I have not done a lot of scale replacements, but the few I have done were re-scaling blades that I really liked. When I separate the blade from the damaged scales I find that some razors have a thin inner washer (on the inside of the scales next to the tang) (some are a thin plastic and others are a very thin brass) and others don't have this inner washer, i.e. the tang is against the inner part of the scales. What are your thoughts on this? When you put on new scales do you always insert an inner washer (scales, inner washer, blade, inner washer, scales)?
Depends on th scale material. The only razor I ever rescaled, was done in rosewood. I used inner washers and I'm very happy with the result. For ivory scales, inner washers increase the likelihood of breaking the end of a scale. The Bengal shown below has inner washers, is ivory, and has a broken end. Of my ivory scaled razors, the only ones that have broken ends like that are the ones with inner washers. And of my ivory scaled razors with inner washers, about half of those are broken that way.
Personally, not a fan of inner washers. I have used them, and on some razors, they dont want to tighten up enough.
Those numbers were based on impressions which formed a long time ago. I just checked and I only have two ivory scaled razors like that.
Brass and on every single razor I ALWAYS place the flat of the washer against the scale, inside or outside