Acrylics, mother of pearl, MOT, cracked ice and perylic

[silenthunterstudios]

I have never been a big fan of mother of pearl, cracked ice, acrylics etc. Some have looked neat, but I usually would have never even cast a second glance at a knife with any of these materials on it. I recently traded into a Northfield Ben Hogan, with sea pearl perylic and long pull, and pinched bolsters. I like the pattern, and wanted to try the knife out, figuring that if I didn't like it, I would not have a problem trading it for something else. Turns out I really like it. Might just be the subdued sea perylic matched with the patina and the long pull. Just seems like something a gentleman gambler might have carried a hundred and fifty years ago.

I have read in Knifeworld that storing acrylic handled knives with other type knives is detrimental to both the acrylic scales, and other knife materials. Something about the chemicals used in the scales affecting other materials, causing them to break down quicker. Can anyone tell me the ins and outs of acrylics?

 

[Obsessed with Edges]

I have never been a big fan of mother of pearl, cracked ice, acrylics etc. Some have looked neat, but I usually would have never even cast a second glance at a knife with any of these materials on it. I recently traded into a Northfield Ben Hogan, with sea pearl perylic and long pull, and pinched bolsters. I like the pattern, and wanted to try the knife out, figuring that if I didn't like it, I would not have a problem trading it for something else. Turns out I really like it. Might just be the subdued sea perylic matched with the patina and the long pull. Just seems like something a gentleman gambler might have carried a hundred and fifty years ago.

I have read in Knifeworld that storing acrylic handled knives with other type knives is detrimental to both the acrylic scales, and other knife materials. Something about the chemicals used in the scales affecting other materials, causing them to break down quicker. Can anyone tell me the ins and outs of acrylics?

Not acrylics, but celluloid specifically. That stuff is a very nasty & ugly animal unto itself, due to the 'outgassing' of chemicals from the material, which is corrosive to anything steel in close proximity. I have a link (I think) to a good article about it; I'll see if I can find it and post it here.

Edit:
Here's that link to the article about celluloid -->: http://www.oregonknifeclub.org/celluloid_02.html

So far as I know, celluloid is the only material which is capable of damaging other nearby knives & materials. Other synthetics (acrylic, delrin, etc.) have some of their own issues, in that they can break down or degrade (fade, shrink, become brittle) in themselves, from exposure to UV light or chemicals. But those won't harm anything else in the process.

 

[Bigfattyt]

Any pics of the Ben Hogan.

That pattern tickles my funny bone. The fact that the handle swell hides the sharp tang, and the nice slim profile make me want it.

 

[akadave2]

Its the shrinking that bothers me. I dont think I have ever seen Delrin shrink...anyone here?

 

[Pipeman]

Acrylic doesn't shrink, celluloid does. As for gassing, I have found the ones to go most often are the paper celluloid type. I have also found that handles that are gassing (pre decay) usually leave a very dark "patina" on the back of the blades where they sit out of the slots. That dark "patina" eventually becomes pitted if the celluloid is left on the knife. If celluloid is stored with other knives it can affect all of them. Pretty but nasty stuff and down right explosive.

Best regards

Robin

 

[Thomason]

I was under the impression that acrylics (as in GEC ) are fine. It is the old celluloids that are nasty stuff. Correct?

 

[Pipeman]

Acrylics are fine. If I remember correcty celluloid was made from Nitroglycerin in part. I have had the stuff burst into flames when grinding and old handle off a carving knife. It will fill your house with smoke in seconds and pretty much won't go out until it's all burnt.

Regards

Robin

 

[eisman]

Nitrocellulose, not -glycerene. Used to be called gun cotton too. Nice stuff. That would be a good spy tech idea, scales of explosive. Sad its true of the really old ones.

 

[qncygnnr]

Acrylic plastics (properly mixed and cured) do not "outgas" unless they are exposed to strong bases and acids, or sustained extreme environmental stressors (heat, cold, saltwater, etc.). The biggest issue with any clear plastic (other than melting or flammability) is vulnerability to "crazing" (when the surface of the acrylic becomes milky and loses its transparency - a type of surface etching). Synthetic lubricants may have addititives that can cause etching - great care should be exercised when used on knives since many of these products are designed for metals.

Celluloid is another beast altogether and is not "stable" in the modern conventional sense.

IMHO the "safest" way to maintain any of the GEC LG, or any other exotic cover material is to use mineral oil. It is the most "natural" lubricant and protectant commonly used in our hobby and is very benign (that's why its the largest component of baby oil). Stag, bone, real pearl, and real abalone are "oragnic" even when stabilized (which usually means impregnated with plastic resin) to create mechanical strength - but can still be damaged by surface etching that may not be polished out or removed without creating additional damage. Better to be safe than sorry.

 

[silenthunterstudios]

Any pics of the Ben Hogan.

That pattern tickles my funny bone. The fact that the handle swell hides the sharp tang, and the nice slim profile make me want it.

Two Northfields, and a Tidioute. Two clip points, and a spear point. Two long nail pulls, and a crescent nail nick. Three great knives any way you look at it.

 

[TomTerrific]

Two Northfields, and a Tidioute. Two clip points, and a spear point. Two long nail pulls, and a crescent nail nick. Three great knives any way you look at it.

Indeed, that is a very nice pattern, IMHO.

 

[T. Erdelyi]

All plastics will eventually over time, outgas, whether the outgassin' will damage the knife depends on the environment and the additional substances that come in contact with it.

Modern plastics as mentioned above will discolor, shrink, crack and get brittle but for the most part ya won't see much in the knife's normal life.

Biggest mistake with celluloid is when it stored in a close quarters sealed container/box, as the celluloid degrades it has no place to dissipate to, so it basically gets stronger and more aggressive/destructive to the knives stored near it.

Store plastics in a ventilated box, keep em seperate and make sure the celluloid is stored by it's self, if you see the scales startin' to change, decompose orchange tecolor or texture remove it immediately from the other knives, it'll accelerate the break down of other similarly scaled knives.

Celluloid is a tickin' time bomb and no 2 will decompose at the same time unless stored together, i have several celluloid scaled knives that are from the 40s and 50s that are just fine, I had aknife from Czechoslovakia from the 40s and it was fine until 6 years ago when I noticed that the exposed edges of the of the closed blade were beginnin' to discolor, within' a few months the blades were pitted, rusted and basically impossible to open, luckily I removed from my other celluloid knives and was able to save most of 'em, (they all were startin' to get a little discoloration in the exposed part of the blades.

Again as far as modern plastics, (mostly anything after the late 60s early 70s was relatively stable). Still ya gotta watch, some cleaners, anything with citrus/petroleum based solvents could affect the finish on more modern plastics.

The materials in your storage medium could react with certain modern plastics, ya need to store knives like these in as inert a medium as possible.

Hope this helps a little.

 

[T. Erdelyi]

Stagalon, Delrin, G-10, FRN, Carbon Fiber, Perlite, Cracked Ice, most of these are stable, Micartas you might have to watch with some solvents.

There's a lot of info on the stability of modern day plastics, google it, it'll give ya some good late nite readin' material.

 

[kc custom]

If there is full disclosure I see no problem using it. I've seen old stuff look great after
50 years and look new, and seen the same stuff go completley to hell in 2 years.
Many natural materials are not guaranteed forever. It will burn alright. celluloid.
Ken.

 

[Obsessed with Edges]

Its the shrinking that bothers me. I dont think I have ever seen Delrin shrink...anyone here?

Maybe just a bit of shrinking, but not in all cases. Sometimes, with older Delrin or similarly-covered knives, you'll notice gaps widening near the bolsters, which indicates the Delrin has shrunk a little bit. I've noticed this a lot on older Schrade and Schrade-Walden Old Timers with the brown sawcut Delrin scales. Many of those seem to have pretty wide gaps between the covers and the bolsters.

Another variable with Delrin is, it's gone through a lot of formulation changes over the span of decades (Delrin was originally patented back in the '50s). Even today, there are dozens of different formulations of Delrin, depending on the intended application. Some are made for greater strength or rigidity, others are made for increased chemical resistance, and so on. I'm sure each behaves a little differently over time.