Micarta Question

[paladin]

Are there shrinkage / deformation issues with the coarser CANVAS MICARTA?

I know the linen micarta has created some issues on the older Goddards & Caly's...

I'm guessing it's a resin issue rather than a fiber issue when it comes to the deformation over time...but still just wondering if the CANVAS variety was more stable or no?

Lotta smart people here with a lot of experience...thanks in advance! :spyder: :D

[SpyderNut]

Good question, Paladin. I just recently finished making a folder that has dark green canvas Micarta handles. As of now, I have yet to notice any moisture/swelling issues. I suspect a lot depends on how the Micarta is finished. If left in its natural "unfinished" state, the canvas type of Micarta will feel quite grippy but will stain very easily from oils from your skin, etc. I opted to finish my handle scales to a medium-high polish to help prevent moisture from soaking into the handle. Basically, I started with 400 grit sandpaper and then worked my way up to about 1000 grit. I then wiped the handles down with FP-10 oil and then re-sanded with 1000 grit. The handles no longer have any staining issues whatsoever. I have read that Micarta is slightly more prone to warping than G-10 because it is comprised of cotton fibers vs. synthetic material such as fiberglass. Time will tell, I'm sure.

[Zenith]

One has three different types of Micarta.

Paper, Linen and Canvas.

The following was said by Jerry Busse I believe.

"Micarta was developed by Westinghouse earlier in the last century. It has a higher tensile strength than steel, it is impervious to changes in temperature and it will not swell, warp, or crack, even under adverse conditions, once it is on the knife.

There are three types of micarta and several grades of these three types. They all consist of layers of either paper, linen, or canvas. Paper is the most decorative of the three. I have seen paper micarta handles that are 20-30 years old that continue to look great and perform like the day the were made. Linen micarta is the middle grade when it comes to toughness and durability. I used linen exclusively throughout the 80's and very early 90's. It is very attractive when smoothed out and very strong. Canvas is the toughest of the three grades. It surpasses linen micarta by a large margin for strength and durability. Canvas also offers the best overall texture for slip resistance. It is probably the least attractive looking of the three grades unless you suffer from Busse Combat Nuclear Syndrome. In that case you can only find "beauty in the performance". Cosmetics be damned!

It would be difficult to go wrong with any of these three grades."

[paladin]

Thanks for the replies SpyderNut & Zenith!

Zenith...as for the quote from Busse "it is impervious to changes in temperature and it will not swell, warp, or crack, even under adverse conditions, once it is on the knife..."

that last clause gives me pause...

Busse makes fixed blades, and I can see how when you rivet something to 1/4th of an inch of solid steel how it would not "swell or warp"...

But with the open or semi-open construction of a folder, with the added factors of pivots, locks & various other moving parts and when the Micarta can't use a solid bar of steel for a splint/support...then, I believe, we've seen over time Micarta is prone to warping / shrinkage...

So, back to my original question...Does Canvas Micarta shrink more / less / same as the linen & paper varieties?

[The Deacon]

I'm not questioning Sal's experiences with Micarta, but they do appear to differ remarkably from those of others. Al Mar still offers their Eagle, Hawk, and Falcon ultralights with unlined Micarta handles, and their Eagle Classic with Micarta scales over bolstered steel liners. Other companies still use it on folders as well and at least some of those are imported. Many companies use it for fixed blade scales as well and, despite what some may think, simply being attached to a 1/4" thick steel slab will not keep something from warping, srinking, or swelling. I'd just add that I have dozens of Micarta handled Spydercos in my collection and, aside from some orange discoloration around the pins on a couple white Micarta handles, have never had an issue with any of them. I can understand that it's not an ideal material to tap for small, fine threaded, screws, but neither are G-10, CF or NGF, so they're all best used on models with wire clips, liners that can be threaded for a 3 screw clip, or no clip at all.

So, back to my original question...Does Canvas Micarta shrink more / less / same as the linen & paper varieties?

Assuming all three are phenolic Micarta, I'd say "the same" since none of them shrink once cured. Thermal expansion/contraction may be another story, but I suspect that it would be the resin, rather than the "filler" that expanded/contracted, so once again a wash and, given that dimensional stability is one of Micarta's strong points likely to be hard to measure on something the size of a knife handle. Certainly no greater or easier to measure than the expansion/contraction the other parts of the knife would also be experiencing.

[Zenith]

So, back to my original question...Does Canvas Micarta shrink more / less / same as the linen & paper varieties?

I cant answer that really, I have experience mainly with canvas micarta with my Andre Thorburn Custom with Canvas OD Micarta. I am a OD Canvas Micarta fan and this folder has seen some really hot weather (49°C or 120°F), water, cold. I have not dropped it yet. I have a few other customs with OD Canvas Micarta as well and really love it.

[Mallus]

I'd like to see more Micarta handles! Upon a quick googling I came about the following data:

http://www.professionalplastics.com/pro ... aSheet.pdf" target="_blank

It seems the stability of phenolic based composites varies. For instance, NP629 "is a paper based phenolic that is a machining grade (...) can be used in dry or high humidity conditions", whereas NP602 "
is a paper-based laminate with low phenolic resin content (...) not suitable for applications that require resistance to high humidity".

Now, I understand that Spyderco is very busy with the all the projects that they are running as it is. However, testing the properties of prospective Micarta handle materials would be a nice summer job project for a wannabe material scientist! :)