Sheathing Baltic Trader

[SCHOONER_SARA]

We are searching for options (affordable to our limited budget) to sheath our tired 1904, 70' L.O.D., (100' sparred length) 100 ton dilplacement, oak plank on oak frame, wrought iron fastened Baltic Trader schooner for the purpose of making her seaworthy again. Our first choice would be to properly rebuild the vessel in the traditional manner, but unfortunately that is not financialy feasable for us. We believe the vessel is worth saving and hope to keep her alive for at least another 20 or 30 years until a time when maybe there will be others with the means to rebuild her properly. We have heard some success stories of sheathing with ferrocement in Europe, but can not find anyone here on the west coast of U.S.A. that has even heard of such a thing. We are looking for any information that may help in determining specifics necessary to accomplish sheathing this vessel with ferrocement.

 

[ccscott49]

Never heard of it over here. I would have thought the movement of the timbers, would crack the cement, just as it does caulking putty, or paint. People have sheathed in glass fibre, but have the same problems. There's no help I can give you, apart from do it traditionally. IMHO

 

[martinschulz]

All I can do to help you is to give you the Internet-adress of a good friend of mine. He owns the WILLOW WREN a 1886 built Smack. Apparently this ship got cement on the hull as early as 1910. Back then it was done very thin to save the ship from the terredo-worm. Then she was in a mud-berth for almost 20 years. When new owners wanted to sail her again a better and thicker ferrocement-coating was put on in the 70s. And nowadays she is still sailing and doing great.

here is the url:
http://www.willow-wren.de
(isn't she a real beauty?)

When you write Uli (the owner) an email feel free to ask him anything you want. He is very much informed on the matter.

 

[Trevethan]

visit www.ferroboats.com. There is a mine of info about ferro sheathing. It seems fairly straightforward, and the website owner (Colin Brookes) I think) is very knowledgeable about all aspects of ferrocement boatbuilding.

Surprisingly, once sheathed many wooden boats need extra ballast as they end up lighter than when they were all wood - putting pay to the myth ferro boats are heavy!

I think the most important thing to remember is get professional advice and help. A good ferro boat will usually be plastered in one day and then wrapped to slow down the curing process. For a boat your size, this entails considerable skilled manpower!

A lot of people tend to look down their noses at ferro boats, expecially here in the UK. Generally because in the 70's there was a rush of home built boats made, very poorly, were generally much too heavy (teh hull should ideally be less than an inch thick) and when the owners we unable top sell them for what they thought they were worth, they met unfortnate accidents, for which insurance was collected. ... which is why they can hard to insure.. especially a home build.

I am a fan however.. and most people think the hull of gayle louise is steel. At some point in the next few years we will lift her and take off the epoxy coating and redo it at which point I hope by dilligent sanding we can make her appear like glass.

Ferro is easy to repair too with a mix of epoxy and cement ( I actually use a product called stone repair and works very well!

Good luck!

Regards,

Nick

She had a deep, throaty, genuine laugh, like the sound a dog makes just before it throws up

 

[mtb]

Yes Colin your right imho and what happens in a heavy sea , the hull is bound to flex !!.
Cheers
Mick

smile you'l be on your boat soon ;-)
<A target="_blank" HREF=http://homepage.ntlworld.com/boats/>http://homepage.ntlworld.com/boats/</A>

 

[Trevethan]

properly apllied, i.e. thin enough concrete is supposed to flex too though. I always thought it might be a bit stiff but apparently will flex very well if done right...

She had a deep, throaty, genuine laugh, like the sound a dog makes just before it throws up

 

[mtb]

Interesting but I'd tend to think if it's thin then there are more risks associated with soft and hard spots due to variation of mix .
Obviously I'm just a bod who's not done Ferro cement but plenty of building and personally would not own a boat made of this material.

mick


smile you'l be on your boat soon ;-)
<A target="_blank" HREF=http://homepage.ntlworld.com/boats/>http://homepage.ntlworld.com/boats/</A>

 

[chippie]

I was under the impression that reinforcing was attached to the existing hull so that in effect the old hull was really a mould for what is virtually another hull on the outside.
I share your reservations but see it as an acceptable way of saving a boat that would otherwise be economically irrepairable.
If it works , it is an acceptable solution in my opinion.
Finding another boat that has had it done successfully would be the answer.

 

[martinschulz]

Ehm - for the Willow Wren this works nice since 1910 which is a longer time than the age of most boats we are talking about here.

 

[martinschulz]

sorry!

Ehm - for the Willow Wren this works nice since 1910 which is a longer time than the age of most boats we are talking about here.

 

[Trevethan]

Which is why the job needs to done properly by people who know what they are doing, rather than Fred in his shed with a roll of chicken wire and a bucket of quick drying....

I've owned glass and wooden boats in the past (all generally small, and at first was a bit prejudiced against ferro like many others, but while in the US spent an afternoon on a Sampson Sealord.

Listened to owners enthuse and point out its many good points and that opened my eyes.



She had a deep, throaty, genuine laugh, like the sound a dog makes just before it throws up

 

[paulstevens]

re: ferro sheathing, willow wren etc.

I remember willow wren being sheathed here in my home village of Maylandsea. If my memory serves the work was carried out by the Kingston brothers and their father.
Contrary to all the pundits dire predictions the method worked and as Martin says below willow wren is still going strong.
Just to show their faith in the job the Kingstons subsequently dragged another old wreck out of the mud, a revenue cutter from about 1860 I think. They repaired this boat in the same way, including repairing structural frames with ferro, then sailed her round the world without incident.
I think I have some description and specifications of this work somehere, If I can find it I will post again. Whatever the purists say this kind of repair must be better then the vessel being lost forever.

regards paul stevens.

 

[Jacket]

If I could work out how to make it appear I'd post a picture of a test I carried out last year. It shows a concrete beam, abot a metre long and 10cm deep, being loaded up with a hydraulic jack. The beam bends through an angle of almost 20 degrees from end to end. While there is some fine cracking on the underside (the tension side) none extend more than halfway through the slab.

So I'd doubt that you'd have to worry much about flexibility of a ferrocement sheathing.

 

[mtb]

But Lintles and beams have quite substantial reinforcing . I've seen the work done re bridge beams that are made using steel cables which are tensioned , then once the concrete has set the cables are released thus compressing the concrete increasing compression strength. I understand the way in which a lintle works and yes they do and can flex .
It's the thin layer that I keep thinking about yes the hull can be prepared to accept the concrete but unless there's a chemical bonding which adheres to the timber completely which at this point I don't believe it would over a period of time, because of the nature of wood re acidity and moister content not forgetting the drying out.
Does the leaching of old antifouling or tar have an effect on the bonding.
Yes the layer has reinforcing but how substantial can that be given the layer thickness. Also if the concrete is bonded to the hull it wont be flexing in a way that would allow it to keep the shape because the hull would be either holding it or moving it .
Then what about the heat given off when the concrete sets due to the chemical reaction does that not create air pockets. With a new hull there is air both sides .
Yes I know I may be going on but that's how I think things through and learn when some one helps me to better understand a practise.

cheers
Mick

smile you'l be on your boat soon ;-)
<A target="_blank" HREF=http://homepage.ntlworld.com/boats/>http://homepage.ntlworld.com/boats/</A>

 

[SCHOONER_SARA]

Re: re: ferro sheathing, willow wren etc.

We are intending to box in her keel, stem and sternpost with 1" and 1/2" mild steel plate through bolted. Specifically what we are looking for is details on minimum steel reinforement requirements and type of concrete mix. Application can be accomplished on marine railway, vessel fully resting on keel blocks held upright by outboard whalers. The actual concrete application will be blown on as in gunnite - shotcrete application then hand troweled fair (hopefully).
Thanks for the help!