What Calk/Sealer to use?

Surley · Post by **Surley** » Fri Sep 26, 2008 11:57 pm

Hello, we need your input.

We have just replaced the chain plates (six) at the mast of our 1971 Alberg 37 MkII Yawl. After 37 years of service it was time. The replacements are more robust and of course the new holes don’t line up with the original one. It is time to seal/bed these. We would like input on what sealer/calk to use! Should we use 3m’s 5200, 4000 or 3100? What about Boat Life polysulfide or Sikaflex 291? A lot of options / opinions. If she were yours what would you use?

Ron & Kaye Surley
SV “My Girl” _/)

Rachel · Post by **Rachel** » Sat Sep 27, 2008 1:15 am

Welcome to the forum, Ron and Kaye. That's a nice boat :)

Can you elaborate on the part about the holes not lining up? Is that where you are caulking? Slot in deck or holes in bulkhead down below?

Can you post a photo?

Rachel

Hirilondë · Post by **Hirilondë** » Sat Sep 27, 2008 7:59 am

The holes not lining up and choosing bedding compound I don't think should be considered related at all. The loads on chain plates are tremendous. You have to eleviate the bolt holes misalignment! Once you have resolved that problem and you can get the mechanical fastening required to do the job the compound will simply be a water-proofing bedding and any of the products you named will work.

I would not use 5200 or 4200. You don't need the adhesive properties of the products and they will make refastening or replacing in the future more of a pain than it needs to be. Some people feel a security from using 5200 for some applications, but I seriously question whether it will save your mast if the fasteners or the attachment point fail. I like Sikaflex 291-LOT for chain plate deck openings and covers.

I think your most important question concerns the mechanical fastening and how to resolve the holes misalignment. The photos Rachel has requested might help elicit some suggestions.

Sailordave · Post by **Sailordave** » Tue Sep 30, 2008 8:42 am

Am in a similar quandry over what to use for rebedding deck hardware. Not interested in 5200, etc. Will probably use either Sika291 or BoatLife Caulk. Practical Sailor did a test of caulks some time ago and Boatlife got good scores on flexibility which is important for things that take cyclical loads.

Ceasar Choppy · Post by **Ceasar Choppy** » Tue Sep 30, 2008 9:13 am

Can you tell us which holes don't line up??? Are you talking about the holes for the bolts to mount the chainplates on the knees, or are you referring to the holes in the deck.

The Sikaflex is probably the best caulk to use here because it will actually adhere to the metal of the chainplate. But you need to prep the metal with alchohol.

I would stay away from anything with silicone in it to avoid problems down the road.

As Dave says, don't be afraid of using something less permanent than 5200. Being able to remove hardware-- even chainplates-- is a GOOD thing.

Jason K · Post by **Jason K** » Tue Sep 30, 2008 10:07 am

Will probably use either Sika291 or BoatLife Caulk.

The LifeCalk (their spelling, not mine) will turn yellow/brown very quickly. I would suggest either 3M 101 or Sikaflex 291.