MacGregorSailors.com

Hey guys.

I discovered that the chain plates from the shrouds on my '02 26x are leaking pretty bad when it rains. I have removed the 3 bolts on the sides of the hull and pulled the chain plates out. I also want to remove the other piece that is mounted directly to the hull and reseal it as well, but it is attached with rivets rather than screws. Or maybe it's just glued down really good Not sure how to go about removing it. I don't want to break anything, but I'm considering drilling out the rivets and replacing with screws. Not sure if that is a good idea or not.

The other question I have is what to use for sealant. The research I've done so far has led me to a few ideas. The sealant needs to be flexible from what I understand so silicone is out. Sounds like butyl tape and/or butyl rubber sealant are the top picks. I found some butyl tape, but I can't seem to locate any of the sealant that comes in a tube. One boat supply shop recommended Sikaflex construction sealant which is a flexible polyurethane. I have been able to locate some of this, and I also have a similar flexible polyurethane sealant made by Loctite and another by Gorilla.

Any suggestions from someone who has done this project before? Thanks.

Those are basically just covers. Two rivets hold them, which you can drill out easily to remove. I used butyl tape to seal them. Don't use something stiff, as the chainplates flex in/out a little with changes in load, mostly from the inner stays, which are angled inboard and not vertical. But if you do, use it between the chainplate and the deck, so it's not imparting any load to the cover. I cleaned the hard caulk out before I realized that I was wasting my time; just needed to rebed the cover to stop water ingress.

I believe I used aluminium pop rivets to reinstall the covers - not worried about galvanic corrosion, especially since they're not structural.

Other sources of leaks that can look like chainplate leakage include anything bolted or screwed to the deck, especially the sliding hatch keepers, and the rub rail and deck joint, or so I believe from discussions here but haven't checked out for myself.





I think that gray stuff is sealant I hadn't finished cleaning, but it was one of the first jobs I did when I got this boat, so recollection is getting a bit hazy. Easy job, though. Do the forestay cover while you're at it.

Cool thanks. That’s great info going to get after it tonight

I may have found a solution to well known top side water ingress through the chain plates. I really did not want to go through the hassles of dismantling
the fasteners or de-riveting the cover plate. What I used is PR-1005-L (PPG Areospace) which is a one part, synthetic rubber solution. Yes, it's an aviation product and it's
not something you can buy anywhere...and it's not exactly cheap for a pint can. https://www.skygeek.com/prc-desoto-pr-1 ... -pint.html

It's used as an integral aircraft fuel tank slosh coating over an existing PRC type sealant. I applied through the gaps of the chain plate with a curved tip syringe. I worked the
chain plate laterally while squirting it in until it started to set up and then back flowed. I went through a few syringes before it would not take anymore. I carried out a water leak
check before and after and it stopped the water within minutes after I applied it.

It cures quite fast and more so if the sun is out and higher ambient temps. Their may be other
areas of the Macgregor with top side leaks where you can apply this product. It's more like a light
syrup with good flow.

From the product description.

"The uncured material is a thin syrup suitable for application by brush, fill and- drain, dip, or spray. It cures at room temp. by the evaporation of solvent to form a smooth, tough, flexible transparent film having excellent adhesion to common aircraft substrates and polysulfide sealants. "

See the following pics of the application.





With the plugs removed in the cabin. Obviously you can only see the inbd side of the plate but I have to assume the otbd is similar.



https://photos.smugmug.com/Boats/New-Ma ... 4047-L.jpg

https://photos.smugmug.com/Boats/New-Ma ... 4050-L.jpg

In conclusion...I have not tested it with my mast up and working the sails and chain plates. Due to the heavy snow pack in north/central British Columbia this past winter
I had a shroud/spreader tube break including a bent mast carrier. Yup, another power boat summer. The mast carrier socket also needs to be replaced due to stress cracks. Amazing that
the binnacle never got damaged. Fiberglass is crazy strong. That's another story...all replaceable parts from BWY.

It's easy enough to check that you have rectified any leaks by sticking tissue through the plug holes and pouring water down top side. I'll continue to monitor the chain plates and if need
be and can always apply more if the gap opens up. Is this an easy fix...dunno yet? The fact that it remains flexible and tough and with good adhesion it just might work. We'll see.

I am not sure what the issues with silicone sealant are for colder climates, but I have used silicone sealant on my 26X for 15 years. I keep it in a slip in Central Florida so, you know I get a lot of rain. I scrape the old off about every 2-3 years and reapply a new "glob". I have never had a leaky chain plate that I know of.

I've just drilled out the rivets and put butyl tape in there, then used small screws and nuts to put the cover plate back on. Been dry for three years so far...

I used butyl tape in the end as well. It's been a rainy summer in Alaska and the leaks seem to be gone