re caulking dried out hulls

[modwena]

I have just bought a 1924 built 25' carvel planked gaff rigged Norfolk Broads river cruiser.
She has been out of the water for about three years and the seams have opened up showing gaps in the caulking.
I had a recaulk in mind using cotton then sykaflex instead of putty.
My concern is that when the boat is put in the water the seams will close up pushing the sykaflex out.It has been suggested that I first try to drench the hull so that she takes up before I recaulk, others have said this is not nesessary.
Any comments would be greatly appreciated.
Also the hull is coated in black tar varnish, should I replace this with a more modern antifoul?

[Ian McColgin]

SneakyFlux is lovely stuff but not for caulking.

[rodcross]

When I bought my 40 year old boat, she'd been on the tarmac(sp?) for a hot summer and there were a number of open seams. I didn't dare remove or add any cotton and I didn't dare put any shmoo in the seams that had any chance of compressing the wood. A half a can of Slickseam later she floated. I'm glad I did no more than that. She tightened up in a day. It scares me to think how easy it would have been to wreck it or spring a plank. My vote would be to do as little as possible, get her thoroughly wet and only then assess the need for any seam treatment.
What's black tar varnish?

[This message has been edited by rodcross (edited 01-03-2002).]

[modwena]

Will getting her wet effect what I can use to pay the seams with?
I know for sure that some of the cotton needs replacing, and thought that I would have peace of mind by doing the lot,also a lot of the putty in the seams is falling out
and will need replacing.I was thinking that the whole job would be easier done while dry.

Black tar varnish is a black tar like paint which is painted on below the water line and can build up over the years to 0.5 inch.and more.

[Scott Rosen]

I like Rod's answer. You shouldn't attempt a caulking on an old dried out hull until you know how much the seams will close when wet. Slickseam is the right stuff for temporary sealing, and it will stick to the wood wet or dry. If you want to, you could haul the boat mid-season and caulk it then.

I'm not going to reopen the putty versus goo debate here.

[Noah]

The only problem with this theory is that the slick seam will prevent other stuff from sticking later on. It is very hard to clean the stuff off of a seam.

Though I still recommend getting the boat wet before doing anything. It is amazing how much some woods swell/shrink. WIthout knowing what the wood is that you have it is hard to know.

Good luck.
Noah

[RGM]

Refasten the planking and anything else that might warrant it prior to re-calking her. If you have spaces between your planks that are "wide enough to throw a cat thru" then you should soak her a while, close up those gaps a bit and then do any refastening if so required. What is she planked with? Is the planking flat sawn or quarter sawn? If there are gaps between the faying surfaces of the planks and frames clean out any debris in those spaces with a hacksaw blade that has been hammered flat (take the set out of it). A dull blade is better, you're not really trying to cut any wood structure or old fasteners, you're just trying to do some cleaning. Following the hacksaw blade treatment blow the spaces out with compressed air or better yet vacuum them out. You might want to squirt some kind of perservative or "snake oil" into the spaces that you've recently cleaned out with the hacksaw blade. Refasten the planks as necessary. Leave the old cotton and seam compound in place, if you are re-fastening prior to soaking. It will serve as half-assed spacers while refastening any planks. Once the planks are re-fastened reef out the old cotton (if you're going for the full re-calk), Secure some burlap, muslin, bed sheets or similar material to your hull (exterior) and start soaking it down with a garden hose/yard sprinkler. The process doesn't have to go on around the clock (that would be nice if possible), thorough soakings done frequently will work. Keep the material fastened to your hull good and wet. It could take as long as three weeks. Start calking her up when the gaps between your planks have closed up enough to suit you. Some people (as rodcross describes) have success by putting their dry boats in the water supported by slings for a day or two (hopefully) and just keep pumping the water out until the bilge dries up. After which they either sail happily off into the sunset or haul the boat out and assess what seam repairs if any they need to do. With old planking that is wet I think you might have better luck with putty as a seam compound. Either that or consider using a seam compound that likes some moisture such as any of the polyurethane products (ie, 3M 5200, Sikaflex 231) and be willing to live with their disadvantages. As far as anti-fouling paint goes, what seems to work the best in your neck of the woods? What's legal or illegal? How much time if any will the boat spend out of the water? Are you going to be in salt water or fresh water? I'm not familiar with "black tar varnish" but I'm guessing that it is a concoction made from pine tar, turpentine and varnish or shellac. It might be ok in fresh water, not so good in salt water. Good luck.

[modwena]

Not sure whether she has quarter sawn or thro and thro planking, I am reliably informed she is redwood on oak frames, the planks being 1inch thick and attached to the frames with copper/bronze? roves.The planking looks very secure and the old girl seems to have kept her shape well.

She is sailed on the Norolk Broads, a network of about 6 rivers and ancient flooded peat cuttings on the east coast of England. They are mainly tidal and the water is some what brakish

[Stan Derelian]

Just a curiosity question here... When you say redwood, you wouldn't be talking about California redwood would you? I can't imagine it used for planking.

[modwena]

Apparently so,she is planked with Californian redwood. I would be interested to know why you think this strange,from what I have heard redwood and water go together quite well.

[modwena]

Originally posted by RGM:
Refasten the planking and anything else that might warrant it prior to re-calking her. If you have spaces between your planks that are "wide enough to throw a cat thru" then you should soak her a while, close up those gaps a bit and then do any refastening if so required. What is she planked with? Is the planking flat sawn or quarter sawn? If there are gaps between the faying surfaces of the planks and frames clean out any debris in those spaces with a hacksaw blade that has been hammered flat (take the set out of it). A dull blade is better, you're not really trying to cut any wood structure or old fasteners, you're just trying to do some cleaning. Following the hacksaw blade treatment blow the spaces out with compressed air or better yet vacuum them out. You might want to squirt some kind of perservative or "snake oil" into the spaces that you've recently cleaned out with the hacksaw blade. Refasten the planks as necessary. Leave the old cotton and seam compound in place, if you are re-fastening prior to soaking. It will serve as half-assed spacers while refastening any planks. Once the planks are re-fastened reef out the old cotton (if you're going for the full re-calk), Secure some burlap, muslin, bed sheets or similar material to your hull (exterior) and start soaking it down with a garden hose/yard sprinkler. The process doesn't have to go on around the clock (that would be nice if possible), thorough soakings done frequently will work. Keep the material fastened to your hull good and wet. It could take as long as three weeks. Start calking her up when the gaps between your planks have closed up enough to suit you. Some people (as rodcross describes) have success by putting their dry boats in the water supported by slings for a day or two (hopefully) and just keep pumping the water out until the bilge dries up. After which they either sail happily off into the sunset or haul the boat out and assess what seam repairs if any they need to do. With old planking that is wet I think you might have better luck with putty as a seam compound. Either that or consider using a seam compound that likes some moisture such as any of the polyurethane products (ie, 3M 5200, Sikaflex 231) and be willing to live with their disadvantages. As far as anti-fouling paint goes, what seems to work the best in your neck of the woods? What's legal or illegal? How much time if any will the boat spend out of the water? Are you going to be in salt water or fresh water? I'm not familiar with "black tar varnish" but I'm guessing that it is a concoction made from pine tar, turpentine and varnish or shellac. It might be ok in fresh water, not so good in salt water. Good luck.

Thanks RGM you have answered several of my next questions already, but could you please explain the disadvantages of using something like sikaflex231.

[Stan Derelian]

I am surprised at the use of redwood. I can't recall ever seeing a boat in California that used it for planking. Definitely rot resistant--especially old growth stuff like you must have, but it is a quite brittle wood subject to splintering with a crushing blow, and I would imagine difficult to bend.

Are there other boats in your area that used it? If so, maybe it had something to do with holding up in the brackish, acidic(?) water from the peat bogs?

[RGM]

The main disadvantages of using something like Sikaflex would be that it would make future removals/repairs a little more frustrating than they normally would be if you were to use some type of putty, and getting a good bond to old material is risky, even if you take all of the right steps. That's your call. Rubber in planking seams can be ok to deal with. It's gets more difficult when the stuff is used as a bedding compound and to make up for poor workmanship. "Shipwright in a tube" so to speak. When applied properly these rubber compounds can be really tenacious and do the job that they were intended to do. However, the rubber compounds are less "surface tolerant" than putties. So everything that you have recently read about cleaning, degreasing and sanding seams (ala Scott) is extremely important. If you use these compounds you want everything going in your favor. Do not cut corners here. That includes using the recommended seam primer. Sikaflex does make a primer for their urethane compounds, use it. It sounds like you really want to go that way, or perhaps you've already purchased the material. That's fine, it will probably work just fine for you providing you take all of the steps that have been detailed. As mentioned before, read all of the fine print. In closing, you may experience difficulties when making future repairs (which really aren't that bad for just planking seams, it cuts with a knife). There's high potential (to say the least) for getting the nasty stuff all over everything while you work with it (clean-up can be a bitch so have the recommended solvent on hand). Wear all of the appropriate safety gear that you can stand, read the Material Safety Data Sheet before you embark on this adventure. There's a high potential for failure if any/all of the proper steps aren't taken, ESPECIALLY when dealing with old wood, unknown or questionable moisture content, etc. Putties aren't as technical, they usually work pretty well, they're relatively cheap, they're basically idiot proof. I'm not saying that you are an idiot, far from it. I believe that you are a smart and conscientious person that intends to do the best job that you can with the material and resources that are available to you. Good luck modena.

[This message has been edited by RGM (edited 01-04-2002).]

[This message has been edited by RGM (edited 01-04-2002).]

[Ed Harrow]

I've been thinking about the redwood too. Might it be something else - cedar? Don't know, don't know enough to know, but I, too, have never known of a boat planked with redwood.

[Dave Fleming]

RGM's thoughts/comments are just what I would do.
That "REDWOOD" thing has got me puzzled too.
Whilst redwood does well as pickle vats, wine vats, exterior house trim and porch material, I dunno if I would trust it for boat planking. It is brittle and splits easily.
Of course in big thousand gallon vats with 2 inch plus planks all coopered together that is not a big problem.

Personally, I have yet to see a boat planked with it out here on the West Coast of the USA.
Another thing redwood( California ) is not too friendly to steel fasteners. Acidic I believe. Copper/Bronze or SS seem to be the metals of choice for use with it.
This is most interesting, I do hope you will post more about the history of your boat and others that are in your area and similarly constructed.

[RGM]

I believe that modwena has some really fine old growth Western Red Cedar out of Canada for his planking. Being in the the U.K. the original builder may have had a nice pipeline to Canadian suppliers. Just a thought. How about some pictures?

[This message has been edited by RGM (edited 01-04-2002).]

[modwena]

I started sailing with the Green Wyvern Yachting club in 1985, it has a fleet of about six club boats that take children from inner city schools on sailing holidays(adventures) for around seven weeks a year.
There are actually over 300 river cruiser class on the broads with more being built.
The Broads is the uks newest national park.
They are tidal and therefore the water is slightly salty. The Club website is at www.gwyc.org.uk/ (http://www.gwyc.org.uk/) where Modwena and other river cruiser class can be seen.

Modwena was built by Ernest Woods at his Cantley yard in 1924. She is believed to be the sister ship of Elf. Still in original layout, Modwena has a main cabin with 2 berths and a fore cabin with a quarter berth and WC/wash basin. The roof fully lifts to give a height of 5ft 6in in the cabin. The only changes to have been made under the water are some extra pieces grafted on the fore and aft of the keel and a spade rudder, which was installed in 1984 after being grounded on the Waveney. The original rudder was severely bent so a replacement (Iroko on a stainless frame) was fitted at Eastwood Whelpton. The new rudder is a huge improvement being far lighter and yet still sensitive.

Modwena
Sail Number 87
Built 1924
Builder Ernest Woods, Cantley
Length 25 ft
Beam 7 ft 6in
Handicap -18
Sail area (Main + topsail) 302 + 110 sq ft
First year with Club c1978
(quote from gwyc website)

As for the caulking the boat yards on the broads are leaning towards using goo but I think the DIYers are still with putty.
I must admit I would prefere something easy to use but high maintenance.
She will be out of the water for about 5 months every winter when she shall get a new coat of paint anyhow so any loose or hardening putty could be replaced then.

I was told the planking is Californian redwood by the previous owner, I shall inquire as to why he thinks this. It is known that Ernest Woods was a builder of very sturdy boats.
I did get a look at the timber in the planking recently and it was hard to tell what it is .I must admit I have never seen Cali. Redwood in the flesh. I am thinking now that he may have meant European Redwood(scots pine). Any one any ideas of how to distinguish between the two? Or does it even
matter?

[modwena]

I am informed the lloyds registry of yachts has it stated that the planking is Californian Redwood fort those of you interested.

[Thad]

Ernest Woods, 1937 in Horning, was the builder of our SEA HARMONY as well as two of the other Albert Strange boats built for the Suffling brothers.

[Bob Cleek]

Well, I live in the redwood country and I've cut a whole bunch of it in my day. NO WAY would anybody be ABLE to use it for boatbuilding, even if they tried. Given the size of your boat, you wouldn't be able to keep a plank fastening in it without splitting the plank ends, that's for sure. Now, the old growth redwood which would have been available in 1924 was a much tighter grained wood, to be sure. Still, even that would never have been suitable for planking. It is likely red cedar or some other similar wood. Wood names seem to change when crossing borders. One man's pig is another's pork. You've got larch in one place, tamarack in another and hackmatack elsewhere. Same for locust and acacia. Our Douglas fir here where it grows is your Oregon Pine when it gets to the UK. Aside from redwood's splintering characteristics, it is also very soft. You can dent it with a fingernail. And... this for you trivia freaks... redwood is (as far as I know) the only wood that swells in the direction of the grain rather than across the grain. It gets longer, rather than wider, when wet... or so they say. That would eliminate it as a planking wood from the start. Now, if you want to know if it is really California redwood, take a little tiny splinter and stick it into your skin. If it is festering and oozing puss in fifteen minutes and hurts like hell... it's California redwood! It has a very high tanin content, which causes that. (BTW, it is used for water tanks and hot tubs and has been for years, but in those applications the planking is thick, usually 2" minimum, and the tanks are bound tightly with iron bands with adjustable turnbuckles... and they still leak. LOL

[modwena]

Well Bob,
I suppose there must have been some mistake at the boat yard in 1924. As you said, names can get mix up.
However I have to point out that the planks on these boats were steam bent into place then clamped until there shape held, then fixed, so splintering at their ends may not have been a problem.
As for the expansion along the grain ,all timbers do this to a certain extent, some more than others.Soaking the end grain in a sealing compound helps reduce this.Redwood must also expand across the grain just because it is a wood with the same stuctural make up of any other soft wood.
When I read about the softness and brittleness of redwood It did get me thinking.
As I was poking away at the seams of Modwena I pushed a little too hard on one edge and was amazed at how soft it was,not like a sponge but almost 'crispy'and a few splinters broke off.So this works with your description of the timber.The hull of modwena, as with alot of the older broads boats, is painted with a substance called black tar varnish, which inpregnates the timber then builds up on the surface to make quite a hard protective layer. If she is redwood maybe this is what has protected her all this time.
The planking on Modwena is unusualy thick, (over 1 inch) for a boat of her length and purpose,being only sailed on rivers and broads, with lots of oak (also high in tanin) ribs and frames giving support.

Apart from my attempts at rubbishing your claims Bob,the thing to me that points towards her NOT having Californian Redwood planking, is that no one in California has ever heard of boats being planked with Redwood.
My only counter to that is to point out the occasional quirks of my fellow countrymen.

I shall not continue to hypothisise and will carry on the Redwood theme if I can get hold of some evidence to settle the thing either way.

Back to my original problem, I have contacted the boat yard on the broads that maintains a large proportion of the River cruiser class fleet, thinking that he will know how best to approach my problems.
When I hear from him I shall post his advice.

One piece of info I have got is that Modwenas seams are payed with glazing putty!Apparently great for one season but fell out after two,surprise surprise.

[Stan Derelian]

"Crispy, soft, and splintery." Sure sounds like redwood. And the inch thickness supports the idea for sure. How has it reacted to any iron that might be in it? Keep at the identification. The history of how it got there would be interesting. Are the other boats planked with the same stuff? Like Bob, I grew up with redwood, and there was never a thought of using it for boats. Maybe it was used in your area (rivers) because someone there knew it is so resistant to rot.

...a little aside...after the '89 earthquake the city of Santa Cruz replaced their water mains, and found that some of them were hollowed out redwood logs...still functioning after 100 years.... Also, Bob, my redwood hot tub didn't leak a drop for 12 years, and then when it started a liberal application of Boat Life kept it going for 3 more.

[modwena]

It is possible that redwood just happen to fit the bill on the broads and I will look into whether other boats have been planked with it.Your open mindedness is refreshing.

Thad,
It is good to hear from someone else with a boat made by Ernest Woods ,the guy got around as I have found info showing he had a boat yard back in 1905 on the broads, not in Cantley or Horning.
What is your planking made of?

[Thad]

Woods was in Cantley when he built Charm (33') and Charm II (40') in 1921 and 1925 respectively. Sea Harmony (33', 1937 -- all three based on the 28.5' 1917 VENTURE design) is planked in teak on rock elm with a greenheart backbone and lead ballast. I was pleased to hear of your boat whatever her planking. Do you know the book ON THE BROADS by Anna Bowman Dodd?