Wooden Boom refit. What are castings bedded in?

Ric in Richmond · Post by **Ric in Richmond** » Fri Feb 13, 2009 9:13 am

Hello Ladies and Gents!

I am wooding and varnishing Andiamo's original boom.

I know it has been done before so the bedding compound for the end fittings is likely not original.

I swear it is plumbers putty or window glazing compound that has hardened up. Is dolfinite like that? Tan, softens with heat, feels slightly waxy?

Any products you have used to bed cast bronze to wood where there is a small gap to fill?

Post by **Tim** » Fri Feb 13, 2009 9:28 am

Dolfinite would fit the description that you seem to have.

Hirilondë · Post by **Hirilondë** » Fri Feb 13, 2009 10:21 am

Yeah, Dolfinite would fit that description. It must have been on a long time to get hard though. It stays pliable for a long time.

It is also what I would use to put it all back together. Dolfinite has virtually no adhesive properties, and everything will come apart next time with little chance of damage to the spar.

Rachel · Post by **Rachel** » Fri Feb 13, 2009 12:30 pm

As long as we're on the subject, a couple of questions:

1) Have any of you (or do you advocate) added anything to the Dolfinite? I've heard about people doing so to try to recapture some of the "good" toxic qualities of the "good old" Dolfinite. I can't remember offhand what they added though, sorry. I could probably turn up the info if needed.

2) Is Interlux's "Boatyard Bedding Compound" equivalent, if it's on hand and Dolfinite isn't?

Ric, I bet that boom is a gorgeous hunk of spruce, isn't it. :)

Rachel

Hirilondë · Post by **Hirilondë** » Fri Feb 13, 2009 1:53 pm

Rachel,

1. I don't know what you would add or what improvement would be achieved, so I wouldn't add anything to it. They can be thinned using linseed oil if there is a need.

2. Both are linseed oil based, so they are most likely almost the same product. These products are today's version of very ancient products used in the days of wooden boats. There is no high tech chemistry involved. They are basically powderized solids turned into mush by adding linseed oil.

Idon84 · Post by **Idon84** » Fri Feb 13, 2009 2:15 pm

Currently all of my wood mast and boom fittings are 5200'd on. I've been slowly working on removing it. Dolfinite would be the material of choice here then? Below is a pic of the lower spreader attachment. Gotta fiddle away at that 5200 for a while... ugh!

[img][img]http://i271.photobucket.com/albums/jj14 ... G_0178.jpg[/img][/img]

Rachel · Post by **Rachel** » Fri Feb 13, 2009 2:48 pm

Idon84 wrote:Currently all of my wood mast and boom fittings are 5200'd on.

Any chance you can still shoot that person?

Dave,

I dug into the memory banks (supplemented by a search :) and found what I was remembering. The thought is that the anti-fungal properties that Dolfinite traditionally had are no longer there, due to current environmental standards, and that therefore it has lost some of its good properties. Various additions have been proposed to restore that. I haven't used Dolfinite (yet), and I don't know how true any of this is, but it's what I was curious about.

Hmm, I hope this isn't too much information, or to much "hearsay," but I find it interesting. All of the information is from posts in the archives of the Woodenboat Forum, and was found by searching "Dolfinite add," in case anyone would like to read more (or I can help anyone to find the exact source). Each section is a different person's input.

Dolfinite has been used as a traditional bedding compound even though it's anti-fungal qualities are essentially non-existent now. You can add some copper preservative to it or even some borite powder.

The old formula had a heavy-duty fungicide, pentachlorophenol, that I believe is now banned. It really worked. I don't know if the present product has any fungicidal properties. I have mixed a good dose of copper napthanate in the new stuff. Seems to mix ok. I guess I'll know if it worked in 20 yrs or so (it was in the old as well).

Yep, word is that the "fungicidal" in Dolphinite was outlawed. The new stuff isn't as nasty as the old stuff, so I suppose it isn't as deadly. You COULD mix Di-al into [it as I do into] mine. This is tributyl-tin in a kerosene type solvent. It is sold at paint stores to add to paint to prevent mildew. It is outlawed in bottom paint and stuff as well... this isn't legal advice! LOL

I think Dolphinite is OK as a bedding compound, but half the cans of Dolphinite I've bought in the last few years are skinned over when you open them and the stuff dries out in place pretty quickly. I'd never bed windows with it again, for example, and avoid bedding pads with it as well. It's OK for buttering screws, or maybe butt blocks.
If I can, I'd use something else though such as one of the Pettit products (for bedding or paying underwater seams) or even Sikaflex. Like they say, 5200 isn't a bedding compound....
If you do use dolphinite and the stuff feels like it's going on a little dry, you can mix linseed oil back in and that seems to help rejuvinate it and maybe even help it last longer. I don't think it's as good as it used to be for some reason, and not just that it lacks the fungicides. But I mean...the stuff dries out in the can.....

If you prime the bedded wood parts with red lead before using dolphinite, the oil won't be absorbed into the wood, and it will last longer.

Again, I hope this isn't too much - or inappropriate - information. I debated, but I know that there are many folks on here who do like to delve into a subject, I decided to post it.

Rachel

Hirilondë · Post by **Hirilondë** » Fri Feb 13, 2009 4:06 pm

Probably turning this into more than Ric bargained for, but it is all useful information.

I have no doubt that there is some if not a lot of accuracy in the comments concerning fungicide. Early paints used a lot of nasty components like lead, tin and copper. No one has yet come up with a modern paint to replace red lead for wooden boats. A big part of why it is so good is that nothing grows on it.

I agree that Dolfinite is not a good choice for paying out seams. It works well between layers in double planking, but as it has little adhesive property and it doesn't stay well in places where it is not sandwiched in. Many Concordia sky lights were glazed in some form of boat yard bedding, and it has a limited life for being water proof. It was the best in its day for this, but not any more.

As to whether the author you quote is right or not about it not being as good in other respects now: I can't say. He might very well be making a very subjective comment based his experiences with other "new" products.

The author also mentions priming wood before bedding to avoid the leaching out of the linseed oil. This is very true. But prevarnishing a spar does the same thing.

Idon84 wrote: Dolfinite would be the material of choice here then?

It would be my choice, but some would choose a polysulfide.

Rachel wrote:Any chance you can still shoot that person?

He sure deserves it.

Idon84 · Post by **Idon84** » Fri Feb 13, 2009 5:47 pm

Rachel Said

Any chance you can still shoot that person?

No... He's dead now. Love to figure out what he was thinking in this and a few other areas though...

I'm almost finished removing all that 5200... Sharp chisels with a steady hand, my new friend PB Blaster to soften it up and plenty of towels for clean up.

All for the love of a boat...

David · Post by **David** » Fri Feb 13, 2009 6:33 pm

Keep the faith Bryon. You're doing beautiful work.

David

Rachel · Post by **Rachel** » Fri Feb 13, 2009 6:54 pm

Dave,

Thanks for the additional input. I agree that I went a bit past the sort of information that Ric would need for his boom; paying seams is definitely a different (and more demanding) ball game. I just find the topic interesting, and it had been lolling in the back rows of my brain for a while now. I know you're a carpenter, and I figured you for the sort who would have some modern outlook, and cut through the hype (if there were any), and yet also balance it with a traditional perspective.

Also, when a thread is developing, I always have half a mind on the idea of someone (maybe me :D) searching the topic in future, in addition to answering the question of th original poster.

Rachel

Idon84 · Post by **Idon84** » Sat Feb 14, 2009 1:42 pm

One day at a time! Little by little. Thanks for the comments!

Ric in Richmond · Post by **Ric in Richmond** » Sun Feb 15, 2009 9:41 am

Wow the thread exploded...in a good way!

More info is always better.

I am going to get some dolfinite..but I think it may be almost the same as DAP window glazing. Certainly smells and feels the same.

I'll set up a sample of each, since I have a can of window glazing and compare them over time.

Yes Rachel it is a great hunk of spruce. It smells great as it heats slightly and the varnish yields to the scraper.

Hopefully I can get a thinned coat on today so I can finish it up.