MagnaCut Corrosion Resistance testing thread

[Bill1170]

All this talk of galvanic corrosion has reawakened an old wonderment of mine. How close on the GC scale are common stainless blade steels and the titanium used for handles on fancy folders?

I also wonder how electrically active carbon fiber scales are. I knew a guy who raced a carbon trimaran in Florida. He told me the carbon hull was so noble it ate the 316SS fasteners that touched carbon, necessitating annual replacement.

[Woodpuppy]

I would have thought the carbon functioned as an insulator.

I was wrong wrong wrong.

[razehound]

Yeah no carbon fiber is technically conductive. That's also why you can't anodize scales that have CF inlays.

[aicolainen]

Yeah no carbon fiber is technically conductive. That's also why you can't anodize scales that have CF inlays.

This discussion is mostly outside my wheelhouse, so I wont get too involved, but I think there is relevance in defining what's technically conductive.
While certainly not a super conductor, some forms of carbon is used in plastic ESD packaging to achieve anything from static-dissipative to EMI/RFI protective properties.

[Bill1170]

Universal motors use graphite brushes to put electrical power into the commutator (segmented part that rotates).

Not only is carbon electrically conductive, it is also very “noble.”

[Cscottsss]

Sold my Native 5 salt to a friend a while back because the DF2 Salt got much more pocket time while fishing. I'll be picking up another one when the Magnacuts hit retailers. Thanks for testing the Mule out Lance!

[asdfghjkl]

Thanx Lance.

Hi Crox,

Spyderco is constantly testing corrosion in any possible situation. That's how we learn and improve. Coming out with a production knife that will reliably work for the user in salt water environments, as not an easy endeavor. Gail and I sought that solution for decades before making it available to you. We had to kiss a lot of toads. Now that we have many years of lab testing and Real-World-Testing and we are pleased to be able to serve you with our solutions.

sal

There is a company out of Signal Hill, CA called Forever Bolt. They take stainless steel hardware and process it to remove all contaminates from manufacturing and to remove the carbon from the surface of the hardware. It makes the bolts, nuts, screws etc 100% corrosion proof. Not sure if you are aware of it but it works.

[bleasure]

fwiw, I've been using my mc mule as my exclusive kitchen knife after i recently moved into a temporary situation for a job. it's un-handled, has sat wet in the sink for days at a time, & has been cutting tomato, onion, pickles etc. i've been inconsistent in washing and drying it. no rust or tanishing of any kind to be seen after about a month so far

[sal]

Hi Asdfghijkl,

Welcome to our forum and thanx for the tip. We'll look into it.

sal

[asdfghjkl]

I took my magnacut mule for a dive a week ago. It has stock scales in place. After the dive I gave it a fresh water rinse. I took the scales off yesterday and there was “corrosion”. I wasn’t thinking and didn’t take pictures. I scrubbed it off with a scothbrite pad. I can only see a couple small pits remaining. Could be due to the hardware from the scales. I’ll say this though, I have a benchmade fixed blade from 2003 that is made from H1. Even it suffered from this after long enough. So the Waterway style of handle is a definite benefit for any fixed blade being dunked in salt water.

[RamZar]

I took my magnacut mule for a dive a week ago. It has stock scales in place. After the dive I gave it a fresh water rinse. I took the scales off yesterday and there was “corrosion”. I wasn’t thinking and didn’t take pictures. I scrubbed it off with a scothbrite pad. I can only see a couple small pits remaining. Could be due to the hardware from the scales. I’ll say this though, I have a benchmade fixed blade from 2003 that is made from H1. Even it suffered from this after long enough. So the Waterway style of handle is a definite benefit for any fixed blade being dunked in salt water.

The only corrosion was under the scales (where the hardware attaches) and not on the blade?

[VooDooChild]

I took my magnacut mule for a dive a week ago. It has stock scales in place. After the dive I gave it a fresh water rinse. I took the scales off yesterday and there was “corrosion”. I wasn’t thinking and didn’t take pictures. I scrubbed it off with a scothbrite pad. I can only see a couple small pits remaining. Could be due to the hardware from the scales. I’ll say this though, I have a benchmade fixed blade from 2003 that is made from H1. Even it suffered from this after long enough. So the Waterway style of handle is a definite benefit for any fixed blade being dunked in salt water.

The mules have a magic ability to corrode under the scales. I dont know if its the rough handle finish or hardware or moisture being trapped in or what.

Plenty of us had corrosion under the scales on the lc200n mule as well. I did after a few times out on the boat.

[asdfghjkl]

I took my magnacut mule for a dive a week ago. It has stock scales in place. After the dive I gave it a fresh water rinse. I took the scales off yesterday and there was “corrosion”. I wasn’t thinking and didn’t take pictures. I scrubbed it off with a scothbrite pad. I can only see a couple small pits remaining. Could be due to the hardware from the scales. I’ll say this though, I have a benchmade fixed blade from 2003 that is made from H1. Even it suffered from this after long enough. So the Waterway style of handle is a definite benefit for any fixed blade being dunked in salt water.

The only corrosion was under the scales (where the hardware attaches) and not on the blade?

Yea it was only under the scales if that wasn’t clear. I’m thinking of trying to find some type of plastic rod to use as a substitute for the hardware, epoxy it all into place. Which will seal the interior completely and remove all other metal. But maybe that discussion is for another thread.

[twyych]

Slightly off topic, but does anyone know of any hardware options for kydex that are more corrosion resistant than those from spyderco? The bolts I use to secure my titanium clips to a sheath turn into a rusty mess after just a few dives.

[Michael Janich]

Dear Twyych:

You might try nylon screw hardware.

Stay safe,

Mike

[Woodpuppy]

Aluminum rivets?

[alphaneuron9]

Lance,
Any new updates? Did you keep using the MC mule after your GC testing? Interested in seeing if the pitting worsened with some more real world use.

[Bill1170]

I took my magnacut mule for a dive a week ago. It has stock scales in place. After the dive I gave it a fresh water rinse. I took the scales off yesterday and there was “corrosion”. I wasn’t thinking and didn’t take pictures. I scrubbed it off with a scothbrite pad. I can only see a couple small pits remaining. Could be due to the hardware from the scales. I’ll say this though, I have a benchmade fixed blade from 2003 that is made from H1. Even it suffered from this after long enough. So the Waterway style of handle is a definite benefit for any fixed blade being dunked in salt water.

The only corrosion was under the scales (where the hardware attaches) and not on the blade?

Yea it was only under the scales if that wasn’t clear. I’m thinking of trying to find some type of plastic rod to use as a substitute for the hardware, epoxy it all into place. Which will seal the interior completely and remove all other metal. But maybe that discussion is for another thread.

I made cork handles for two Mule Team blades. To secure them I used epoxy plus two blind pins. The pins were stainless screws with their heads and points removed. I figured the threads would engage the epoxy firmly and the epoxy seals the pins and the tang faces from the air/water. One of these was a kitchen knife for several years. It is too thick a blade for most kitchen uses, and now it lives in my shop. There was never any water intrusion under the cork.

[asdfghjkl]

I finally finished my magnacut mule for in water use. I replaced the stainless hardware (from the Halpern scales) with G10 rods and glued it all together with marine grade epoxy so its all sealed from water getting in. I'm not a professional knife maker, so it's not perfect, but it works really well. I would post some pictures but i have no idea how to do that.

I took it on a dive the other day and left it wet. After a day there was some signs of corrosion inside the spydie hole. I polished it up with the Dremel to get rid of any possible machining contamination so we'll see how it goes after that.

[JSumm]

I finally finished my magnacut mule for in water use. I replaced the stainless hardware (from the Halpern scales) with G10 rods and glued it all together with marine grade epoxy so its all sealed from water getting in. I'm not a professional knife maker, so it's not perfect, but it works really well. I would post some pictures but i have no idea how to do that.

I took it on a dive the other day and left it wet. After a day there was some signs of corrosion inside the spydie hole. I polished it up with the Dremel to get rid of any possible machining contamination so we'll see how it goes after that.

Here is a thread that Vivi started. I use the Direct Link option. I just keep the website open on a different window on my browser. Once you do it a couple of times, it becomes 2nd nature and will only take a few seconds.

viewtopic.php?t=83968