I have some 304 SS vacuum fittings that are scratched and need to be repaired. I can't really use an abrasive to polish the scratch away because doing so would change the shape of the part and ruin it. Is there something that will stick to 304 SS (like some type of solder) that could fill in the scratch and then be polished flush with the rest of the surface?
Todd
I'm not aware of anything that would work for you and not be noticed. If how it looks doesn't matter, you may be able to fill the scratch with silver solder and then restore the physical characteristics. The other option that comes to mind is to heli-arc the area.
Harold
Are these fittings for vacuum or ultra high vacuum service? The difference is of course the sealing technology. O-rings are much more tolerant of surface imperfections than the copper crush gaskets used for ultra high vacuum work. For ordinary vacuum use I've repaired dings and scratches in the sealing surfaces with high tin solder or silver solder and scraped back down to a smooth surface. That works okay with O-ring seals, but not with copper crush gaskets for ultra high vacuum work. There we'd use a TIG torch to build up and then machine back down to a sealing surface.
Yeah...they are conflat flanges for UHV. Problem is, I don't really see how I could machine them....unless I had some kind of specialized jig that attached right to the CF face and performed the operation. Oh well, maybe I'll try my luck with silver solder and if that doesn't work just get a replacement part.
Thanks, Todd
I'd try cutting off any protruding metal using some sort of blade, and then filling in the hole with indium, or gold, if you want to bake it.
I have never dealt with UHV systems.
If you are going to try silver solder, you might consider a low temp silver bearing solder. I have fairly good luck using Harris Stay-Brite
8 and Harris Stay-Clean liquid flux. It works very well for me with stainless fabrications. It is fairly hard material but soft enough to hand machine (file, scrape, etc.) and flows very easily. I'm sure it would fill the scratches easily. Here is a link for you to see:HTH, PJ
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