Sealing Chainplates

[purplerobbie]

The chainplates on my boat leak quite bad and i need to seal them.
Does anyone have any ideas on the best way to do it?

If i seal them from outside will the force of the sails putting pressure on the chainplates flex them and cause it to leak again?

Would i be better off sealing them on the inside where they will be less movment?
Or will sikaflex flex enough for this not to be a worry?

Would it be better to not pull them up tight let the sealent go off the pull them the rest of the way so it would be like a rubber gasket? Or will this just break the seal on the bolts?

If i pull them tight while its wet most of it will be pushed out and any movement will cause it to break it's seal?

Or should i put sealent on everything and everywhere in the hope that something will hold?

Rob

 

[Adamastor]

I did a job like yours about 10 years ago, and the plates are still 100-cement. Basically, whatever sealant you use is going to be like rubber when it cures, so capitalise on that. Slack off your shrouds so the 'plates "relax" into their natural, unstressed position, remove chainplates if possible and re-fit or rather bed them with lotsa goopy stuff, masking it off well, and cleaning off the excess before the stuff goes off. Let the sealant cure, and then tension the bolts up. The dried goop will have bonded as it dries, and the couple of thou' that you'll tension it down will in effect compress the gasket you've just made, and make everything absurdly watertight. If the plates cannot be removed with ease, slack em off till you can get some goop-a-flex behind the plates and let that cure, then nut everything home. Enjoy your leak-free yachting!

 

[bigwow]

Anyone that has had as many boats as you Rob should know the answer to all these boaty questions!
/forums/images/graemlins/laugh.gif

 

[purplerobbie]

[ QUOTE ]
Anyone that has had as many boats as you Rob should know the answer to all these boaty questions!
/forums/images/graemlins/laugh.gif

[/ QUOTE ]
Yes but all the others have managed to keep the water on the outside!! /forums/images/graemlins/blush.gif
This one really is a wreck /forums/images/graemlins/confused.gif

 

[davidbains]

I've taken two chain plates out recently. Visiting the boat in torrential rain was most instructive!
I cleaned them up and fitted new bolts. Used Sikaflex on the outside half and after refitting them I topped up on the inside with Unibond "Sets like Nails" exterior, which is a greatly underestimated boating product!! It doesn't set after the tube's been opened unlike Sikaflex.

 

[VicS]

[ QUOTE ]
Would it be better to not pull them up tight let the sealant go off the pull them the rest of the way so it would be like a rubber gasket? Or will this just break the seal on the bolts?


[/ QUOTE ] That's the way to do it. Tuck some little spacers between them and the hull that you pull out when the sealant has set. Then tighten down by holding the heads of the screws still, while another tightens the nuts, to prevent breaking the seal around the thread. If you have used Sikaflex 291 they are unlikely to move anyway

Important to seal the screw thread into the substrate especially if they are stainless to prevent crevice corrosion