hey I recently got a forge welded blank from a fellow smith and he asked me to finish it for him, now I'm at the etching stage and am using vinegar.

my question is how long should I leave the knife in the vinegar? because its been in there for over a day and theres no patterns coming up yet.

It is possible that he mistakenly forge welded a few pieces of the same steel together, but he is a good bladesmith and doubt he would do that.

thanks
christian

something isn't right if it's been in the vinegar for 24 hrs and no patterns. maybe try ferric chloride and neutralize with tsp...

Gene

thanks gene, I checked it again this morning and it appears to have started etching more. I'll leave it in there for another day see if anything changes. I would probly put it in a stronger acid.... if I had one, but I do not right now.

What temperature is your vinegar and surrounding area at? you could warm it and it may speed up the reaction if that is necessary.

the vinegar has stayed about 60-70 degrees, but even then it should have shown a pattern after 3 days, but it hasnt so Im just gunna have to wait till I can get some stonger acids.

I have never had any luck with vinegar. Get your self some feric chloride. If they don't have it at a local radio shack go here http://www.mgchemicals.com/distributors/us/distributors_us_va.html it has all the distributors in Va. that sell there brand. Mix it 4 parts water to 1 part f.c. and do not leave it in very long just a quick dip at first and you will be able to see a pattern if there is one there. Clean with windex to get all the f.c. off then sand lightly with 1000 grit to take the oxides off the high parts.

Bob

Was the scale and other stuff removed before placing it in etching solution? Coatings on the blade can hinder etching.

Was the scale and other stuff removed before placing it in etching solution? Coatings on the blade can hinder etching.

Anything that will etch steel will remove scale.

the vinegar has stayed about 60-70 degrees, but even then it should have shown a pattern after 3 days, but it hasnt so Im just gunna have to wait till I can get some stonger acids.

I've used vinegar on band saw and pallet banding which I've been told aren't that different in carbon content but do react differently to acid etching. I got a pattern overnight with vinegar but it was slight and washed off easily. However I used muratic acid available at hardware and big box stores diluted with water by about half for 45 minutes and got a deep etch that still wasn't significantly different in color (you could remove the darkness with steel wool) but texture wise was adequate for what I wanted. I don't have a great deal of experience but , after 3 days, I'm guessing your first suspicion of the metals being too close in content makes sense to me.
Scott

thankfully I just picked up some muratic today, and I sanded the blade a lil and found some small areas that where a little higher, but I think what happened was my freind hammered it WAY thin so I couldnt do much grinding, and I dont thik he twisted it or tried to pattern it in any way so I think Im just on one layer cause I also got lines on the spine. so Im gunna polish it up and put a gaurd and handle on it.