Ferro Cement Weeping Spots ?

[Craig McIlrath]

Hi guys- and gals-

Some advice? Are weeping spots something to be concerned about? Red/ rusty in colour. Appears to be a slight bubble under the paint that pops easily and leaks a few drops of moisture. I have been told to chip/ grind down and apoxy.

Should I be concerned?

Cheers,
Craig

[smallyachts]

The recommendation is a good start, but more importantly where is the moisture coming in from.

If you fix the cosmetic issue, it will undoubtedly come back if you do not stop the moisture from coming in to start with.

Is it in the area of the chain locker?

Is it close to the screed material in the sheer or bulwark of the hull?

Both areas are common locations for rust blisters on ferro-cement hulls.

Water migrates in a downward direction (above the waterline ) so you should be able to see if you can identify where the moisture is coming from in a line directly above the rust weep.

A very common failure point in keeping moisture out of the hull work is underneath the cap rails if you have them.

Amazingly, most designs that I am familiar with use some type of angle iron or flat plate to develop the screed line. The very thin layer of cement ( 1/8" to 1/4") eventually allows moisture to hit the iron below it.

Especially if the builders were not cautious and used insufficient bedding material around all the bolts, or if the cap rail material was not sealed. I have traced rust blisters up to a couple of feet away due to this type of a failure on a number of hulls.

[britskip]

I have a Samson C-Breeze, bought in May last year and still in refit. I had blisters on hull, peeled off a pretty crappy paint job to reveal the bare hull,spotted round marks on hull that seemed to be coming off, hit with hammer, piece broke away revealing metal basket and crunbling hull. Clean out hole, plenty of quality rust proofing liquid and wash off. fill with epoxy cement, or epoxy glue. be careful, one could be many. I traced my blisters to some previous damage around gunwhales where water was seeping in.

[CSY Man]

Are weeping spots something to be concerned about? Red/ rusty in colour. Appears to be a slight bubble under the paint

Yup:

Big problems coming yer way:

The chicken wire embedded in the cement is rusting and therefore expanding, then cracking the concrete.

The brittle result can be seen here:

[britskip]

yeah, mine came as a result of a poorly laid towing hawser by previous owner. site looks just same, repair is extensive and the only cure. have it done properly. at least its notn osmosis!!!

[britskip]

after removing ALL epoxy covering, redoing the whole hull smoothing, fairing and painting, 1 year later blisters start coming back. soooo annoying. Anyway, advice is to grind off the iron capping rail (see small yachts above) al way around gunwhales and pour in runny cement to fill right down deep inside. Maybe fibreglass over top then.

[britskip]

Hi, I bought a Samson C-Breeze about five years ago, still 'doing it up' after being misled by Gulf marina brokers in New Zealand. I completely stripped down the hull to the concrete, fixed anything that needed fixing, and re-epoxied it all. Just back from the bow was some bubbling under the paint work. After the strip down this proved to be some crumbling cement, and these little sunken spots, resembling sink holes in a limestone area. A neighbour with a vast experience of ferro-c boats told me to crash them with a hammer, get rid of all the loose stuff back to the steel mesh, treat with rust preventer and then refill with pre-mix epoxy cement mix. Great, unfortunately they came back, not as many but still there. Neighbour reminded me that he had told me to remove the steel capping put on top of the bulwarks. It had been exposed in places and started to rust. I used a grinder, removed the steel 1/4 " steel strip then used a very, very watery cement mic pouring it in to seep down through all and any space in the hull. After drying, fair off with some epoxy and cover with fibreglass sheet. Hopefully you will see some improvements.

[Stonefloat]

I've a Sampson C-Farer , and was battling an ongoing rust bleed coming from under caprail . When boat was hauled two years ago bit the bullet and used a needle scaler
(Small air hammer) and grinder to remove the steel 1/4 inch flat bar under the caprail . Then used rust converter ( painted on ) then sikadur 32 as a bonding agent then filled the void with sikatop 1-2-3 . After a couple seasons the repair is perfect !
It is a very easily achieved repair for the amateur . Love my Ferroboat !
Cheers Stonefloat


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[AmberSands]

Hi guys just lifting out and noticed this. Any ideas?