I know this is a difficult one because I've been looking for months and only found one thing that might work but it will be £200.

I do jewellery repair and especially a lot of metal finishing, so polishing, brushing, sanitising etc and sometimes I need to do this on intricate chains and straps. I have techniques for doing this but they could be better which is why I’m looking for some sort varnish or lacquer that I can masks of polished areas with then apply abrasives to the whole work piece then dissolve the varnish so the polished parts stay polished and brushed parts are brushed.

I can and do use tape but it has its limits and is only so practice and is incredibly time consuming on some items. There are a few products aimed at the industry but they are useless to put it bluntly. They from a loose latex layer.

I really appreciate any suggestions and would like to add I’m not looking for a different way of doing things I’m just asking if anyone knows of a protective coat that can be applied to metal that can then be dissolved in anything that won’t damage the metal. Thanks.

I did consider that I was just worried the shellac would gunk all the abrasive dust and brushes together.