all right, say you are rust bluing a knife blade and don't want the edge to get the treatment. was discussing this on another forum and a guy that does acid etching of circuit boards says that he uses a marker, like a sharpie, and blacks out the areas that he doesn't want etched, and sur enough those areas don't get etched. would that work with rust bluing solution? I'm sure if you applied it with a q-tip you could probably do a good job keeping it off the edge, just curious.

Red

Red,unless you checked it out, I would doubt seriously that a magic marker would protect metal from acid. Brownells sells a liquid that engravers use and I believe it is called acid safe. You paint it on the area you wish to protect and then go at it with the rust bluing. You would need to inspect the area to make sure it is still covered and not carded off by the wheel.

I can't think of any material that will stand up to the acid environment and the carding required for rust bluing.

The ferric chloride etch that is used for printed circuit boards does not require anything like carding (firm wipe with steel wool).

I suspect that simply bluing the blade and then resharpening it will do want you want to do. You'll lose a little material on the edge.

Why not just re-sharpen the knife when your finished bluing it.

Use clay & build a harmon line. Of course it is soft so you will have to keep reapplying it.

Oils in the clay will ruin the blue.

you figure that it might leech out at the edges? In that case I stand corrected. forgot about the oils. Maybe a rubberized (bathroom/kitchen) caulking then. Trying to think out of the box on this one.

I think a lacquer would work. You'll have to be careful when you are carding, probably have to re-apply the lacquer at least at the edge but if a person absolutely had to protect an area that is how I'd try it first.

quote:

Originally posted by Scrollcutter:
Why not just re-sharpen the knife when your finished bluing it.

I think this is the best solution.

The problem with all this masking is that it will have to be redone after every carding. It will be almost imposible to maintain a line that follows the true edge without messing up the bluing or rusting the edge.

Just resharpen the edge!

I had said to just resharpen, but of course there is always discussion of other ideas. what brought it all about was that I am getting ready to start shaving with a straight razor and was thinking about trying to rust blue one of the blades. just for fun. I think I'd have to take some 320 grit paper to it first, has a mirror finish. I have a couple of old ones though that were my great-uncles and they already are patina'd anyways, rather than try to get them to luster a deep blue might be cool, then with resharpening the edge you'd have a slick looking silver edge setoff against that dark bluing.

saturday will be first day shaving with the cut throat, we'll see if it is as cool then as it sounds.

Red

The following is gleaned from two different books.

The knifemaking book by David Boye has a section on acid etching of blades. They use a wax mixture to prevent the acid from etching the steel where its not wanted.

The Custom Gun Digest book has a section called Seminar of the Masters. In that section there is a mention of FUME Bluing, which is putting the part to be blued in an air tight box with a mixture of two acids. Supposedly the fumes blue the metal.

If one put those two together, i.e. waxing the blade where you didn't want the fumes to blue the blade, and used Fume bluing, perhaps it might work.

Only way to know would be to try it on a polished piece of scrap steel.

Once again we have 22WTF joining in where he doesn't know shit from shinola. Okay, that very common. For your edification, SFB's, fume bluing is just another way to start the rust bluing process. Still have to boil in water and card it off. Now take off the dunce hat and go out for recess.

Over the years, I've made up about a half dozen knives using 0-1 steel, and rust blued the blades. I did nothing to the edge to protect it during the bluing as I wait till the knife is assembled to do any blade sharpening. That works.

Don

I experimented with fume bluing some 20+ years ago. It finishes to a beautiful texture and color.

Alas, it has the wearability of red lipstick on a pig.

Bob Emmons used to fume blue. Unfortunately his, like mine, could be rubbed off with a not too vigorous thumb. :-(

quote:

Originally posted by Customstox:
Once again we have 22WTF joining in where he doesn't know shit from shinola. Okay, that very common. For your edification, SFB's, fume bluing is just another way to start the rust bluing process. Still have to boil in water and card it off. Now take off the dunce hat and go out for recess.

Customsucks

Once again we have the little boy with nothing else to do before bedtime except to bother people here on AR.

If you would have read my post dumb shit, (maybe you can't read) you would have seen that it was not my suggestion to fume blue. I stated right from the start that I READ the information in Two Books. If you want to call Mr. Boye and Mr. Pilkington dunces thats fine with me. But I bet you didn't even try what I suggested, so it would seem that it is you who don't know shit from shinola.

Now little boy, why don't you go out and play with your little friends for awhile before mommy calls you in for bedtime.

quote:

what brought it all about was that I am getting ready to start shaving with a straight razor

I went down that same road once. I was unprepared for the difference in technique required to maintain a straight razor versus a good knife. The edge on a good, properly sharpened straight razor is so delicate, just stropping a few degrees off-angle or too hard can ruin the blade and require it be sent to the factory for resharpening.

No sh##t, its a whole 'nother ball game. That's why most barber shops use disposable-blade straight razors; the time investment to keep them up is un-economical.

Point being, carding the blade will ruin it for shaving.

I'm not trying to discourage anyone. A well sharpened straight razor produces a shave unlike anything today's high tech multi-blade vibrating wonders can provide. But sharpening one is 99% of the work. Try googling some pages on sharpening procedures from the makers (many are still German) and go for it!