Getting broken aluminum tube out of stainless sleeve

[J--]

Put it in the freezer over night. Aluminum contracts more in cold than steel.

[tbowers]

Remember I can't get the spreader ends off the shrouds either because those end cap screws are also frozen with corrosion so the only way to put the spreaders in a freezer is to de-shroud the whole boat and put that all in a wad, wires and all, in the freezer lol. Uhhh... unless I throw away all that food that ain't gonna fit.

[Highlander]

pour hot water & baking soda over the joints & scrub with an old tooth brush or similar may have to do ot a few times it will eat & dissolve the corrosion then use a small screw driver & hammer & dig & pry out the brkn ends , the shroud ends can be placed into a jug of hot boiling water & baking soda & let then steep until clean & free up the screws working them back & forth

J

[NiceAft]

I'm thinking out loud here (Metaphorically speaking), but what if you drilled out the screw, took a long metal punch which is thin enough to fit in the hole, and with a hammer, gave a good wack to put a bend into the aluminum? This may crack the corrosion enough at the hole area so as to allow any corrosion eating substance an entry point. After a while, another wack, and repeat of the process.

I don't know if WD-40 is designed to loosen this sort of problem, but if it is, the long, skinny straw that attaches to the spray can should fit into the hole and supply pressure for penetration at the point needed. Again, only a thought. This is something I have never encountered.

Ray

[Russ]

Do you have some photos of this? I've never seen aluminum corrode that badly. Makes me wonder what else is.

The freezer idea is clever. I've seen that work like magic on things. Maybe use a can of compressed air upside down to freeze the metal.

[Tomfoolery]

Do you have some photos of this? I've never seen aluminum corrode that badly. Makes me wonder what else is.

I've been wondering about this myself. Those spreaders are hardly a tight fit. Maybe someone rolled their own, and hammered them in. Tube is normally spec'd by OD and wall thickness, but there is non-standard tube out there where the OD is all over the place. Like some of the tube in the BORGs.

[grady]

Dry Ice? you can take that to the boat.

[Russ]

Do you have some photos of this? I've never seen aluminum corrode that badly. Makes me wonder what else is.

I've been wondering about this myself. Those spreaders are hardly a tight fit. Maybe someone rolled their own, and hammered them in. Tube is normally spec'd by OD and wall thickness, but there is non-standard tube out there where the OD is all over the place. Like some of the tube in the BORGs.

Hmm.. good point. Makes sense that they may not be correct size.
I take mine out when on the trailer. Easier that way. They are far from tight.

[Tomfoolery]

Do you have some photos of this? I've never seen aluminum corrode that badly. Makes me wonder what else is.

I've been wondering about this myself. Those spreaders are hardly a tight fit. Maybe someone rolled their own, and hammered them in. Tube is normally spec'd by OD and wall thickness, but there is non-standard tube out there where the OD is all over the place. Like some of the tube in the BORGs.

Hmm.. good point. Makes sense that they may not be correct size.
I take mine out when on the trailer. Easier that way. They are far from tight.

Same here. A rather sloppy fit at that. That's why I found it odd that they're stuck, corrosion or not. A little slop is a good thing, as when the shrouds are relaxed, the spreaders pull up (toward the top of the mast) in their sockets, but are more or less loose when tensioned, as the upper half of the shrouds stretch (of course). Tight fitting spreaders will have to flex when the shrouds are detensioned, at least more than if there's a little play in the socket.

Some pics sure would be nice . . .

[RobertB]

I have been following this thread - most ideas are valid but there seems to be several issues that should be addressed in order:

Broken spreaders will require replacement - unless you are planning on splicing in new sections. Replacement will require serviceable end caps. Recommend you purchase new spreaders and end caps if you are unable to work the end caps loose. End caps can be cut free. Or, drill out the screw threads and replace the screws.

Corrosion is there, cause is not so important. If soaking with lubricants, acids, etc has not worked, a physical method is required. One that often works for me is to quickly heat only the steel part (only) and have a method to get a solid grip on the aluminium inner sleeve to pull it out. Mask the mast and use a hot torch such as a MAPP gas torch. Get the steel as hot as you dare (red). I expect this will work. If not, carefully cutting and/or grinding the inside sleeve in order to pull it away from the outer sleeve is next. This has a higher risk of damage to the spreader mount.

Worst case, replace the spreader mount also. Just make sure you do not damage the mast and everything is easily replaced.

[Russ]

Corrosion is there, cause is not so important.

For the immediate problem, the reason is not important. Getting it out of the fitting is the issue at hand.
However, I'm not so comfortable is dismissing the cause. It's not normal. Perhaps some galvanic action or weird electrical wiring problem.


--Russ

[mastreb]

This is the sort of thing I would take one look at and just order replacement parts for from BWY (while they're still available).

Matt

[tbowers]

I'll post a pic of the corroded and stuck tube tomorrow.

[kmclemore]

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.

[kadet]

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.