Mast Step Replacement

October 2001: How do you say "Arrggghhh....". When I bought this boat, I made sure to check out the mast step. It looked fine! The surveyor thought so too. That's because it had been cracked so long that the crack was full of packed-in dirt. So I went to clean it up prior to restepping the mast,
and here's what I saw...
I sat there and stared at it for about an hour, trying to make it go away.
I took a walk, but when I came back it was still there. Visualizing my objective didn't work. Darn.

Clearly, when they built this boat they didn't build proper support under the brittle cast aluminum step. They tried, but they missed by about 1/8" and didn't bother to make it right. Hmmph.

At first I thought it had been cracked when they torqued down on the keel bolt, and then the builder just kept moving the production forward. However, as I kept on cleaning I could see that the nut was about 1/8" above the plate. In fact, it was loose and I took it off with my bare hands.

It's a good thing this boat has 8 keel bolts! Since the nut had obviously been loose for years and years, I felt safe in taking it off and undoing the lag bolts holding the plate down.

Here's a little side note: Glen welded my new step out of aluminum stock. I dropped by the shop while he was welding it, watched for a while, and he was clearly enjoying himself.
I felt really good about that, because when someone really enjoys what they're doing they tend to do a good job.
And he did. However, at one point he turned to me and said "This is going to be the most expensive mast step you've ever seen..." Which made me consider that maybe I should have shopped for an original casting...
After all, with the support I built it won't be stressed again!

Then I scrubbed the entire area really well with Acetone and a bronze brush, which removed the rest of the paint. It was easier than grinding (and a heck of a lot less messy) and got down into the nooks and crannies.

I really didn't need to put down that much cloth, since there was nothing wrong with the area structurally, but now it's just a little stronger, and will look much nicer. Of course, no one will ever see it. I just couldn't bear the thought of always knowing how ugly that looked under there.

The next weekend, Glen hadn't finished welding a new step, so I did some other stuff. I set two more layers of cloth over the area to build it higher, then filled the boat up with water just for fun.

Well, not really just for fun -- I'm going to paint the bilges as long as I'm this far into it and needed to clean it really well. It was fun to watch my new bilge pumps kick in as the hose went full blast. It also gave me a chance to study how water flowed through and aound the liner, so that if I see water coming in one place I'll know what areas of the hull might be letting water in... heaven forbid I ever need to know that! I also am going to add a few limber holes where needed.

I really didn't want to get into this. However, here we are. After pulling the cabin sole out of the boat (I guess this is a good time to refinish it) I pulled the plate off.

Structurally, we're okay. The cracks you see are just cheap putty used to fill in low spots so water wouldn't collect under the mast. That putty is brittle, so when the step cracked it stressed the area and created a bunch of hairline cracks through the putty. Then the cracks filled with dirty water, making them look huge. As long as I'm here, I might as well make it right...

11/18/2001 -

There! That's a little better.

12/10/2001 -

Below, Dave drills the final holes in the new step, so I can bolt it to the stringers.

I set this aluminum bar across the stringers, and you can see the gap below. There are two woodblocks there -- totally encased in putty -- which should be even with the bar. This is why the mast step cracked...

Just seeing that keel bolt without a nut
gives me the willies.

I took a grinder to the area (thus creating next weekend's project: Vacuum The Entire Boat.) I didn't grind down much, as there's a structural fiberglass stringer right across the keel bolt, and the putty is just putty (and the dust from the grinder
was impossible to catch with my wet-vac.)
I just wanted to expose enough substrate to ensure a good bond.

Now it's bolted in. The next time I'm at the boat, I'll pull it off, and remove the wax paper. Then I'll fill the lag bolt holes with polysulfide LifeCaulk, and lay a serious bead of caulk between the stringers and the step, so that water running out the back won't wick underneath but will drip down to the bilge. Then it'll be ready to torque the keel bolt down to 350 foot pounds. (I'm going to have somebody from the yard come over and do that just before we step the mast.)

I injected epoxy into all the little cracks. They were minor -- one syringe filled them all. Then I made the thickest epoxy putty I could, and with a wide putty knife smoothed out the area, so there wouldn't be any air pockets when I laid fiberglass cloth.

Finally, I criss-crossed 2 layers of 24 ounce heavy fiberglass back and forth, over the stringers and then over the mast step area, then over the stringers again. Just to make it pretty I covered the tops of the stringers with 9 oz cloth, and set a couple of 9 oz strips laterally in the middle.

Note: If you ever end up doing this, mask off the bolt with tape. It might save you from spending a Sunday afternoon with a bright light, magnifying glass and Handy Dremel Tool with wire brush attachment picking epoxy out of the threads!

Here's the new step. It's welded from half inch aluminum, then black anodized. First I trial fit it, lined it up and drilled new holes in the stringers.

Glen drilled drain holes in the back support, so that water that runs down the mast will drain towards the stern and directly into the bilge.

When I built up the area under the step, I made sure it wasn't higher than the stringers. Naturally, it's a little bit lower, but I want solid structure supporting the entire step. Plus, I don't want all the stress on the stringers -- it should push down directly on the keel structure. So I mixed up a super thick paste of West System epoxy and microfibers, and plopped it down over the underlying structure. Then I covered it with wax paper, because I really don't want to glue the mast step into place. It might need to come out some day, like if I need to drop the keel for a repair.

Update March 2002 -
After dropping the cabin sole back in... I bought a 3 inch thick block of ASH at a nearby hardwood store, and made blocks to hold the mast in place. I took some 1/2 inch UHMW Polyethelene and made identical blocks that sit under the Ash blocks, so that water running down the mast won't hit the Ash blocks and wick up. You can see some of the plastic on either end -- it's blue -- as I made some shims out of it as well.
The other shims were from existing Ash blocks that weren't damaged by water, and they fit, and I'm in a hurry to get this boat sailing...