Michael Bullington 5 #1 Posted March 16, 2010 I got a m12 down and the rod froze to the crankshaft,,,all parts look great except the piston and rod which broke ,,,the crankshaft has aluminum stuck around the lobe for the rod....has anyone tried acid to remove the aluminum? if yes....did the engine hold up? Share this post Link to post Share on other sites
Roger from southern Iowa 1 #2 Posted March 16, 2010 Short answers, yes & yes. Needless to say but, you can never be too careful. Treat the acid like it's dangerous! Open well ventilated area. All protective gear in place. Share this post Link to post Share on other sites
rickv1957 73 #3 Posted March 16, 2010 You might want to mike journal after it is cleaned up for proper size,Rick Share this post Link to post Share on other sites
sorekiwi 761 #4 Posted March 17, 2010 I've heard of the Muriatic acid technique, but I've never done it and dont know too much about it. You can probably find some info with the google.... I've cleaned up a few journals with emery tape, starting with 180 grit or so and plenty of WD40. Mic it when your done removing the aluminum to see if its still within spec, if so you can finish the polishing using the "wrong" (non abrasive) side of the tape. This one (the crank!) lived to fight another day... If its worn beyond spec you can get the journal ground at a machine shop, and use a rod with a -.010" bore. Last time I checked it was about $50 for the machining. Share this post Link to post Share on other sites
tophatbufflo 2 #5 Posted March 17, 2010 Use lye like in drain cleaner it does a good job on cleaning alumnium out of files. Share this post Link to post Share on other sites
daemon2525 5 #6 Posted March 17, 2010 I have used muriatic acid to clean a crank and the engine is still running. I would recommend using it outdoors, although I did not. I tried brushing it on and it worked so slowly that I would have been brushing for years. So I designed a bowl that would go under it and allow the crankpin to hang in the acid. It worked great with one little problem. It rusted everything within 10 ft of the process. I lost a set of digital calipers and a set of feeler guages. Rusted them to the point that they could not be saved. They were never in contact with the acid and were not really that close. Share this post Link to post Share on other sites
Michael Bullington 5 #7 Posted March 18, 2010 thanks for all the replies guys....that acid is some rough stuff!!!...It is working on the crank though....i got to do it one more time if i can stand it....then polish and mic the journal. Share this post Link to post Share on other sites
