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Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Mast Step

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frich
Captain

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USA
418 Posts

Initially Posted - 12/05/2003 : 16:28:56

Going to start my first winter project, mast step halyard plate. When I remove the original mast step will I be in for any suprises? Is this held in with a bedding compound, and if so what is the best method to remove it?

Should I bed the new halyard plate?

Thanks
Frank Rich
84 C25 SK

Edited by - on

dgabel
1st Mate

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USA
75 Posts

Response Posted - 12/05/2003 : 17:39:55

I did this last Spring.

I found the step just lifted up, but I bedded it when I reassembled everything.

I expected, and found, that the holes on the plate I got from CD did not match the holes in the mast step. So I went to a local welding shop and had them match the holes in the plate to the holes in the step, so that they would all match to the holes in the deck.

They almost did, but not quite. So I drilled out the holes in the cabin top oversized and filled them with epoxy. After it hardened, I drilled through the mast step/plate combo into the cabin top, and then reinstalled the lag screws that were holding the whole thing to the cabin top. I bedded the thing so that water wouldn't get into the boat through the cabin top.

That's all there was to it. Just took some time and a little care.

Dave Gabel
Walkure
'79 tall rig, fin keel
Sail # 1484

Edited by - on

Leon Sisson
Master Marine Consultant

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USA
1893 Posts

Response Posted - 12/05/2003 : 18:13:16

Frank Rich,

I upgraded the mast hinge (or tabernacle) on my 1979 C-25 a few years ago. It went pretty much as Dave Gabel described. I have my own drillpress, and so got the hole pattern right on the first try.

After drilling the original holes 1/2" oversize down to, but not through, the deck liner, I refilled them with glass reinforced epoxy. After that cured, I redrilled them to the original 1/4" diameter all the way through into the cabin. (I had to cut two notches in the top of the compression post for nut and wrench clearance.) I then thru-bolted the new parts, bedding both with polysulfide sealant.

It's important not to let rainwater get into the deck here. (Well, anywhere really.) A deck stepped mast places an enormous compression load on the deck when heeled. I've seen several boats that were built with plywood core under the maststep that have developed a depression in the deck there as the water soaked core rotted into mush. Once the wood looses its strength, and the fiberglass starts to crack, the work to repair this problem right usually makes a real mess of the deck in that area.

Good luck!

-- Leon Sisson

Edited by - on

Bill Holcomb
Admiral

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USA
769 Posts

Response Posted - 12/06/2003 : 08:49:06

Hi Frank,

Do as Leon suggests. Drill through the cabin top and use SS bolts, nuts 'n washers instead of the lag bolts. This won't matter much when sailing, but makes a huge difference when you are raising and/or lowering the mast. What you don't want to happen is have the step pull out of the cabin top when raising or lowering the mast.

Bill Holcomb - C25 Snickerdoodle #4839

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frich
Captain

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USA
418 Posts

Response Posted - 12/06/2003 : 18:12:13

thanks guys
I may wait on this one till the weather warms up a bit. Epoxy and cold dont mix

Frank R

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frich
Captain

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USA
418 Posts

Response Posted - 12/06/2003 : 18:33:19

thanks guys
I may wait on this one till the weather warms up a bit. Epoxy and cold dont mix

Frank R

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Randall
Navigator

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123 Posts

Response Posted - 12/08/2003 : 21:47:58

The cabin top under the mast step is rotted out on my boat. The PO squirted various kinds of goop around the bolts, and torqued them down until the cabin top and liner meet, but he couldn't stem the leaks. What is the best way to rebuild the area?

I was figuring on using a roto-zip to cut out the cabintop area under the mast step and either filling it full of fiberglass or bedding a piece of plywood into place. What's the right way to go?

Randall

Edited by - on

Buzz Maring
Master Marine Consultant

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USA
1769 Posts

Response Posted - 12/08/2003 : 22:10:40

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Randall
 The cabin top under the mast step is rotted out on my boat. The PO squirted various kinds of goop around the bolts, and torqued them down until the cabin top and liner meet, but he couldn't stem the leaks. What is the best way to rebuild the area?

I was figuring on using a roto-zip to cut out the cabintop area under the mast step and either filling it full of fiberglass or bedding a piece of plywood into place. What's the right way to go?

Randall
<hr height="1" noshade id="quote"></blockquote id="quote">

Hi Randall,

'Sorry to hear about your problem. I had a small soft spot underneath the mast tabernacle that I repaired with "Git Rot," and it worked great. I hate to say it, but I think your cabin top might be too damaged to repair with that stuff ... it is designed to repair smaller areas where there has been some delamination in the core of the deck.

I would suggest you start a completely new thread in the "General Forum" ... you might not get the responses you're hoping for in this thread.

'Just a thought ... good luck!

Edited by - on

Leon Sisson
Master Marine Consultant

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USA
1893 Posts

Response Posted - 12/09/2003 : 18:18:48

Randall

Re: "The cabin top under the mast step is rotted out ... What is the best way to rebuild the area? I was figuring on using a roto-zip to cut out the cabintop area under the mast step and either filling it full of fiberglass or bedding a piece of plywood into place. What's the right way to go?"

I had to make this same repair on a previous boat. I started by tracing the footprint of the mast base (a.k.a. tabernacle) onto the deck. (If you have, or plan to install, a base base plate for halyard turning blocks, you could go as large as that footprint if needed.) After removing the tabernacle, I cut through the upper skin of the deck on the footprint line. (This is where that RotoZip gets to justify itself to the household accountant.) I pried up the rectangle of fiberglass, setting it aside for possible reuse. Next, I dug out all the plywood core directly under the tabernacle all the way down to the fiberglass deck liner. At this point, I was able to reach sideways between the two fiberglass skins, and dig out the small remaining pockets of rot in the core. After drying the wet but undamaged core, I then primed the pockets with epoxy resin, and packed them with reinforced epoxy mush. I also cut a piece of plywood the correct size to replace the rectangular portion of the core that was removed. I presaturated this patch (there's a formal woodworking term for it, but it escapes be) with epoxy, and bedded it into the hole with reinforced epoxy mush. Try to get this piece to recess as much as the original core. I then reinstalled the rectanular piece of original fiberglass deck using more thickened epoxy, a layer of wax paper, and smooth heavy weights.

Keeping the surface size of the patch underneath the mast base hardware cuts way down on the cosmetic impact of the repair. Ideally, one would taper the patch into the surrounding fiberglass at a 10:1 or 12:1 scarf angle for maximum strength and stress distribution. However, that requires a lot more cosmetic finish work to make it look good.

Another way to restore or improve the strength of this repair, as well as hide the cosmetic aftermath

, is to fabricate and install thick aluminum or stainless steel rectangular plates above and below deck, centered tastefully on the mast hardware like little place mats. I radiused all the corners and gave the aluminum a weather proof chemical treatment that turned it a metalic yellow-gold color (similar to anodizing). The finished repair looked like it was supposed to be that way all along. The 1/2" total added thickness of the metal didn't change the geometry of anything enough to require more than minor standing rigging tuning to compensate.

In a C-25, you'd likely need to trim the compression post and maybe notch the bulkhead to compensate for the thickness of the lower reinforcing plate.

-- Leon Sisson

Edited by - on

Dan86
Navigator

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130 Posts

Response Posted - 12/11/2003 : 19:24:37

The deck under my mast step is very solid, I think. I am installing the new mast step this weekend and am overdrilling the holes for epoxy and redrilling at the correct size. Since I do not have any areas of weakness (i think) would drilling several large diameter holes under the mast plate, but not through the liner and filling with epoxy, be a good idea? I guess my thought is to head off any compression issues with several "pillars" of epoxy.

Dan, 86

Edited by - Dan86 on 12/11/2003 19:25:47

Leon Sisson
Master Marine Consultant

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USA
1893 Posts

Response Posted - 12/11/2003 : 20:27:04

<blockquote id="quote">quote:<hr height="1" noshade id="quote"> would drilling several large diameter holes under the mast plate, but not through the liner and filling with epoxy, be a good idea? I guess my thought is to head off any compression issues with several "pillars" of epoxy.<hr height="1" noshade id="quote"></blockquote id="quote">I think you get that feature for free if you use the poured in place epoxy and fiberglass bushing method Dave Gabel and I described above (on 12/05/2003)

The compression load of the mast extrusion isn't on the middle of the hinge. The load is out at the edges, right were the bolts are anyway. As long as you don't have weak core there now, and keep water out of the core in the future, I don't think the stock construction is prone to premature failure.

-- Leon Sisson

Edited by - on

Dan86
Navigator

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130 Posts

Response Posted - 12/11/2003 : 21:05:56

Leon, I thank you once again for your wisdom. I have proceeded several times with your advice and have done well. Thanks again. Dan

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