1973 SF Mast Step Reinforce

Rafael Garcia

New Member
I recently bought a 1973 Sunfish, I have taken it out 3 times and I love it. Although it is in very good shape it is leaking water inside the hull through the Mast Step and the Daggerboard trunk. I have read about Mast Step Failure and I would like to reinforce it. I already cut an inspection port close to the mast step. There is NO plywood donut at the bottom of my step.

My question is , how do I go about reinforcing it?

I already bought Fiber glass cloth and West Epoxy and 206 hardener and my plan was to add a few layers of cloth and epoxy at the bottom of the step and also glace over the step to eliminate the leaks.

Any suggestions on how to re-enforce the step would be greatly appreciate it.

Also any tips on how to eliminate leaks from dagger board trunk are welcomed too.

Thanks.
 

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Your plan sounds good, add another layer of fiberglass to what is there. I'd get a structural filler like 406 colloidal silica to thicken the epoxy that is added to the bottom and top of the mast step, it will fill in voids and help the fiberglass cloth stick. You can also buy epoxy already thickened that dispenses from a caulk gun cartridge, THIXO from Jamestown Distributors or Pettit Flexpoxy. Mix some up and fill in all around the step. Then lay a saturated piece of fiberglass over the top of that and bed the cloth into the thickened epoxy.

You also need to fix the crack or ship inside the tube, some thickened epoxy or epoxy putty on the end of a long stick will address that issue.

Daggerboard repairs will be similar, if you know where the leak is then repair the outside of the area and reinforce from inside if needed. Sometimes it is a gelcoat chip on the bottom of the trunk. Other times a vertical split along the front of the trunk. We usually inject neat epoxy into the crack then work thickened epoxy or Marine Tex epoxy putty in on top of that, leaving a little extra on top. When it dries we smooth it with a file or dremel. Check daggerboard fit.
 
Your plan sounds good, add another layer of fiberglass to what is there. I'd get a structural filler like 406 colloidal silica to thicken the epoxy that is added to the bottom and top of the mast step, it will fill in voids and help the fiberglass cloth stick. You can also buy epoxy already thickened that dispenses from a caulk gun cartridge, THIXO from Jamestown Distributors or Pettit Flexpoxy. Mix some up and fill in all around the step. Then lay a saturated piece of fiberglass over the top of that and bed the cloth into the thickened epoxy.

You also need to fix the crack or ship inside the tube, some thickened epoxy or epoxy putty on the end of a long stick will address that issue.

Daggerboard repairs will be similar, if you know where the leak is then repair the outside of the area and reinforce from inside if needed. Sometimes it is a gelcoat chip on the bottom of the trunk. Other times a vertical split along the front of the trunk. We usually inject neat epoxy into the crack then work thickened epoxy or Marine Tex epoxy putty in on top of that, leaving a little extra on top. When it dries we smooth it with a file or dremel. Check daggerboard fit.
This looks like some great advice. I will buy the filler today.
 
This is what I was able to accomplish today. Working with epoxy was way more challenging than I originally thought. I lost half my resting on the fist try. It's better to work with small batches first.
 

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I lost half my resting on the fist try.
"All your base are belong to us"? ;)
___________________

I use "slow-set" epoxy hardener exclusively, but in warm temperatures, sometimes you have to hurry! :confused: (Product 206-West Systems).

To extend working time even further, I have a piece of flat slate (stone) that I keep in the freezer, and put the epoxy mixing container on it. Not perfect, but works better... :cool:

It's been suggested that epoxy repairs to the mast step interior can be smoothed by the use of a balloon. Dollar Tree stores has a pile of them for...$1.

More forum chatter on mast-step repairs:
Repairing a crack in the mast step | SailingForums.com
 
Watch the regular and fast set don't smoke or catch fire on you!!...in warm temps especially.
 
Here is some of the pictures of the repairs I made to the mast step and dagger board trunk and inspection ports installation.
 

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:) Clever use of a carabiner. I'd use the carabiner installed on your deck inspection port cover to hold my cellphone bag from any water that would soak it. What purpose does it have in your case?

What diameter is the inspection port in the cockpit bulkhead?

I used MarineTex to smooth some chipping on the forward-most part of the bow. A second whack dislodged the MarineTex patch, leaving a hole to the interior. :confused: I won't be using MarineTex when a proper epoxy repair is called for. :oops:

YouTubes aren't showing up on my screen, nor are some thumbnails at this forum—only. :confused: Any idea why this has just started to happen?



.
 

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:) Clever use of a carabiner. I'd use the carabiner installed on your deck inspection port cover to hold my cellphone bag from any water that would soak it. What purpose does it have in your case?

What diameter is the inspection port in the cockpit bulkhead?

I used MarineTex to smooth some chipping on the forward-most part of the bow. A second whack dislodged the MarineTex patch, leaving a hole to the interior. :confused: I won't be using MarineTex when a proper epoxy repair is called for. :oops:

YouTubes aren't showing up on my screen, nor are some thumbnails at this forum—only. :confused: Any idea why this has just started to happen?



.
The carabiner I will use to hold a dry bag with goodies and such. Both inspection ports are 6 inches in diameter. I do like the room when I'm fixing the inside with my hands.
 

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