Ferro Cement Hulls ?

[Carouse]

thanks for the imput Boreilas,i'll take that onboard,I was thinking of painting antifoul on while primer is still sticky.happy scraping

[Jolly Roger]

I once owned a Ferro Cement hull and have been following this thread with interest. Since it has over 300 responses anyone wanting to buy should be aware of the following:
I recently flew from Orlando, Florida, to Nassau, in the Bahamas, to look at a “55’ custom schooner,” which is advertised at having 14’ beam with a Ferro Cement hull. The boat is on Yachtworld YW# 75498-2082766. 1991 Custom Staysail Schooner Sail Boat For Sale - www.yachtworld.com This is a gross misrepresentation, and I want to alert anyone who might be interested in traveling to see this boat, not to expect even a 45 footer.
The actual length is 41’ on deck, (stem to stern) and 11’11” beam, (even including toe-rail overhang). It has a longer than normal bowsprit, but even including this the overall length is only 49’6”. In no way is this a 55 foot sailboat, and nowhere near the volume a 14’ beam gives.
I told the listing agents, who said they faithfully followed the owner’s information. But so far Think Yachts have made no alterations, either to the YW listing, or their own website.
I suggested they ask the marina to measure it if they did not believe me.
The regular and accurate description would be a 41’ schooner—some difference!

[Brent Swain]

For all their faults, a good ferro cement hull is light years better than a heavy displacement wooden hull.( Dead Vegitation)

[wolfaroo]

Hola fellow Ferro Cement hull owners (& supporters/naysayers alike)... hope all are well. It's nice to discover this helpful site and contributors in this thread certainly have some very useful knowledge/experience of FC. Like an earlier poster stated, the guys who fully understand FC, those who built many boats and refined the processes involved, are now few and far between. It is through sites like this we can *hopefully* rediscover those old, and new, trade secrets and useful tips - I certainly hope so because like some earlier posters I too didn't find the info I was looking for at ferrocement.org other than 'buy their book'.

I did buy the book and now have it here in front of me; it is useful and contains some very helpful information. But it does lack specific details. For example, for certain repairs it suggests using epoxy 'mortar' but doesn't elaborate to provide the ingredients and/or ratio of materials to be mixed. Likewise it doesn't mention what epoxy mix is recommended for larger repairs (as we all know there are many types available).

I would be very grateful if anyone here could provide the names/type of epoxy & epoxy/mortar mix recommended for various repairs:

1> Small surface cracks/cosmetic repairs above & below the waterline
2> larger scrapes/gouges above & below the waterline
3> holes and large areas of damage above & below the waterline
4> large areas of structural damage

In the Hartley book, various mixes of cement/sand/epoxy are recommended for 1 to 4 above but I have since been advised those are completely out of date and a much more suitable epoxy is now available requiring no cement/sand. No-one here knows the name however! Any ideas???

[Boracay]

I'd suggest talking with the cement and epoxy putty manufacturers as to the best product for your requirements.

In the good old days we used whatever we could get our hands on but the continuing threat of litigation has put an end to such silliness.

For the mortar Richard Hartley recommended (from memory, please check) "A Grade" Portland cement with clean sharp river sand and a proper amount of pozzolan to "waterproof it.

The epoxy putty that I used was (on the recommendation of a friend working for the manufacturer) made by a small company that not longer appears to be in existence.

Whichever way you go I suggest using the best quality materials possible.

[wolfaroo]

Thanks for the info Boracay.

This is what I've found thus far (and please feel free to add/amend any details):

Cement mix
The current Hartley thinking is to use the slightly more expensive SR Cement (Sulphate Resistant), which means there is no need to use pozzolan. The sand mix is recommended to be 85% soft sand, 15% sharp sand with no particles larger than would fit through a no. 8 sieve (and obviously all the sand is of the washed variety with zero salt content). Depending on who you talk to, the ratio ranges from 1.5:1 sand to concrete, to 2:1 sand to concrete. For plastering/very large repairs this is ideal.

Epoxy Mortar
Used for large holes and very strong repairs, this is a mixture of epoxy, SR cement, fine silicon sand - so far I have been unable to obtain recommended types of epoxy used in this mix and the component ratios have alluded me too. Any ideas anyone?

Epoxy Putty
I have written to a number of manufacturers to find out more info as there seems to be very few people who will recommend a type/brand for use with ferro cement below the waterline - please come forward someone!

...I will keep you posted with any info as I [re]discover it.

[Boracay]

All of the above looks way better than what we worked with 40 odd years ago.

Any reason why you would not use the epoxy/mortar below the waterline on smaller patches?

[Borealis]

This meassage is regarding epoxy for FC repairs. I wish I had photos of some of my 'fixes'. The epoxy that I have been using is called "AqiataPoxy", made by Raven LIning Systems in USA. This product comes in a paintable thickness and a putty.

i have been using this epoxy underwater for 15 years as a commercial diver to do corrosion control and concrete crack repairs. ihave also used it to form up weak corroded pipes pending replacment. It cures very rigid and is excellent for stiff or rigid substrates. Becaseu of the supply I have on hand for business and because of my experience I have used it confidently on my FC hull above and below WL.

2 years ago I used to fill voids, sanded and painted over. Presently, I have found that the adhesion of the epoxy to the hull and paint to epoxy has been excellent. The old, fully cured epoxy is more resilient to chip or breakage than I expected. This last week I found some rotten cement just belwo the WL and i chipped it away then grinded it out, about 8" long, 4" high and 1/8 to 1/4" deep. I applied the Aquatapoxy paint over the 'void' and then heated it till it flowed to ensure coverage in all the crannies. Let this dry overnight and scrape down the high, sagging lumps. This will be filled with Aquatapoxy putty, faired, sanded and painted.

This material is about $75 USD per gallon and its 1:1 mix ratio. So far I have been using it for voids and corrosion control repairs that do not have forces placed against it. I have been interested in mixing this epoxy with different sandy ratios to see what the result would be or using a portland cement powder.

Aquatapoxy is safe for food so it is 100% solids and has no VOC offgassing, tontoxic and has nearly no odor. I'm not a salesman here but rather imparting to you what is definately working for me. Incidently, in years of application to submerged cement and steel surfaces I. have yet to see the product chip or separate from the substrate. I am so confident that I place a guarantee on my underwater work that it will not fail .

If you want more details and application tricks let me know.

[Borealis]

By the way, I was just looking at a 40 FC boat sitting in a parking lot for sale. I found a rather interesting case. While examning the hull the paint looked great but in the general area beneath where the engine would mount I noticed an oily like stain in the paint. It seemeed like somebody splashed a pint of of diesel against the hull. When I found this condition on both sides in the same area I was puzzled. I went aboard and snooped beneath the sole and found the bilge full of oily water. This turned out to be directly above the oily stains on the outside. My conclusion is that the oily bilge water seeped through pinholes in the cement and saturated the bottom paint from the inside out.

Any comments on this? Can this boat be saved?

[Carouse]

Hi Wolfaroo, try SIKADUR 31/41 made by Sika Aust, all the imformation you need on there website

[Brent Swain]

Diesel will disolve cement.

[Watercolor]

I have talked to a few people who have ferro cement boats. Your information seems to be correct. It really depends on attention to detail. There is one person who might really be able to help you. His name is Jay Benford. He's a naval architect out of St. Michaels, MD. He's designed some beautiful and some funky boats, but he did work with ferro cememt for a while. I think his web site is Benford Design Group.

He's a really nice guy. We just sold our Benford 39 double ender. It was and is a beautiful boat.

[Filthywrench]

I have a 1970 Hartley 39 built in South Africa. I have been pretty happy with the boat and have had some ocean sailing experience with her (Trinidad to Cleveland, Ohio via Bermuda). The only things I don't like is she's slow and I get a lot of weather helm. I'd like to sail her to Ireland, but I'm afraid that with the light winds that I might encounter between Bermuda and the Azores (at least from what I've read) it might take longer than I have available. I would be very interested in talking to other owners about the design. It might be my particular sail plan. Any comments from owners or people who are familiar with this design would be greatly appreciated. I've also tried to find links to other owners, unsuccessfully. Thanks.

[Borealis]

HI all, I've been out of the loop for a couple months. Here's my message:

!FREE 40' SAMSON FERRO HULL!

I picked it up last week as a derelict vessel that was not tended to for a long time. It is currently hauled at Port Townsend, WA as is sceduled for crushing next week. I am responsible for the cleaning and sanitation of it prior to crushing. However, as a Ferro boat owner i recognize a good hull when I see one. Its verry nice lines, good construction, cement hull/deck, wood coach roof, cockpit. Coach roof is rotten and mast is destroyed.

Truly a good hull to be used for a reconstruction. For someone who wants to build an offshore capable boat this is the foundation for you.

Marcus

Huh, what do you know, someone just called me and wants to buy it. Anyway, if your interested reply or call 541-941-1925.

[MattDamon2927]

Hi All,

Just back from the first test sails of Black Wind in the Pacific out of LA. Regarding Filthy Wrench's questions above I think a lot may have to do with the sail plan - although I don't know it for your particular boat. My Samson C Deuce is 54'/27 tons and a cutter rigged ketch. I recently replaced the small fly jib with a large roller reefed Genoa, and I was very impressed. Even in very low winds she picked straight up to 5.5 knots which although is not fast, it is good for light airs and has given me great faith in her sailing ability.
I myself expected very poor performance due to her weight but speaking to a pro he advised me it would matter very little if the sail plan was large enough and well designed, which obviously makes sense. I think we are well aware of the the concerns in ferro boats regarding design changes to the hull etc due to amatuer alterations, but less thought is probably given to the hugely important sail plan. It could be a place to start?
After clearing out the previous owners several tons of kit, a good clean up, an engine and sail test I am now one large step closer to setting sail for good - make sure you drop me a line in advance of passing by this way Stone Age!
By the way, a couple of questions to you all in the west: Although I had good conditions, what are the tactics for the large and seemingly constant swell coupled with very light winds in the pacific regards sailing, or is the only real solution to get a big engine!!!?

James