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20-07-2018, 08:45
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#1
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Registered User
Join Date: Jul 2018
Posts: 16
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Ferocement crack - fixable or the boat trash?
I'm looking at beautiful (at my taste) ferrocemment boat.
It's storred on the hard for recent years.
It's Colin Archer type 45ft hull with gaff ridging. I like the condition except one doubtful point on the bow part of the keel.
I'd appreciate an oppinion on several questions:
1. If this crack may be fixed or conservated?
2. If so - what's the method and which materials to use?
3. How long may the conservated or treated region may hold?
Pictures of the crack attached.
What do you think?
Thanks in advance
Robert.
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20-07-2018, 09:35
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#2
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Registered User
Join Date: Nov 2015
Posts: 372
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Re: Ferocement crack - fixable or the boat trash?
I'd wonder how corroded the wire mesh within the concrete is nearby the cracks. Likely have to take the concrete well back to reach solid mesh before any repair.
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20-07-2018, 09:42
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#3
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Registered User
Join Date: Sep 2016
Posts: 503
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Re: Ferocement crack - fixable or the boat trash?
Ferrocement is among the easiest to fix provided the armature isn't corroded, there is no way to be sure though.
One way is to hammer the area out, if it corroded, cut it out and weld in new wire armature and reapply the cement.
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20-07-2018, 10:24
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#4
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Registered User
Join Date: Jul 2018
Posts: 16
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Re: Ferocement crack - fixable or the boat trash?
What's the criterion of go/no go?
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20-07-2018, 10:54
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#5
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Senior Cruiser
Join Date: Mar 2010
Location: gettin naughty on the beach in cornwall
Boat: 63 custom alloy sloop,macwester26,prout snowgoose 37 elite catamaran!
Posts: 10,594
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Re: Ferocement crack - fixable or the boat trash?
Quote:
Originally Posted by navado
What's the criterion of go/no go?
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price probably!
it can be fixed but repairs may not last long with the risk that the corroded armature may be far more extensive once you start chipping away.
epoxy and various types of filler with addition of new mesh if needed,corrosion inhibitor on exposed metal are generally used to fix ferro.
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20-07-2018, 12:03
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#6
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Registered User
Join Date: Jul 2018
Posts: 16
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Re: Ferocement crack - fixable or the boat trash?
Quote:
Originally Posted by atoll
price probably!
it can be fixed but repairs may not last long ....
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How much time is that? Months? Years?
What it depends on?
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20-07-2018, 13:07
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#7
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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Re: Ferocement crack - fixable or the boat trash?
Navado-
With ferrocement, part of the problem is that a lot depends on the build and builder. You don't know if they used rusty rebar, or clean and degreased rebar, or properly washed or salty sand in the mix. You don't know if they mixed or cured properly. You don't know, without some digging, if the rebar was set properly. So, you need someone who knows ferrocement, there at the boat, to dig in and see what you've got. Which may require extensive digging.
Unless of course if was built by a reputable yard.
That's one reason why homebuilt ferro has such widely varying prices and opinions.
If you ask the seller, maybe they'll let you dig into it. Maybe not.
One year at a skipper's pre-race meeting, the YC started their briefing by reminding attendees that the committee boat had been clipped by some folks in the prior year. And that as a result, be advised that the committee boat would now be a rather large ferrocement barge, hit it at your own risk.
They can be wonderfully strong, but you'll need someone with eyes and hands on the boat to tell.
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20-07-2018, 15:45
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#8
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Senior Cruiser
Join Date: Mar 2010
Location: gettin naughty on the beach in cornwall
Boat: 63 custom alloy sloop,macwester26,prout snowgoose 37 elite catamaran!
Posts: 10,594
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Re: Ferocement crack - fixable or the boat trash?
Quote:
Originally Posted by navado
How much time is that? Months? Years?
What it depends on?
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with ferro there are so many variables,but probably every time you haul out,which means every year realistically for piece of mind.
the amount of time the boat spends out of the water and air temp will also have a direct effect on the speed that the hull degrades.
in freezing temperatures pockets of trapped moisture can cause cement to burst off.
as can rust pockets with prolonged exposure to air which is probably the cause of the current cracking on the hull.
epoxy and cement expands and contracts at different rates so your repairs can develop hairline cracks letting moisture in, which will need further repair.
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20-07-2018, 16:03
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#9
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Moderator and Certifiable Refitter
Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,242
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Re: Ferocement crack - fixable or the boat trash?
Any mobile industrial radiologists or other NDT operators in your area?
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
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20-07-2018, 16:10
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#10
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Registered User
Join Date: Jul 2018
Posts: 16
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Re: Ferocement crack - fixable or the boat trash?
Quote:
Originally Posted by hellosailor
Navado-
With ferrocement, part of the problem is that a lot depends on the build and builder. You don't know if they used rusty rebar, or clean and degreased rebar, or properly washed or salty sand in the mix. You don't know if they mixed or cured properly. You don't know, without some digging, if the rebar was set properly. So, you need someone who knows ferrocement, there at the boat, to dig in and see what you've got. Which may require extensive digging.
Unless of course if was built by a reputable yard.
That's one reason why homebuilt ferro has such widely varying prices and opinions.
If you ask the seller, maybe they'll let you dig into it. Maybe not.
One year at a skipper's pre-race meeting, the YC started their briefing by reminding attendees that the committee boat had been clipped by some folks in the prior year. And that as a result, be advised that the committee boat would now be a rather large ferrocement barge, hit it at your own risk.
They can be wonderfully strong, but you'll need someone with eyes and hands on the boat to tell.
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This particular boat has all the history, plans and documentation describing bould and curing process.
Can you please suggest parameters what I should look at specifically?
Do you know knowledgeable person to consult with?
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20-07-2018, 16:12
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#11
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Registered User
Join Date: Jul 2018
Posts: 16
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Re: Ferocement crack - fixable or the boat trash?
Quote:
Originally Posted by Wotname
Any mobile industrial radiologists or other NDT operators in your area?
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Only in medical occupation. What's your suggestion?
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20-07-2018, 16:25
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#12
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Moderator and Certifiable Refitter
Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,242
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Re: Ferocement crack - fixable or the boat trash?
Quote:
Originally Posted by navado
Only in medical occupation. What's your suggestion?
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To have the damaged and nearby areas x-rayed to determine the state of steel core.
This is not an uncommon practice, find the nearest commercial NDT business and ask them what they can do. They may also have other techniques and methods.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
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20-07-2018, 17:06
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#13
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Moderator and Certifiable Refitter
Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,242
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Re: Ferocement crack - fixable or the boat trash?
Regarding ND testing, the degree to which a repair to ferrocement can be successful is dependant on the current state of the steel armature (core).
To determine the state of the steel, one either has to remove the existing plaster / cement or have it x-rayed etc.
As it appears the OP doesn't yet own the boat, the current owner may not be happy to have the crack bashed apart but he/she shouldn't have any objection to an ND test.
This may help the OP in deciding if and to what extent a repair can be made.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
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20-07-2018, 17:38
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#14
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Registered User
Join Date: Jan 2015
Location: Gympie
Boat: Volkscruiser
Posts: 2,652
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Re: Ferocement crack - fixable or the boat trash?
As a surveyor the worst I have seen was a similar repair like that and they chased it for at 10 feet before they were happy with the condition of the steel and mesh. I hope that boat is cheap or free before you consider buying it.
I have seen another 50 foot ferro where they chased all the rust weeps and the yacht had so many holes in it that they ended up scrapping her.
That’s the problem with ferro, fix that repair and next year who knows where the next issue is going to be?
Cheers
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21-07-2018, 02:17
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#15
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Registered User
Join Date: Jul 2018
Posts: 16
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Re: Ferocement crack - fixable or the boat trash?
I think I can have proper reparement of the boat in the winter, but need to go 1500Nm to the required location. What do you think is the proper conservation procedure of these cracks? Will epoxy fillment of cracks save cracks expansion for several months? The painting is required for sure, but what else?
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