Acid wash and stonewashing

Harden Knives

Harden Knives

Joined
Aug 7, 2013
Messages
405
Hey all, Im getting better at making knives and am looking to do some acid washing and acid stonewashing. I hear its a great rust resistant finish and know I need to get a flawless satin or mirror finish before doing a stonewash. I plan to go to harbor freight and get that 5lb stonewash vibratory thing but what im concerned about is what media to get, ive seen triangles, corn cob, cylinders and lots of other stuff.
I have never used a stone tumbler before and want to get your opinions on what you think about stone washing and what media I should use. If you have any tips or tricks I'd love to hear them.

Once I get the perfect stone wash or acid wash worked out I will get a tutorial up so all the newbies such as myself can see.

Thanks in advance,
Alex.
 
Why do you feel that you need to get a perfect finish before acid/stone washing? It certainly couldn't hurt but a bead blasted finish should suffice I'd think. Now if you plan to skip the acid the better starting finish would probably be a good idea.

Here's what I know. I've acid, then stone washed a number of knives with varying degrees of finish refinement. I haven't noticed any notable difference in the end product. I haven't yet stone washed a blade without first giving it a ferric chloride bath so I can't comment on that. I have, however, owned a number of Sebenzas with a tumbled finish and they are fantastic. For more on that I recommend watching the Chris Reeve shop tour videos on YouTube as they talk about it and show a little of the process.
 
The small HF vibratory tumbler will hold most smaller 6-6.5" inch knives pretty well... that may be stretching it but they come out nicely. I'd get the bigger tumber if you can, it depends what size you need to tumble.

Get the ceramic media, use enough windex (or the like) to dampen the media and clean often

You do want a clean finish, no scratches that you can feel. 400 grit is good... tumbling will bring scratches out if they are deep.

Make sure your knife is super clean then do a quick etch in ferric chloride/3 parts water to bring out contrast later in the stonewash. A drop of soap will help the etchant work more evenly.

I do a quick stonewash, 10-15 minutes generally...
 
Strigamort said:
Why do you feel that you need to get a perfect finish before acid/stone washing? It certainly couldn't hurt but a bead blasted finish should suffice I'd think. Now if you plan to skip the acid the better starting finish would probably be a good idea.

Here's what I know. I've acid, then stone washed a number of knives with varying degrees of finish refinement. I haven't noticed any notable difference in the end product. I haven't yet stone washed a blade without first giving it a ferric chloride bath so I can't comment on that. I have, however, owned a number of Sebenzas with a tumbled finish and they are fantastic. For more on that I recommend watching the Chris Reeve shop tour videos on YouTube as they talk about it and show a little of the process.
Click to expand...

Daniel Fairly Knives said:
The small HF vibratory tumbler will hold most smaller 6-6.5" inch knives pretty well... that may be stretching it but they come out nicely. I'd get the bigger tumber if you can, it depends what size you need to tumble.

Get the ceramic media, use enough windex (or the like) to dampen the media and clean often

You do want a clean finish, no scratches that you can feel. 400 grit is good... tumbling will bring scratches out if they are deep.

Make sure your knife is super clean then do a quick etch in ferric chloride/3 parts water to bring out contrast later in the stonewash. A drop of soap will help the etchant work more evenly.

I do a quick stonewash, 10-15 minutes generally...
Click to expand...

Thanks for the tips! I will definitely get the largest tumbler that I can and ceramic media sounds like a must.
 
If your talking about that vibrating pos that HF sells I'd skip it and spend the extra cash on a Dillon precision one, much better quality and quieter. Well worth the extra cash.
 
anybody know where to get a decent tumbler in Canada? our version of harbour freight doesn't carry one and I need to get something that will tumble knives up to 11" OAL and I absolutely love a nice tumbled finish.
 
While at a knife show in Louisville last year I examined two knives side by side with "stonewashed" finishes. I don't recall the two makers names but they were both very forthcoming with their techniques. One used a professional rig (sounded like a big rock tumbler) while the other guy used a PVC pipe with the ends capped and placed in his dryer. They didn't look much different as far as finish goes. The dryer guy also used broken ceramic tiles for media. My own thinking is that one would want to make the pieces as close to a uniform size or weight to get a consistent finish but I have yet to experiment with the technique.
 
Richpoolboy said:
If your talking about that vibrating pos that HF sells I'd skip it and spend the extra cash on a Dillon precision one, much better quality and quieter. Well worth the extra cash.
Click to expand...

Looks like the dillon is dry only =(

rustyrazor said:
anybody know where to get a decent tumbler in Canada? our version of harbour freight doesn't carry one and I need to get something that will tumble knives up to 11" OAL and I absolutely love a nice tumbled finish.
Click to expand...

I've thought about rigging something up with the dryer but sounds dangerous.

Thanks for the awesome tips guys, really appreciate it.
 
Er... I meant to mention that I used the dryer for a while as my tumbler. A common method is river rock (the smooth ones found by the fish tank supplies at the pet store) plus wd40 in a plastic jar. Tape around the lid. Either stuff the dryer (don't recommend it), or wrap a towel around the jar with tape. No heat setting.

My problem with the above method is that the towel slipped off and the jar broke. :o That makes for an unhappy wife. Trust me on that.

SO... I compared that finish to one done simply by shaking the jar for a little while. Honestly, there wasn't much of a difference, if any.

A fancy set up using proper abrasives and a nice machine? Can't fault anyone for going that route. In my case I only had a few blades to do so it wasn't worth a big investment. If you're in the same boat you might give it a shot to see how you like it.
 
Strigamort said:
Er... I meant to mention that I used the dryer for a while as my tumbler. A common method is river rock (the smooth ones found by the fish tank supplies at the pet store) plus wd40 in a plastic jar. Tape around the lid. Either stuff the dryer (don't recommend it), or wrap a towel around the jar with tape. No heat setting.

My problem with the above method is that the towel slipped off and the jar broke. :o That makes for an unhappy wife. Trust me on that.

SO... I compared that finish to one done simply by shaking the jar for a little while. Honestly, there wasn't much of a difference, if any.

A fancy set up using proper abrasives and a nice machine? Can't fault anyone for going that route. In my case I only had a few blades to do so it wasn't worth a big investment. If you're in the same boat you might give it a shot to see how you like it.
Click to expand...

Thanks man,

problem is, im not married and still in highschool. My mom would murder me if I did that, not to brag but we have a higher end dryer and washer combo and I would really prefer to stray away from household appliances.

I will gladly try any other method if you have one.
 
Well, there's the other one that I wrote about that you quoted. :p

I understand regarding the dryer. I wouldn't do it again. I did it in the first place because it was the method that was recommended to me. I try not to mention it as a viable solution, at least not without having a good system worked out that eliminates most of the risk.

The only things you'll get by doing it by hand is a finish that you may or may not like and a workout.

Some low risk experimenting and exercise are two things I never discourage. ;)
 
Google Homemade or DIY rock tumblers.
you could probably cobble something together for little cash.
 
An old pottery wheel rigged vertically with a 8" OD sterl pipe works really well. Use an old dryer motor to power it and voila...pretty dang good tumbler. My uncle made one and his only expense was pottery wheel from local hobby lobby.
 
It would really suck to have a spill in the dryer, but considering the cost of even a cheap commercial machine makes me confident that a spill proof solution could be found. How about a pvc pipe long enough to hold the knife, filled with lubed media, and with the end caps superglued on. It could be stuffed inside a pillow or stuffed animal to pad the inside of the dryer. As long as the heat was not turn on it should do fine. Still happy wife, happy life. (or mom)

Do you have a tread mill? I'm pretty sure I could channel my inner MacGyver to turn a tumbling vessel with one of those. Making the vessel bumpy would give the vibratory action in addition to the tumbling. Stationary bicycle? You could do swords in a garbage can rolled down a hill. :p

Or buy one. I just have too many tool needs ahead of one of those. I am interested to know if there is a benefit for the hobby makers in a professional unit?
 
I stone washed a blade and my kershaw cryo in the dryer, just to try it out.
I used an old squeeze type water bottle, a handful (just a handful) of round pebbles, about a teaspoon of olive oil. I put the water bottle inside a pair of old socks and tied it with paracord. In my dryer the bottle by itself would spin all the way around the drum and then pause a little before being tapped by the paddle ridge on the drum to send it spinning around again. That made it pretty gently on the dryer. When I tried putting the bottle in with a couple of blankets it beat all around and made a heckuva racket.
Stonewashing came out about the same both ways.
IMG_1297.jpg
Etched with Ferric and then stonewashed for 40min.
 
Last edited:
I inherited an old pulley driven Craftsman wood lathe last year. I am researching swapping the pulleys out to gear it down and hopefully it will be slow enough to act as a tumbler. I figure even if it isn't slow enough to use the spindle directly, I could use it as a drive roller to turn a drum similar to some of the homemade units.

Chris
 
k.. divorced, so no problem with the wife and the dryer is a pretty big piece of crap (cuz im a single guy and don't care as long as it keeps drying my clothes, lol) however, I think I've got a contraption in my head. if I get two more blades finished this week, I'm gonna try and make it happen. whether it works or not, i'll try to post pics and show you guys.. it'll either work and voila" or it won't and we'll all get a bit of a chuckle.

fingers crossed.
 
I actually use this media from McMaster Carr:

4918A911 CERAMIC MEDIA, COARSE, V-CYLINDER, 1/2" X 1/2", 10 LB PACKAGE
4918A918 CERAMIC MEDIA, COARSE, TRIANGULAR 22 DEG, 5/16"X7/8", 10 LB

I have the large tumbler from Harbor Freight, which will hold about 20lbs of media.

If you plan on tumbing blades, you need to finish them to at least 400 grit.

I then apply a heavy bead blast finish to the blades, and put them in the tumber for various lengths of time.
 
You must log in or register to reply here.
Back
Top