Posted by tubachopper on December 11, 2002 at 19:08:18:
My student has a StPetersburg with a very rough moving 1st valve slide. The alinement looks good. I tried lava soap and hand laping but it seems like the slide is of very hard metal, maybe nichol. The lava does not cut like it does on a brass slide. Just thought I could get some advice before I get out the emery cloth. H E L P ! ! !