Open mesh on ferro hull

[Mazu]

There is always a lot of opinions on these forums both pro and con. I own a 43 year old Morgan which is fiberglass. It needed some work to bring her back and I have spent the last two summers doing so. but before I did ANYTHING, I got a structural survey performed. If it came back in any way bad I was prepared to walk away as there are just too many reasonably priced boats out there. Fortunately the boat was sound and the upgrades began. A survey will also give you a rough idea of what you are in for should you decide to move forward. Sometimes the $$ and the time required just aren't worth it. Saying that, my project turned out to be much bigger and more expensive than I thought and I would never do it again. With a good survey you have a better idea of what your up against from a professional viewpoint rather than only peoples opinions

[Sven Heiligenst]

Thank you all for your good and comprehensive advice, there is obviously a wide range of opinions from "chuck it !" to "no problemo" ...I will navigate my way through.
Regarding the boat: it is a Samson design, professionally built in 1978 by a Finnish company that specialized in fireproof coatings for power plants and petrochemical industries, so I hope they got their cement mix right for the boat. Well built interior by finnish boat carpenters, equipped for live aboard in harsh climates with insulation and a danish refleks oven connected to a water heating system. Powered by the original Ford Lehman Marine 2712, revised recently. I bought it in Denmark last winter and sailed it through rough seas to Lübeck, Germany where we arrived on New Years Eve. It will now stay on the hard until spring and right now I am still removing paint and loose parts and identifying problems. I will keep you posted and send pictures as I move along.
Thanks to all

Sven

[upston]

Thanks Gord, bets forum out there. I learn something every day

[redhead]

You are absolutely right in that the materials and procedures used during the original build determine the lifespan of the boat. Ours was yard-built over a 2 year period, using 6 masons for the process. It was dried for 30 days in a temperature controlled space, which I understand is critical to the integrity of the hull.

Unfortunately, too many were built in backyards by people trying to get the most boat for the least money and that reputation will always follow them, I think. I've seen some disasters and understand most people's skepticism. It's not my job to convert anyone to the FC Boat Society (if there is one...)

One of the things I like most about us "sailor folk" is our compulsion to think outside the box. One of the things I like least is the recent trend to condemn anyone who doesn't think inside one's own box (Mono vs Cat, sail vs power, coastal vs blue water). Seems to me I log on every day to learn something, and if we all just repeat each others ideas, I learn nothing.

Gotta go put my soapbox away. G'day all.

PS Here a picture of mine after some work -

[gbowen]

Sven:

I am a retired civil engineer and I have been active in ferrocement and marine concrete since 1971. I have built two boats. I believe your problem is not a big one. If the surface rust after sandblasting is the only problem you have, it can be solved. I built my first boat in NZ in the 70s, the golden decade of ferro. We had user groups like the Waikato Ferrocement Association and the New Zealand Ferrocement Marine Association. We had a shared grout pump and I think every boat built was drilled and grouted.

If you do not have leaks inside or outside that stream rusty water, then I do not believe you have a serious problem. Cement paste is a high pH and dissolves rust and galvanizing. The fact that the cover was thin indicates the care the builders took in keeping the weight down. You may need only a cement wash after a light abrasion of the rust to control further mesh rust. An additive like Sika Latex makes the wash very sticky. For a sealer, I used a water miscible epoxy and diligently pursued any breaches in the seal coat over the years. Sometimes I went 5 years between haul outs.

I thought I once found a ferro boat beyond repair. I built a portable grout pump and flew to Hawaii to grout it. It was a big luxurious boat. When I pumped it, the slabs fell off revealing black paste. I wrote an article about it for the Journal of Ferrocement. A man bought the boat with a bag full of diamonds and put a 3/8 inch layer of fiberglass over the hull. He said he had done it before.

There is always a solution. My boat fell off a transporter and I repaired a hole in the hull. Later I sailed for 31 days with the rail down on that side from Pago Pago to Honolulu. I thought a lot about that repair particularly bashing into the NE trades and swells followed by Hurricane Gilma.

A word of caution with epoxies. Coat tar epoxies are great but you need to control your application conditions and start other paints while the epoxy is curing. There are "non-blooming" water miscible epoxies, easier to use and easy to clean up. If the epoxy blooms or forms a waxy cured coat, it must be abraded to get paint to stick.

In any case Sven, take heart. I can send you photos of ferroboats that were saved after terrible mishaps. It is easy to repair (or at least possible) in most instances I have seen.

As far as books on ferrocement, there are two definitive works: Ferro-Cement by Bruce Bingham and Hartleys Ferrocement Boatbuilding. Gainor Jackson was a wonderful man and his book was interesting but hardly definitive. Morely Sutherland, the co-author, did not do any of the writing. He was commercially motivated and did not share many secrets. The US Navy wrote a ferrocement boatbuilding manual. It is available on the internet. There have been a number of advances in cements. I love the silica fume additive as a pozzolanic material.

I have tried to upload a file showing my 52 ft LOA boat in a boat yard in Sitka, Alaska.

Regards,

gbowen

[rwidman]

Originally Posted by Sven Heiligenst

Hi
I am working on 43 ft ferrocement hull that was badly sandblasted years ago and now shows the first laywer of mesh in many areas, some are already rusty.
I want to put on epoxy, what would be the best treatment for the mesh before painting it ? Thanks a lot
Sven

Just remember, if you intend to use the boat that you are betting your life on the advice of strangers on the Internet who may or may not know what they are talking about. In an case, they have not seen the boat, only a photo.

I know nothing about this type of boat but if it were mine, I would find one or more local people with experience with this type of boat and get their opinions even if I had to pay for them.

[DumnMad]

Great looking boat Sven.

Our boat hit a container in 2012. Delivery path was past a wrecked container ship Leaked just enough to set the pump off every once in a while - I thought it was a few drips leaking from the toilet. Then 2 years later on the slip we saw what had happened.
No problem breaking a 300mm bit of the bow out and patching with epoxy-cement mix. No sign of the patch 3 years later.

[Sailorbob8599]

Originally Posted by bigman1

I don't think ferro hulls will last like grp because the mesh is made from mild steel, once the salt gets at it corrosion corrosion corrosion. .The best that can be done is to patch, but what about the unseen parts.

Not all FC's were built with mild steel, I know of a few that used stainless steel. Not just the rod structure but also the chicken wire.
Don't know how that worked out for them, but it sounded to me like a good way to go.

[Scout 30]

Originally Posted by Sven Heiligenst

Thank you all for your good and comprehensive advice, there is obviously a wide range of opinions from "chuck it !" to "no problemo" ...I will navigate my way through.
Regarding the boat: it is a Samson design, professionally built in 1978 by a Finnish company that specialized in fireproof coatings for power plants and petrochemical industries, so I hope they got their cement mix right for the boat. Well built interior by finnish boat carpenters, equipped for live aboard in harsh climates with insulation and a danish refleks oven connected to a water heating system. Powered by the original Ford Lehman Marine 2712, revised recently. I bought it in Denmark last winter and sailed it through rough seas to Lübeck, Germany where we arrived on New Years Eve. It will now stay on the hard until spring and right now I am still removing paint and loose parts and identifying problems. I will keep you posted and send pictures as I move along.
Thanks to all

Sven

The boat looks AWSOME! I really doubt that anyone that owned a boat like this would just walk away from it because the hull needs repair. I know I wouldn't. I've done major blister repairs before & this is really no different in terms of scope. I would caution that thickened epoxy is not really suitable for areas that need significant building up without adding layers of glass.

Post more pics!

[NCboatrx]

Originally Posted by Deltasailor

Sorry to say but it is FxxxD. Cut your losses and find a similar GRP hull and move all the fittings.
A friend of mine bought a abandoned hull which was rusting for about 10 years plastered it with ferro and fitted it out.
Sailed it out to Madira. On his way back home 5 miles off the Azors it went down like the stone it was. A week in a life raft almost killed him and his wife. Once rust has got into the wire all the integrity/strength in the hull has gone! Chuck it!

Deltasailor. Do you know how many lightly built fibreglass boats have gone down? Yours is one of the the suspect ones that should not cross oceans.

[danielamartindm]

At this point, it's a matter of dollars and cents. Before investing more, consider the ultimate resale value of the vessel. I suspect it will not prove a viable proposition, but that's just an opinion, and subject to the enjoyment you might derive from it between now and closing. Good luck in any event.