At 03:21 PM 18/01/2008 -0800, Ty wrote:
>Hi All, I have been a long time lurker, Mainly when
>I have gotten a new bicycle. Well, I just got a 531
>tubed Major Nichols touring frame that has been
>neglected. It has prevalent rust. I want to do what
>ever is going to be best for the frame. I am willing
>to scrape off the paint and sand with some kind of
>wheel. I had considered reverse hydrolysis, but fear
>for the brazing in the lugs. I have also heard that
>molasses was an effective rust remover. My primary
>concern is with the brazing. Any input is greatly
>appreciated. Thank you, Ty
With a really old, rusty frame, I would be leery of any agressive mechanical means to strip the paint. The pros like to use media blasting to remove both paint and rust, but I'd be afraid of perforating badly rust pitted areas. I have a similar project awaiting and plan to use a heavy duty paint and varnish remover, with the help of a small stainless steel or brass brush. When the paint is all gone, I have 2 options; oxalic acid or phosphoric acid to remove the rust. I think phosphoric is more aggressive, but I don't yet know what it would do to chrome dropouts, so I'll have to experiment. Yes, I too read about the molasses project on Bike Forums, but I've heard a lot more about oxalic acid doing a good job and have used it on a chrome chainset and headset parts. Oxalic is good with chromed parts because it does not leave a black coating like phosphoric. However, phosphoric leaves a good base for painting.
Apparently oxalic acid crystals are sold as wood bleach by hardware stores and building supplies, but no place I tried in my area had heard of it. I ended up getting the stuff from a mail order taxidermy supply house. I don't know where you're located because you didn't sign off as per CR list rules, so I can't suggest where to try.
John Betmanis
Woodstock, Ontario
Canada