[Public-List] hole free deck cleats

[Rachel]

On Dec 4, 2011, at 11:17 PM, David Tessier wrote:

> 
> I welcome your interest.I want to drill and tap dead end holes into the underside of the cleat base and screw in suitably long studs with "permanent" thread lock compound.

Ah, okay, interesting!  Thanks.

> The resulting cleat with its protruding studs would be installed on our A30 deck with a suitable (w.r.t thickness and properties)  flat gasket making the seal, excluding the threads as a leak pathway and obviating the need for a sealant..

I have a question then.  If I'm understanding you correctly, the cleats will end up working similarly to if they had studs welded to the bottom.  In other words, there will still be a stud-and-its-hole leading from the bottom of the cleat, through the deck, and into the boat (where you will have the fastener head and a welded-stud cleat would have a nut).  So I'm trying to envision how that would change the leak potential much?  Granted, you would not have the small area around the head of the fastener, so it would change it some; but I wonder if the majority of such leaks don't come from water getting in around the base and then traveling to the fastener and working their way down?  I don't know, but I guess I suspect that because that's where you have dissimilar materials and more chance for different expansion or flex properties.

>  This will make a seal analogous to ones used in the industrial water equipmment field, whence I come.

I'd like to hear more about that.  Do they also have the issue of dissimilar base materials?  Do they use things like channels and O-rings?  Or?  

>  As usual, a backing pllate under the deck (and possibly one on the deck too) would complete the installation.

I like the design where stanchion bases, chainplate top plates, etc. have little molded "hills" they sit on, on deck.  Keeps nuisance water from just sitting there.  I think if I had another boat without them, I would add them (molded, or routed from G-10 or similar).

Some folks have been tapping the holes through the deck for hardware fasteners.  On the one hand, I think it sounds like a good idea:  There is no "gaping" hole where the fastener goes in, and there is the side benefit of easy solo installation (and then you just go below and add the nuts at your leisure).  On the other hand (and to my non-engineer-qualified mind), then I wonder if there is a problem in not being able to torque or "pre-load" the fastener properly?  My guess is that wouldn't matter in a deck hardware application, but I still wonder about it.

I have a co-worker/friend who has begun using rubber gaskets under things such as stanchion bases.  He recently crossed the Atlantic, so likely had some of the leak-inducing twisting and such that comes along with beating, but I have not been in touch with him since he left.

That's where metal boats shine: You can just weld your hardware on!

Rachel
ex-#221



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