Chainplate Rebeding And Depth Sounder Question (so I Don't Clog Up Boards, Thank You)

[stephenronning]

Hello: my sailiboat has water stains on the bulkheads and so I need to rebed my chainplates. What do I use to rebed them? Also: I need a depth finder. Someone on craigslist has a GAMEFISHER DEPTH LOCATOR for $25.00. He says it doesn't take a transducer? Does this sound right? Did they ever make a model that just shoots the signal through the bottom of the unit itself? Thank you. Stephen
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[Ross]

Stephen, Where would you sit to view the display on this depth sounder? All that I have seen had a display screen and control panel connected to a power supply and to a transducer. I would be very leary of something so mysterious.

 

[sailingdog]

The big issue is the bulkhead. I would examine for any signs of rot or delamination. If it has any, you need to repair it or replace it properly. As for bedding the chainplates, Butyl Tape is a good choice.

As for the depthsounder, yes, many can shoot through the hull, provided the hull is solid fiberglass, rather than cored.

 

[Stu Jackson]

John C36 and others have posted chainplate

repairs in great detail. Try the C36 and C34 websites.

 

[mark_swart]

I use silicone sealant from your average hardware store or walmart. Take off the old chainplates, clean all of the old sealant off with a knife, clean all surfaces with acetone, then apply silicone sealant. I have used this same procedure on three different boats, and in every case it was still watertite a few years later when I got rid of the boats.
Do NOT use 3M 5200 -- it is a permanent adhesive.
If it makes you feel better, you can also buy smaller tubes of pretty much the exact same silicone sealant from your local marine store for $7, versus the $3 you pay at the hardware store. They are a little handier to keep onboard as opposed to the big tube and caulk gun!

 

[Jalepeno]

Have a look at Mainesails' excellent maintenance site:

http://www.pbase.com/mainecruising/boat_projects

Jalepeno CAL 2-25

 

[sailingdog]

Silicone has no place on a boat, other than on the tips of cotter pins and for bedding lexan or acrylic glazing. It really doesn't work very well. Most chainplates move too much for any silicone-based caulk/sealant to work for any length of time.

The best sealant for deck hardware is butyl tape IMHO. 3M 4200 or Sikaflex 291 or LifeCalk are also good, depending on what you're using it for. You can get the butyl tape for about $5 a 3/4" x 30 x 1/16" roll or so on-line or from your local glass repair shop. It is cheap, relatively elastic, stays soft and pliable for a long, long time, and is sticky enough to work well in most situations. Very easy to clean up after as well.

3M 5200 also has no real place on a boat, aside from possibly the hull-deck or hull-kell joins.

I use silicone sealant from your average hardware store or walmart. Take off the old chainplates, clean all of the old sealant off with a knife, clean all surfaces with acetone, then apply silicone sealant. I have used this same procedure on three different boats, and in every case it was still watertite a few years later when I got rid of the boats.
Do NOT use 3M 5200 -- it is a permanent adhesive.
If it makes you feel better, you can also buy smaller tubes of pretty much the exact same silicone sealant from your local marine store for $7, versus the $3 you pay at the hardware store. They are a little handier to keep onboard as opposed to the big tube and caulk gun!

 

[stephenronning]

hi I got lucky on that gamefisher..she's a dinasaur..but she had an RCA jack in the front of her...i plugged in my transducer to it and BINGO! She works great! Probably close to 30 years old...for $30.00 I did great~!
Also: I picked up the cheapest silicone I could get...I've used it before when I replaced all my portlights it worked great...I'm sure it will work just fine. Bulkheads got some wet spots...not too worried bout it. I'll get it done sooner or later but for now I'm sailing and loving it!
Stephen

 

[sailingdog]

Also: I picked up the cheapest silicone I could get...I've used it before when I replaced all my portlights it worked great...I'm sure it will work just fine. Bulkheads got some wet spots...not too worried bout it. I'll get it done sooner or later but for now I'm sailing and loving it!
Stephen

Good luck with the silicone. I think that the improper use of silicone sealant on boats has cost more in the way of repairs than anything else, short of drilling through a cored deck and not potting the holes properly.

 

[MattObjects]

I second Sailingdog's comments about silicone caulk. My project boat's bulkheads had water stains down them, the result of seepage from silicone caulk used to bed chainplates. Inside the cabin, the caulk looks fine-- clear and rubbery just like the day it was applied. But on the deck, where it has been exposed to UV light, the caulk has been reduced to a gray ashy powder that you can brush right off. The caulk was applied a few years ago when the PO purchased the boat. In my experience, saving a few dollars on materials is hardly worth the price of knowing you'll have to redo a repair in a year or two, if it lasts that long.

 

[Stu Jackson]

Inside the cabin, the caulk looks fine-- clear and rubbery just like the day it was applied.

There shouldn't be anything underneath inside. The caulk is supposed to stop water from getting IN. Having the caulk below only traps water above it, meaning the deck.

 

[sailingdog]

Stu's made a very good point. All the sealant should be ABOVE the deck, not inside the cabin. If there is a leak, you want to see the water show up inside the boat, rather than get caught in the deck core where it can do a lot of damage that will go unseen.

There shouldn't be anything underneath inside. The caulk is supposed to stop water from getting IN. Having the caulk below only traps water above it, meaning the deck.

 

[Maine Sail]

Good points guys

Stu's made a very good point. All the sealant should be ABOVE the deck, not inside the cabin. If there is a leak, you want to see the water show up inside the boat, rather than get caught in the deck core where it can do a lot of damage that will go unseen.

Beyond just spotting a leak a far more important reason is to prevent oxygen starved water from being trapped next to stainless bolts. This will lead to crevice corrosion and possible failure. In the event of a stanchion this could be a life or death situation.

As Stu and Dog said never seal the cabin side with any sealants as they can cause further deck rot and lead to a catastrophic potential bolt failure..

Deck leaks are generally NOT the fault of the sealant but rather a result of the installer. Even Silicone can be leak free for many years if the installation is done right. Unfortunately Silicone contaminates surfaces and should be avoided when ever possible.

The best way to prevent core rot is to remove some core from between the skins and pot the holes with thickened epoxy..

 

[MattObjects]

Stu's made a very good point. All the sealant should be ABOVE the deck, not inside the cabin. If there is a leak, you want to see the water show up inside the boat, rather than get caught in the deck core where it can do a lot of damage that will go unseen.

Both of you are absolutely correct, IMHO. The sealant inside the cabin was one of many interesting choices the PO of my boat made and one that was not repeated in my repair. I mentioned it only to indicate the difference in the condition of the silicone inside vs outside the cabin as evidence of my suspicion that sunlight is what caused the outside silicone to degrade so completely.

 

[Hermit Scott]

Is colloidal silica a good thickening agent for potting the holes?

 

[sailingdog]

For thickening the epoxy... yes, perfect...

Is colloidal silica a good thickening agent for potting the holes?

 

[Ed Schenck]

Chainplate rebedding.

I have been following this thread and most anything else where MaineSail is involved. I guess we should be grateful for long Maine winters.

And I have studied Maine's and other websites and threads. I still do not see what I am looking for, i.e. the long term fix for chainplates.

Butyl tape is mentioned but I do not see that working for me. I have six chainplates for shrouds and all are thru-deck. They each have a small plate with two screws around them, maybe 2"x3". About every three years I clean out the old silicone and reseal. Unlike some above experiences my silicone is always pliable. But it does lose its adhesion.

The holes are only slightly larger that the stainless chainplate. But big enough that I can tell that there is core missing. So it would seem that I need to either: 1) cut out a rectangle of skin and do the large core replacement project(already discussed on Cherubini site) or 2) try to simply enlarge each hole and fill with an epoxy mix.

Regardless of which, 1 or 2, I still do not understand how to make that rectangular hole. It has to be the right size and perfectly angled. And it has to allow for the chainplate to be inserted and removed. Does it need to be snug or should one leave room for the sealant?

In the picture of an H37C coring project(not mine) you can just make out two of the three chainplates.

 

[sailingdog]

The chainplates need to have a bit of space around them, since they tend to flex and move a bit as the boat moves. If you have the deck right up against them, they'd bend and fatigue and then snap at that point.

I would pull the chain plates, one at a time, fill the gap between the laminate layers with thickened epoxy after checking to make sure the core is dry... then replace the chainplates. Leave the opening so that there is about 1/8" of space all around the chainplate. Fill that with butyl rubber and cover the underside of the coverplate with a layer of butyl rubber and then snug it down... and I'm pretty sure your chainplates will stay nice and dry.

 

[Ed Schenck]

That seems like sound advice as far as it goes 'dog. But I still don't see how I get that hole made. Doesn't filling the void also fill the hole? Then how do I make a new hole of the right dimension and angle? Maybe use a piece of wood of the correct dimension and then drill it out?

And as I wrote above, even if I replaced the core in a wide area I would still have to figure out how to make a solid epoxy hole.

 

[sailingdog]

I'm saying you should fill the gap, in-between the top and bottom layers of laminate where the core material was, with thickened epoxy and leave the opening OPEN. The thickened epoxy can be injected into the gap between the two layers using a syringe and then faired even with the edges of the hole. Properly thickened epoxy will fill a gap like that and not drip or sag.

Another way to do this is to tape the edges of the hole off with duct tape or something similar, and then drill a few small holes around the perimeter of the chainplate opening and inject epoxy into one until it comes out the others...

The holes are only slightly larger that the stainless chainplate. But big enough that I can tell that there is core missing.