Mast Step Spacers

[Brian Duff]

We occasionaly come across the need to shorten an aluminium mast because of physical damage or corrosion at the bottom (probably from all those darn rivit mandrels and old drilled out then punched-through rivits that end up down there ! )

I have either build a new step which is built in such a way to raise the mast up a couple of inches ( or however much is needed) to keep everthing the same height, or I have also other times added a spacer of Alum plate under the old step if only a little bit needs to be built up.

I was wondering what other materials have been used for spacers, and how they worked. I am thinking plastics or composites? Also, how much do you consider too high to stack spacers, versus building a new step ?
I have never stacked Aluminium spacers more than 1" tall, opting rather to build a new step which makes up the needed distance.

[Ian McColgin]

Originally Posted by Brian Duff

We occasionaly come across the need to shorten an aluminium mast because of physical damage or corrosion at the bottom (probably from all those darn rivit mandrels and old drilled out then punched-through rivits that end up down there ! )

I have either build a new step which is built in such a way to raise the mast up a couple of inches ( or however much is needed) to keep everthing the same height, or I have also other times added a spacer of Alum plate under the old step if only a little bit needs to be built up.

I was wondering what other materials have been used for spacers, and how they worked. I am thinking plastics or composites? Also, how much do you consider too high to stack spacers, versus building a new step ?
I have never stacked Aluminium spacers more than 1" tall, opting rather to build a new step which makes up the needed distance.

Ahoy there,

One local Bristol 40 sloop lost a couple inches to corrosion so we built up a new under the mast step pad - I'd been promoting wood but another friend made it - of Corien. There were many jokes about the risk of "molecular creep" but thus far (third season) it appears just fine.

I still most like a well sealed stout wood - pine, locust, oak, whatever - for workability but most anything that is crush proof will work.

G'luck

Ian

[osteoderm]

i've used West 404 in similar high-compression applications to great success. However, here in our yard we've ended up going ahead and replacing the whole step; once corrosion at the heel of the mast has gone far enough to warrant cutting a couple inches off, the step itself is usually getting pretty shot as well. Yes, mast steps can be a real bear to re & re, but stacking spacers and such atop a questionable step does little for my peace of mind. Otherwise, i really like the Corian idea!

[Brion Toss]

Hi there,
Corian! Well, I don't know the properties of it, but all you need is something that will resist compression, and not readily absorb water. Plus, with Corian, you can get it in colors to match the upholstery.
We've used UHMW in the past. Also custom pouring of the stuff (I forget the name) that you can make engine mount beds out of. But often we'll just build a new step, when, as noted above, corrosion is a problem there, too.
As for how high, I think this is a significant issue; coming up from where the step is fastened means building a moment arm into the step, so the bolts and mast base could see loads they were never designed for, especially if the rig is tuned slack, and the top of the mast gets a bit to leeward. So when we build tall new steps, we make them on the absurdly stout side.
Fair leads,
Brion Toss