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twhite 10-31-2012 09:57 AM

Bronze sail track on an aluminum mast
 
Hi folks,

Shannon and I just bought an Ingrid 38, and we're looking at putting a track up for a storm trysail. The track I have is bronze, I have all the slides with it also. the slides are bronze also. At first I wasn't going to use it because of the corrosion issue, but then I got to thinking that winch bases are also bronze and they go on with an adequate insulator, and don't seem to cause much problems. So, I was thinking about putting it up with a UHMW spacer behind it. But then I was thinking that I should use aluminum strip as a sacrificial element. Or should I just forget the whole thing, and get some stainless strip?

I should mention that the masts are painted aluminum. Probably with awl grip.

Thanks, and best wishes,

Tom

Brion Toss 10-31-2012 05:26 PM

Options
 
Hi,
An aluminum spacer would be the most fun, as it could expand, fracturing the mast and/or the track and/or tearing fasteners out.
UHMW behind the bronze would isolate nicely, assuming you also Tef-Gelled the fasteners along their entire length. One objection is that the bronze track would almost certainly be your heaviest option.
Stainless T-track is no longer a good option, as thickness and width of the stuff has become extremely variable, ,making for uneven joints and jammed slides.
My favorite option is Schaefer's Batt Slide track. It is light, smooth-running, and, properly positioned, leaves you the option to install Strong Track or other mains'l luff systems, because the slides run inside the track.
Fair leads,
Brion Toss

twhite 11-02-2012 07:34 PM

Thanks Brian,

Good point about the aluminum, the reason I mentioned it is because the mast came with fairing plates of some kind of cast aluminum. They don't seem to have caused damage yet, but the rig has only been up, and the boat has only been in the water a couple of years. Now I remember that About a month ago, I rescued a couple of cheek blocks from a friend of mine's boat. They had been mounted with aluminum spacers, and the aluminum had expanded. It warped the plate on the blocks, and put a good sized (probably permanent)ding in the fiberglass underneath. the aluminum itself had turned into a flaky substance that looked like a good pastry crust. But no, I didn't taste it. So, UHMW it is. Which is fine with me, I can radius it to fit the mast much easier than I could aluminum. And, I will go ahead and replace the aluminum plates.

Thanks for the tip on that Tef-Gel . I'll get some of that and try it. I have been using one of the varieties of Loctite, the blue for screw threads, and either the red or the green for rivets. Of course, if I want to count on pulling the screws out, I just go ahead and Heli-coil them right from the start. That stuff seems to have held up fairly well, but I haven't been able to follow it for all that many years.

Best wishes, Tom

Brion Toss 11-02-2012 08:03 PM

Follow-up
 
Hi again,
Glad to help. I'll add that, while LocTite has some metal-isolating effect, it isn't ideal to begin with, and diminishes over time. A very thin layer of Tef-Gel is effective, and durable. Also, I've found that spar sections are typically much too thin for effective use of Helicoils; try Riv-Nuts.

Brion Toss 11-02-2012 08:04 PM

Follow-up
 
Hi again,
Glad to help. I'll add that, while LocTite has some metal-isolating effect, it isn't ideal to begin with, and diminishes over time. A very thin layer of Tef-Gel is effective, and durable. Also, I've found that spar sections are typically much too thin for effective use of Helicoils; try Riv-Nuts.
Fair leads,
Brion Toss

twhite 11-02-2012 08:28 PM

Hi Brian,

For those that are listening in, a screw has to have a certain amount of thread to hold. I think the figure is about 2 times the diameter of the screw. So, a 1/4 inch bolt should have about a half-inch of threads. So I have not yet screwed anything into a mast. If you do have to, a bunch of small screws are better than a few larger ones. The Riv-nut option is a good one also, but whatever you do don't get the Chinese ones They strip out while you're putting them in.

Thanks again, Tom

marujo.sortudo 11-03-2012 07:48 PM

There are various bits of bronze hardware on Mimi Rose's painted aluminum mast. Nothing as sizable as a bronze track, mind you. Still with an insulating layer of roofing rubber, SS fasteners, and TefGel, there's no problems after 21 years...


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