Welding Problem - MS to SS

We really didn't help, did we? Just a bunch 'o know-it-alls.

That's part of the problem here. And the beauty. There are plenty of opinions, all dispensed by people who, mostly, are trying to help.

But, in the end, it's free advice.

Sorry for the rudeness, welcome to CR4.

Come on back.

Did you consider using sacrificial anodes viz Aluminium, Zinc or Mg ?

Neither the space between the sliding tubes, nor their shape (round, rectangular?), was given. If the space permits, consider inserting slider pads of UHMW-PE. I have seen this done even on telescoping crane booms, as wear parts that must be renewed from time to time.

Thanks Tornado

I know what you mean, but my project is adjusted to fit and then bolted in position and may never be moved in or out again unless someone fits a different length unit into it. It is the cosmetic appearance I am worried about if it happens to be used in a marine environment.

Buck.

In my experience in marine environments, "double dipped electrogalvanized" is pretty much over-rated these days. Do you really need the metal strength, or could you consider some sort of composite construction?

A chromed rod and a tube with seal and silicone protective coating

Thanks Bwire

A sensible answer, but unfortunately crome plating is probably dearer than a stainless rod and the crome would be destroyed in the weld process. I have manufactured my product successfully for twenty years but now with the event of our Government selling us out to the Chinese in a so called "Free Trade Agreement" I have had my design stolen and reproduced in China and now have to manufacture a new and better model to prevent going broke, hence I must produce a Superior model at less cost. So the use of seals "0" Rings etc are out. I have an alternative model in mind which does not use the Telescopic method and I shall probably Settle for that.

Thanks

Buck