Lee, I don't think any chemicals will help. They cannot get inside, and they cannot reduce the bulk of the rust.
I would use heat and force. I would set up to use hydraulic jack(s) to separate the pieces, welding or clamping tabs on the steel for the jacks to push against if useful. Then heat the outside part with several blow torches (I use a oxy/acetyline rosebud) whilst cooling the inside part with dry (or wet) ice or even just water, and when everything is smoking and steaming apply as much force as you can. Whack on the pipe to loosen it as you heat, cool, and jack it but take care not to whack on the part where they are together for fear of locking them. If you can't separate them consider cutting out the stuck part and make a new joint to weld on. Alternately, you might cut two or three slits longitudinally along the outside pipe at the joint to let it spread, then clamp or weld them back up after you separate the pipes. Cut a 1/8" or 1/4" pipe coupling in half and weld them on the joint (drill through after welding) to add grease fittings when you get it apart or make a new one to prevent this from happening again. Norm S/V Bandersnatch Lying Gloucester MA > [Original Message] > From: Lee Haefele <[email protected]> > To: <[email protected]> > Date: 7/6/2010 11:58:47 AM > Subject: [Liveaboard] Off topic mechanical issue > > I have 2 concentric steel pipes, ~6" diameter, held together with set > screws. The 2 pipes are within each other, rusted tight. This is the > adjustable height tube for an aerial lift on a 1 ton truck. It needs to be > separated to mount unit to a van. Have tried PB blaster for 2 weeks, tried > a 12 ton jack and a huge blowtorch. No movement. We are trying Coke A Cola > next. What could shrink the rust material? With more disassembly we could > apply more heat. (Need to remove wires and hoses.) > Lee Haefele _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
