Now that's getting seriouskadet wrote:If all else fails soak it in a solution of Sodium Hydroxide (caustic soda/lye) it will dissolve the aluminium and leave the stainless steel intact. Caution the reaction produces hydrogen and some nasty caustic steam do it outside in a well ventilated place away from any source of ignition.
Unless of course you enjoy the effort, but I am sure there are other projects that also need your attention, after all, we are posting about a boat 
kmclemore wrote:Applying heat will likely not work as the aluminum will not only heat up faster than the stainless steel, but it will also expand at a faster rate, such that with the application of heat it will simply make the joint more tight, not less.
Cold might work a bit, but only if it is extreme cold and applied rapidly - i.e. a cold spray applied inside the aluminum. I fear this will be difficult to accomplish effectively, though.
So... my suggestion is to use a carbide Dremel bit, working slowly and carefully but with the bit at a high speed, cut a slot inside the aluminum just to where it contacts the stainless. Once you've got the slot cut in the full depth of the aluminum, use a sharp cold chisel to tap the seam in between the aluminum and the stainless, starting at the slot and working your way around, essentially crushing the aluminum a wee bit such that it can then be pulled out.
That's what I'd do, but I'd carefully cut a few slits in the aluminium with a hacksaw blade and lift them to release the hoop (or is it arch) effect. The SS may only need a polishing after that. But nothing to lose by getting the aluminium out, since the worst case scenario is to replace it all anyway.RobertB wrote:Me, I would probably be real stubborn, get everything apart, see how bad the parts are and buy everything new anyhow.
Your doing good to order a new one 
Just looking at your pics, you might be good to order a set of shrouds as well. Looks like theres a fair amount of rust in that cable in the background. If theres rust mid cable you should give a real close inspection on your fittings (it can be twice as bad inside them). I'd hate to see you have to order a mast to top it offtbowers wrote:
. Check you forestay while you're at it just to be safe. If they look like that I'd be replacing them. $55 for ea upper and lower shrouds and I think $40 for the forestay (from what I remember) cheap insurance.
Your post contains more patience than I possessIxneigh wrote:I'd wrap that SS piece in a towel, clamp it tight in a vice and chip out the aluminum with a small cold chisle. Or even an old wood chisle. A dull one. Thin crppy aluminum actually chisles pretty easy. Do not use a sharp one or you may score the SS. Insert the chisle between the SS and aluminum and carefully separate. Don't just pound the crp out of it. But work patiently with eye to the SS.
The Dremel idea is also good of course perhaps better however reaching deep into something may be difficult and require (way) more patience then ixneigh possesses
Good luck.
Ix
I would have been on the phone with BWY long ago. Acid's, chissels, cold packs, Dremel's, Coca Cola, & prayers to the almighty along with a few swear words I'll bet 
. He (tbowers) Bit The Bullet, Tossed In The Towel, Said His Last Hoorah. Enough was enough, he bought new parts. Now he can address other boating problems He might even be able to sail instead of being on the Mac site 
Here in Philly, it's still not quite the time, so I read these posts instead Do you sail in fresh, salt, or both?tbowers wrote:> you might be good to order a set of shrouds as well
I was checking those out. No broken strands and they look good but yes with a light rust coating in places. If I get new ones how long do you guys experience they get like this? Does everyone usually replace if they get rust? I'd think that means all of you are replacing the shrouds every 2 or 3 years or so?
