Mysterious White Goo

[rnummi]

The white substance you are looking at has the consistency of wet caulk. It's been on the hard for 6 years and it's still spreadable, wet. Any ideas?

[tego]

Howdy Rick, It's probably dolfinite. It never "hardens" and has the consistency you mention. It's great stuff for above waterline sealing, but I don't like it for below the waterline. It has been used, however, on " woodies" for well over a hundred years or more, above and below. Ben

[rnummi]

Ok, what do I do with it? Scrape it off, leave it alone? It looks like a sealant betwixt skew and keel? Wouldn't epoxy be better?

[tego]

It's a very good sealant unless there's a lot of movement of the parts. I'd probably leave it. Definitely don't use epoxy as a sealant-ever! That shoe is bolted to the keel and needs a real sealant. Dolfinite or 4200 or even 5200, but not epoxy. Ben

[rnummi]

Wow....so they goo'd the shoe to the keel.... The goo is like wet caulk. You can literally run your finger through it and wipe it away. At least w 4200/5200 you get some solid feel to it. It's like making a model boat. You put Vaseline at the point the shaft exits the model hull to keep out water. Doesn't seem very leak proof. I'll go with your "leave it alone" but I'm still a little skeptical.

[Sprig1]

Look in the back bilge compartment and see what it looks like in there. What's shape is the shoe in. Is your rudder connected to it. Shake it to see if its loose. I would think 4200 or 5200 to bed it

[catalina_mike]

I would take a look in the keel.. Wondering if there was a slow leak and the filled the bottom up. It's around the shaft packing also it looks like. Interesting mystery for sure.

[tego]

Rick, You'll find a lot of old timers who swear by dolfinite. It's used a lot on wooden boats, primarily now for deck hardware. It beats the heck out of silicone. There's never a problem with disassembly and it really is a good sealant. I've seen joints and hardware that were bedded with it 50 or 60 years ago and they're still not leaking. That being said, if it were my boat, I'd probably reseal the shoe with 5200. I love that stuff below the waterline. The dolfinite will simply wash away with mineral spirits or lacquer thinner after you disassemble the joint. Get it really clean before using any of the newer sealants though. The 5200 is an adhesive sealant and will contribute to the strength of the whole whereas the dolfinite is simply a sealant. Ben

[rnummi]

Perfect.... I was grinding my teeth the last couple of days thinking about it. "That can't be right.... The whole boat watertight integrity is dependent upon some sort of super white lithium grease?" I'll climb under and get it out. Same with around cutlass?

Thanks Ben.

[tego]

Rick, It's a different story with the cutlass bearing. The dolfinite will work well there because all you really need is a sealant and you may have to pull that little bugger sometime. The cutlass housing is attached by two bolts that actually do the work. If you do decide to change the sealant, use a non-hardening sealant. Ben

[smacksman]

The fastenings are the strength of the joint, not the sealant. Personally I would prefer the non-hardening sealant that will move with vibration and thermal expansion over the years.

[rnummi]

I'll go with you guys as usual... The "leap" of faith in those that have gone before me....

[tego]

5200 never hardens up. It stays flexible and absorbs vibration very well. Just don't try to pull it off. Ben

[rnummi]

Which one 5200 or Dolfinite takes bottom paint?

[tego]

5200 will retain the paint much longer than dolfinite. The dolfinite, as you observed, is very soft and can be wiped away with a finger. There should be very little exposed at the joint and I've never seen barnacles attached to the caulk (either type). Bottom paint sticks to cured 5200 but it can be scraped off rather easily since the 5200 is flexible. Ben