Ferro Cement Hulls ?

[Steve Bean]

One objection to sandblasting is that it tends to accentuate small, insignificant superficial cracks. I have seen this on my hull. I don't think it has caused a problem, but I will not sandblast again. I'm not sure that wet blasting would avoid this undesirable effect. You could try it on a small spot and then decide whether to continue.

[Stonefloat]

Originally Posted by Steve Bean

One objection to sandblasting is that it tends to accentuate small, insignificant superficial cracks. I have seen this on my hull. I don't think it has caused a problem, but I will not sandblast again. I'm not sure that wet blasting would avoid this undesirable effect. You could try it on a small spot and then decide whether to continue.

+1 last year we were looking at different ways to take 30 years of bottom paint off Avalon settling on a form of blasting (eco-quip)

ABSS EcoQuip Wet Blast System - YouTube

.A local contractor had a unit and was willing to test a small area using a medium fine bead, at first it looked terrific and let him continue but have to admit like steve has suggested it magnifies small hairline cracks .After the hull was blasted down to bare ,we used three coats of epoxy barrier so hopefully never have to do again. I think the water blasting method is least abrasive of sandblasting. Hope this helps......cheers, Stonefloat

[Yachts66]

What about cost? How does it compare with traditional sand blasting?

[BillAU]

Originally Posted by Stonefloat

+1 last year we were looking at different ways to take 30 years of bottom paint off Avalon settling on a form of blasting (eco-quip)

.A local contractor had a unit and was willing to test a small area using a medium fine bead, at first it looked terrific and let him continue but have to admit like steve has suggested it magnifies small hairline cracks .After the hull was blasted down to bare ,we used three coats of epoxy barrier so hopefully never have to do again. I think the water blasting method is least abrasive of sandblasting. Hope this helps......cheers, Stonefloat

I would like to see the up-close result after the blaster had been used to clean a FC hull or/and deck And yes, what are the costs involved

[Stonefloat]

Originally Posted by BillAU

I would like to see the up-close result after the blaster had been used to clean a FC hull or/and deck And yes, what are the costs involved

To answer some questions,the yard we were in was looking for a newer method to deal with bottom paint removal on all types of boats, wood, frp,steel ect...and I just happened to be a good guinea pig lol. I had reservations because of what colin brookes has mentioned about sandblasting, but getting no-where with other methods and the fact that in our neck of the woods bottom paint removal is highly scrutinized we thought we would give it a go. Since the yard was involved ,this made the whole process easier. Now on to price, they typically charge on a square footage basis but in my case we set a flat charge of $1500 which I thought was good value. This included nearly 75bags (60lbs) of medium fine bead and containment and clean-up.The eco-quip was much less abrasive than typical sandblasting and therefore took 14hrs (way more than the yard estimated,( hence good value).. would I do it again....probably ,as there was minimal damage and a good etch for the epoxy barrier coat. Hope this helps, cheers....Stonefloat

[banyandah]

I'd be wondering about where it thins out to fair in. Will those thin edges of concrete not crumble and bits will lift from the deck. In Australia we have a product called Bondcrete, Added to a rich portland mix and it bonds to thin layers, Just not sure how it'd go on a deck. But you can always shot off a text and ask the maker.
In the 90s, we sandblasted Banyandah after she had lived a long and full life. Found a few imperfections but basically the operator took off every layer of paint and left us a perfect surface to flood with thin epoxy.

cheers,

[Steve Bean]

In the case of the sandblasting of my FC hull, the worst problem was that there were hundreds of small bubbles in the original epoxy sealant. Between the bubbles the coating was perfect and strong. The mortar under the bubbles was perfect, smooth and clean. Unfortunately I was not able to be present for the sandblasting. The bubbles disappeared instantly and then those areas were exposed to the further blasting to remove the rest of the epoxy, resulting in a very rough, pockmarked surface. There were only two small spots where the mesh was exposed. The issue of the superficial cracks was not significant. I would have been much better off to blast only enough to get rid of the bubbles and leave the good epoxy, add a coat or two of epoxy, then fairing and bottom paint.

[Lilly Bolero]

I have a 52' Ferro gaff schooner, I love it! low maintainance, cheap to buy and I recently tested its strength by parking it on a reef and slamming it with head high waves for 12 days - it survived well where I don't believe wood or fibreglass would have! now after extensive research I have found the repairs to be easy and inexpensive - I am fonder of ferro than ever!

[awab]

Hello,
I looked into the wet blasting a little bit more. There are attachments on the market for 80 us till 400 us for pressure washer between 2500 and 4000 psi.
Does somebody has first hand experience.
It looks to me they are good for little jobs but not for a job what stonefloat did.

thanks
peter

[Badsanta]

Wow 1000 posts. I did not know there was such intrest in this.

[DumnMad]

Originally Posted by Lilly Bolero

I have a 52' Ferro gaff schooner, I love it! low maintainance, cheap to buy and I recently tested its strength by parking it on a reef and slamming it with head high waves for 12 days - it survived well where I don't believe wood or fibreglass would have! now after extensive research I have found the repairs to be easy and inexpensive - I am fonder of ferro than ever!

You are a cracker Bolero. Not many go to that much trouble to test their boats. Hope you got some tax back for the R&D expenditure. Thanks for the report.

[Stonefloat]

Originally Posted by Lilly Bolero

I have a 52' Ferro gaff schooner, I love it! low maintainance, cheap to buy and I recently tested its strength by parking it on a reef and slamming it with head high waves for 12 days - it survived well where I don't believe wood or fibreglass would have! now after extensive research I have found the repairs to be easy and inexpensive - I am fonder of ferro than ever!

Totally agree ! After mishap with Avalon ( don't ask) now carry buckets of Portland & sand ......easy fix !!

[Ironman162]

After all said and done, I feel sure you would agree that if it still floats after 40 years it stood the test of time.

Moral of the story, buy a old Ferro in good condition for next to nothing and live the dream

[haiqu]

Originally Posted by awab

What kind of fairing compound you guys would use to do this on a ferro hull. I am thinking to try this on my decks. I already started to remove the old paint with a torch. It came off relatively easy this way. Now some sanding and I can try the above system.
I also have to find some material what is not to expensive. The area I have to cover is quite large.

Hope to hear some ideas and nice to be back on the forum

peter

On the cabin top I've been using a product called Parfix Multipurpose Filler, made in New Zealand. It's designed to be used indoors or outdoors, but you can't get it wet for the first two days after application otherwise it cracks. After that it's hard as a rock and takes quite a bit of sanding to level out.

It sells here in Australia in hardware stores for $13.00/kg premixed. I've used about 25kg so far for timber dry rot repairs and I can't see why it couldn't be used for the deck.

Rob

SV Keppelena, Sydney

[steve ripples]

Different topic - but I wanted to contact all you enthusiasts keeping the ferro flag flying (some fool is going to say 'ferro flag? Nah, too heavy). Anyway, I'm wondering (just quietly and carefully you understand) about building. I've read Benford and Hartley and Cairncross and Greenfield and masses of stuff on the web and want to try and assess a particular design and build project. Something of a compromise size and fairly easy build, manageable by one man under sail. For the kind of conditions here (UK coast) and the kind of sailing I've done and want to do (UK coasting, north to south and some way upriver where possible) and my traditional leanings - I like the looks of the Samson C-Mist, gaff rig, 32 ft, 11' beam and draft a just ok for my purposes 5ft (don't want to go any deeper).

My problem is how to get hold of the plans? Hartley's took on some of Samson's designs but not the C-Mist. Does anyone have any leads please?