Rubber wedges--old tire?

[JohnV]

There's a big old tractor tire washed up on the shore near me, with fat, thick bar treads. I keep thinking I should saw off some of the bar treads and shape them into mast wedges. I researched a little and found that store-bought wedges are a harder grade of rubber than typical tire rubber, but I don't know whether that difference is significant.
For me, making my own gear for the boat is half the fun of owning it, but it still has to work.
Any thoughts on this?
PS I'm still figuring out how to get the tire off the shore and off to a dump but that's a different project.

[Ian McColgin]

A lot depends upon how the mast and partners have been designed but in general wedges should be firm. I've dealt with those poured plastic partners collars which I don't like because they must always allow a nudge of rattle but poor as they are (yeah, I'm prejudiced here) they are better than something that will not support the mast and that, given their coefficient of friction, will be hard to set or to get out.

Rather than wasting your time on a bad job, make a set of nice hardwood wedges fitted to your mast and numbered so you can get them back the same way. I make mine with an inside L or corner for a lip that goes out past the partners' collar. That keeps a wedge from falling through before you get them all in.

G'luck

[JohnV]

Thanks for the reply, Ian. I have hardwood wedges that came with the boat. I had thought that rubber ones might put less stress on the mast at the partners. But I guess I don't have anything scientific to base that on.
John

[Brion Toss]

Hi,
I agree that the tire rubber would be too soft: the main purpose of wedges is to form a couple with the mast step, turning the mast above the partners into a stiffer, cantilevered section. Soft wedges diminish stiffness. One could theoretically damage the mast with wedges, but they would have to be very hard (there is a reason you don't see metal mast wedges) and driven in very firmly. Still, it is a good idea to fill in the entire perimeter, to spread the load, and to have a bit of radius at the tops, to avoid a stress riser there.
Or you could just install Spartite, which I have never known to become loose over time, let alone rattle. Ian, did this happen to you more than once?
Fair leads,
Brion

[Ian McColgin]

Of a group of us who rig and unrig our boats together, three have spartight. Generally if we remember to use Ivory Liquid to lube between the mast and the spartight and the spartight and the partners' hole, it was not too horrible a chore. But because the holes - these are glass boats with aluminum masts - are parallel sided rather than very finely tapered, there's perforce a bit of gap on both sides of the spartight. It's so slight - remember the Ivory - that the owners don't have any complaints. When out with them in certain conditions I can hear and feel the vibration as a tapping translated into the hull but glass boat owners seem to live with a cacophony of metal on metal or plastic rattles that we woodenboat heads are not used to.

I think my prejudice is that I'd not use this method on a wooden mast. And I don't like the strain of getting the mast out in the fall.

And I like tapping wooden wedges in place.

Spartight is not evil. Just not so much for a retro like myself.

G'luck

[Brion Toss]

Hi Ian,
Thanks for the context. Other than Vaseline at first installation, we never apply lubricant here. Of course, we don't take out masts regularly, but when we do, a few seconds of moderate crane strain will pop the Spartite free. I can't recall a difference on wooden, carbon, or aluminum masts, nor yet any tapping, so it would seem that there's either an installation difference that we are overlooking, or the tapping you are hearing is due to some other fiberglass-boat oddity.
Also, I will confess that I don't much like tapping wedges in, and distinctly don't enjoy whanging them out again.
Fair leads,
Brion