Search
C36 Maintenance 102 - Intermediate
Cleaning & resealing the C36 Chainplates
by Bruce
Landsberg
6/25/2006
The chain plates on the earlier Catalina Mark I and Mark IIs, probably on every sailboat, ultimately leak.
The plates are under constant stress and movement as the load on the rig changes. Eventually the sealant bond between the chain plates and the deck will fail. Water can then seep below decks rotting bulkheads or worse, into the core area inside the deck. This can lead to delamination and rot -- which quickly becomes expensive to fix.
Newer boats have an improved design that starting around 2004, and this procedure really does not apply to them. These newest models still need resealing, but less often.
You should check every month or so where the chain plates terminate to be sure there is no evidence of water/water stain. If you find that a chain plate is leaking - it is an easy fix. Fear not – by attending to this about every 4 years or on condition (evidence of a leak), you’ll keep your boat in pristine condition.
Materials needed
- Boatlife Life Seal – white – it’s a polyurethane
silicone sealant that seems particularly well-suited for this
application. I buy it in the smaller 2.8 oz tubes simply because,
unless you’re doing a lot of fittings, you’ll have the stuff for
years and it’s better to have fresh material.
Polysulfide caulk will also work, but DO NOT use 3M 5200 to rebed your
chainplates!
- Anti-Bond – designed to break the seal of the old sealant.
- In the past I always used a solvent cleaner such as acetone. However, I was recently recommended to use alcohol instead of acetone on fiberglass. Seems like we're always learning new/different ways to do things.
- An ample supply of paper towels and one or two plastic trash bags.
- And appropriate size stainless cotter pins or ring pins, and possibly a few spare stainless phillips head screws (in case you drop one in the water).
Tools
Measuring tape, knife, screw driver, Dremel tool with assorted small bits, other implements of torture used to dig out old sealant, needle nose pliers, adult beverages, suitable music.
Time needed
It takes about 45 - 60 minutes per stay.
My recommendation: It’s best to do this on a relaxed day and do one side of the boat. Return another week and do the other side.
And you really should not start this project close to dark, when rain is imminent, or when you will be voyaging in the next 12 hours or so. Temperatures should be above 60 degrees F, or as recommended by the sealant manufacturer.
Procedure
1. Measure the distance from the bottom of the turnbuckle to the “shoulder” of the stay as shown. Write it down! This will help you to return the rig to its original tuned setting.
2. Disconnect only one stay at a time. The mast will remain supported - the other five stays will hold the rig just fine. On most boats the turnbuckles for each stay are covered by a small stainless drum/cylinder. Just slide the drum up the stay to gain access to the cotter pins.
Remove the cotter pin inside the turnbuckle and rotate the turnbuckle to loosen the stay only enough to get the clevis pin out of the chain plate just above the deck – you’ll need to remove the second cotter pin that holds the clevis pin in place. Secure the stay somewhere convenient with a light piece of line. Put the clevis pin in a safe place where you won’t lose it.
3. There are two Phillips head screws that secure a stainless plate to the deck. Remove the screws using a proper size screwdriver so as not to chew them up - or, if despite your best efforts, they become less than perfect specimens after your efforts, replace them. You’ll be glad you did when you repeat this procedure in another four years. Secure the screws and the cover plate in the same safe place as the clevis pin.
4. Start digging out the old sealant. Use your knife to open up the old sealant in as many places as possible – dig it out as much as possible and spray it with Anti-Bond. Go have an adult beverage while the stuff works. Come back and dig out more, repeat. Use any and all tools to get as much of the old sealant out as possible.
Have another beverage and keep working.
5. Clean the area thoroughly with acetone and let it dry completely. Apply the Life Seal liberally – working it into the opening around the stay as deeply as possible. Avoid getting sealant beyond the area of the plate – if you do, clean it up immediately. Since the sealant shrinks slightly overfill the crack just slightly.
6. Put the cover plate back in place and tighten the Phillips screws. Some say to do this only partially and then come back in 24 hours to finish tightening down. I tightened mine all the way to not break the seal around the screws later. No leaks after 4 years but to each his own.
Try to keep the Life Seal in the work area as much as possible and use paper towels liberally putting them into the plastic trash bag after one use – the stuff is wonderfully tenacious and sticks to everything so this is not the time to economize on towels or let them blow around.
7. Reinstall the clevis pin and ring/cotter pin, Now, tighten the turnbuckle until the measurement matches your starting point – reinstall the last cotter pin in the turnbuckle, and admire your work.
Another owner
tip:
Owner Gene Foraker stressed the importance of getting all the old
gunk out before replacing the caulk or the new caulk won't seal
correctly. Gene also suggested, after checking the tension with a
ruler, to loosen the stays in pairs (i.e. starboard & port sides
to avoid excess strain from side to side). Gene said he
loosens the turnbuckles by counting the number of turns, that he
uses ten turns (for example), and when he's ready to reverse the
procedure, he simply tightens them ten turns. This makes
tightening them correctly a simpler task.
You can hire a professional, but it'll cost ya
At typical boat yard rates you just saved yourself about $75 for that one stay, plus materials. Total job on a C36 averages about $500. It’s not glamorous work, but the pay is pretty good for a weekend. And when you're done, you'll know it's been done right, and you'll have that much more knowledge about your boat.