Need help with mast head removal

[Captndan714]

Im trying to remove the mast head assembly from the mast itself in order to re-wire my tricolor light and vhf antenna. From the looks of it, my mast head sits inside the mast and there is one bolt that goes all the way through the mast, which Im assuming also runs through the mast head assembly fastening it to the mast. Pretty straight forward.... except that Im unable to remove the bolt from the mast. Ive gotten the nut off and the bolt spins freely. I was unable to hammer the bolt out from the nut side, so I cut the head off of the bolt to see if I could pull it out from the nut side. After still being unable to remove the bolt, I noticed that there seems to be some type of collar or nut on the bolt inside the mast, preventing it from coming out. Not sure how this is even possible, but Im looking for some sort of insight on how to get this thing off. What am I missing?

[Blue Crab]

I'm with you: I want to know. A pic would really help, I'd think. Once you get a pic in your pictures file, start a reply and look for the paper clip, top line above.

[zeehag]

so glad my masts are spruce.
i have had a few of those here on my boat--but not mast head bolts--- mine are formosa bolts but sound similar

[Cheechako]

Bolts going through the mast have a tube around them on the inside (compression tube) so that when you tighten the nut the bolt doesnt deform the mast. My guess is that the aluminum tube is corroded permanently onto the stainless bolt. I've not seen an unwelded masthead fixed on that way though. How far down is the bolt from the end of the mast?

[Captndan714]

I will try to get some pics up soon. It sounds like it may be a compression tube of some sort that has fused itself to the bolt. How do I get it out?? The bolt sits I would say 2-3" from the top of the mast. I went by West Marine today and I also called Island Packet directly and got "I dont know what to tell you" from both.

[Cheechako]

Tough one. Some say coca cola, vinegar or acid will eat the corrosion, but I doubt it can get very far down inside. If you could support the bolt head side of the mast with a deep socket, and drive hard on the bolt threaded end, could you maybe break it free?

[sailvayu]

The thing is you say the bolt spins freely. Can you turn it by hand without much resistance? Does it move back and forth in the mast at all? I am leaning to thinking there is a collar or nut inside the mast if you can turn it.

[knot smart]

patience, spray it with PB Blaster penetrating oil..(kind of like WD 40, but works better) spray it, let it sit , spray it , let it sit, let the oil soak in..try it again the next day

[Captndan714]

Here are a few quick photos I snapped this morning. The first two are of the side where I cut the head off of the bolt, so it is now flush with the side of the mast. The third is of the opposite side where I removed the nut from the bolt.

[sailvayu]

Ok it is an older style mast and that sucker is right in the middle so it does not look like there would be any lock rings or other tricky crap in there. I am guessing it is seized to a aluminum sheave inside. That would give you some movement but not let it slide through. You could test that theory by seeing if you can turn the sheave inside without turning the bolt. At this point, and this is just me, I would go at it with a drift and hammer and see if I could get it to move. If that does not work or you are afraid of breaking something inside I would drill it out a bit just to make it shorter. You only have to drill it down so it clears the mast wall and that is not a lot. Once you get it clear of the mast you should be able to just slide the head off the mast. Text book case! keep us posted.

[Cheechako]

Yeah, there may be no compression tube, it may be the sheave that is frozen to the bolt...? When you turn the bolt freely, does the sheave turn? You may have to carefully center punch on bolt center and drill away enough bolt to get rid of material to pull the whole thing out.

[Captndan714]

Pardon my ignorance, but what would be the difference between a compression tube and a sheave? They sound similar to me. Anyway, I did finally get the mast head off last night by doing just that. I cut off the excess bolt on the threaded side and drilled both sides down until they cleared the mast wall, and then I was able to hammer the mast head off. There is some sort of tube (compression or sheave) that had fused to the bolt preventing it from being pulled out. Ill put up some pics this afternoon.

[Cheechako]

Pardon my ignorance, but what would be the difference between a compression tube and a sheave?

The sheave is what your halyard goes around... the "Pulley". Love to see the pics.
Compression tubes can be inside the mast supporting the mast wall, or can be flush with the outside of the mast (hole in mast same size as the OD of the compression tube) Did that bolt support the sheave? The tangs for the upper rig wires were not on that bolt right? Strange way to mount a masthead.

[hellosailor]

You might try some Kroil (mail order only) or PBlaster (sold in chain stores) to break the corrosion. They are not the same as WD40, they attack corrosion chemically with much better results.

If that doesn't work, sometimes icing the parts own and thermal cycling them with either a CO2 bottle or torch helps. The torch is more common but the CO2 can't detemper the metal or set your boat on fire.

If you center punch the bolt very carefully, then use a hardened drill bit (i.e. carbide) to drill it down, that's also an option. Drill in with a smaller bit until you are past the mast thickness, then use larger bits to open up the hole in the bolt until you've practically eaten the bolt away. From both sides.

When you replace the new bolt and compression tube, stuff the tube full of TefGel or another anit-seize paste before you bolt it up.

[Captndan714]

Here are some pics of the mast head removed. Next Ill be taking a sawz all to the compression tube to remove it in pieces. The pin does not hold the pulleys in place, it simply runs through the mast head to hold in in place inside the mast. Kind of a ridiculous design if you ever plan to get the mast head off in the future...