinding so I'd look for something at or over 250 degrees to be on the safe side.

Eric
 
I didn't reply because I figured it was obvious that you used a soft epoxy. There are harder epoxies. But, epoxy is not going to be nearly as hard as micarta, which is phenolic resin.
 
Hankins said:
The epoxy ordered has a Shore hardness rating of 65 which is about the durometer rating of a contact wheel. Press into a contact wheel and you can make a fingernail impression.
Got it because the price was half of the 85 shore rated epoxy. Wanted to get closer to Micarta hardness so I will bite the bullet and buy the better stuff.
There is a 90shore rated epoxy out there but that is even more pricy for experiments!
Click to expand...
Don t waste your money , find epoxy like one I recommended you and make that micarta .
 
Not sure where what type of phenolic resin you are using to compare with, but Micarta is made with a PF resin, not PU like countertops. Even PU resins are denser than epoxy and close in temp range.
Phenolic Formaldehyde (PF) resin has higher density and hardness according to my charts.
It does not matter in knives anyway, but PF resins have a breakdown temp of over 400°F. Epoxy maxes at around 350°F.

The biggest reason you can't make PF resin composites at home is how it is cured. That is why people use two-part high density epoxies to make MyCarta.
 
Do yourself a favor and contact Polymer Composites in Ontario Ca. Talk with Gerald who is the chemist. He will tell you exactly what you need for the correct formulation for your mycarta. They sell their products on Ebay.

People are using the wrong resins for the intended purpose.
 
I’ve done a bit of experimenting with several different epoxy formulations, as well as pressure pots, and vacuum chambers for homemade composites and I haven’t been pleased with any of the results.

If I wanted a custom, epoxy composite that would hold color throughout the years, I’d just contact Greg and Mikie at G-Carta. Their marerial is the best, most consistent modern epoxy based material I’ve used.

Personally, I’m a fan of phenolic conposites since they age and patina over the years…. So I had Current Conposites press me some U.S.A. made rag/burl phenolics out of burlap/canvas/and linen specced by me. I prefer phenolic over epoxy binders, not only because of their ability to patina, but also their chemical resistance, and ease of polishing, compared epoxy. I consider the minor increased strength from high-end epoxies to be more or less negligible.

IMG_8899.jpeg
 
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I use a lot of stuff from Current as well! I made the first knife ever with AmeraGrip handle material for them, too. Great product, different designs and patterns too!

I use MarineGuard 8000 for my home made laminate handles. It cures pretty hard and I am very happy with the end results! I used to use MAS Low Viscosity Epoxy years ago, but it was more flexy and a bit softer and took a lot longer to cure. With the MarineGuard8000, I put everything into a mold in a press, put a small personal desk heater near the press and then put a big cardboard box over it and I can unmold it in about 4 hours or so. I usually wait a bit longer before I bandsaw it down from the blocks, but it's usually good to go in a day or two after unmolding it, depending on the weather.
 
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