There are chemical and metallurgical reasons NOT to use anything containing hydrochloric acid to clean the grades of stainless used in exhaust manufacture. These reasons will show up as random rusty spots over time, and rare but possible, cracking at stressed areas if it was left on long-term in tight folds or welds. If you do take this route to remove the brown surface discolouration, at least re- passivate the metal immediately after thoroughly washing the hydrochloric off with water. The easiest get passivating solution is Citric acid, buy as crystals, make a 5 - 10% solution by adding to hot water, and soak the parts for 30-60 minutes.leave to dry overnight then wash with water.
The method of cleaning stainless steel exhausts with household bathroom products with a hydrochloric acid content was put to the test earlier this morning. Due to the shelf unavailability of Harpic (which featured in all relevant YouTube reviews I had seen), Domestos was used instead stating a hydrochloric acid content of 8% per 100 ml of undiluted product. For the purposes of my test, I applied by paintbrush an arguably hesitant coat of 15ml of undiluted product to half the exhaust pipe (leaving the other half untreated for 'before and after' comparison purposes). I left it to work on its own for 8 minutes only (as despite its thickness, it was starting to evaporate this warm morning in the Mediterranean South) before scrubbing it with a scouring pad and then rinsing it off with water. As can be seen in the pic, the end-result is promising. Near-effortlessly, the metal came through the thick black layer that had become embossed over the exhaust tube from time, use and neglect. I consider that if a more generous amount of product was applied (so as to ensure a greater amount of hydrochloric acid to do the 'magic'), better results could be achieved. The thorough use of a scouring pad is necessary however, as the ‘magic’ does not happen on its own. Despite being denounced on chemical and metallurgical grounds, I can certainly see this method as an essential first stage (yet not a total solution on its own) in any quick attempt to bring back the factory bling in any stainless-steel exhaust.
Theres a video on you tube explaining why u shouldn't use "bleach". The professionals use citric acid.
Pay somebody to do it. Had four systems polished locally over the years - fantastic finish and never more than a hundred quid.
but what about all that elbow grease? - some of us have little cartilege left now, and don't even get me started on shoulders* * I do apologise - wrong Forum.
@Chris yeah, you need thi post chris...https://www.ducatiforum.co.uk/threads/ball-joint-rod-end-bearing-specs.96922/unread
I did my exhaust this morning with a 3M product called Scotchbrite Advanced Extreme Scrub and water. They are like a sctochbrite on steriods.
Hi. Took a couple of minuits to do this bit. Seriously quick. The pads must have corundum or simular in them because they will cut stainless.
