Little experiment testing out anti scale blade treatment

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Seedy Lot

Joined
Apr 15, 2019
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Have been meaning to run this little experiment for a while and since I had a chunk of 14C28N scrap sitting in the bench I figured time was right.

One sample had no treatment, one 2 coats of NoScale 2000, one two coats of graphite, and one the standard foil packet.

https://imgur.com/a/7phc7kk

Austenitized for 15 minutes at 1935 F, plate quenched, cryo, and one 2 hour temper at 300 F. This is what they looked like after the heat treat.

https://imgur.com/a/8g2nvS5

And Rockwell results starting with foil packet.

https://imgur.com/a/F3Q4uoE

NoScale 2000

https://imgur.com/a/AdbxHhT

Graphite

https://imgur.com/a/Le7oSS2

And the do nothing sample.

https://imgur.com/a/KrVFru4
 
Assuming from the patterns, the top left "after" coupon is the foil wrap? Looks to be the cleanest or most free of decarb out of the oven. Yes?


Thanks for the info!
 
Seedy Lot said:
No. If I ground through decarb they would all be the same hardness.
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Interesting results , now I wonder if it worth using foil at all ? Looks that Stainless Steel can bear these temperatures and time ? If it was a carbon steel at these temperatures would have been lost half .
What kind of oven you have ? If it seals well that can explain this ?
 
Thesian said:
Assuming from the patterns, the top left "after" coupon is the foil wrap? Looks to be the cleanest or most free of decarb out of the oven. Yes?


Thanks for the info!
Click to expand...
Yes the top left "after" coupon was the piece of steel in foil pouch.
 
Natlek said:
Interesting results , now I wonder if it worth using foil at all ? Looks that Stainless Steel can bear these temperatures and time ? If it was a carbon steel at these temperatures would have been lost half .
What kind of oven you have ? If it seals well that can explain this ?
Click to expand...
I was curious as I have read of people using NoScale with good results. I don't know how well the NoScale would work for a higher oven temperature and longer soak times.

My oven is a Paragon and the samples were about 6 inches in from the door.
 
Seedy Lot said:
Yes the top left "after" coupon was the piece of steel in foil pouch.
Click to expand...
I use the foil now....and every time I wrap one and cuss the sharpness of it, I think about the no scale. Actually, when i buy the foil, I also think of the no scale savings as well. So far, I'm in the not sold camp though. hope someone has an equivalent and cheaper option some day, but foil still looks to be the best from what I have seen.

P.S. Not sure it is as evident on the coupon, but if you do a partially ground blade with no treatment, it comes out looking like a blackened marshmallow. The decarb is not kind to the belts in removal and it plain sucks. Mine was on 3v to boot. Last time I do that.
 
Ken H> said:
Did you at least clean (grind) off the residule from the Graphite and NoScale 2000? What did the foil wrapped Rc test show?
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If I’m looking at the pictures and captions correctly the first photo is foil wrapped, second is no scale and third is graphite. Any grinding on the sample would invalidate the test which is to see which methods produce the least decarb, in which foil did the best, no scale a close second and graphite being the worst. Like the OP said if you grind everything clean they would likely all show the same hardness under the decarb. I used to do2 coats of no scale for stainless but after talking with the guy that makes the products he actually recommended cleaning the surface almost like doing a very light coat then wiping off the clay then put one good coat, I use a good paint brush for water based paints. I’ve gotten more consistent results that way then 2 coats. His reasoning was that applying two coats the second coat can wipe the first coat leaving uneven spots, unless you are using a spray gun to apply.
 
Joshua, I hear what you're saying. The Graphite will leave a bit of residual graphite, etc on the surface of the blade. That needs to be cleaned off, and I suspect the NoScale 2000 also leaves a bit of residue on the blade. Even on foil wrapped blades I'll do a quick pass on a flat platen to clean up and leave a nice shiny surface for testing - I like 320/400 grit for testing.

Agreed, this "clean up" might well remove a couple thou of decarbon, but that really doesn't matter in the real world - that's going to get cleaned up anyway.

With that said, I've used Graphite for SS, but normally will foil wrap SS. I do like the Dry Graphite for high carbon steels which still needs a bit of cleanup.
 
I was actually surprised at how well the noscale worked. Joshua mentioned using it in a different thread and I realized I needed to try it again. I actually dismissed it as I have questioned my own results when using the noscale on low alloy.

Now I am rethinking my foil use for certain patterns, if I am going to grind off some metal then noscale might make a lot of sense.
 
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