stop waters

[rkrough]

I'm putting the keel together and ready to drill for the stop waters. I'm wondering if they are still necessary with the modern epoxy adhesives and coatings we use. Any thoughts?

Rich

[Ian McColgin]

Yes.

[RGM]

Definitely

[Bruce Hooke]

Rich,

I would say that it depends on the nature of the joint and the pieces being joined.

If you are talking about a joint that is glued with epoxy in a way that you can expect the epoxy to last then no I don't see why you would need stopwaters. If you are talking about a traditional joint with bedding compound in it, that possibly joins two laminated pieces, then yes, I would definitely use stopwaters.

If the keel is, say, laminated out of 3/4" stock and the glue joints cut across the rabbet then I certainly would NOT put in a stopwater at each glue line. That would greatly weaken the keel, among other issues. On the other hand, if that keel meets up with a separate laminated stem and the joint between the two is a standard scarf connection with bedding compound in it then clearly a stopwater would be required in that seam. Even if you were to glue that stem to the keel it might not be a very reliable joint, especially if the keel and stem were not laminated, so it that case a stopwater might be called for (in fact it would probably be better not to glue the joint but rather to bed it).

So, there's may take. Do take this with a grain of salt because, of course, I don't have any details on your actual situation.

[Ian McColgin]

Bruce makes a nice clarification. For the purpose of stop water location, imagine a laminated member as if it were solid. No need for stopwaters where a rabet crosses a glue line.

You might well add a stopwater wherever there is a 'clothspin' scarf - ===>->====. Imagine the '-' as a round stop water. This is not so much a real stop water as a way to ensure that the apex of the scarf has no voids.

[RGM]

What exactly are you building? Small, medium or large? Separate keel, stem, sternpost, horn timber, etc?

[rkrough]

It's a 25' lobster boat. The keel has been shortened to use an outboard motor. The plywood is butted into a rabbet on the keelson. The keel will be bedded using 5200 onto the keelson I'm also using 5200 on the scarfs The arrangement I have only needs two 3 stop waters total. I made big sections. Thanks for the information I wasn't sure if stopwaters were still in common use.

rich

[True Love]

Please forgive my ignorance, but could someone help me out w/a brief explanation of how a stopwater really works to "stop water?"

[rkrough]

TL, I'm not a 100% certain. But I beleave they act as a dam to keep water from wicking through the joint between the sections of keel and or stem. Since the dowels are made of pine and are installed perpendicular to the grain of the wood I assume the swelling of the dowel when wet acts to seal the joint.

Rich

[Lulworth]

What's a stopwater you ask? It's the softwood dowel whose circular end is visible here at the butt joint between the fore- keel and aft- keel timber sections. Note the stop water crosses the apex of the rabbet. In this case the aft and fore sections have pulled too far away for the stop water to work but if the gap between the two sectitions was smaller, the dowel would swell as it got wet and form a tight seal. That's my understanding anyway!

David

http://www.imagestation.com/picture/sraid33/p769bf3c83379ab87f99cacc183f0e480/fd3ff64d.jpg

[True Love]

I guess I'm still a little puzzled at how you decide where to put them. I know the plans tell you, but I mean the logic of it.

By the way Lul, love your choice of boats - where the heck did you find that S boat? I have had my eye out for one. I saw some of your pics (but kept getting my program fried trying to get past the pic with the two new frames, for some reason). I look forward to seeing your progress. Cute kid, too.

[Lulworth]

T.L.:

Stopwaters go where ever there is a path (typically a joint) in the timbers of a boat that would allow water to go from outside the planking to inside (thus consituting a potential leak). This usually means a joint at the stem or possibly in the keel timber if it is made up of two or more sections.

So you want an s-boat? If you live on or near Narraganesett bay, finding one is simple -- contact the Narragansett s-boat class chief honcho. There are (I understand) several around looking for owners. I found (maybe I should say, I was found by) mine by agents of someone who had signed a contract promising to only sell the boat so someone who would keep it on Narraganset Bay. Such is the local enthusiasm for preserving an active one design fleet that is almost 100 years old. I bought it from the guy for $1.00 and, I must say, I was robbed. And it wasn't just his unrestrained joy when I hauled it out of his workshop that first tipped me off. (I'm kidding of course, I knew what a mess it was before I ommitted to it). There are quite a few sboats around since it was (in my words) the sunfish of the robber baron class. If, in the unlikely event that you live in or around RI/MA/CT and you are serious about an sboat, email me at ftldco@aol.com and I'll get you in touch with the folks that know all about sboats in this area.

David

[Allen Foote]

YES! Use the stop waters. Regardless of epoxy ect.....those seams will need the extra swelling of the placed stop waters. They expand when swelled to keep joints TIGHT.

[True Love]

Lul- I like anything built for speed on the water. S boats being just one of the nimble beauties which fit that description.

Alas, I live in the land of corn and soybean but am not totally averse to driving up to Lake Michigan to sail. Used to have a boat up there.

Are all S boat owners determined to keep their boats in RI?