Polishing and etching: when and how?

[Croccifixio]

Originally Posted by Ian

Croccifixio:

You will find differing opinions about how best to polish a blade. I think most of us use high grit sandpaper so as not to scratch the surface. I start with nothing coarser than 400 grit and work up from there using progressively finer grits.

Be careful with what you use to etch the blade. Read the forum posts carefully and get an idea of what others use. And remember that each time you etch the surface you will create a little roughness to the blade, so you don't need to have a mirror polish on it before etching. In fact, I have found that if the surface is very smooth you can get droplet formation from surface tension which can give an uneven etch if left to stand. Any oil or grease on the blade has the same effect, so make sure you remove any oil/grease before you etch. I use rubbing alcohol (isopropyl alcohol) to remove any residual oil/grease.

I suggest that you start with cold and relatively weak etching solutions and work your way up until you achieve the effect you want. Highly acidic solutions can damage the blade by etching deeply, so start low and work up--you are not trying to emulate the finish on a keris.

There is a lot of information on these pages. But much of what we do comes down to trial and error. Fortunately, if you don't like the effects of a particular etch, you can again polish the blade and try something different.

Ian.

Thanks Ian. I cleaned up the blade as best I could with warm soapy water, alcohol, and dishwashing liquid. Then I tried the warm vinegar etch for 10 minutes. Neutralized with baking soda slurry and cleaned it up with dishwashing liquid and a bit of car polish. Worked really well, and I like the kris even more now! Instead of that yellowish tint, it has a whitish-gray palette which I like more.

Although I have learned my lesson, and will not do this on an older kris with more value (the initial reason for etching was that after removing the active rust, the shiny steel shone underneath and made for a pretty bad contrast to the yellowish patina).