I was recently reading about the differences between industrial micarta, made with phenolic, and home made micarta, made using epoxy. The one big source I found for the information (okay, two sources... but they either belonged to the same guy or one completely plagarized the other) said that micarta made with epoxy was inferior due to air bubbles and sensitivity to heat.
But I see people using epoxy bound micarta for handles on here, and have seen at least one forum member successfully selling it. Samples I've seen from Shadetree Phenolics look incredible, and the tutorials I've seen on making it sound like a fun project to set up some day.
So I'm looking for people who've worked with the epoxy based micarta to explain just how sensitive to heat the stuff is-- like will it melt from excessive hand friction from heavy use, or would I have to hold a lighter to it? If the material is overly sensitive, is it possible to CA seal it to increase moisture and heat resistance? Would that greatly effect one's ability to establish grip on the micarta?
And if by chance anyone who's made the epoxy micarta comes by, please share any tips and tricks you have for crafting the material. I'm always up to learning even if I decide to work with other materials for the majority of my projects.
-- Oh, and on a side note. I'm a bit confused on the type of filter/respirator necessary for working micarta. If someone could explain the letter/number system and naming convention on those to me, I'd greatly appreciate it.
Thanks for the compliment. I don't know if making composites could be considered to be "fun" though.
If done correctly, it can rewarding, but done incorrectly, it can be a messy frustrating nightmare.
Regarding air bubbles, most probably that would be an issue related to technique and not to materials. There could be an out gassing issue related to a specific product, but in my experience it is a rare occurrence. I suggest checking with the manufacturers regarding working temperatures of the cured resins as well as curing and working temps while mixing and laying up (this is important-- temps have a significant effect on working times and viscosity). Out gassing may happen if you try to cure at too high a temperature, but you'd have to work at it.
When starting out, I tried quite a few different resins and the epoxy is by far the best in my opinion and experience.
I use aero-marine, water clear, UV stabilized epoxy to make all my composites. I cure it under heat and pressure with a secondary cure in my hot-box. If it works for boat hulls, car chassis and airplane wings, it will work great for knife handles. I have used phenolic resins for specialized non knife projects in the past, but it is prohibitive for a number of reasons for knife scales.
The high quality epoxy resin I use costs about ten times what poly ester resins (eg Bondo) does. Simply put, I don't use it just for the sake of spending more money, I use it because it makes a superior product.
As mentioned by others, viscosity is very important. About the thickness of water helps saturation of the substrate ("wetting") and the importance adequate saturation cannot be stressed enough.
That being said, the substrate (whatever fabric you choose) needs to be able allow the resin to fully saturate. Anything with a waterproofing, anti rot or similar treatment will not work.
All in all, the best tip I can give you or anyone else interested in making their own composite materials would be to contact an established maker and have them make it up for you. I know a guy who is pretty easy to work with...
If they said that epoxy based stuff was bad because of air bubbles and sensitivity to heat they are wrong on both counts. If they are having air bubble problems then they need to change how they make the stuff. May be using to thick of a epoxy or even to thin just have to learn how to work with a given epoxy. Sorry no other way to put it. G10 that is factory made would be worthless if that where true since it is epoxy based. Some epoxies deal with heat better then others that is true but almost across the board they are better then any polyester resins that you get for fiberglass. Epoxy also almost always has better impact resistance and a lower water absorption rate. If you get a really good epoxy comparing it to polyester resin is not even close.
If you are making any stuff to sell then spend the extra money and use epoxy you will get a better more durable product in the end. Almost all epoxies benefit from a post cure heat treatment. You often have to check with the company that makes it to get this info. One of the epoxies I use gets a 4-6 (at least) hour post cure heat treatment at 160-180 degrees. Sets it up like a rock, takes a better finish. That is by the instructions from Dow Chemical. So so unless they are running around where it is above 180+ degrees....the epoxy is fine. Sounds like someone does not want to spend the money on epoxy so they are making excuses. Hope that doesn't sound to harsh I just make a bunch of this stuff and there are knifemakers out there that are turned off from any homemade "micarta" (closer to G10 but another rant lol) because they have used some that was poorly made, from poor materials and lump all of it together.
All excellent points Mark.
As you mention checking with the company is a great idea; the manufacturers are generally very helpful and willing to make sure you get the right product. A phone call or two is very informative.
Mark has a very valid point.
I am one of those who have been a dissuader of folks making their own. I call it MyCarta, since Micarta is a registered trade name...and you can't make it at home.
The products I have handled and tried have been inferior to poor, mostly due to improper materials.
The use of a properly matched (matched to the purpose) epoxy resin, hardener, and laminate material will make a good product. However, it has been my observation that 95% of those trying to make MyCarta use the wrong resin. You need a low viscosity, slow setting, slow curing, water clear, rock hard epoxy.
Polyester resin, Bondo, etc. won't work.
What you buy on the shelf at the hardware store, auto supply, or at the marine supply, is not made for knife handle use. Contacting the manufacturer's tech department and discussing the proposed use will get you a resin/hardener match that will make your life easier. It will make a good handle laninate.....It won't be cheap, though. I suggest System Three or West System for good results.
Final comment:
Two of my most disliked, and wrong terms often posted on forums and in print are calling the fuller on a blade a "Blood Groove" and calling home made handle laminates "Micarta".
Stacy
Stacy, your comments are spot on. Kindly notice I refer to myself as a composite maker or laminate maker.
Micarta, as you state, is like using the name Xerox as a generic term for copiers or Kleenex for all tissue paper. I should also correct folks that refer to my stuff as phenolics. I have made phenolic products for other industries, but not for knife scales. I was making that stuff before I began supplying to knife makers, which is where the name came from.
I do have to agree that the commercial, factory made products are mechanically and technically superior to the handmade stuff, but a custom composite properly made from high quality materials is very tough, performs great, and offers many positive aesthetic possibilities that factories will not or cannot offer.
Again, as mentioned already, contacting the manufacturer will save a lot of trouble and money.
