CPM154 heat treat weird coloring help

[Patrice Lemée]

Heat treated this one the same as the others I did before. Hold at 1950°F for 45 minutes, plate quench. Used foil and a strip of paper inside the pouch (hence the gray rectangle on the blade).

Weird thing is the coloring near the tip. Looks a little like atmosphere got in there maybe? Or is it related to the thickness of the blade at that point? Any idea and if it can affect the heat treat? Haven't tested the blade yet.

Thanks

 

[Stacy E. Apelt - Bladesmith]

That is nothing to worry about. It is just caused by the oils, smoke, etc. in the packet. It is a surface feature unrelated to any HT event.

 

[AussieBosun]

it may also be caused by a pin prick hole in the foil from the tip of the blade allowing oxygen to enter

 

[Patrice Lemée]

Thanks Stacy, that's a relief.

AB, I was careful and didn't see any holes but of course it doesn't need to be very big to suck oxygen in there.

 

[John Katt]

I get the same thing with 440, doesn't seem to affect the blade any

I'm a little skeptical on putting paper in the foil pack, There is a lot of oxygen in cellulose that must be released when the paper burns ,is there a net gain or loss? or is it more of a good luck superstition ritual, like throwing rice at a wedding or salt over your shoulder ;0)

 

[Patrice Lemée]

... or is it more of a good luck superstition ritual, like throwing rice at a wedding or salt over your shoulder

Pretty much John. I'd love to know if it is needed or not.

 

[butcher_block]

looks liek a pin hole but not too bad and i dont think the tip is affected (tips and knife heels are where the foil can sometimes be stressed and "leak)
i have not put paper in my foil packs in years jsut use the foil roller thingy to bend foil flat close to the blade then crimp the end

 

[Patrice Lemée]

Foil roller thingy Butch?

 

[butcher_block]

got it years ago looks liek a paint roller but the wheel is like 3/4 inch tall and about the same wide all plastic. mine is long since busted but it was nice to have for hard crimping the foil folds. i keep telling myself ill make another one but a small piece of cocobolo with all the corners rounded works nearly as well

 

[Stacy E. Apelt - Bladesmith]

Look in the paint section of the hardware store for similar rollers.

 

[John Katt]

Pretty much John. I'd love to know if it is needed or not.

I guess the other thought I have, The surface area inside the foil pack is 25 to 30% larger then the surface area of the blade, and because the foil will heat at a much faster rate then the knife will, the O2 should be used up by the foil long before the knife gets hot enough to start the chemical reaction


Or at least in my simple mind that's how it should work ;0)

 

[Busto]

I was scratching my head one day thinking of the best way to seal the edge uniformly and digging around I found a roller I had purchased from the hardware store for seating that rubber spline on my screen door. Works great and was like $4.00 and has different size rollers on each end. Sounds similar to what Butch mentioned above.

 

[John Katt]

I was scratching my head one day thinking of the best way to seal the edge uniformly and digging around I found a roller I had purchased from the hardware store for seating that rubber spline on my screen door. Works great and was like $4.00 and has different size rollers on each end. Sounds similar to what Butch mentioned above.

I have been thinking about buying another one of these, I had one years ago for bending fascia, but I think I may have left it on the bumper of my pickup and lost it long ago

http://www.tools-plus.com/malco-s9r.html

 

[Busto]

I have been thinking about buying another one of these, I had one years ago for bending fascia, but I think I may have left it on the bumper of my pickup and lost it long ago

http://www.tools-plus.com/malco-s9r.html

I have looked at these also but for my small usage I couldn't justify the price....Good for bending sheet metal but does it have the force to close doubled up small crimp on the SS Foil???

 

[Busto]

I found a photo of what I used.

http://www.homedepot.com/p/Phifer-Spline-Roller-with-Wooden-Handle-3007666/100392344

 

[John Katt]

but does it have the force to close doubled up small crimp on the SS Foil???

I used mine a few times to fold aluminum fascia down flat to create a butt joint on the rare occasion when I wasn't able to tuck behind something, after getting a nice straight fold I would still use a pair of pliers to tighten the crimp on the foil

 

[Busto]

I used mine a few times to fold aluminum fascia down flat to create a butt joint on the rare occasion when I wasn't able to tuck behind something, after getting a nice straight fold I would still use a pair of pliers to tighten the crimp on the foil

I always worry that I will rip the foil at the last second when I'm squeezing the pliers.... so now I fold and roll and fold again and roll seems to work ok..then roll around the profile of the blade with light pressure.

 

[ChristoDart]

Good rubber rollers can be found at higher end art supply stores in the screen printing section.

 

[Patrice Lemée]

How important is it to make sure the pouch is the smallest possible, either by sizing at first or re-folding at the end?

 

[Busto]

How important is it to make sure the pouch is the smallest possible, either by sizing at first or re-folding at the end?

Probably not all that important however I have experienced that the pouch does puff up and that allows the blade to shift around if the pouch is much larger than the blade and I want it to be as flat as possible when I plate quench. Reaching into the furnace for a hot pocket with tongs/needle nose pliers I want a secure grip on the tang not the crimp of the pouch just cautionary measure I can screw a lot of things up just don't want it to be this.