Forced Patina on SR77? Looking for advice.

ScottsBad

ScottsBad

Joined
Feb 13, 2015
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Just received an INFI and SR77 Big Finish MMD. Love these choppers, they are exactly what I was looking for. They will most likely be users. Because big knives require more maintenance, I'm thinking that I want to put a forced patina on the SR77 because I'm thinking it will help to slow corrosion when in use.

So I have some questions if anyone wants to lend me their experience.

1. Will a forced patina act a little like bluing on a gun to help resist corrosion when not clean and well oiled?

2. Has anyone had experience with forced patinas? And what do they use to create the finish?

3. Has anyone any experience with S7 or SR77 on the best strategy to reduce the speed of corrosion in difficult environments. I'm looking for tips and tricks.

Thanks for any help on this subject.
 
  1. yes, probably not as well as bluing
  2. yes, vinegar
  3. yes, oil. keep dry. Keep an oil soaked rag in a ziploc and you're good for days. wipe the blade with something else 1st to remove dirt or water, like a pants leg
Shortly after vinegar patina
xYixIyOl.jpg


After use. It hasn't rusted at all, simply gotten darker. Experience from 1095 says that the blade can still rust but acts D2 where it doesn't pit unless you sit it something that corrodes it. I think the rougher patina'ed surface holds oil a bit better than a shiny surfaces but a polished surface sheds water very well. Stone-wash is about the worst for corrosion resistance as far as finishes go.
GVlnjvMl.jpg
 
Hey
1) Yes it will help a lot, if its done thoroughly covering the surface. This is done by submersing/covering the blade completely. Either wrapped in papertowels soaked in whatever you're using (lemon juice, vinegar, mustard, some other acidic liquid), or dipped in the liquid, as I explain in #2.

2) Heating the juice, vinegar, or acid will speed up the process A LOT. I have completely blackened a Mora carbon steel by boiling apple cider vinegar, pouring it into a champaign flute (a long thin glass), and just letting the knife sit it it until the bubbling mostly stops and the finish is dark enough. The vinegar will produce bubbles on the surface as it reacts with the metal. Fun to watch. Took about an hour. I've also done a mustard patina on an M4 knife. Just dab it on in whatever splotchy design you like, to make an interesting finish. Let sit over night. You can even rinse off what you put on the first time, and apply more mustard and wait again. Rinse, repeat to your heart's delight.

3)I have not done this to S7 or SR77, but they are high carbon steels, so the above methods should work about the same.
 
Oh and if/when the patina wears through use, you can just redo the process and it will recover the bald spots/scratches.
 
Looks good. Yeah, that was my take, that a rougher finish would hold oil better. Kinda like phosphate coating on AR barrels and bolts.

I wonder what a blued blade would look like?
 
Very good advice. Thank you. Has anyone anyone used straight up acid or cold bluing?

I like the idea of blotching with mustard too.
 
TheGrownUpKid said:
Hey
1) Yes it will help a lot, if its done thoroughly covering the surface. This is done by submersing/covering the blade completely. Either wrapped in papertowels soaked in whatever you're using (lemon juice, vinegar, mustard, some other acidic liquid), or dipped in the liquid, as I explain in #2.

2) Heating the juice, vinegar, or acid will speed up the process A LOT. I have completely blackened a Mora carbon steel by boiling apple cider vinegar, pouring it into a champaign flute (a long thin glass), and just letting the knife sit it it until the bubbling mostly stops and the finish is dark enough. The vinegar will produce bubbles on the surface as it reacts with the metal. Fun to watch. Took about an hour. I've also done a mustard patina on an M4 knife. Just dab it on in whatever splotchy design you like, to make an interesting finish. Let sit over night. You can even rinse off what you put on the first time, and apply more mustard and wait again. Rinse, repeat to your heart's delight.

3)I have not done this to S7 or SR77, but they are high carbon steels, so the above methods should work about the same.
Click to expand...

Going to try the heated vinegar on a Rodent 6 that was stripped and bead blasted. Have used the Brownells Oxpho Blue with excellent results, just not for food prep with the knife.
https://www.brownells.com/gunsmith-...ld-bluing-chemicals/oxpho-blue--prod1072.aspx
 
ScottsBad said:
??? Is there such a thing?
Click to expand...
Yea you can make triple++ or stronger instant coffee, maybe stick that knife in a thermos with it overnight, tip up so the tip doesn’t get darker from sitting in the bottom, agitate it every so often, it’s not nearly as fast as vinegar or acid or as dark but it’s pretty cool
 
ScottsBad said:
Very good advice. Thank you. Has anyone anyone used straight up acid or cold bluing?

I like the idea of blotching with mustard too.
Click to expand...

I've never blued S7 but I have blued SR101. I'll bet they'd act similar. Here's a 711 with cold bluing. I like the way it performs. If you wear it down to shiny steel, just clean up the blade and wipe it down with some more bluing agent. The only downside I've heard with bluing vs patina is that a blued blade may not be food safe. I don't know that for 100% but I've seen it discussed.

HgX7m8Z.jpg


The 'rat in the back has a forced mustard patina

8v6F0VQ.jpg
 
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I've heard the coffee patina is more of a staining than an actual patina as patina is a chemical reaction with an acid and I'm not sure coffee is acid enough though there is certainly a variation in the acidity of coffee.
 
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