Anti Scale Coatings

[Tom Lewis]

Thanks, Rat Pack, I have used Brownells but sometimes I get pitting. I will try your method next time I heat treat.

 

[RAT Pack]

Perfect, that answers my question. My concern was that it interfered with hardening but if it is the same as his other method and is what he expected as a best case that is good news.

RAT Pack, thanks for the follow up.

As I have previously stated, we're all in this together!
Also, if you have tried this process with the graphite spray, I would like to include your process, results and any pix. As I stated before, I am putting together a list of procedures and results with different metals. If you want to contribute, you can e-mail me at ron@bellablades.com. I will make the list available on my DIY website going forward. Thanks

 

[Ken H>]

As a follow up to Ron's (Rat Pack) info on Dry Graphite.
Yesterday (Sunday) got around to HT'ing an AEB-L and 14C28N coupons using the dry graphite as protection rather than SS foil. I also quenched a RR spike knife using the dry graphite as coating. The RR spike knife was soaked for 5 minutes at 1500F, quenched in plain water. I didn't include photo since you've well documented using dry graphite with high carbon, but the result is smooth with no scale at all. This is the product I used 'n ordered from Amazon. https://www.amazon.com/dp/B0094IZ3BA

The 2 coupons were both clean ground to 120 grit prior to coating with two fairly heavy coats of dry graphite and dried overnight.

The coupon above is AEB-L and soaked at 1925 for 5 minutes shown as it came from aluminum quench plates. From what I can tell it's as smooth as before HT with no scale I can tell, no pitting or anything.

The square coupon above is 14C28N soaked for 8 minutes at 1950F, the coupon on right is the AEB-L coupon in first photo. As expected the 1925F coupon is lower 58 Rc value due to the low temp used. I was pleasantly surprised with the 14C28N coupon at 63 Rc. Both where clean ground with 120 grit on 2X72 grinder.

Above is the other side of the two coupons where I ground with 120 grit on 2X72 for a clean surface for Rc testing. While this is NOT a valid scientific test, it's enough I'll be using Dry Graphite for my next knife blades for more testing.

 

[Stacy E. Apelt - Bladesmith]

One thing that can tell you a lot about having decarb is to etch the metal in FC after cleanup. The decarb will etch as dark spots and the hardened stainless will be pretty much untouched.

Another is to measure the metal thickness before and after the cleanup. This tells you how much material you have to remove to get to clean metal.

 

[Ken H>]

That's the amazing thing Stacy, the only material that seems to need removing is the coat of graphite which is like a very thin layer of paint. The metal below the graphite seems to be as smooth after HT as it was before HT. Since that is only 2 samples I'm not as yet prepared to say "this works", but it sure seems like it will work. I'll be trying it on the next blade in a few days.

 

[mooniesdl3]

As I have previously stated, we're all in this together!
Also, if you have tried this process with the graphite spray, I would like to include your process, results and any pix. As I stated before, I am putting together a list of procedures and results with different metals. If you want to contribute, you can e-mail me at ron@bellablades.com. I will make the list available on my DIY website going forward. Thanks

I am certainly planning to use this method when I finish my HT oven and start heat treating, I have some 26c3 and cruforge V to do. I'll let you know the outcome.

 

[RAT Pack]

Thanks, Rat Pack, I have used Brownells but sometimes I get pitting. I will try your method next time I heat treat.

Tom,

Let us know how it works. I too have occasionally had minor scale when using powder or clay. I have had none since using the graphite. If there is an issue with the graphite, it is that it seems to be impervious to solvents and I'm reasonably certain that boiling won't do any good either. Options: leave it on (looks nice), blast it off (I use 80 grit garnet), or belt sand (I use 400 grit). Happy testing!

 

[Hankins]

Were all these done in an oven or has it been tried in a forge?
B'laster 8-GS Industrial Graphite Dry Lubricant - 5.5-Ounces

 

[Ken H>]

As far as I know, oven only. A forge would have very high temps in the direct flame and it'd be hard to keep it from flame. Perhaps in muffler tube? Hey, it only costs a small bit to try, so try it.

 

[Stacy E. Apelt - Bladesmith]

I have a couple cans of the "Blaster" graphite in the shop. Looks like we can't get the "Extreme" version in the USA. When everything is up and running I plan on using it on carbon steels and experimenting on stainless steel. I wonder about giving a stainless blade that needs higher austenitization a spray and then wrapping it in foil?

 

[RAT Pack]

Stacy,

I don't think you'll need the foil or the Extreme version of the graphite spray. I will be uploading a paper to my website (bellablades.com) with results of others who have tested this process. I was going to wait for more results, but I think it can provide some useful info, so I will publish it later today. I will still continue to add the procedures and results of anyone who would like to contribute as we go forward.

 

[Ken H>]

I have ordered the Blaster extreme temperature version and it should be here tomorrow or Friday. It's $9 shipped: https://www.ebay.com/itm/293512228353

I'm getting ready to HT another AEB-L coupon and an AEB-L blade today - oven is heating up now. I'll take measurements before and after to see if it gets any thicker due to build up, or thinner due to cleaning after HT.

 

[gcouger]

Rat Pack,

Your discovery of Graphite as a coating to protect steel from Oxidation and decarbonization is big. If the baked-on coat is durable it might do as a lubricating finish.

I can't find any technical data on Blaster graphite spray. As with most MSDS sheets, they hide any real information as a "Trade Secret." All that appears to be in their product is Graphite and volatile hydrocarbons. However, Slip Plate has documentation on their many graphite paints. This is their MSDS sheet library. It
doesn't reveal much to me other than quartz and graphite. There must be some kind of resin, polymer, or ?? that bind that mess together. Then I looked at the MSDS sheet for John Deere's EZ-Slide, finding talc, silica, and graphite.

Slip Plate Arasol is supposed to do the same as Slip Plate #1. The solvent is different. It comes in everything from 1/2 pints to 55-gallon drums.

It acts like it is firing as a glaze, but it isn't hot enough for the mineral constituents and too hot for polymers that might be in the mix. Maybe there is enough stuff for someone else to figure it out.

 

[Mikew3314]

I just finished writing a long reply and it magically disappeared--must have hit something. I'll keep this short! We are a DIY site for knife-makers (www.bellablades.com). I have been testing a different process for prevention of decarb and scale that provides incredible results! In the past we first used powder, then we tried clay. Both worked, but there was still minor decarb and scale, requiring more surface finishing, especially for hardness testing. We do a lot of testing, and publish papers on our results for the DIY community. My latest paper addresses this different approach for dealing with decarb and scale and provides results of the tests. It is cheap (less than $5 at Home Depot) and I know it gives great results on O1 tool steel (1460° F) and in our home-made electric furnace. I still have more tests to run, but take a look. So far, so good. It would be nice to find out what other steels and processes it works well with. I hope this helps.

Incredible! I know this is an old post but I'll be trying this in my gas forge in the next week or so just to see if it can be done. I'm thinking of putting the piece in some square tube to protect it from the flame. I'll repost my findings once I work everything out. This is what I love about the blade smithing community. Everybody shares info freely without worrying about what they'll get out of it.