M4 Patina help

Liquid Cobra · #1

I've searched and read countless threads but I can't find a good answer to my problem.

I purchased a Bradley folder and I've been trying to force a patina all night. I boiled apple cider vinegar and generously applied it to the blade for a really long time and it did practically nothing. I was also doing the same to some super blue and it reacted really well.

So then I took the blade and submerged it in white vinegar for 5 hours, and that did not much at all as well. Currently the blade is sitting submerged in lemon juice.

I just want a nice darker look to the blade. Any help as always is appreciated.

Thanks.

ABX2011 · #2

Mine has darkened naturally from slicing apples. I have forced a patina on other knives by spreading mustard on the blade. I've also done it by wrapping a paper towel around the blade and soaking it with apple cider vinegar.

jackknifeh · #3

I've heard people say M4 doesn't patina as fast as most non-stainless steels. I have the GB and I forced a light patina on it. I don't know if this is normal because when I first got it I kept the blade treated with Tuf-Glide which is a great anti-corrosion product. I couldn't get any patina on it at first and couldn't figure out why until I remembered about the Tuf-Glide. I would wipe it with a Tuf-Cloth every month or so. I don't know actually how long that stuff lasts. I quit using it and about 4-5 months and finally was able to force a light patina by sticking the blade inside a raw potato over night. I think all the things you have tried would work on other carbon steels but evidently M4 isn't as prone to corrosion as most carbon steels. If this is true I'm happy because the only reason I wantd a patina was to guard against bad corrosion (rust) in the pivot where I couldn't see it. Oh yeah, I removd the blade to forct the patina. But since a patina is a type of corrosion and it's hard to force it I figur M4 has a natural resistance to rust. Not like stainless but not as bad as most carbon steel. I'm just assuming this. I don't know about corrosion on a scientific level. Hopefully others will chime in on this. Your post has gotten me curious about my GB and patina again. I'm going to start using it to eat with and cut things in the kitchen and see what kind of patina forms from use. I don't remember the last time I use the tuf-cloth on it so maybe it's been long enough for the protection to have worn off.

Off subject but this is really a good plug for Tuf-glide. I have a carbon steel blade that already has a patina except for the bevel where I sharpen it. I'm going to apply tuf-glide on it and try to force a patina to see what happens.

Jack

Jack

NoFair · #4

If you remove any traces of fat/grease/oil on the blade with acetone it will probably patina easier..

bearfacedkiller · #5

I haven't tried to patina m4 but I have done it with cpm d2. I cleaned it good with alcohol because that is what i had and then used white vinegar. It took 3-4 hours to get where I wanted it. I just washed it when it got to where I wanted it and it has stayed that way for a long while. CPM D2 is supposed to be fairly corrosion resistant but it took a patina eventually.

I agree with the advice to use a solvent to get the blade very clean. Any oil on the blade will slow it down.

I haven't done it and don't know much about it but have read about using etching compounds in the past.

http://www.wikihow.com/Acid-Etch-Steel

Kind of like that. Again, I have no experience with that.

Liquid Cobra · #6

Thanks for the tips. I've had the blade sitting in an apple all morning. I keep checking it and it's starting to darken. Hopefully it will look nicer than it smells.

Next M4 blade I get I'm just going to oil it and keep it happy. This is too stressful. Super blue was such a rush, I can't help but feel let down by this process. If M4 is as tough as people say it is, and it's this resistant to rust it truly is a super steel.

jackknifeh · #7

Liquid Cobra wrote: Super blue was such a rush, I can't help but feel let down by this process. If M4 is as tough as people say it is, and it's this resistant to rust it truly is a super steel.

I'm getting th D'fly with super blue when it comes out and looking forward to it. I think I'll do what I can to keep th pivit corrosion fre and let th blade patina naturally.

IMO M4 is a great steel but I'm far from an expert. But, I understand it is used a lot in knives for chopping or cutting contests. Since I know so little that's a big testimony for me. :)

Holland · #8

I put it in a cup of room temp vinegar to 30 min, took out for 5 min and repeated that 3 or 4 times

Holland · #9

Liquid Cobra · #10

That looks really great, nice and even. Mine is darker than it was but kind of blotchy. Also, putting it back together the blade is way off center.

jackknifeh · #11

Liquid Cobra wrote:That looks really great, nice and even. Mine is darker than it was but kind of blotchy. Also, putting it back together the blade is way off center.

Loosen all the body (scale/liner) screws and clip screws. Loosen the pivot screw on one side a lot or take it out. Tighten the other pivot screw all the way until it pulls th pivot pin all the way to th screw head. Then loosen that same screw about 3/4 of a turn. Then put the other pivot screw in and snug it until the pivot is as tight as you want it. Check the blade centering before snugging the body screws. Hopefully it will be centered. If it is barely snug one scale screw on one side. Then barly snug the same screw on the other side. Repeat on the other 4 screws. Hopefully the blad will still b centred. If it is snug all the screws nice and tight but don't strip them. If you are worried about them working loose, use loc-tite. If the blade is not centered during this procss it can be corrected by bending the handle back and forth with the screws loose but tighten them when the blade is positioned. If this doesn't make sense it's because I didn't explain it good enough. I think you will get the idea though. The main thing is to get the pivot adjusted before tightening the other screws. Good luck.

Jack

Nate · #12

Holland wrote:took out for 5 min and repeated that 3 or 4 times

I have experimented some with forced patinas in the past. Adding air into mix is key to speeding things up.

jackknifeh · #13

Apophis wrote:I have experimented some with forced patinas in the past. Adding air into mix is key to speeding things up.

I have forced patina 2 or 3 times by using vinegar and sticking a blade inside a whole potato. How do you add air exactly? I've heard this before but since I can't picture how to add air it doesn't make sense to me.

Jack

Holland · #14

just by taking the blade out of the vinegar for a couple minutes every half hour adds air. it will make the blade patina a lot fast than just leaving it in the vinegar the whole time

jackknifeh · #15

Holland wrote:just by taking the blade out of the vinegar for a couple minutes every half hour adds air. it will make the blade patina a lot fast than just leaving it in the vinegar the whole time

Thanks. I'll write that down so I won't forget. :)

jackknifeh · #16

Holland wrote:just by taking the blade out of the vinegar for a couple minutes every half hour adds air. it will make the blade patina a lot fast than just leaving it in the vinegar the whole time

I was thinking it was more complicated. Right now I'm thinking about taking a fish tank air hose and running the hose to the bottom of the glass of vinegar the blade is standing in. :) Then bubbles would come up all around the blade. :D

Jack

Liquid Cobra · #17

Whoa that's getting fancy. If you do it be sure to post a pic of your results.

bearfacedkiller · #18

I never thought about it but I took it out every so often because air bubbles were forming on the blade and I thought they would mess up the finish. Maybe that helped me out.

kbuzbee · #19

Holland wrote:just by taking the blade out of the vinegar for a couple minutes every half hour adds air. it will make the blade patina a lot fast than just leaving it in the vinegar the whole time

Exactly. And it you REALLY want to speed it up, scrub it with a tooth brush or green scotch bright pad when you take it out. This amazing BLACK "paste" forms IMMEDIATELY. If you wipe it off, you're kinda back to square one. But if you let it set up for a couple minutes, it's permanent.

I discovered this completely by accident, but it's just too cool to watch happen.

Ken

Liquid Cobra · #20

That's pretty awesome. If I've already got one going now, is it too late to go again and try to get this result?