final finish after heat treat

[bgmills]

At this point in time I have no belt grinder. If I leave my cutting edge thickness approximately .030 to .040 thick, will I be able to finish this blade by hand after HT using paper and a lot of elbow grease? Most likely I will be using 0-1 or 1095. What grits should I start with and progress to? Thanks in advance. All responses are greatly appreciated.

[Ray Rogers]

Got to at least 120 or 220 before heat treat. Start at the same grit after heat treat. You shouldn't have any trouble getting it done by hand as long as you like hard work...

[T Blade]

As I am in similar situation, (no belt grinder), I do use a 4" offset grinder to remove forge scale, profile the blade using files, and then sand with 60 grit, then 220 grit before HT. I believe (may be incorrect) that filing right from the forge will prematurely wear out your files, as the forge scale seems to be much harder than the annealed metal under it. I've only completed one knife, so my experience is very limited, but that's how I did it.

Good Luck, and happy hammering

[Bob Warner]

Read this tutorial by Terry Primos it is in the "How To" section.

Scale Prevention During Heat Treating by Terry Primos

You may be able to get to almost final finish before heat treat, you will have less to do after the steel is hard, making it easier on you. You can get to your final thickness before heat treat, saving all the work getting rid of scale after heat treat.

[Jason Cutter]

I also like to use O-1 and previously a lot of 1095, W-1 salvaged from old Wilkinson, Wiltshire files. As I use a grinder, I tend to only rough grind my blades to about 75% of the final bevels. I do a lot of final grinding after heat treat, being careful to not ruin the temper.

But finishing to 95% of the final finish can be done prior to heat treat. Thats what I used to do. I ground progressively from 40, 80 and 150grit, maybe to 320grit prior to heat treat. I also finish with a green 3M Scotchbrite belt. (Too large a grit marking on the blade could potential act as weak points and cause cracks, is what I'm told.) After heat treat, I take off all the scale with an old 80grit belt. If without the grinder, I use 180 or 240grit wet and dry to rake off the scale so I can judge tempering colours.

Ray Rogers has got the gist of it. Its a lot of hard work, but it can be done. Don't use the file - its too hard anyway and exclusively use good wet and dry backed up by a hard surface. Using cheap silicon carbide stones is an alternative way to do it.

The reason I don't do the same level of pre-heat-treat finish. I was getting too much warping, especially if ground too thin. This was eliminated if left a bit thicker.

I recommend going up to 320 / 360 grit prior to heat treat as it is easier to sand off the finer scratches after heat treat. On some knives which I still occasionally make entirely without power tools, I hold the blade in my hand and vigorously grind the edge in on a bench stone (coarse) to make the job easier. After heat treat I use a coarser grit W&D that what I finished with as the harder steel will need a more aggressive grit to get it going (eg.- pretreatment with 360grit, after heat treat start with 240grit).

Thats my way anyhow. lots of different ways to do it.

Cheers.

[Dan Graves]

Try soaking the blade over night in vinegar to remove that nasty scale. Does a pretty good job.

[bgmills]

Ray, T-Blade, Bob, Jason, and Dan. I would just like to thank you guys for taking the time out of your schedules to respond to my questions. Ones I'm sure you have probably answered more times than you care to admit. It is my hope that some day I will be able to answer these same questions for someone else. If I ever get a knife built, it will have definitely been a group project! Once again, thanks. Bill.