Consistent etches (pics of finished knife added)

[Laredian]

I got an issue when etching my blades in ferric chloride. I often use ferric chloride to etch a blade, hand sand the primary bevel back up to the finish that it was and leave the flats etched to create a contrast.
I have done this quite often now and with success, but recently I can't seem to get anywhere close to a consistent etch. What I mean by that is the blade does not have an even, dark finish but rather an uneven blotchy finish.

It's a little bit infuriating because I can't seem to figure out where I am going wrong. My process is rather simple:
I hand sand the blade I want to etch to a 800grit hand rubbed satin, clean the blade thoroughly with acetone and then let it sit in the ferric for 5 minutes. Then I neutralise with baking soda and use some 0000 steel wool to hopefully get an even dark finish on the blade. When I am not satisfied with the colour I do another cycle.
My solution is 3 parts water and one part ferric chloride 40%. My ferric sits in a half meter long pvc pipe that I closed on the bottom with a cap and pvc-cement and has a removable cap on top.

This is what I am getting recently:

I can't get those darker spots on the blade out for the life of me, that you can (hopefully) see on the pictures. I haven't been able to figure out what I am doing wrong exactly, so any advice would be very much appreciated.

Edit: this particular blade I already re-hand sanded once because I didn't like the etches. I even changed out my acid solution completely for a new one and out came the finish you see on the pictures above

 

[Don Hanson III]

Clean blade with soap/water, not acetone. Etch for no more than one minute, then rub the black oxides off with 0000 wool & water, then repeat until you like what you see.

 

[kuraki]

Don's point is a good one, the only thing that works as well as warm dish soapy water that I've found is Windex, to leave a streak/smudge free surface for etching.

After that, etching consistent color is very dependent on the steel structure. Some of this is out of our control and we're stuck with what the mill sent us. Others are in our control within the scope of our heat treating process. So the first question I'd have is has anything changed from what you considered adequate results? Different alloy steel? Different bar(s) of steel? Heat treat process? Blade mass/shape? How you quench?

 

[Laredian]

Clean blade with soap/water, not acetone. Etch for no more than one minute, then rub the black oxides off with 0000 wool & water, then repeat until you like what you see.

Thanks a lot! Do you think I need to re-hand sand everything again before trying this successfully?

Don's point is a good one, the only thing that works as well as warm dish soapy water that I've found is Windex, to leave a streak/smudge free surface for etching.

After that, etching consistent color is very dependent on the steel structure. Some of this is out of our control and we're stuck with what the mill sent us. Others are in our control within the scope of our heat treating process. So the first question I'd have is has anything changed from what you considered adequate results? Different alloy steel? Different bar(s) of steel? Heat treat process? Blade mass/shape? How you quench?

That are some very interesting aspects that I would have never guessed. The steel is 80CrV2, I have used this one often and etched it with success. This particular one is thicker stock than I normally use but from the same supplier. It was quenched in Oil but I cannot say which one exactly because I sent this one out for heat treating. However I am 100% sure that there was no more decarb or anything left from the quench that could have affected the etch. I was trying to be really diligent with the clean up grinding after heat treatment and hand sanding.

Also this might make me look stupid but what exactly is Windex? Just some sort of dish soap? Or for cleaning glass? We don't have that brand in Europe, or at least I have never seen it so I hope you don't mind me asking.

 

[kuraki]

Windex is ammonia glass cleaner. I'm sure you have a similar product. Any ammonia based "streak free" glass cleaner should work. They work because they evaporate completely without leaving trace elements (which would cause streaking on glass). Alcohol and acetone depending on their purity often leave things behind that can impede or otherwise impact the chemical reaction of etching.

Decarb isn't the only thing that can impact it. But if the knife was say, hotter in the thinner area and cooler in the thicker area, or it was quenched in a way that left a thicker area from being "fully quenched" etc, that can show up in the etch. The extreme example of this being actively and purposefully trying to achieve hamon.

 

[Don Hanson III]

Thanks a lot! Do you think I need to re-hand sand everything again before trying this successfully?

Yes, you will need to start fresh for an even etch. The first etch sets the stage for good results. I start with 20-30 seconds, then rub the black off. Each additional etch I do longer, but no more than one minute. If you follow this and get the same results, then it's a alloy or heat treat issue.

 

[Laredian]

Thank you very much again for the awsome advice @Don Hanson and Kuraki. I have etched both knives from my original post and I am quite happy with the results:

First one is the Prototype. As I have already mentioned the clip got way to big because I messed up at grinding a little bit. However since the clip is so long, wide and ground very thin, this thing can deliver a nasty back cut...so I left it black since I thought it fit the knife quite well:

(On the second pic the etch looks like it has a darker area near the plunge...that is because of my bad photography skills)

Second one is the camp knife design as I orignally imagined it with a way smaller clip grind that is not sharp. The blade is also about 1,5cm longer. This one got a two tone finish, with etched flats and re-hand sanded bevels to a 800grit hand rubbed satin. I like how that one turned out:

Let me know what you think

 

[Don Hanson III]

Both look very good!

 

[joedhiggins]

I use a proper detergent degreaser, double wash, and follow the rest of don's advise. Detergent degreaser is just a more concentrated dawn without all the coloring and scent. I use windex and water between the etch and the steel wool. That all being said, if I am not trying to highlight a hamon and just want a dark finish, there are more effective steel blackeners that give a far more durable finish than FC.

 

[Bob Duguay]

I use a proper detergent degreaser, double wash, and follow the rest of don's advise. Detergent degreaser is just a more concentrated dawn without all the coloring and scent. I use windex and water between the etch and the steel wool. That all being said, if I am not trying to highlight a hamon and just want a dark finish, there are more effective steel blackeners that give a far more durable finish than FC.

What would they be?

 

[Laredian]

I use a proper detergent degreaser, double wash, and follow the rest of don's advise. Detergent degreaser is just a more concentrated dawn without all the coloring and scent. I use windex and water between the etch and the steel wool. That all being said, if I am not trying to highlight a hamon and just want a dark finish, there are more effective steel blackeners that give a far more durable finish than FC.

Do you mean like parerkizing? That is the only one I know of that gives a durable dark finish and I only know that because I read it on this forum. I would not know how to properly parkerize a part, only that I think you need a solution with phosphoric acid and manganese or iron (depending on the colour you want I believe). Also I don't know if the process used for gun parts gives a desirable finish for blades....would have to read up on that.

Other than that I can only think of a forced mustard patina. I've tried that and absolutely hated the results. It just looked dirty and awful. However Nick Wheeler has a youtube video of a gentlemens fighter he made where he said he used a forced mustard patina which looks absolutely amazing. I have no idea how exactly he did it though to achieve that look.

 

[joedhiggins]

What would they be?

I can't remember the brands off the top of my head, whenever I am at a hardware store or autozone I buy one of the detergent based cleaners. Simple green works well, but I generally try to find one with no coloring.

Do you mean like parerkizing? That is the only one I know of that gives a durable dark finish and I only know that because I read it on this forum. I would not know how to properly parkerize a part, only that I think you need a solution with phosphoric acid and manganese or iron (depending on the colour you want I believe). Also I don't know if the process used for gun parts gives a desirable finish for blades....would have to read up on that.

Other than that I can only think of a forced mustard patina. I've tried that and absolutely hated the results. It just looked dirty and awful. However Nick Wheeler has a youtube video of a gentlemens fighter he made where he said he used a forced mustard patina which looks absolutely amazing. I have no idea how exactly he did it though to achieve that look.

Parkerizing works. So does hot bluing. No treatment will stand up to being treated like a splitting wedge through logs. The easiest method of a deep, enduring black is to use a rust brown like plum brown in several (hot) applications, rubbing down with 0000 between applications. Makes a deep black that holds up as well as any hot blue.

 

[Laredian]

I was under the impression that hot blueing is also not that resistant against scratches.

 

[joedhiggins]

Nothing is particularly scratch resistant. Most surface finishes can prevent corrosion but very few, and none we really use on knives, significantly prevent surface scratching from true abuse. Magnetite, black iron oxide, what we get from bluing and hematite, what we get from parkerizing are both about the same hardness as hardened steel, and thus will be scratched by the same compounds that will scratch steel. Bluing, especially rust blackening is extremely good at holding oil to the surface of a blade, which can help prevent some scratches. There are also some abrasion resistant coatings, these won't necessarily prevent scratches, but rather reduce their depth or severity. Cerakote and duracoat both do this to some degree, as do the aforementioned processes. Both cerakote and duracoat are softer than the underlying steel, but are lubricous and provide some abrasion resistance.

There are probably some coatings that would drastically improve scratch and abrasion resistance (TiN) but I know of nobody doing this on handmade knives. If you want these qualities, Just go with one of the highly abrasion resistant tool steels and have fun grinding.

 

[Laredian]

So I've finished the botched camp knife turned fighter.
It's made from a little over 5mm thick piece of 80Crv2 that tapers quite nicely. Ferric chloride etched blade and the handle is black linen micarta with red liners and nickelsilver pins.

Now that its done I quite like it. It's really nimble in the hand and balances just behind the ricasso.

 

[Stromberg Knives]

I think it looks great! Well done!

 

[john april]

everything looks great ! nice plunges

 

[Bob Duguay]

So I've finished the botched camp knife turned fighter.
It's made from a little over 5mm thick piece of 80Crv2 that tapers quite nicely. Ferric chloride etched blade and the handle is black linen micarta with red liners and nickelsilver pins.

Now that its done I quite like it. It's really nimble in the hand and balances just behind the ricasso.

Very nice looking knife. I really like the dark FC etch. I have seen guys dip the finished knife handle and all in the FC. What handle material is not effected by the FC? Does it effect Dymond Wood?

 

[Laredian]

I think it looks great! Well done!

everything looks great ! nice plunges

Thank you very much!

Very nice looking knife. I really like the dark FC etch. I have seen guys dip the finished knife handle and all in the FC. What handle material is not effected by the FC? Does it effect Dymond Wood?

I usually always do the final etch before handle assembly. I have however etched a knife with a canvas micarta handle already in place because I scratched my FC finish on the knife. It did not have any effect on the micarta...however I would not have done that with the knife I postet in this thread because I think the red liner material would have been affected. Also I would be very sceptical about putting wood into ferric chloride, but I know too little about wood to give a qualified answer on that topic.

Etching the whole knife with handle attatched might even provide some advantage because you could etch your tang inbetween your scales and give that part also a protective patina.

 

[Laredian]

So to complete this here is the second knife finished:

Steel and handle material is the same as the other one, only the blade shape is different. High saber grind with a more stout tip and smaller unsharpened clip.

Thanks for looking.