Aluminum vs. Stainless cleats

[bwindrope]

I've been doing some research on whether my current aluminum deck cleats are sufficiently strong or whether I should swap them out for stainless. I've read a few references in Pardey and Leonard but nothing definitive. I've scanned online but it's a needle in a haystack.

My current aluminum cleats are original to Aeolus and are in great shape. They are adequately sized with good backing plates and I've removed and rebedded them all over the past year. As I walk the docks in Friday Harbor I see many, if not most, sailboats have aluminum cleats. However, I know many standard products and installs are crap, so I don't trust that too much.

Although used essentially for dock lines right now, they are also used for my 3 strand anchor snubber line at the bow and for towing dinghies in calm waters and such.

I'm interested in hearing from someone who is knowledgeable about cleat failure or metallurgy of these two options. Has anyone had any experiences with the cleat itself breaking? I know people pull them out of decks due to poor installation, but that's not my concern.

I appreciate any wisdom on this subject.

Also just finished the removal and complete servicing and re-installation of my Edson steering system. Oh joy. Know it inside and out now, and that she is solid.

[sailingdog]

While metallurgy isn't my area of expertise, I do know that aluminum is far more prone to fatigue related failure than stainless steel... so that would be one serious point in favor of stainless steel. Aluminum is also much weaker, which is a second point. Third, aluminum is more susceptible to corrosion.

[bwindrope]

Thanks sailingdog, that all makes sense and is good info. I'm not too surprised there have been few responses to this question because it is a bit esoteric. Not many people have experience with failing cleats or conditions that would stress them enough to break.

Part of my interest in this is just this question. On boats, as elsewhere, there is always a stronger way to do something, but that is not always the best way. It is an easy trap to seek strength at all costs, given the rational fear of calamity, and yet we don't use 1 inch wire on our rigging because you can't tension it properly. We don't build hulls that are 2 inch thick solid glass in all places. We make trade offs with weight and expense that will stand up to what is asked of them.

This is the heart of my question about aluminum cleats. I've never seen or heard of one failing, though there is no doubt that stainless has superior qualities. Is it situation where they are used extensively on production boats because they are plenty strong enough and lighter, or for some other reason. Cost-wise they are about the same as stainless, so that doesn't seem to be the driver here.

Remain curious on this point, and may just have to live with it!!

[pdqaltair]

Originally Posted by bwindrope

Thanks sailingdog, that all makes sense and is good info. I'm not too surprised there have been few responses to this question because it is a bit esoteric. Not many people have experience with failing cleats or conditions that would stress them enough to break.

Part of my interest in this is just this question. On boats, as elsewhere, there is always a stronger way to do something, but that is not always the best way. It is an easy trap to seek strength at all costs, given the rational fear of calamity, and yet we don't use 1 inch wire on our rigging because you can't tension it properly. We don't build hulls that are 2 inch thick solid glass in all places. We make trade offs with weight and expense that will stand up to what is asked of them.

This is the heart of my question about aluminum cleats. I've never seen or heard of one failing, though there is no doubt that stainless has superior qualities. Is it situation where they are used extensively on production boats because they are plenty strong enough and lighter, or for some other reason. Cost-wise they are about the same as stainless, so that doesn't seem to be the driver here.

Remain curious on this point, and may just have to live with it!!

(with an opener like that someone will take this of-topic)

What I see is cleats that are too small for the line. We all see huge dock lines instead of good chafing gear, the rope stuffed around the cleat the best it can be stuffed. The same for over-sized snubbers and bridles. All of the load, really, should be down low on the first 2 passes, and so for the cleat to fail, either the mounting was poor or it was so undersized the load was on the horns. There really should be no loads on the horns, and so breakage is very rare.

The same thing happens when 2 lines are placed on the same cleat.

I might go bigger rather than SS. However, I don't know what you have.

[sailingdog]

BTW, Cleats should be sized so they are about 16x the diameter of the normal docklines used on them in length. If you use 1/2" docklines, the cleats should be 8" at a minimum.

[jrd22]

bwind- like you I have not seen aluminum cleats fail in normal use. Most all are an alloy, and therefore much stronger than "aluminum". Unless the cleats on your boat are way undersized, or severely corroded, I would seriously doubt that changing to ss would accomplish much more than emptying your wallet (just my 2 cents).
If you get by Blakely stop in and say hi.

[brak]

My boat has aluminium cleats that are original to her - i.e. 37 years old. I had them all rebedded and reinstalled, and as part of that process - inspected. Of the 6 that are there, one failed - a side of fastener hole had a microscopic crack in it and I was able to break it off. Essentially if the integrity of metal is breached, it will admit water, go through a freeze-thaw cycle and fail completely. If not - it seems to do fine.

So, personally, I inspected the cleats then and keep re-inspecting them occasionally so that if I find another crack - it's time to replace.

Incidentally a new cleat I used as a replacement is aluminum too.

One thing to consider is how the cleats are installed. For example, mine have a hole pattern that does not match anything currently sold. So, if I were to replace them - I'd have to balance potential improvements of new cleats with the weakening of the deck (due to more holes drilled in same general area). I went for less holes

[bubb2]

Ditto for the above. I seen far more cleats ripped out than broken. Of the broken cleats I have seen 90% of those were the galvanized dock cleats and not boat cleats.

[NCC320]

Several years ago, the boat that was across the pier from me had an aluminum bow cleat fail in a hurricane (storm was down to 70-80 mph when it hit us.). The boat dropped down onto a piling and was out of commission almost a year having the hull and deck repaired. I should note too that the cleat seemed a bit small to me. But on the basis of this one incident, I wouldn't take too much concern. I've seen lots of other boats with what look like large cast aluminum alloy cleats that held up well. If I had them and they were ample size, I wouldn't run out and exchange them for stainless without a good reason...like evidence of cracks. But I would prefer stainless steel if I had my choice up front.

[tager]

What's wrong with Nylon?