Mast Alignment

[Rob]

I had a small leak which I believed was coming from where the mast electricals pass through the deck. I decided to address the problem. Since I would need to unstep, I thought I might as well replace all the standing rigging. Since I was replacing the standing rigging, I thought I might as well replace all the running rigging. Since I was replacing the running rigging, I thought I might as well get new lifelines and pelican hooks.

You get the picture.

Anyway, the leak was at the base of the mast. It also appeared that the aluminum mast step was corroded - so I had a new one ordered and installed.

Since the rigs has been put back up, I had a weird feeling that the spreaders were not perfectly aligned. I chalked that up to an optical illusion as it's hard to tell what's straight and what isn't from just walking around the boat. Recently, I decided to investiagte more carefully. Looking up at the spar from the small hatch just aft of the mast did indeed confirm that the spreaders were a little out of alignment (maybe 5 to 7 degrees?). I applied a liitle fore and aft pressure to the shrouds, which seemed to help a little.

Anyway, I've raised the issue with the folks who did the work, and it is my best guess that the new mast step wasn't milled exactly like the old mast step - accounting for the misalignment.

Is this a major problem? Should I be thinking about unsteping and re-doing the mast step (perhaps by re-milling the bolt holes)? On the other hand, would the learned folks on this board consider this to be a non-issue? Is some small amount of less-than-perfect alignment common?

All comments welcome!

Thanks

 

[EGregerson]

mast

It seems to me that if the mast step were out of whack, the mast would be tilted. What the surveyor did to mine in checking storm damage was to stand behind the boat and line up the backstay with the mast. If they line up, the mast / step should be ok (front to back (or bow to stern)). If the spreaders are out of whack, i don't see how it would relate to the step. The spreaders bolt to a plate in or thru the mast. If yours are 5 - 7 degrees out front to back , i would say the bolts are not thru the spreader properly. If 5 to 7 degrees up to down, i would suggest checking any spreader boots and see if they're binding and / or the bolts are loose. Hope this helps.

 

[NateHanson]

Are you saying that the mast is rotated 5-7 degrees, so that it's not facing perfectly forward?

I wouldn't worry about a slight discrepancy, but 5-7 degrees sounds like quite a bit. I think I'd complain to the guys that did the work. See if they'll cover the expense.

 

[EGregerson]

spreaders

No I wasn't suggesting the mast was torked; but i guess that's a possiblility. But i would think the shrouds, forestay and back stay (if properly coupled) would hold it straight. Look for a seam or channel running up the mast; it should shoot straight up without any meandering. I attached a drawing of what i imagine the various configurations of the spreaders. Looking from the hatch behind the mast , do you see any of these?

 

[Rob]

Yes - the mast seems to be rotated a little from it's previous position. The mast has, well, an "egg" shaped cross-section, and the step plugs into that cross-section. As I say, I think the bolt holes in the replacement step must have been ever so slightly different from the original step, leading to this suspected mast rotation, which is really only discernable by looking at the orientation of the spreaders.

 

[Rob]

EGregerson: Thanks for the diagram. No, I don't see anything like that (as explained in my previous post).

I have a carpenter's protractor, which I took out and eyeballed to get a better estimate of the misalignment. I was way off with 5 to 7 degrees. It's more like 2 degrees, probably not more than 3 degrees, but could be as little as 1 degree. That doesn't sound like much, but the misalignment is evident. As I say, I could tell something wasn't right just by walking around the boat. If any of you guys looked up through the aft hatch, I'm pretty sure you'd say: "Hey, did you know that your spreaders look a little out of wack?" (or to that effect).

A repair would probably require hauling and unstepping (again) and installing a new mast step. If the new step is milled exactly like the one that's one the boat, I guess the bolt holes would have to be filled with epoxy and new holes re-milled.

It may not be worth it, but this is a bummer. After all the work that's been done (and I've been doing a LOT over the winter beyond mere rigging), it's a bit like two steps forward, one step back.

 

[EGregerson]

bummer

it's a bummer when u go to all the trouble and expense to do it right; only to have some (hopefully) minor thing creep in. You wanted it perfect but it's not quite. That kind of stuff happens to me all the time it seems. But as long as the boat is stucturally sound and sails right, that's the main thing. I can't imagine that the mast thing would affect sailing performance an awful lot. I have a feeling that by the end of next summer you will have pretty much forgotten about it. And no one else will notice that it's even flawed.

 

[Seth]

Making sure

If I hear you right, the mast is twisted in the step slightly. The mast track should run down to the bottom along the aft side of the rig, and from what you are saying, the mast track is no longer aligned with the centerline of the boat, but is off to one side...

Hate to say this, but I would not accept a step that did not allow the mast to sit straight in the boat, and the supplier should cover the cost to correct this..

This is not something you can "tune" back into alignment, and yes, it is a bummer. It is a hassle, but if this is really what has happened, you really should get it corrected.

Let us know what else we can do help,


S

 

[Rob]

Conclusion...

I didn't want this thread to linger without posting a conclusion. Thankfully, I dealt with a very reputable rigging company that knows what they're doing. Though they were busy, they took a look at the spar and agreed that an effort should be made to reposition the mast step.

Today we unstepped. After the usual wrestling match with all the caulking, the step was repositioned. The mast was re-stepped and everything has lined up nicely.

Happy! That is all...