Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 08-08-2012, 13:49   #16
Registered User
 
awab's Avatar

Join Date: Jun 2012
Location: Italy
Boat: s&s, motorsailor, 55 feet
Posts: 94
Re: ferro cement repair question

thanks hellosailor,

I am not talking to make the mast shorter. I think I could cut out the bend mast section. lets say its about 6 feet. than get the same mast profil of 6 feet. now with a good fitting inner tube of lets say 10-12 feet make a splice.
This would give back the same mast hight.
hope I make myself clear with this explanation.
Still have problems to explain myself in english.

the part with the 500 us. I dont understand why I should spent 500 us for material to repair a part of a FC boat with a resin mix if it could be done otherwise.
Its only do know how do to it right. Its basicly the same of replacing a blank in a wooden boat. There also would be the chance to replace the blank with a nice piece of carbon fiber but it makes more sense to replace the wooden blank with a wooden blank of similar quallity.

Is there anybody who has more info about mast splicing.
Where to get mast profils to buy.

thanks
peter
__________________

__________________
awab is offline   Reply With Quote
Old 08-08-2012, 14:23   #17
Registered User

Join Date: Jan 2006
Location: Minnesota
Boat: Samson 39 Encore
Posts: 93
Re: ferro cement repair question

It's interesting some of the misinformation that has been propagated by some on this forum regarding ferro. White glue or binders available from home centers can be used. Whether or not Elmers glue is waterproof is a complete non-issue. You are not depending on the glue to waterproof the hull, you are using it to bind new cement , which cures through hydration, to the old. The only thing I have found that will remove it is xylol or xylene and it will soften most latex binders. If you want the best go with a very old product called Concresive LPL. It's now sold by Brock White and is like the name implies a very long pot life epoxy which is green in color. If I recall right the pot life is several hours.

And oil or diesel can be removed without too much effort by allowing degreaser and water to soak through it. Diesel will pretty much run right through cement, as has been stated many times on CF. My boat had very heavy oil penetration (large black places on the outside of the hull in the bilge area). These washed clean and a neat epoxy--epoxy filler--interprotect 2000--bottomkote adhered very well. The cement was as white/gray as the rest of the hull before the epoxy treatment was applied.
__________________

__________________
encore is offline   Reply With Quote
Old 08-08-2012, 14:41   #18
Registered User

Join Date: Jan 2006
Location: Minnesota
Boat: Samson 39 Encore
Posts: 93
Re: ferro cement repair question

Attached are two pictures, one showing the mess in the ballast area, the engine had a cracked case and instead of fixing it the po just kept dumping oil into it which ended up in the ballast. Brookes suggested drilling holes in the side and flushing it but I removed the ballast and flooded the bildge with degreaser/water until it ran clean.

The other picture shows the outside of the hull in the ballast area. When I tried drilling it didn't seem that the hull strength had been compromised, in the leak area.
Look on Colin Brookes forum, read his book or email him. He has much knowledge in this area as opposed to a persistent poster who has been spreading nonsense for along long time.
Attached Thumbnails
Click image for larger version

Name:	dirty ballast.jpeg
Views:	99
Size:	34.4 KB
ID:	44552   Click image for larger version

Name:	rudder area.jpeg
Views:	105
Size:	23.9 KB
ID:	44553  

__________________
encore is offline   Reply With Quote
Old 08-08-2012, 15:45   #19
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,051
Re: ferro cement repair question

"This would give back the same mast hight.
hope I make myself clear with this explanation.
Still have problems to explain myself in english."

No need to worry about your English, it is certainly better than my Italian.

Yes, actually you would be making two splices, and splicing in a new section. Masts are often too long to ship in one piece and sometimes you'll see a boat with one splice in the mast because of this. That is always where one section has been placed inside the two halves of the mast, and then both halves are riveted up to it. In order to replace a missing section, you will need to match the missing section, and then insert two sleves, one at the top and the other at the bottom, making two splices. That certainly can be done but I've never seen one repaired that way. I would think that trying to match the missing section would be very difficult unless you had a plain mast extrusion, not tapered, nothing fancy.

"the part with the 500 us. I dont understand why I should spent 500 us for material to repair a part of a FC boat with a resin mix if it could be done otherwise."
And that is the question. There are many many different concrete mixtures, all with different properties, and many additives, all with different properties. If you make it yourself, you need to be sure you are making the right mix. Part of what you pay someone else is the cost of resin (which is usually expensive) and part is the cost of shipping. Especially if they are shipping a mixed material and not just selling you additives. But then you are also paying for their expertise and reputation. If you can be sure of what you are making, and you can make it yourself locally, then there is no need to pay them for that. The question is, how certain will you be that your mixture is as good as a professionally made mixture?

Encore, if you have used white glue as a binder, that's great. But in the masonry business I've only seen latex (or fancier) additives, never one from casein, never a mention of white glue. Except from boatbuilding sources, which all say never to use white glue where water or moisture resistance is a problem, because it will fail. I can't see how it would perform in cement unless something unexpected happens in the cure. Given the cost of an additive designed to do the job? I'd use the additive and not gamble on something coming apart five or ten years down the line. Or twenty.
__________________
hellosailor is offline   Reply With Quote
Old 08-08-2012, 15:56   #20
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,247
Re: ferro cement repair question

It is not normal to weld reinforcing but is normal to lap the bars about 40 times the diameter. Ferro with 2:1 mix will be like glue and compatible with the surrounding so no failure due to incompatibility.
This quote from a fisheries management site;
"A major repair will be necessary where the mortar is severely damaged and the reinforcement is either sheered or bent out of shape.

The loose mortar must be removed back to where the mortar is sound. By using a lump hammer against the mortar on the inside and another hammer on the outside, the loose mortar can be pulverised so that the staples in the mesh are visible. The staples can then be cut and the outside mesh slit to allow the loose mortar to be released. The outside three layers of mesh are cut back into overlaps around the damaged area so that the inside mesh and rods can be carefully cleared of any loose mortar remaining and the inside mesh remains undamaged.

Any distorted or sheared rods may be cut out and new rods wired or welded into place. Three layers of mesh are then cut to suit the size of repair and overlapped to the existing mesh left protruding from around the damaged area. All the mesh is through stapled and tidied up.

The edge of the old ferrocement is painted with a suitable epoxy adhesive for joining mature mortar to fresh mortar. The damaged area is then plastered as required.

Suitable curing will need to be carried out following the plastering operation. This can be achieved for below water line damage by relaunching after 48 hours and keeping the area immersed, and covered in wet hessian cloth on the inside of the hull. For other areas a suitable curing membrane may need to be used to enable the vessel to be put back into service as soon as possible. The longer the period of curing carried out the better." Cheers, Nick
__________________
DumnMad is offline   Reply With Quote
Old 26-09-2012, 23:05   #21
Registered User
 
awab's Avatar

Join Date: Jun 2012
Location: Italy
Boat: s&s, motorsailor, 55 feet
Posts: 94
Re: ferro cement repair question

Update from OZMA.

I am finally on the boat and working hard.
Perhaps you guys remember the story with the leaking diesel trough the hull.

It has been different after all. After very good cleaning of the engine room I found out following.

!. The engine room has a layer off fiber glass preventing contamination to the hull.
2. The diesel tanks are ok. Outside rust but no leaks. They are built of steal and separated from the hull.
3. The coloration we have seen on the outside of the hull what looks like diesel or oel penetration is in reality tar epoxy which colored on some spots the old antifouling.

This was also the reason for no hearing any kind of difference when knocking with a hammer on the hull. It made the same sound on the darker parts the on the lighter parts.

The hull is super sound and an incredible example for the quality of ferro cement as a building material for boats. After 9 years of no maintenance sitting in a boat yard the hull after cleaning seams perfect.

One big help in the cleaning process has been a wonder full tool. I bought a hot water pressure cleaner from karcher model hds 1000. I was lucky to find one used for a very good price. After the renovation I always can sell it again. This pressure cleaner is made to fight oel spills on beaches etc. Without this tool I would no have been able to come to such a fast result. Its worth every cent.

The keel cooler is not a keel cooler. It has been a miss information from the yard. This is actually the water-intake for the main engine and the genset.

When I discovered the boat I had only one day to see it and then I had to leave for Europe. I only made some pictures. After cleaning I have to say I made the right decision to buy the boat. The problems I was thinking I had dissolving.

I did not ad the time to make pics but will do so and post them to you.
After All the effort you had with me this is the least I can do.

Thanks and I will keep you updated.
peter
__________________
awab is offline   Reply With Quote
Old 12-12-2012, 10:07   #22
Registered User
 
Yachts66's Avatar

Join Date: Sep 2005
Location: In the Jungle, on an Island near the beach
Boat: Roberts 45 Mariah's Child
Posts: 654
Images: 15
Re: ferro cement repair question

Hope this post isn't too late, but my boat before this one had a splice in the mast, here is how it was done and it worked just fine: In addition to the section like you intend to cut out, you will need 8' of aluminum tubing formed to fit inside the mast. This serves as a reinforcing sleeve to strengthen the mast at the joints at either end of the new section. I would run the sleeve 2' on either side of the joint. Maybe 18" would work, but on days when the wind she blows hard, I would feel better knowing I had 2' of material up there not just 18", but that is up to you. The sleeves should fit snuggly inside the new section and the mast. Once everything is fit, cut slots in the mast (a router with a carbide tip blade works just fine for this) and new section so you can weld everything in place. Assemble the mast, clamp everything in place and only tack weld the assembly. Your tacks should be at least 2" apart. Do not over weld and do not weld one side all the way up and leave the other side un-welded. Fill in between the tacks working from one side to the other, from one end to the other. All this to avoid any distortion, you always want to keep things in balance. Once it's all welded up you can grind the welds smooth for aesthetic purposes if you wish or leave as is and paint. Hope this helps.

Thomas
__________________
We don't stop playing because we grow old, we grow old because we stop playing! Ben Franklin
Yachts66 is offline   Reply With Quote
Old 16-12-2012, 10:25   #23
Registered User
 
awab's Avatar

Join Date: Jun 2012
Location: Italy
Boat: s&s, motorsailor, 55 feet
Posts: 94
Re: ferro cement repair question

thanks Thomas
This repair sounds logic to me. How wide this slots should be.

In the meantime I found out that the main mast is straight. Has only some damage on the mast head and foot.
The mizzen mast is the real problem. In the beginning the boat used the mizzen mast as a try stack. The exhausted created pinholes and weakened the mast from inside.
I think I have to look for a used replacement. The mast is only 43 foot high. Should be no problem to find something sooner or later.
From this time comes also the idea that the boat has a keel cooler.
In the meantime some where in the past the engine got converted to raw water cooling .

Here are some pics from my progress so far.

Flickr: awabflickr's Photostream

Just having a work stop for 3 month and will start in spring again.

all the best
peter
__________________
awab is offline   Reply With Quote
Old 16-12-2012, 12:13   #24
Registered User

Join Date: Jun 2012
Location: here and there
Boat: P30
Posts: 199
Re: ferro cement repair question

I have no experience with ferro boats, but i do have some knowledge of Ferro Construction and concrete in general.
As mentioned earlier, although welding is not usually used for reinforcing mesh or bar, it can work. these usually rely on the developed overlap tied together.
someone mentioned 40x the diameter and that sounds about right.
another item to consider: most likely the mesh is galvanized. welding will remove any galvanizing and expose the mesh to possible corrosion (rust).

there are companies which specialize in concrete bonding agents.
here is one:
Bonding Agents | Sika Corporation U.S.

these products state "moisture tolerant". I'd look into what that may mean.
for my own curiosity: is the outside of the hull treated in some way to render the concrete impervious?
__________________
S/V Voyager
smaarch is offline   Reply With Quote
Old 16-12-2012, 19:22   #25
Registered User
 
Yachts66's Avatar

Join Date: Sep 2005
Location: In the Jungle, on an Island near the beach
Boat: Roberts 45 Mariah's Child
Posts: 654
Images: 15
Re: ferro cement repair question

They don't need to be wide, you can cut with 1/4" router or even less. 3/16" would be fine. The welds just keep the sleeve in place and transfer loads evenly through the mast and sleeve.
__________________

__________________
We don't stop playing because we grow old, we grow old because we stop playing! Ben Franklin
Yachts66 is offline   Reply With Quote
Reply

Tags
ferro

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:31.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.