Becker BK 9 -- what # grit to use?

[mthall47]

OK, yet another question from me.
I like the BK 9, but want a "smooth" finish. My local knife shop guy recommended sanding it by hand starting with about a #500 grit and finishing with #1500 grit. Anyone have any idea how that would actually work? Could I get the smooth, satin finish I want, or would I end up with a very scratchy, ugly looking blade?

 

[Jeff Clark]

I guess that you are removing the baked on black epoxy finish rather than just sharpening the blade or polisihing the black finish. The 1500 grit would leave you with a very smooth and shiny finish--assuming you did all of the preliminary steps adequately. I think that the real problem is the blade finish underlying the epoxy coating. I think that the Beckers are left with a rather rough finish before the coating is applied. If that is the case you will need to smooth the blade considerably before you get to the finer grits. I would guess that you need to start with around a 100 grit on a nice hard and flat sanding block. You need to remove all of the epoxy that way and get your flats "flat" and smooth. If there is an appreciable hollow grind you will have problems getting that neatly polished.

You will need to work your way up slowly to at least 600 grit. You might find that is fine enough for your liking. You can keep going to 1500 grit if you want a mirror finish.

 

[mthall47]

Thanks for the advice. I have never tried something like this before.
When you mentioned the preliminary steps did you mean start with course grit like the 100 and work up from there? Also I do not know what kind of sand paper to look for. Sand paper designed for metal, and not wood? Wet or dry sanding? (Actually I don't know how much water wet sanding takes)

Thanks again for everyone's input on this.

 

[WarRaven]

On mine i finish with around 1500, then switch to rubbing compounds, then a cleaner, then wax to protect.

Use only high grade Wet automotive sandpaper, not wood or other.

Do not use dry, always use wet.

Starting off at a 100 grit may leave deeper then nesc scratches, i my self start at around 400 an work my way up up.(However i do not own any Coated blades) And aswell depending on how smooth the steel is already, i mean if its factory polished, start off way higher grit like 1200, if it is satin or less, 500 an up.

When getting ready to switch grades higher, i really use the paper, it last forever, get used to it and love it, use a bucket on the floor between your legs with warm water and start polishing, you wil prune but heal normally if you spend any time at it.

Then for touch ups from usage scratching ect, i use 1500, then polish routine and all is well again.

Oh, and i Wax, Wax, Wax ANY metals i have done this too, more for keeping my oily skin off of it and keeping it in top form.

WR

 

[me2]

Try Bob's notebook under "The Manual" on this webpage. It has extensive info on hand satin finishing. www.engnath.com
The site used to sell ground and heat treated blades ready for final finishing out of premium steels for the time. He stopped at 220 grit with the coloring left on from the heat treating.

 

[mthall47]

Thanks very much.
One of the main reasons I like this site so much is that people are ready and willing to share the knowledge they have -- especially with people like who want to learn but are starting pretty much from the beginning.

 

[Jeff Clark]

You could remove the epoxy coating by soaking the blade in carburetor cleaner then scraping with a razor blade. At that point you can see how smooth the underlying finish is. You start with coarse grits (low numbers) and work your way to fine. You need to test a little to see if the grit you are using seems coarser or finer than the finish that Camillus left originally. You don't want to roughen the finish when you start, but you want to be able to take off any high spots relatively quickly. You want to use something like 3M brand Wet or Dry paper. That is silicon carbide metal polishing grade. You can find down to about 600 grit at places like Home Depot or WalMart. If you look at automotive supply stores (or the automotive department of some other stores) you can find even finer grits that are used to polish automotive surfaces.

Note that carburetor cleaner will also attack the handle of the knife so you either need to remove the handle before attacking the paint or find a way to protect the handle from the carb cleaner. For example you could put carb cleaner in a tall can and cover the can lid with heavy polyethelene plastic. Then stab the blade through the plastic and into the carb cleaner. Let that sit overnight before scraping off the epoxy. Avoid the fumes of the carb cleaner. PS. By carb cleaner I basically mean xylene.

 

[Temper]

Find a way to trap the paper onto a block and fix that to a bench or make a kind of saw horse and use it length ways and straddle it to get close to the paper. Make sure its at a comfortable height because you are going to be at it for a good while. I think it will be worth the effort but be warned that the 9 is probably ground quite coarse under the coating and its very time consuming to prep it for a bright finish when you have to remove every single wayward grit mark. I did a mirror finish (#2000) on an Ontario Spec Plus fighter because the coating was scratched to hell. It looks pretty good, but it was a lot of work.