Anyone been with any strippers lately?

Father & Son Traditional Sharpening said:
Just to set the record straight.... if you can see it... then what you would call it is scale from the heat treatment.

The main concern with decarb is not oxidation but the other properties of the steel...

"A decarburised-surface-layer has lower tensile strength, elastic properties, hardness, wear resistance and fatigue strength (endurance limit) than those of interior portions of the part."

"Decarburisation cannot be detected by visual examination of steel parts and tools. It is revealed by microscopic examination, or by measurement of hardness."

Both quotes are referenced from the following article :
www.engineeringenotes.com

Heating of Steel: Oxidation and Decarburisation | Metallurgy

ADVERTISEMENTS: When a steel part is heated to high temperatures for heat treatment, its surface reacts chemically with the surrounding medium in the furnace. The furnace atmosphere may consists of various gases depending on the conditions of combustion and the temperature The common furnace...
www.engineeringenotes.com

It is possible the Alumabrite may have actually removed some decarb if it dissolved the steel but hard to say, again, without microscope or hardness testing.

I would be more concerned with whether or not that product is safe for all metals, some chemicals can actually cause embrittlement in steel.
Click to expand...

I read the article, thanks...my takeaway is:

Decarb. :

1. Is bad if you are working with tight specs. as far as finished tolerances because the product may require addition machining and thus go under spec. Such as a roll pin that has to be very exact in diameter and wouldn't be cost effective to have to machine further.
2. Invites rust.
3. If it is to be removed, must be physically/mechanically removed down to virgin steel.
4. Is more prevalent in high carbon steels-- steels high in Cr tend to inhibit decarb. formation.
5. It occurs when certain gases / elements are present in the HT furnace.
6. Lessens surface strength of the steel.

I never considered decarb as all that big an issue for big ol' BUSSEs that we knock around-- still don't...but I'm glad that I always chose to sand or grind it off now that I've learned this ^^^....Thanks!
 
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PeteyTwoPointOne said:
I read the article, thanks...my takeaway is:

Decarb. :

1. Is bad if you are working with tight specs. as far as finished tolerances because the product may require addition machining and thus go under spec. Such as a roll pin that has to be very exact in diameter and wouldn't be cost effective to have to machine further.
2. Invites rust.
3. If it is to be removed, must be physically/mechanically removed down to virgin steel.
4. Is more prevalent in high carbon steels-- steels high in Cr tend to inhibit decarb. formation.
5. It occurs when certain gases / elements are present in the HT furnace.
6. Lessens surface strength of the steel.

I never considered decarb as all that big an issue for big ol' BUSSEs that we knock around-- still don't...but I'm glad that I always chose to sand or grind it off now that I've learned this ^^^....Thanks!
Click to expand...

We still don't know if what we are looking at for INFI is decarb or scale (meaning patina). From the article:

"Generally both these surface phenomena, oxidation and decarburisation take place simultaneously. If the rate of both these processes are equal, or even when the rate of oxidation is faster than decarburisation, then the steel surface lying immediately below the scale layer is not decarburised and has the same composition as the interior of the steel.
: : :
Decarburisation depends on the chemical composition of the steels. Chromium, if present in steel, makes it less sensitive to decarburisation, as it reduces the diffusion of carbon, and itself produces thin, adhering and impermeable film of scale, which physically prevents interaction of carbon and atmosphere of the furnace. Elements like Si, W, V and Mo increase the tendency of the steel to decarburisation."
 
ferider said:
We still don't know if what we are looking at for INFI is decarb or scale (meaning patina). From the article:
Click to expand...
I get it...

Let's assume it's not decarb. , then what are the likely suspects of what it could be?

I've never seen scale "rust" on immediate contact with oxygen....so I'm personally betting against that one unless what I've been calling "scale" my entire life really isn't.

OTOH, I've literally watched stripped Busse's rust before my very eyes >>> Blades that still has that layer of, I'll call it mystery sauce on it.

Hey, maybe what we think is decarb. could be Thousand Island dressing-- that's the secret sauce on Big Macs-- allegedly...then again 🤔 , I don't think Ronald McDonald's ever made a definitive statement about it. 🤷‍♂️ :p
 
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PeteyTwoPointOne said:
OTOH, I've literally watched stripped Busse's rust before my very eyes >>> Blades that still has the layer of, let's call it, mystery sauce on it.
Click to expand...

Remember, I have one of your strippers, still going strong, and I very much respect your opinion :) Were this INFI ?
 
PeteyTwoPointOne said:
I've literally watched stripped Busse's rust before my very eyes
Click to expand...

I’ve seen enough folks mention this to think it might not be the exaggeration I initially took it to be. That would make for a really cool video, literally watching rust form out of nowhere.
 
ferider said:
Remember, I have one of your strippers, still going strong, and I very much respect your opinion :) Were this INFI ?
Click to expand...

Yeah, Roland, it's all good...I love this kind of discourse I learn a lot this way. Please don't take my teasing personally, I don't think you are taking it that way, BTW, just a pre-emeptive statement.

But yeah, iirc, I removed the stuff with a dremel stainless brush and various grits of sandpaper after I removed the paint with chemical stripper-- Jasco.

I finish up with scotchbrite bonnets and Mother's Chrome Polish-- all those steps are fairly abrasive >>> unlike my posts <at least I hope you interpret it that way> :) .
 
ferider said:
Photo after bead blasting and sharpening :) came out great, IMHO !

i-qvVc3rg-X2.jpg
Click to expand...
Excellent :thumbsup::cool:
 
Father & Son Traditional Sharpening said:
Just to set the record straight.... if you can see it... then what you would call it is scale from the heat treatment.

The main concern with decarb is not oxidation but the other properties of the steel...

"A decarburised-surface-layer has lower tensile strength, elastic properties, hardness, wear resistance and fatigue strength (endurance limit) than those of interior portions of the part."

"Decarburisation cannot be detected by visual examination of steel parts and tools. It is revealed by microscopic examination, or by measurement of hardness."

Both quotes are referenced from the following article :
www.engineeringenotes.com

Heating of Steel: Oxidation and Decarburisation | Metallurgy

ADVERTISEMENTS: When a steel part is heated to high temperatures for heat treatment, its surface reacts chemically with the surrounding medium in the furnace. The furnace atmosphere may consists of various gases depending on the conditions of combustion and the temperature The common furnace...
www.engineeringenotes.com

It is possible the Alumabrite may have actually removed some decarb if it dissolved the steel but hard to say, again, without microscope or hardness testing.

I would be more concerned with whether or not that product is safe for all metals, some chemicals can actually cause embrittlement in steel.
Click to expand...
skyhorse said:
Excellent :thumbsup::cool:
Click to expand...
I thought decarb is caused by heat over 700 degrees and not the result of any stripping agent ?
 
Couldn’t leave well enough alone on my stripped fatty BGFSH… Had done a little hand shaping prior to using Rit dye on the scales to turn them maroon, but they still didn’t feel quite right in hand (eta: with the thicc stock they were just a bit too big for my mitts vs. my bgfbm and I wanted a custom fit). Got aggressive on them today and wet-sanded with very coarse 60-grit paper.

EAF8-DDE0-8176-4-E85-A006-FCE4-BE59-CB45.jpg


Hand feel is greatly improved for me. Debating whether to leave them as-is or go for a full hand-shaped finish. Whenever I’m finished shaping, the plan is to re-dye them either a darker maroon or maybe straight black.
 
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Anybody stripped SR-77 ? How much finishing does it need after coating removal ? Thanks !
 
ferider said:
Anybody stripped SR-77 ? How much finishing does it need after coating removal ? Thanks !
Click to expand...

It really depends and the steel is only one factor, some like this one I would expect to be easily taken near satin finish being full flat ground. Others which are convex or saber would likely have a lot of tooling or other marks/dimples.

 
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