Chainplate sealing

[Roger Long]

I got two chainplates installed this morning. Many thanks for talking me into the solid epoxy "butter" fit. I was able to torque the bolts right up and it feels rock solid. I would lift the boat with these and stand under it.

Best of all, I was able to correct the chainplate angle of the lowers to bring them more into line with the shrouds. Endeavour was a bit casual about things like this. The epoxy is shown in red.

With the bedding fill I was considering, I would have had to make the flanges flat against the deck flange.

I caulked the "V" deck cut out with Butyl tape rammed in hard with a screw driver and other implements. Great stuff. This feels like just the seal I was looking for.

I didn't have such good luck with the cover plates however. I can get a good seal all around the deck but the tape won't come up through the gap between the cover plate slot and the chainplate. This leaves a trough for water to collect in, evaporate, get very salty, more water, etc. Seems like certain crevice corrosion.

This is what I would like to see with the Butyl shown in gray and something else in magenta:

Seems like I would be better off with something like polysulfide under the cover plates. Or, is there a way to make the Butyl do this?

 

[charles baird]

roger,
what about 5200 if you are just filling a void

 

[Roger Long]

what about 5200 if you are just filling a void

Boat owners should be required to get a note from their mother before being allowed to purchase 5200.

 

[DannyS]

Uh-Oh... I can see where this is going.

 

[charles baird]

i will see you at the marina

 

[All U Get]

Hi Roger,
What did you do to prep the area that you epoxied? Did you just sand it or wipe it with acetone? The reason for asking is that my large cleats fore and aft have been less than robust and I have made up aluminum backers for them. Setting them in a bed of G-Flex would seem like the best solution. Your thoughts.
All U Get

 

[Roger Long]

What did you do to prep the area that you epoxied?

I love my Ryobi cordless drill (Thanks to everyone who suggested it). I've been using it as an angle grinder all over the boat and it just doesn't quite. I bought two spare batteries and could have saved that hundred buck because the batteries last longer than I do. There isn't a lot of torque though because I've been using a 5/8" diameter rasp bit with a hemispherical end.

The rasp bit is great. It tears into fiberglass faster than any cutting wheel or other tool I've used. I can even cut right through old tabbing where I want to remove it and it leaves a very toothy surface that is perfect for fiberglass adhesion. Best of all, due to the low speed at the small diameter surface, it doesn't sling stuff as far. The larger and heavier chunks it tears out don't float around and work their way into clothing. If you use a light touch, you can get almost any surface you would want for secondary bonding.

 

[All U Get]

Thanks Roger, sounds like a plan.
All U Get

 

[Stu Jackson]

Roger, why not make the magenta the same as the gray? That'll seal it for good.

I agree, 5200 should not be sold to any boater without 666 years of experience, boating, not just living.

So, we rented this car during our vacation in New Zealand last month. The car licsense plate? DSE 666.

 

[Maine Sail]

Roger,

So long as your deck plate screws have good purchase that is a perfect application for butyl.. In order to get the tape to squish up through the hole you need to wrap the chain plate above deck and apply butyl to the bottom side then drop it over and hand press and screws it into place..

 

[njsail]

adding my 2 cents. If you use butyl don't forget to isolate it by sealing it with some type of polysulfide or silicone sealant since butyl runs black streaks if you have any exposed to the elements. I learned that when I replaced my ports with new found metal stainless ports set into butyl tape. A quick rim of sealant and no more runs.

I have to agree on the 5200. Never use 5200 on chainplates since it doesn't have any give and if you torque your rigging the gap will change shape and the 5200 will not have give. One of the best sealants I started using over a decade ago is Silpruf sealant. It's a professional glazing compound used for commercial window sealing. It sticks to stainless nicely which not all sealants do well.
I have info and links for GE Silpruf here if you are interested.
http://ipphotos.com/view_ad.asp?Ad_ID=644

 

[Roger Long]

So long as your deck plate screws have good purchase that is a perfect application for butyl..

That's the problem. The cover plates have been redone over so many years that the screws are going into holes filled with epoxy. I did everything you suggest and pushed down as hard as I could. Even where the butyl came through the slot a bit, it wasn't making a seal and I couldn't get real tension with the screws.

One thing, it was cold. Will the butyl soften with head and would a gentle application of a heat gun make this work?

 

[bria46]

I re-bedded my chain plates last fall using Dow Corning 795. Use blue painters tape covering the deck around the SS chain plate cover, over fill the the deck area and slot thru the deck with 795, let the 795 oozo out by pressing down on the SS chain plate cover, Let the 795 cure for 24 to 48 hours. cut thru the 795 with an exacto knife cutting around the SS plate cover and masking tape. Simply remove masking tape with the remaining 795 stuck to it. Dow Corning 795 WILL clean up with paint thinner. Oh, buy surgical gloves for this process,

 

[chp]

Just rebedded my chainplates using butyl. You want it either warm out or warm things up a bit. The butyl will get soft and gooey and will ooze up through the gaps in the cover plates. After I just scraped off the excess. Didn't know about the black marks from the butyl. Will keep an eye on that one. The butyl gave me an instant seal as it has been heavy rain here for 2 days and the bilge is still dry.

 

[Roger Long]

butyl runs black streaks

Were you using RV butyl tape or the good stuff that Maine Sail sells?

 

[Steve Dion]

Roger:

I agree. I bedded my new boarding stanchions in the butyl that I purchased from MS and it has not changed. A little oozed out when I frist screwed the stanchion into place and nothing has changed since then. No discoloration either.

The old Hunter Cherubini's had the hull/deck joint sealed with butyl and that was not a problem with that product either.

I have been sold on this stuff long before MS had it for sale, but I do think there is a difference in quality.

 

[Maine Sail]

Were you using RV butyl tape or the good stuff that Maine Sail sells?

NFM sells BLACK butyl tape and the stuff is horrific. I have talked to Richard till I am blue in the face about getting him to switch to gray but he has resisted. I suspect, based on the packaging, that he is getting this out of China, where his ports are made, and paying a very low price for it and can't get the gray color for anywhere near the price he pays for black. I installed my NFM's with black and I have regretted it ever since. It is not the same consistency as a premium quality glazing tape in my experience with it.....

 

[gettinthere]

Pitch the black butyl and switch to gray!

 

[maarty]

Roger,
Since the cover plates are not a strength item, and you want to seal the area, I suggest the use of 3M 4200 or Sikaflex Professional Construction sealant (available in various colours). The most common mistake made with a bedding compound is to over tighten; which squeezes out most of the sealant. You want to have a flexible gasket, so to speak, and not a paper thin layer of sealant.You have also mentioned that you can't get real tension on the screws.

I suggest that you don't have to get real tension on the screws. Light tension will do it.

Here is the fix for the cover plates:

Put the plates into place, and mask off the area around with blue painters tape.

Tape 4 pieces of spaghetti, (yes, spaghetti!!!!) into place at 4 corners, with just 1/8 of an inch of the tip of each piece protruding into the area where the cover plate will sit.

Also mask off the top of the cover plate so that only 1/4 inch of plate is exposed around the area where the chainplate comes through. Mask off the chainplate so that only 1/4 is exposed above the final position of the plate.

You are now ready to caulk: put a generous amount of caulking where needed. Carefully press down the cover plate until it bottoms out, and is just touching the spaghetti tips. Replace the screws: LIGHTLY fasten the screws so as to not crush the spaghetti. Now, with gloves on, break vertically the spaghetti pieces, so that the 1/8 pieces stay in place. Smear away caulking so there is a smooth fillet around the plate and the area around the chainplate and cover plate.

It is smart to remove the tape at this point, as it is easiest to take off.

You now have a nice gasket under your cover plates with a really good seal. The spaghetti tips will disappear with time. Just a dab will fill the indents. These cover plates will probably out last you, and if you do need to open them you will be able to, because you didn't weld them with 5200.

Good luck!

 

[RichB]

Thanks from Florida. So now I know how they do it up Nawth.
I am getting to that part of a deck core repair at the chainplates. I was starting to imagine how I would seal the cover plate.

Butyl with a polysulphide frosting or GE sillpruf or Dow 795 and only the grey/good butyl tape from Maine Sail and SPAGHETTI. Got it! Love these forums. A home for the fleas A hive for the buzzin bees ... ... ..