Very Little Gravitas Indeed*

[David Taylor]

I use diluted phosphoric acid to clean up after silver soldering. Works with steel as well as non-ferrous metals but you can't leave the steel in there too long.

Those coupling rods are excellent, and hand shaped too! Really well done.

I like the look of that machine you bought too. Jig borers are meant to be very accurate.

 

[Arun]

I should add that the sulphuric acid made no cosmetic improvement to the castings. . . . . And maybe I shouldn't add that sulphuric acid near full strength is allegedly safe enough to dip your hand in. Apparently, it's when it is watered down that it becomes dangerous.

Now having said that here, I'll find out if that is true or not.
-Brian

I really wouldn't try that. You are right that water is needed [to create H3O+ ions] but [and it's a very big "but"] conc. sulphuric acid extracts moisture from anything near it and given that you are 70% water, it makes no difference to the nasty unpleasant end result whether you dip your hand in it or just allow the vapour [probably largely sulphur trioxide [SO3]] to caress your exposed skin. {SO3 + H2O = H2SO4}

Arun

 

[simond]

Do as you know you ought-er,
and add the acid to the water.

I suspect there was a second couplet bemoaning the fate of those who didn't, but I can't recall...

Best
Simon