Busse bead Blast?

[verisharp]

Some other obviously lower quality bead blasted knives get small rust spots. Any problems with Busses bb finish... I've only owned satin & coated bussekins so how does it hold up???

 

[OldPhysics]

They call their version "double cut."

I've got 3 double cut Busses I got in 2006 ... not a spot of rust (of course, I'm not pulling the handles off to look).

Mind you, I take pretty good care of my knives. However, I do have a double-cut AD that's seen quite a bit of carry and abuse -- no rust spots.

 

[Liu Kang]

I think that you need to protect them by keeping them oiled or whatnot. That's just my two cents. That's why I prefer satin

 

[thatmguy]

I've got my original DC Assault Shaker, and never put anything on it, and it barely any patina at all.

Been used for food, a few "non-scientific" field tests, and still looks great.

DC is my favorite finish.

I'll try to get pics this weekend.

 

[R0CKETMAN]

Why would a BB finsih require any added care than satin? in terms of corrosion resistance of course.

 

[verisharp]

Why would a BB finsih require any added care than satin? in terms of corrosion resistance of course.

To the naked eye, bead blasted finishes look complete, but alas, they are not. Small microscopic pieces of the blade steel are not coated when a knife is bead blasted( The BB coating misses small areas). So when the knife is exposed to the elements, these areas that were "missed" during the finishing process rust, and created little specks of rust on your knife!

 

[OldPhysics]

To the naked eye, bead blasted finishes look complete, but alas, they are not. Small microscopic pieces of the blade steel are not coated when a knife is bead blasted( The BB coating misses small areas). So when the knife is exposed to the elements, these areas that were "missed" during the finishing process rust, and created little specks of rust on your knife!

Additionally, there is more actual surface area on a bead-blasted knife. Instead of a smooth, flat surface ... you have little hillocks and valleys. More surface area = more steel available to form rust. Additionally, it's possible to retain moisture in those valleys.

See? Not complicated at all. Quite common-sense, really.

 

[R0CKETMAN]

To the naked eye, bead blasted finishes look complete, but alas, they are not. Small microscopic pieces of the blade steel are not coated when a knife is bead blasted( The BB coating misses small areas). So when the knife is exposed to the elements, these areas that were "missed" during the finishing process rust, and created little specks of rust on your knife!

Additionally, there is more actual surface area on a bead-blasted knife. Instead of a smooth, flat surface ... you have little hillocks and valleys. More surface area = more steel available to form rust. Additionally, it's possible to retain moisture in those valleys.

See? Not complicated at all. Quite common-sense, really.

Geeks....

Still not there. So, what rust inhibitive qualities does a satin finish posses over a BB finish? I'm "crystal" on the "physical" differences.

 

[OldPhysics]

Geeks....

Still not there. So, what rust inhibitive qualities does a satin finish posses over a BB finish? I'm "crystal" on the "physical" differences.

Hmm. A full answer would simply fill the screen with additional geekiness ... might just irritate you more, rather than help.

In general, the satin surface is less retentive to moisture and exposes less steel to moisture -- therefore less rust occurs than on a bead blasted surface.

It's not really rust inhibitive ... it simply is less prone to rust.

INFI itself appears, by experiment (not theory), to be quite rust resistant on its own (in bulk form). It's clearly not a stainless steel, but in practice it behaves as though it is very close to stainless. I've fiddled about a bit with some of my blades and found it very hard to get any rust going at all. There have been other pieces of anecdotal evidence on the forum that agree with my observations.

Admittedly, I've never had the time, facilities, or $$ necessary to do proper scientific tests.

 

[rbmcmjr]

To the naked eye, bead blasted finishes look complete, but alas, they are not. Small microscopic pieces of the blade steel are not coated when a knife is bead blasted( The BB coating misses small areas). So when the knife is exposed to the elements, these areas that were "missed" during the finishing process rust, and created little specks of rust on your knife!

In theory, your post makes sense. In practice, I don't find that to be true. There is some element of passivation that occurs due to the second media blast (hence the "double" in DCBB) that makes such a finish very corrosion resistant. My big user ZTSH has all sorts of smoothing scars in the DCBB but rust has never made an appearance.

 

[verisharp]

In theory, your post makes sense. In practice, I don't find that to be true. There is some element of passivation that occurs due to the second media blast (hence the "double" in DCBB) that makes such a finish very corrosion resistant. My big user ZTSH has all sorts of smoothing scars in the DCBB but rust has never made an appearance.

Interesting.... some of my lower quality bb kershaws have rust spots (but I can't complain about it... they are cheap knives that obviously don't compare to HQ blades). I was just wondering if DCBB busses happen to react similarly in the presence of moisture...

 

[OldPhysics]

In theory, your post makes sense. In practice, I don't find that to be true. There is some element of passivation that occurs due to the second media blast (hence the "double" in DCBB) that makes such a finish very corrosion resistant. My big user ZTSH has all sorts of smoothing scars in the DCBB but rust has never made an appearance.

I have wondered something similar. Perhaps the 'valleys' have a shape that just doesn't retain water? Perhaps the crystalline planes exposed simply have much lower reaction rates? Those are at least plausible.

I went so far as to do a lot of 'deep cleaning' on one knife's butt. No change in the rusting behavior at all ... so, I infer that the second bead blasting leaves no coating (thought there might be a layer of plastic or some such).

 

[Bigfattyt]

To the naked eye, bead blasted finishes look complete, but alas, they are not. Small microscopic pieces of the blade steel are not coated when a knife is bead blasted( The BB coating misses small areas). So when the knife is exposed to the elements, these areas that were "missed" during the finishing process rust, and created little specks of rust on your knife!

Double cut is not a coating. It is sandblasting. So what it is doing is simply making the surface a uniform "rough" finish. The finish is actually rougher with more surface area (micro pores) for moisture to get down inside. (course you might have simply been referring to the uniform mat finish given to the steel).

It is finish that many like. It seems to be a bit more durable (does not show scratches and wear) near as much as satin will.

That said, In a high salt environment it will, I repeat will show rust spots. It is still Infi, but I have seen pics of double cut rusting a bit.


On a side note, I got my satin BAD to rust a bit two weeks ago!!!!!!!! I went on a 2 day canoe trip. On the second morning, I went swimming with the BAD in a kydex sheath (with a pistol lanyard attached to my belt and run though the rear talon hole just in case it fell out while canoeing). I left it in the sheath against my wet waist for the rest of the day! Got some tiny rust spots right around the logo. Unfortunately, it also came off after using a couple more times later in the week. So now, you can't tell where the spots were!

Gotta love infi!!!

 

[R0CKETMAN]

Isn't satin a finish achieved by polishing? I understand BB will not be as uniform.

So, where do the corrosion resistant qualities of the steel come into play? Satin or BB, same steel.

Disclaimer: my experience is with SS 1911's with polished flats and BB rounds.

 

[Bigfattyt]

Isn't satin a finish achieved by polishing? I understand BB will not be as uniform.

So, where do the corrosion resistant qualities of the steel come into play? Satin or BB, same steel.

Disclaimer: my experience is with SS 1911's with polished flats and BB rounds.

It is the same steel. But the more polished surface gives less "traction" for the water or corrosive agents to get into.

If you have ever had high carbon steel. You will notice a real difference in how the exact same steel reacts with different finishes. A mirror polish will resist rust better than a rough finish, or bead blast finish will.

If you have ever media blasted glass, and then gotten the glass wet, it does not bead water off any more. Even if you wipe it with a dry rag, it will retain a bit of moisture, and will hold it much longer than than smooth glass.

With bead blasted steel, If you look at it under very high magnification, you will not only see high spots and low spots (think mountains and valleys) but you actually get metal pushed over micro holes (like caves). When being struck with high speed impact material (like bead blasting), the metal will actually push and become plastic at the very surface. The blasting medium acts like hundreds of thousands of meteors striking the surface. It is on such a micro level that you can't tell with the naked eye.

Another analogy is to take hard packed soil. Dump water on the soil. It will run off pretty quickly, and not absorb very deeply.

Take that same soil, and cut deep grooves in it with a plow. Dump water on it, and the water has some place to sit and collect in the grooves (like lower grit finish steel). Or, take the same dirt, and poke hundreds of thousands of holes in it, and the moisture has a place to pool.

The same thing goes for acids and moisture and salt in your fingerprints (or what ever you get on the blade that has potential to cause rust). Mirror polish will be easier to keep rust free, and easier to wipe stuff off.

 

[OldPhysics]

Thanks, BigFattyT. I could not have said it better ... and probably not even as well!

 

[RussMo]

It is the same steel. But the more polished surface gives less "traction" for the water or corrosive agents to get into.

If you have ever had high carbon steel. You will notice a real difference in how the exact same steel reacts with different finishes. A mirror polish will resist rust better than a rough finish, or bead blast finish will.

If you have ever media blasted glass, and then gotten the glass wet, it does not bead water off any more. Even if you wipe it with a dry rag, it will retain a bit of moisture, and will hold it much longer than than smooth glass.

With bead blasted steel, If you look at it under very high magnification, you will not only see high spots and low spots (think mountains and valleys) but you actually get metal pushed over micro holes (like caves). When being struck with high speed impact material (like bead blasting), the metal will actually push and become plastic at the very surface. The blasting medium acts like hundreds of thousands of meteors striking the surface. It is on such a micro level that you can't tell with the naked eye.

Another analogy is to take hard packed soil. Dump water on the soil. It will run off pretty quickly, and not absorb very deeply.

Take that same soil, and cut deep grooves in it with a plow. Dump water on it, and the water has some place to sit and collect in the grooves (like lower grit finish steel). Or, take the same dirt, and poke hundreds of thousands of holes in it, and the moisture has a place to pool.

The same thing goes for acids and moisture and salt in your fingerprints (or what ever you get on the blade that has potential to cause rust). Mirror polish will be easier to keep rust free, and easier to wipe stuff off.

Yes Sir, well said Bigfattyt!!! I've had DCBB rust on me here but took a little 0000-steel wool and or a 3M-Fine Scotch Bright and took it off just fine. Used a .22 cal steel bore brush for cleaning out the talon holes as well.

 

[thatmguy]

I know at one point, Jerry went through the BB process, essentially the first pass is with a media size that very very basically peens the metal, closing most pores, and gives it a BB look.

The second media is a larger size that provides a second peening, further closing the pores in the metal, and providing a surface less ideal for moisture retention.

Hope that makes sense.

I also have several coated blade with what appear to be DCBB tangs, and few of these have anything beyond a very very minor patina, even with hand salts.moisture.

A few of the forum members have done their own using Jerry's recipe, and I don't recall any issues of their DIY outcomes.

Yours in Nuclear Peening...
Hammy

 

[Bigfattyt]

I don't want anyone to think I am not a fan of Double Cut finished Busse's. They look great, and hold up to use much better than satin (from the standpoint of visible scratching etc).

Eventually with use, the Double Cut finish will smooth out (much like coating smoothes over time). The double cut finish is also very easy to renew. Much quicker and easier that trying to fix a scratch on a satin blade!

That is why a lot of users like it.

If you live some where that has a high humidity and salt content (ie warm coastal, like the florida swamp etc), you would likely have to take extra care of satin finish, the same way you would have to take a bit more precaution with the steel is all.


It is still Infi, and the great thing is that even if you are able to get Infi to discolor or show rust, it is not a deep pitting rust like you will get with higher carbon steels!

As I said earlier above, I some times actually try to get my Infi to rust (I am sick I know). Or to take a patina.

In a kydex sheath with no drain hole, after swimming with the BAD, and leaving it in the sheath on horizontal on my belt for the rest of the day on the canoe trip, I was able to get some tiny discoloration//rust right around the laser cut Busse logo. That literally disappeared after wiping the blade off the next day, and cutting up some potato's with it. No evidence it was ever there, no pitting, nothing.

Same goes for my Muck. I thought I had finally found a good substance for a nice blue patina. The first time I cut hot BBQ chicken with Sweet Baby Ray's BBQ sauce on it (as well as a dry rub underneath) I got an instant blue discoloration which I was stoked about! I then tried washing it off with soap and hot water (normal cleaning for a dirty knife in the kitchen). The blue actually stayed.

Then the next time I cut something in the kitchen, it was magically gone (More hot chicken if I remember correctly). No trace.

I have been using satin infi for a few years (stripped infi as well), and have not had any permanent discoloration that did not come off the very next time I used it.

I have left sap and pitch on the satin blades for weeks before cleaning it off, with no rust or discoloration.

I have other "stainless" steels that have rusted, and pitted in the same type of use!


So don't let any talk of "double cut" being more rust prone dissuade you from giving it a try. Unless you live in the coastal marsh, or right in the humid salty sea air, you won't have any major issues.

 

[Steven65]

It is still Infi, and the great thing is that even if you are able to get Infi to discolor or show rust, it is not a deep pitting rust like you will get with higher carbon steels!

I could not agree with your post more!

I live 50 yards from the South Atlantic and my users are carted around in the trunk of my car in all sorts of conditions.
I have found INFI to be more rust resistant than some stainless steel and VERY good in salty humid conditions.

In Theory the double cut finish should be more prone to rust but INFI itself has some magic quality!