Rutland cement hamon

I

Ian Fifelski

Joined
Oct 4, 2017
Messages
528
Hey all
I am working on a little hunter and want a hamon. Several people have suggested rutland fireplace mortar. I have put in on a knife and let it dry a bit and then heat-treated and it fell off in the quench after bubbling at temp. Then I tried letting it dry for 48 hours, and it bubbled in the heat treat and popped off.
Then I saw a short video where someone used it and they put it in an oven at 400*F to harden it. I tried that and it bubbled again.
dscn8528_orig.jpg


Any suggestions on how to get it to stay? Do I need to go thicker? Bring up to 400 slowly?
thanks
-Ian
 
Can you show us the tub of cement?
Is it an oil based or water based product?
How long did you leave it in the oven?
How were you doing the HT?

Not an issue on the bubbling, but what is the steel type?
 
Stacy E. Apelt - Bladesmith said:
Can you show us the tub of cement?
Is it an oil based or water based product?
How long did you leave it in the oven?
How were you doing the HT?

Not an issue on the bubbling, but what is the steel type?
Click to expand...
Here is the tube:
137046427563%20(342).jpg

I am not sure if it is oil or water based. I threw away the bottle some time ago.
I put it in the oven for a half hour and let it heat up with the oven.
I am doing the HT in a forge. The forge was hot, turned the burner all the way down.

The steel is Aldo's 1075.
 
I’m watching with curiosity. I haven’t used Rutland, so I’m no help here.
 
If you can't get some satanite, I would suggest you switch to Rutlands fireplace cement. The gray cement works OK. I think the black stuff has an oil in it.

Satanite is far better, IMHO, and it is a powder, so you only need to mix up an ounce to do a knife. Most folks who use it in making a forge have extra and will gladly give you a ziplock bag of it. It is cheap to buy from laces like HighTemptools.com or any of the knife suppliers.
 
I am going to try a few things before getting some satanite.

I re-coated it and put it in the oven to heat up with the oven to 250 degrees. Let it in there for a while (about 2 hours) and no bubbling yet and its dry. Lets see what happens in the heat treat.
 
I have used the Rutlands Black. I generally let it dry out in an oven set around 200˚f. It has popped off in places during the quench a few times but not often. Could have just been sloppy blade prep on my part. But it does work. I would still get the Satanite. I haven't yet but I'm planning on it. If a product or process is widely regarded as the best and it is cheap as well it seems like a no brainer.

YTk7RYP.jpg
 
I just heat treated it and the clay did bubble a bit but it stayed on while heating and stayed on in the quench. Edge is hard and the spine is soft and it is now tempering. I put it in the oven at 375F. I am shooting for 60 rc.
So it seems 200-250F is a good temp to harden the clay.

Question, Is there a difference between tempering it for 2 hours and tempering for 2, 1 hour cycles?
 
I did a quick etch in ferric and the activity is mediocre. I don't expect much more from 1075, but it could be much better. It is also pretty close to the edge. It could be how I applied the clay or the heat treat.
What do you think?


dscn8544_orig.jpg

dscn8546_orig.jpg
 
I use the black rutlands constantly. I use to have the same issue when I mixed water to thin it. I now apply it ro a very clean blade. Acetone wipe down. I now apply, wait long enough that I can touch it without it being on my finger ~10 minutes then into the evenheat. The clay will sometime fall off during the quench but I've been getting good hamons.
 
There is a big difference between a two hour temper and two one hour tempers. The first temper tempers the brittle martensite and makes it tempered martensite. It also converts the retained austenite to martensite. The new martensite forms upon cooling to room temperature. This is now brittle martensite, and needs the second temper to remove the brittleness. Some high alloy tool steels need three tempers for this reason. You can cool the blade between the tempers by sticking it in water or running the faucet over it. It doesn't have to slow cool.
 
Thinking it over, I don't think I left it soak long enough. So the hamon pattern is subtle because it was mostly the edge that was heated.
 
Stacy E. Apelt - Bladesmith said:
There is a big difference between a two hour temper and two one hour tempers. The first temper tempers the brittle martensite and makes it tempered martensite. It also converts the retained austenite to martensite. The new martensite forms upon cooling to room temperature. This is now brittle martensite, and needs the second temper to remove the brittleness. Some high alloy tool steels need three tempers for this reason. You can cool the blade between the tempers by sticking it in water or running the faucet over it. It doesn't have to slow cool.
Click to expand...
Thanks for this. I never fully understood it but this is very clear. :thumbsup:
 
Thin clay is how to get an active hamon.

The actual hamon won't be fully revealed until after clean-up grinding and sanding. It may increase even more at 1000 grit. The type of etch also affects what shows.

Here is the Cliff Notes of what I do ( you can search for my full instructions on yaki-ire and hamon polishing in old threads with the custom search engine):
Coat the blade with a thin wash coat of satanite ( melted milkshake thick) and dry with a hair dryer.
Coat the hamon shape with a slightly thicker satanite (like yogurt or sour cream). The clay coat should be a tad higher than where you want the hamon to fall.
Dry well.
HT and quench in fast oil.
Wash off and temper immediately.
Clean up on the grinder to 400 grit and check hamon.
 
Stacy E. Apelt - Bladesmith said:
Thin clay is how to get an active hamon.

The actual hamon won't be fully revealed until after clean-up grinding and sanding. It may increase even more at 1000 grit. The type of etch also affects what shows.

Here is the Cliff Notes of what I do ( you can search for my full instructions on yaki-ire and hamon polishing in old threads with the custom search engine):
Coat the blade with a thin wash coat of satanite ( melted milkshake thick) and dry with a hair dryer.
Coat the hamon shape with a slightly thicker satanite (like yogurt or sour cream). The clay coat should be a tad higher than where you want the hamon to fall.
Dry well.
HT and quench in fast oil.
Wash off and temper immediately.
Clean up on the grinder to 400 grit and check hamon.
Click to expand...

I’d like to see a Stacy Apelt hamon!
Got some pics?
 
I'll try and remmber to shoot some photos. I have some Hitachi Blue blades to do the HT on if I get a break from work ( Christmas is the jeweler's time of year to work all the time). I have a few blades ready for togi that I could take a shot of.
 
You must log in or register to reply here.
Back
Top