Exhaust system tarnish: help is at hand!

[Darren69]

Had read the same in previous posts and can also keep your u bend stain free so win, win!

Does anybody know if it only works on stainless or can I use it on my titanium pipes too?

[Luddite]

Originally Posted by Darren69

Does anybody know if it only works on stainless or can I use it on my titanium pipes too?

Hydrochloric acid (up to a 10% solution) is used to clean titanium but it is recommended that it is used with a corrosion inhibitor (such as ferric chloride) to protect the metal. Having said that, an inhibitor is also recommended when using hydrochloric acid to clean stainless steel but, for our purposes, with the frequency we use it and the short time the acid is in contact with the metal, I don't think we need to worry.

If you are concerned, citric acid (for descaling kettles, etc.) used in a 25% solution, or nitric acid in a 10% solution can be used with no need for corrosion inhibitors.

Originally Posted by Luddite

Hydrochloric acid (up to a 10% solution) is used to clean titanium but it is recommended that it is used with a corrosion inhibitor (such as ferric chloride) to protect the metal. Having said that, an inhibitor is also recommended when using hydrochloric acid to clean stainless steel but, for our purposes, with the frequency we use it and the short time the acid is in contact with the metal, I don't think we need to worry.

If you are concerned, citric acid (for descaling kettles, etc.) used in a 25% solution, or nitric acid in a 10% solution can be used with no need for corrosion inhibitors.

I use essence of ant: formic acid, for descaling the kettle. Would that work as well? It doesn't come in gel form, so far as I know.

[Luddite]

Originally Posted by The Clockie

I use essence of ant: formic acid, for descaling the kettle. Would that work as well? It doesn't come in gel form, so far as I know.

Acid will act on the oxidation to remove the oxygen, so formic acid would work. Like citric, it is considered to be a 'weak acid'. In contrast, hydrochloric is a strong acid. The pH values, assuming the same concentration of 0.1N(M), are 2.3 (formic), 2.2 (citric) and 1.1 (hydrochloric).

So formic and citric acids will be less effective than hydrochloric, but also less damaging (if that's a concern). If you look at my earlier thread, you'll see that the Australian formulation for Harpic contains formic, rather than hydrochloric, acid, presumably for environmental reasons.

For what it's worth, the active ingredient in Solvol's own Bluing Remover, is hydrochloric acid. It also contains 'secret ingredients', which probably include a corrosion inhibitor.

http://www.ukmonster.co.uk/monster/s...93&postcount=1

[Ron1000]

I went the time consuming route of buffing with a dremel. Took awhile but I preferred the non-chemical route and it gave me the finish I wanted.