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TRAILMASTER VS TUSK

Rusty, sounds good, I'll drop you an email when they get here. It should be interesting to see how the fairly cheap production items compare to the high end handmade ones.

-Cliff
 
Chrome questions:

Cobalt,

Are you talking about the same chroming process Mad Dog uses in regards to rusting? Or, just a generic chroming process?

Is this beneath the chrome rust argument a theoretical diatribe (eg there's always a point between two points)...or has a knife been produced that flaked chrome revealing rust?

I too was under the impression that a chrome barrel increased wear resistance and rust resistance...the friction and heat of the bullet seem to intensify rusting...just shoot one bullet through a non-chrome-lined barrel and let it sit for a weekend - inspect the bore and see how much rust removing the bullet did. Versus, "playing/training" with an AR-15 for one week during several field exercises, shooting thousands of blanks and cleaning it at the end of the week w/o any internal rust. (Hey I'm lazy).

I'm sorry you've never owned a Case knife...you're missing out...they're good and the chrome prevents them from rusting...

If the chroming processes above do, in fact, permit vapor - does this really matter? I mean metal must be oxidized to rust right? Is air exposure enough or must an oxidizing agent be introduced as well to facilitate the process?

Hope you can answer some of the questions I have...Mad Dog seems to be really educated as to metallurgy and I trust his methods.

Thanks for the entertaining thread,

John

PS Chrome can't be all that bad, wasn't the wicked Terminator all Chrome? He didn't rust and they really tested him...
 
I went back to see if MD had made any statements on this issue, here are some links to the corrosion issue discussed on KnifeForums :

http://www.knifeforums.com/ubb/Forum12/HTML/000536.html

http://www.knifeforums.com/ubb/Forum12/HTML/000554.html

http://www.knifeforums.com/ubb/Forum12/HTML/000591.html

http://www.knifeforums.com/ubb/Forum12/HTML/000606.html

The basic idea is that it does provide corrosion resistance but how much is unknown and you do need to apply a protectant to the hard chromed part of the blade.

-Cliff
 
Cliff,

I just searched the Knifeforums about the hard chrome question. The search on Bladeforums did not work (server error?).

Of the 5 or 6 threads about hard chrome and corrosion one was on testing corrosion. It had a post by Mark Schmitt on MAD DOGs forum (11/3/98)and was very helpful. Most of the rest of the comments seemed to have a lot of supposition about what could happen, and incorrect assumptions. TABING and others have dived with the hardchomed blades and report a discoloration that wipes off. I have had "stainless" blades that discolored in blood and fruit juice. I do not obsessivly wipe my knife blades down with a TUF Cloth after every use or each day. Only if store them for a long period.

It seems that I have read MILSPEC salt spray exposure tests of coatings used on firearms in catalogs from ROBAR, Checkmate and others. A standard salt spray test may be the way to definativly resolve the degree of corrosion resistance.

Please help me find a refernce to the rust beneath the coating incident you mention.

I am not a collector so discolorations and fine surface scrathes in blades caused by a sheath is of no importance to me. I carry and use my Microtech SOCOMs, Crawfords and all my handguns show use.

I do not have a MAD DOG yet but have ordered one.

I am interested in this topic because of the unspecfied negative connotations that seem to be attached to the hard chrome coating with no solid basis?

Cobalt,

I respectfuly disagree, the hard chrome coating in firearms is also intended to reduce corrosion, esp in the case of military corrosive ammo and in cases when the recommended daily maintenance is not performed, say when you are shooting a lot and people are shooting back.

I have a funny story about this: In a Thunder Ranch Urban Rifle class I was partnered with a very fit and motivated special forces guy, at the end of the day he put his M4 carbine away, winked at me and said. " a dirty gun is a happy gun". I never saw any malfunctions for him so I guess he knew how happy to let his gun get.

Noel
 
Noel, in the links above you will see MD comments on his hard chrome and he clearly states that his knives will rust if not protected. Now since the chrome itself cannot rust I would assume he means the steel under it.

I would be interesting to see a comparasion done between the coatings. It would be an easy thing to do and I don't know why the guys who make all the coatings don't simply do it so we can all figure out which one to pick.


-Cliff
 
Noel, as I have stated before, hard chrome does HELP in corrosion resistance, but it is NOT a barrier to moisture as moisture can penetrate and eventually cause rust in the metal part that is chromed. Mad Dog himself said this, as Cliff pointed out. The concern is that you will not see the rust developing because it is under the chrome. It may rust through and fail, but you cannot see it. That is my concern anyway. I don't think this has happened to any MD knife because the people that own them take care of them. It is foolish to think that with a non corrosion resistant steel as O-1 is, that you won't need to maintain it even if it is hard chromed.

Now to the subject of gun barrels being hard chromed. Again, as I stated several times already, hard chrome will help in protecting against rust, but it will not prevent it. The REASON that hard chrome is used is because of wear resistance and it is also easier to wipe the metal off if it is chromed. Check out how many guns do not have hard chromed barrels(most dont). Gee, I guess they all should be rusted by now, NOT. So, I respectfully disagree with your disagreement. Additionally, if only the bore is chrome lined(and it usually is only the bore) then what about the rest of the barrel. How is it protected. Most gun barrels are made of what is termed a chromoly steel. Gee do you think they have a little chrome within their makeup. Maybe this is why they do not rust so easily. Just some thoughts on chrome....
 
Chrome addendum:

I have two Mad Dogs in my kennel...one w/ the old and one w/ the new style chrome.

Intuitively, I think the argument that some rust would sneak in beneath the newer chrome is unlikely. Mainly because one can appreciate the differentially hardened temper lines beneath the new styled chrome.

The old chrome is less revealling and I cannot appreciate the temper.

So, it seems to me, if I can appreciate something as suttle as temper lines, then I could probably detect rust encroaching on my pups as well.

Later - I'm gonna go check my bumpers for rust,

John
 
Cobalt,

I reviewed this thread to see if I misunderstood what you had wrote.

Cobalt posted 21 March 1999 05:00 PM
4. MD knives are hard chromed and CS knives are not. This increases wear rsistance but not corrosion resistance or toughness, so it is not a plus in my opinion.


Cobalt posted 23 March 1999 05:07 PM
Joel, Hard chrome is a plating or surface bonding process that produces a surface hardness all the way up to 74 on the Rc scale. This provides excellent abrasion resistance, so that if you drop the part that is chromed chances are it will not even be marked. However, moisture can still penetrate through chrome bonding, although considerably slower than if there was no chrome there, but moisture *will* penetrate. The problem is that once this has happened, Cliffs fear of not being able to remove the corrosion is quite real since the corrosion is now underneath the super hard chrome. This *will spread throughout the underside of the chrome before it even becomes visible*. I cannot say how long it takes as that all depends on the environment. (emphasis added)

Cobalt posted 26 March 1999 04:08 PM
As for the linning of a gun bore with hard chrome. The hard chrome is there for *wear resistance only not corrosion resistance* since the friction and heat of the bullets as well as the gun oils used keep the barrels from rusting anyway. (emphasis added)

Cobalt, I am not really interested in having people reading our discussion say that either you or I was correct, but I did want to let you know that I thought your response, in light of your statements that I've quoted above, bordered on being rude. Did you have a reason to go into a sarcastic mode other than my respectful disagreement on what I understood you to say about corrosion in barrels? Note that John Callahan also understood you to say that you did not think chrome increased corrosion resistance.

When did I say that hard chrome was magical and meant that no maintenance would ever be required? Just because I don't wipe off my blades every use? When did I indicate a gun barrel without hard chrome would instantly turn into iron oxide?

Please, don't be rude and don't attribute things to me that I did not write. Thanks.

Anyway, my question really is the same as John Callahan's has anybody observed a "RUST" spot growing like a cancerous tumor beneath a hard chrome surface that was undetected for a length of time? Cobalt indicates in his post of 23 March, that it *will* happen, no question about it. Can this be shown in an example of a hard chromed blade or barrel, not a old car bumper?

Corrosion and rust have two connotations in my mind (they are related but do not mean the same thing in all uses of the terms) and a further distinction for me is discoloration is not "rust".

Hoping for more civil discourse, I remain,

Sincerely,

Noel
 
Quick note, John posted as I was writing so comments not chronological.

Off for now,

Noel
 
Noel, civil discourse is the only way and I would not intend to be rude as I don't think you would either. So to the question at hand. You stated the following:

"Cliff,
A question, correction?

Hard Chrome is indeed a vapor barrier, it is chemically bound to the steel surface if I read the

http://www.hausnerinc.com/sealproc.htm

info correctly,"

Well, I hate to bring this up but no were within that url does it state that the hard chrome is a vapor barrier.

Secondly, it even states within that url that the use of hard chrome will help resist corrosion. they also go on to mention the food industry as a good use for their chrome. Since I know a little about the steel used in the food industry, let me explain. Nearly 100%(and of course there may be other stainless steels used also, but the point is stainless steel is used) of the steel used within the food industry is 304 or 316 stainless steel. This steel is extremely corrosion resistant but in the food industry extremely caustic solutions are used to clean equipment when a different batch of food may be run through the same equipment. Thus, even stainless steel as corrosion resistant as these can begin to show signs of corrosion. Putting hard chrome on top of stainless steel makes a good stainless almost impervious to corrosion, although not completely.

So, again, respectfully and with intended civility, hard chrome will resist but not prevent rust. When applied to a steel that offers literally no corrosion resistance by itself, it is a concern if the rust works it's way underneath the chrome were you cannot see it. you cannot remove what you cannot see.

Thus as for your quoting me about my original statement that I don't see hard chrome as an advantage, well I still firmly hold to that. I would rather see the rust develope and be able to take it off than to not see it and find out much much later. If I get a MD knife, you can bet I will treat it as if it were the least corrosion resistant steel there is, because I do not want it to rust without my knowledge.

I hope that it is understood that increased corrosion resistance is not the same as corrosion proof.

Noel, sorry if my writting sounded as abrassive as a DMT coarse stone, previously, I'll try to smooth it out.


 
In the interest of getting back to the reason for this thread, Knife Testing, I will get a little more technical and to the point.

The inherent weakness in hard chrome plating is that it has porosity sufficient to allow corrosive fluids to penetrate the chrome(also called the substrate) causing unbonding of the plating at best and if the hard chrome is well bonded causing intense corrosion on the material underneath.

Now I will quote Pheonix Electroplating Co. who does several different forms of hard chrome plating;

"It is a common misconception that chrome plating provides corrosion protection. This is not the case, only slight protection is given. Hard Chrome is porous at the microscopic level, which can let moisture and chemicals through to attack the base material. If the item is to be used in a damp environment, or where water based inks are used on printing machines, a layer of Nickel plating is required, prior to hard chrome plating."

If you nickel plate you just defeated the purpose of having a really tough bond of hard chrome to steel, so hard chrome on steel is usually not bonded with an intermediary layer of nickel as suggested here. I'm sure MD pointed out that no nickel is used also.

Sorry, but being an ME by trade I just assumed that the above was understood as far as porosity goes. I should not have assumed.

I hope this helps Noel and John.
 
Thanks, Cliff and Cobalt, for the enlightenment.
smile.gif
I learned a lot from you two..
smile.gif
I really appreciate it.

Now the countdown starts..
smile.gif


Dan
 
Dan, we will see how many more blades we can get for this test. Should be real good.

 
Cliff,

I read your intial posts (reviews)...What is a Rockwell hardness tester and where could I get one?

I imagine it as some sort of pressure dependent caliper w/ a gauge...it would kind of be neat to have one to check the hardness of the tupperware boxes of knives I've got; and, if not too expensive, just another factoid column for your tests. Kind of like advertised hardness (theorectical yiedl) versus actual hardness (actual yield).

As for chrome...wasn't Norin Radd chromed and he surfed the Galaxy?

Later,

John

PS Looking forward to the tests...Be Careful.

 
Rusty, the Ontario Survival Bowie and Marine Raider bowie are both 1/4 inch thick aren't they? If so, they sure look beefy, and should provide incredible strength. I don't think these knives even have to be at the top of the list. If they are just half as good as the real expensive ones, they have prooved themselves as worthy, considering their cost. I'll probably get some myself. I've always wanted their big 15 inch OAL Tanto that is 1/4 inch thick also. 1095 steel is an excellent steel.
 
A couple things:
1)I'm pretty sure that one can order a MD blade without the hard chrome, and in fact, one might even get it a little quicker.

2)Instead of buying a Rockwell hardness tester from myour local machine supplier, go to your local friendly machine shop and see if they'll test it for you. One thing though, when I had them test the blade I'm making once it got back from heat treater, they could ony test the flat parts, in my case it was the tang. The bevels on the blade might have broken the diamond bit they use because of the odd angle of pressure.

Spencer Stewart
 
Spencer, seems that the concensus is that you can get it w/o hard chrome. I'll probably order mine like that if he will do it.
 
Wow,

PJ, $800 for a gauge and it doesn't even cut anything...I guess that's out of the picture until I become independently wealthy or Leatherman adds a Rockwell Hardness attachment to their multi-tool. Thanks for the info though.

Spencer, That's a great idea. I may do the machinist visit when I'm back in the States again. Too bad they can't test the edge...I guess that's where knife reviews come into play.

Cobalt, Don't get me wrong, I'm not a chromaholic (well I probably am, but won't admit it, therefore I'll never recover...) But, your nude Mad Dog should look pretty neat. As I mentioned above, I can discern the temper beneath the new chrome so I thought I would be able to discover rust too... Regardless, I'm wondering if the color is uniform on a nude blade or has a bluish/grayish tinge or what? Please describe it if/when you get it...

Still Prochrome,

John

 
John, I'm surprized you can see the multi temper lines through the chrome. What that tells me is that the chrome is very well embedded within the steel's surface and will never come off, that's good. I'm willing to bet that the temper on the "nude" blade will not show as much. Chrome and anodizing has a tendency to make visible many of the imperfections, or perfections as the case may be, on the steel. For example if you have polished steel, the chrome will have a polished look to it. If it is rough the chrome will come out like that also, usually. But the chrome makes it more visible. This is true for hard chrome directly on steel only, not using nickel like is done on some of the foreign guns.

That will be interesting though.

And, John, don't get me wrong, it's not that I hate hard chrome, but it just worries me. The only difference between the two is that the surface of the non-chromed one will mar or scratch easier, but I can live with that.
 
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