sanding before heat treating question??

[ouporblowup]

how well does the knife have to be sanded before sending it off for heat treating?

should i pretty much get it perfect since itll be alot harder to get those little scratches out after its treated?




ooo

 

[Robert Carter]

Its going to have some scale on it after heat treatment. I usually just get my grinds nice and even with 80 grit and take it 70% to where I want it then heat treat cause of the carbon and scale it'll have after heat treat plus if you leave some meat on the edge line it lessens the chance of warp during heat treating just make sure you take the meat off evenly then continue grinding on the hardened blade when your close take to 220 then 400 and as far as you want to take it before you start hand rubbing. I have found that if you surface grind it before you heat treat the scale will come off easier on the flats. I wish you luck on your project.

 

[Stacy E. Apelt - Bladesmith]

It completely depends on the steel type. Carbon steels, 1084, O-1, 5160,1095....will have decarb and should be taken to a 220 grit finish. All grinding defects and deep scratches should be gone, and the surface should be smooth. I usually go to 400 to make sure all the scratches are gone. Leave the edge about .020 to .030 thick.

For stainless steels, take them to almost done, a good 400 grit or even an 800 is needed, and the edge should be ,010" to .015". They should be almost ready to sharpen before HT.

On any super hard steel, Elmax, S90V, Cowry X, etc. take it to as close to done ( except the edge) as you want it to be....because you aren't going to take much metal off post HT.

After HT, go back one grit step to start the final finish -
If you stopped at 220 for carbon steel, go back to 120.
If you stopped at 400 for stainless, go back to 220.