rebbeding chainplates

[jpaulroberts]

I have removed my chain plates from the deck as well as the stanchion that serves as the head vent (they leaked). I am going to re-bed them but I wonder what is the best material to use. Also, should I try and dick out some of the plywood deck core (or balsa) and fill with epoxy first?
THanks, Jerry

[Ted Pounds]

Jerry,

You definitely want to take out some of the core, especially if it is wet.  You need to get it totally dry if it is wet, then fill with epoxy.  A technique for getting out the core is to put a bent piece of coat hanger in a drill, hook it inside the hole and spin it around to dig the core out.  There have been numerous debates on this board as to what the best bedding compound is.   Also your local  West Marine or other chandler can give you advice on that one.  I tend to favor silicones, but not everyone agrees with me.

[Ron Hill]

Jerry : I'd "dick" out around the holes and fill it with epoxy - then redrill the holes again.  I like poly-sulfide caulk.  As I said in a post last week, only tighten down re bedded parts 3/4 of the way until the caulk in partially cured - so you don't squirt it all out.  Then tighten all the way 8-12 hrs later.  
The key to keeping the vented stanchions from releaking is filling with epoxy, redrilling them back out and adding a backing plate.  

[Stu Jackson]

Jerry

A search on the word "chainplates" will get you to lots of the information mentioned above in Ron's & Ted's posts.

I would normally just cut & paste the direct URL for you, but for some reason, the way this board works, is that I can get the search result up on the screen, but the URL ends with "=results" and NOT the actual WYSIWYG.  Sorry.  If you just try the search, you'll finds 2 pages of VERY  related topics.

Also try "rebedding" and "stanchions" for more answers to your ?s.

[jpaulroberts]

OK, I managed to dig out the plywood around the hole for the holding tank vent stanchion.  It was wet. I dry it out and epoxy that before remounting. But the wood is so good around the rectangular chain-plate holes in the deck that I can not dig it out. I've tried bent wire in a drill, etc. It's good wood and will not give way. I think I should just clean and re-bed. The bolt hols are also dry but very compressed. I think I will drill a larger size hole up from inside the cabin but not through the deck glass. I will then fill this with epoxy and re-drill. That will give me a good compression sleeve around the4 bolts. I will also go up a size on the washers on deck so there is more surface area for the 3M 101 to form a seal.

Any thoughts?
Jerry

[Ted Pounds]

The extra large washers are a good idea.  What you want are "fender washers".  They distribute the load better and prevent cracking around the bolt head which happened on mine when a PO apparently over-tightened the bolts.  Fortunately the the fender washers covered the cracking.  I think your idea of oversizing the holes from the inside is a good one.  That's good that all the wood around the chain plates is hard and dry.  If you get a good seal on it you shouldn't have to worry about them for a long time.  

[Ron Hill]

Jerry : Sounds good.  

[jpaulroberts]

I'll let you guys know how it turns out. The plan for the chain-plates is pretty straight forward. For the head-tank vent stanchion it's a bit harder. That wood was a bit damp and by making some digging tools I managed to dig out about half an inch around the main tube hole. The problem is the four bolt holes. They are too small to get much of anything into to dig and the wood is still strong enough to make it hard. So the plan to drill a larger hole up from the inside (stopping at the underside of the fiberglass decking) makes seance. The trouble is (unlike at the chain-plates) there is not enough room to fit a drill between the shelf and the underside of the deck (beside and above the chart table). Maybe I can find some kind of an elbow gear for my drill.

I owned a Pearson Triton for 15 years and whenever I re-bedded any deck fittings, it was easy to dig the balsa core out. This plywood is tough stuff. Thanks again for the prompt advice. Jerry

[Ted Pounds]

You can probably rent a right angle drill pretty cheap for an afternoon if there's a tool rental place nearby.

[SteveLyle]

If the plywood is solid, what's the problem?  Fill the hole with pure epoxy (no filler), it'll soak into the plys of the wood, let it cure then redrill the hole.  Git Rot is particularly good at soaking into wood, even if it's not rotten.  What am I missing?

Some more info on sealants.  Ron and I aren't the only ones that recommend polysulfide for bedding fittings to the deck, including chainplates.  Don Casey addresses this on pg 19 of "Sailboat Refinishing",  William Burr does on pg 94 of "Boat Maintenance"), and Allan H. Vaitses does on pg 145 of "The Fiberglass Boat Repair Manual".

The 2005 West Marine catalog has a sealant application matrix on pg 450.  Various brands of polysulfide are rated "Very Good" for sealing metal fittings to fiberglass, including 3M 101.  The West Advisor on the same pg ("How to Select Sealants") gives a good summary of the applications of polyurethane, silicon, plysulfide and polyether sealants.

Steve

[jpaulroberts]

Steve,
I hear you. The wood around the base of the holding tank vent stanchion was wet so I am dealing with that. My only problem there is not being able to get at the wet wood in the four bolt holes. The pipe whole was easy to dig back the wood half an inch and I'll fill that with epoxy.

On the chain-plate area of the deck the wood seems dry and solid even though they all leaked into the cabin. I just thought that since they are off  I should cut back the wood and build an epoxy compression core around the fittings. So you're saying that if the wood is good, just re-bed with 3M 101 and be happy? I understand about filling the bolt holes with epoxy or git-rot and re-drilling. What should I do about the rectangular holes for the main chain-plate units? Should I not worry about sealing the wood and just re-bed?

Believe me, the less work I have to do the better. I have a lot of projects to do on this boat. I just figured since they were leaking, and since I probably will not have my mast off again for many years I should up-grade the area.
Thanks, Jerry

[Stu Jackson]

Jerry

Some of the links to the old chainplate messages discussed being able to re-bed chainplates with your mast up.  There is no reason you can't do that.  That said, Steve's recommendations on sealants seems to answer all the rest of the questions.  No reason to do anything but seal the rectangular openings at the chainplates, especially since they are still solid.  Thats' what the sealant is for.  It sounds like you had a leak, it got  by the old sealant but didn't mess up the core.  That's great.  Good luck, you'll really enjoy a drier boat.

[SteveLyle]

Jerry,

It wouldn't hurt anything, and would be pretty easy, to 'paint' the exposed core with epoxy.  If you have a leak in the future it would be less likely to cause problems.

But it's held up for 18 years as is - I wouldn't lose any sleep over it either way.  Seal it up like the dikkens and go sailing.

Steve

[jpaulroberts]

Thanks to all of you for the advice. It looks as though I was making a bigger job out if it than I needed too. Since I just bought the boat and I intend to keep it for a long time, I really want to do all the repairs and upgrades right. Thanks again, and it's really great to be part of the C-34 family with all this great support and a group of people willing to share information, etc.

[Mike Vaccaro]

Jerry,

We ran into the same issues with the chain plates.  Turns out the wood was damp, but fortunately there was no rot.  It pays to dry out the wood, and a heat gun or small fan properly placed works wonders for expediting this.  

There is a product that is better than Git Rot, generically, it's referred to as "CDPE" for clear, deep-penetrating epoxy.  There's been some activity on this board, and if you search the net for "Rot Doctor," you'll find a web site dedicated to it's use.  Essentially, it's a very low viscosity epoxy that works via capillary action and is very effective at protecting good wood or repairing damaged wood.  You can thin conventional epoxy with Xylene and achieve similar results.

Another accepted repair technique is to "encapsulate" through deck holes.  If they are round, this means over-boring then filling the hole with thickened epoxy or polyester resin and re drilling the mounting hole.  This effectively provides a plastic barrier to moisture.  This is why some manufacturers use a solid laminate where deck fittings and hardware will be mounted.

Any steps you take to protect the core are a good idea--even if it's just a proper bedding job at the first sign of trouble (leaks), since water damage to deck and hull cores are one of the primary reasons for scrapping old sail boats.  

Due to flexing (especially around chain plates), you may get lucky and get years of service from a sealant or you may not!  Furthermore, all types of caulk have a finite life span, and it's not measured in decades!  If you follow three basic rules, you'll be in good shape:  1.  Caulk is cheap (use it appropriately!); 2.  Don't be in a hurry to torque the fittings (allow the sealant to cure and form a gasket); 3.  Don't wait for problems to go away, re-bed at the first sign of a leak (this is a corollary to the prime directive of KEEP WATER OUT OF THE BOAT AND MAKE THE BOAT GO).

Cheers,

Mike