Lead and tar in the bilge

[The Schooner Etain]

Ok, so as any of you that went to my pictures will know, I got a lovely surprise last weekend while working on the boat.

The original plan was to remove all the concrete that I thought the bilge was full of, and replace it with lead. I was right in the bow and the stern and the engine bed, but a large area in the midship bilge turned out to only have a little concrete, and then the rest was tar and lead.

The question is wether or not I should just leave it all there as is, or if I have to go through and remove it all and then put it all back. My concern with the concrete was that it might have trapped water around the ribs and rot may have started in places where I couldn't see. Is this still a concern with the lead and tar area, or would the tar keep all the water out?

Chris

[Dave Fleming]

Chris, a couple of questions first.
Is the lead ballast loose resting on the planking?
Is it real TAR as in roofing tar or something a little less dense than what I/We usually think of as roofing tar?
How much of the whole area are we talking about?

Give us answers to those questions and then I/We will have a clearer picture of your ballast situation.

[The Schooner Etain]

Thanks Dave, here's a photo of the area in question...

http://www.imagestation.com/picture/sraid19/p4fa36cc119ab98371091462f0e8ae924/fdc6850d.jpg

And a photo of one of the lead blocks...

http://www.imagestation.com/picture/sraid19/pf47b131240c294383bf7513a85e7ed9f/fdc6850f.jpg

Ignore the hole in the middle of it and the scares at the side, that was made by the concrete chipper.

The lead blocks are not loose, they are completely incased in the tar. Best guess is that they put some tar in, set all the blocks in and pour tar over the whole thing, then topped it off with concrete.

The tar seems to be very good stuff, but I'm no roofer. There doesn't seem to be any impurities in it at all, and it's really thick and strong.

As you can see in the photo, the area spans about 7 frames in total. The single lead block that I pulled felt like it would weigh in at roughly 25 to 30 lbs. It seems like there's a whole lot of them, as they are fitted together, one row point up, the next point down.

I haven't noticed any serious rot in the frames where the concrete was, and I am assumming that the tar area would have been even drier. The only problem I might have is if I need to replace the keel bolts under the tar. About half of the iron keel is under the tarred in area.

Chris

[Bob Cleek]

Looks like a pretty common "fix." Ballasting and balance aren't exact sciences and often it is necessary to ballast for trim after a boat is built. She was probably up in the ass and/or had too much weather helm. Since you are in there, you might as well do it right. Remove the concrete, tar and lead. Wood is always better off with the air getting to it. Recast the lead into a ballast shoe and attach it to the deadwood. (Cut a space to accommodate it.) It will do more good the lower down you can get it anyhow. If your tail bumps on a rock, it'll cushion that as well.

[Dave Fleming]

Chris, Bob has made some good points.
If you are into it this far why not go all the way and clean out the entire bilge area?
If you go the addition to the keel method, carefully keep a record of the area where that ballast is concentrated you will want to place the keel piece in that same area.
Regardless of being set in Tar and or Concrete I don't like the idea of inside ballast lying directly on the planks.
Methods I have seen and worked on include a ceiling placed in the way of the ballast, caulked and red lead painted then the ballast laid atop that or the more elegant way is to have the lead cast in a shape that actually spans two adjacent frames and is lagged to the frames there is some space between the backside of the lead billet and the planking so that air and moisture can pass.

Just my .02 cents worth.

[ 05-02-2002, 02:29 PM: Message edited by: Dave Fleming ]

[Dave Fleming]

Now that I think a bit more on this situation. I seem to recall that Cliff and Ken had lead keels on their Coaster. I beleve, without looking at my copy of Machinerys Handbook, that CI is a bit 'lighter' than Lead. Could be that after launching the vessel was found to be floating too high off her marks or tha, as Bob said a problem with balance/helm.

[Smacksman]

Smacks had iron ballast ceiled over with cement from new. Trim was made with iron pigs with rope strops through them to haul about as required. But once positioned, they could be left there untill something major happened like putting an engine in.

The wood seems to get pitted by the cement after a few decades but as long as you have plenty it is not a problem. Just about everything will part company with wood after a while so yes, you most likely will have a gap between the tar and wood. Pour in some salt water every now and again. [natural leakage does it for me on my boats!]

Check that you have keel bolts. If your keel is dunked up from below into the keelson like a smack, then hanging a new lead keel from it would need keel bolts fitted.

Personally I would stick with internal ballast as designed.

[ford]

I have removed the tar/pitch that I put into my boat in 1984, it was located where the ribs fit into the stem, all I can say is the timber underneath the pitch was damp.

[The Schooner Etain]

Ok, I fired off an e-mail to Bill Peterson to find out just exactly what the original design was like regarding the lead. The original design calls for an iron keel with lead trimming ballast. The updated plans call for a lead keel with lead trimming ballast.

So, it seems that the way she is configured right now is the correct original way. He did mention that there's no specification for concrete in the bilge, and he deosn't recommend it. So it's goo to know that I was right in taking that out.

With regards for your concerns Dave, there is a framework of wood in which the lead sits. I had a hard time seeing it because it's covered in the tar as well, but when I removed a piece of the lead with the old crowbar, a peice of the wood framework came with it. It's pretty lightly built, using 1"x2" plywood strips, but I guess you could still say that the lead doesn't sit right up against the planking.

I'm wondering though, doesn't the concept of trimming ballast include the ability to move the ballast around as needed? With it all tarred in place, that's not the case here, but maybe they found the perfect arrangement and then tarred it. My mind is still not made up as to wether to remove it or not. Do you think the tar would have had any effect on the deterioration of the keel bolts under it. If they are as bad as the ones further forward, then they'll have to be replaced and I have to remove the lead anyways, but maybe the tar slowed the corrosion?

If you guys have any thoughts after processing this new data, let me know.

Chris

[Dave Fleming]

All I can say is "when in doubt take it out", ya folla?
Ayup, trimming ballast is just that. Ya never know when you might change a configuration or add some doo-dad that requires movement of that lead.
Any idea of how many pounds of trim weight Peterson is talking about. Seems like he should be able to give you a ball park figure on it.
I would be inclined to build a box over the keel and lay up the lead weights in it.
That way the weight is spread out over big timbers and still down low and the bilge is kept clean and air can get about it, easier to shift about too.
Nothing fancy but hell for stout in that box construction.
Or so says I.
;)