I have just removed the exhaust elbow from my md22 for a wash and brush up. In the past I have used drain cleaner, not very effective, brick acid very effective but maybe a bit aggressive. I have also tried chipping away at the stuff but that,s no good in the hidden channels. Any family recipes out there? Geoff
Drain cleaner is strong base (Sodium Hydroxide), not really dissolving the typical calcium-and-stuff build-up in exhaust elbow.
I tried hot oxalic acid solution, milder than brick acid (a.k.a. muriatic acid, hydrochloric acid) and worked reasonably - took some hours to dissolve the build-up and did not see any evident corrosion.
BR,
Tommi
s/y Anniina
Quote from: geoff on July 07 2022, 20:35
I have just removed the exhaust elbow from my md22 for a wash and brush up. In the past I have used drain cleaner, not very effective, brick acid very effective but maybe a bit aggressive. I have also tried chipping away at the stuff but that,s no good in the hidden channels. Any family recipes out there? Geoff
I tried to take off my exhaust elbow, but it stuck really hard to the pipe.
I tried pushing a screwdriver between the pipe and the exhaust elbow, I also tried heating with a heating gun.
Do you have any advice on how to remove the pipe from the exhaust elbow?
One of the most useful things for boat plumbing work I've got on board is a set of hose picks, which was inexpensive but super useful.
(https://ae01.alicdn.com/kf/S55a716273dde4df4be169d95465d8764h/Precision-Scraper-Gasket-Scraping-Hose-Removal-Puller-Hook-and-Pick-Set-for-Automotive-and-Electronic-Tools.jpg_Q90.jpg_.webp)
Mine was stuck as well . I used a rubber strap wrench to twist the pipe , leaving the elbow bolted up but jubilees out of the way.
Yep second the hose picks have couple on board which I bought off Amazon, used them to get pipe off elbow and toilet pipes which I can never get off
John
The best thing for exhaust crud is to run the engine hard for ten to twenty minutes every trip and blow the soot out and everything else.
Diesels, whether cars, trucks or boats need a good blow through regularly.
I run my 2030 at 3000 at some time on every trip in our 2001 34