Joined: May 2008
Posts: 10,106
Likes: 2,758
From: Fredericksburg, Va
Bikes: ? Proteous, '65 Frejus TDF, '73 Bottecchia Giro d'Italia, '83 Colnago Superissimo, '84 Trek 610, '84 Trek 760, '88 Pinarello Veneto, '88 De Rosa Pro, '89 Pinarello Montello, 'Litespeed Catalyst'94 Burley Duet, 97 Specialized RockHopper, 2010 Langster
WD(Water Displacement)-40 will protect against rust. I have a frame that has been stripped of paint for over 6 months that was sprayed with WD-40 and has no surface rust. I would stop the rust by coating it with WD-40, or at least slow it down.
Keep in mind that if it is a CrMo frame, the steel is somewhat resistant to rust anyway, unlike those with much lower or no Cr in the metallurgy.