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At what point do you replace your sail slugs?

Replacement would be the next step to sail track cleaning and lubing, see threads like:
viewtopic.php?f=9&p=373220#p373220

Tsunami wrote: ↑Fri May 02, 2025 8:28 am Just a "follow up" so we can put this thread to bed.
While the mast was down I used a wire bottle brush to clean out the mast track then sprayed the track with a dry lube. I also gave each slug a shot of the lube as they were fed into the slot. That did the trick, no issues as the halyard pulled the sail completely to the top.
Thanks again guys for all your suggestions.

The question is, how would you know when the slugs are due for replacement? As some slugs might be sewn on, making it a little more complicated than just 30 bucks and an hour of time, it would be helpful to identify old slugs.

Im assuming that slugs are made of lubricant impregnated plastics like delrin / etc. Age, use, and UV will eventual degrade the lubricating qualities of the plastics as they dryrot or become chalky.

In testing out my sail inventory (before I take the new-to-me boat out for the first time), Ive found one of my sails, specifically the one that appears to be original and was left out in the sun when I bought the boat, cannot go up two slugs before they bind. The slugs appear to be stock and are 12mm:






Where as another, possibly newer (still older than dirt) sail slides up and falls down without issue, though it has a different type slug as well. These for sure aren't stock and are 11.5mm:





So to further add to the question and troubleshoot the issue Im having, how might someone identify old slugs vs dirty sail track vs wrong type of slugs

I'm pretty sure that slugs are generally nylon. Mine are more than 15 years old and still working fine.

If they are hanging up start by looking for a problem in the slot. It's not hard to deform it and they seem to be trash magnets. It does not take much to get them to bind. Straighten out any dings and make sure it is clean.

The other thing to look for is a damaged slug. If the slug has come in contact with a deformed track or debris it may have been damaged. Just like the slot, it does not take much to get the slug to hang up. You can usually sand or file the slug back into working shape.

Some folks use lubricants in the slot. I just keep it clean and don't have any issues.

Your pictures had not loaded before I wrote the last post.

I see dirt and damage to your slugs but nothing that can't be fixed.

Thanks Be Free,

• The first several feet of the mast were cleaned with a green scrubby and a microfiber cloth.
• I also cleaned the first two slugs of the sail that wont go up (the first set of pictures).
• Cleaning did not affect any change.

The second sail (the second set of pictures) went up and down without issue without any cleaning, which may show that there are no issues w the sail track.

Do they slide easily at first and then bind or are they tight all of the way?

Be Free wrote: ↑Thu Oct 16, 2025 12:43 pm Do they slide easily at first and then bind or are they tight all of the way?

The original sail (first pics) binds within the first two feet. If the force is not applied perfectly by hand, they bind. There is no chance w the halyard. They will bind and they will not move anymore. Attempt to lower and they bind. Its like they're sand sandpaper against the aluminum. Any friction at all and they bind. (though they feel smooth to the touch)

The second sail (second pics) goes all the way up with little effort and falls down under its own weight without issue.

My only conclusion is that the slugs on the original sail (first pics) are so degraded that instead of having the usual low friction properties of the plastic, they're having the opposite effect.

Most of mine are original. I've had to replace a few that broke off. Mine are not sewn in. I've never seen any like that. However, they have tiny screws that attach them (like your photos).

It would seem it's hard to know what you have that is original or replaced.

If it were me, I'd identify the slugs that slide well and order a set of those. Maybe test the "good" slugs by sliding them all the way up under load.
Then clean the track, inspect it for corrosion, oxidation or pitting, and clear that problem if exists. Then apply a dry slug lube.


This year I FINALLY replaced my main haylyard with a "looped" haylard that allows me to pull the main DOWN as well as UP from the cockpit. Along with the new lazy jacks I wonder why I didn't do this years ago. Keeps me off the deck.

Ditto

Be Free wrote: ↑Thu Oct 16, 2025 9:11 am I'm pretty sure that slugs are generally nylon. Mine are more than 15 years old and still working fine.

If they are hanging up start by looking for a problem in the slot. It's not hard to deform it and they seem to be trash magnets. It does not take much to get them to bind. Straighten out any dings and make sure it is clean.

The other thing to look for is a damaged slug. If the slug has come in contact with a deformed track or debris it may have been damaged. Just like the slot, it does not take much to get the slug to hang up. You can usually sand or file the slug back into working shape.

Some folks use lubricants in the slot. I just keep it clean and don't have any issues.