Painting Ferro-cement?
Andrew Darroch
painting of a ferro-cement hull would be appreciated. It is 20 years old
and well cured. I am planning to grit blast the accummulation of paints
which currently cover the hull and would like advice on whether an epoxy
base and two pack paint is appropriate or if I am wasting my time. Is it
simply going to peel again in time?
Up until now it has just been regularly covered with a cheap house paint
which peels in around a season or two. It has never been completely
stripped, just a bit of a scrape and rub between coats.
Andrew Darroch
Classic Boatworks of Maine
This forms a good bond to cleaned cured cement.
Good Luck and Fair Seas
Marshall and Jo Duhaime,Jr.
Classic Boatworks of Maine - We build and restore classic wood boats.
http://www.nemaine.com/classicboatworks
Andrew Darroch wrote in message
<7ebq90$gl3$1...@reader1.reader.news.ozemail.net>...
Mike Johnston
<city...@ozemail.com.au> wrote:
>Any suggestions on where I could find information on the preparation and
>painting of a ferro-cement hull would be appreciated. It is 20 years old
>and well cured. I am planning to grit blast the accummulation of paints
>which currently cover the hull and would like advice on whether an epoxy
>base and two pack paint is appropriate or if I am wasting my time. Is it
>simply going to peel again in time?
>
>Up until now it has just been regularly covered with a cheap house paint
>which peels in around a season or two. It has never been completely
>stripped, just a bit of a scrape and rub between coats.
>
>Andrew Darroch
>
>
epoxy paint is the way to go. My hull has kept up well for 5 seasons
and still looks great
(see her at http://eisboch.webjump.com)
Sheena 2
38ft ferrow-cement trawler
Smiths Falls, Ont., Canada
The Heart of the Rideau Canal
Pekka
I have two suggestions that might not be very good for you
in terms of availability in your area. If you are interested
I suppose I could arrange for you to get the materials
directly from the manufacturers.
---
1. You could use one-part polyurethane coating from the
German company Vosschemie GmbH, their Estovoss system. It
consists of a penetrating pre-coating G4 and a top-coating
Estovoss, available in a few colors like gray and brick-red,
not very tempting for a boat maybe.
The material as liquid is toxic (contains xylene and MDI=
monomeric diisocyanate) and you would need to wear
respiratory protection or use a fresh air supply.
Transporting the stuff requires special transport for
hazardous/flammable materials.
The system is originally intended to cover industrial
concrete floors. It is waterproof and has very good abrasion
resistance. It can be applied to a humid surface as it is
basically two-part, the other part being water vapour, just
like all "one-part" polyurethanes. I think there are other
manufacturers who have similar products.
The price for the stuff is ca. USD 15 for one kg (FOB at the
factory in Germany, Europe), you would need 0,25 kg/m2 for
the pre-coating with G4 and considerably less for the
top-coating(s) with Estovoss as the pores are supposed to be
sealed with the first coating.
---
2. You could use a new product called Topium, it is a
two-part elastomer that can be cured to soft-flexible or
hard-flexible (hardness Shore A80.... D60). It does not
contain evaporating elements so it is safer to apply but you
would want to use protective clothing and disposable rollers
and brushes.
Topium is a "global" elastomer so it is fit for covering
polystyrene, wood, steel and concrete alike. It is
water-proof, adheres well to almost anything, has good
abrasion resistance and can be strenghtened with glass or
other fibers if needed. The hardener is classified as
hazardous (contains MDI), so it needs to be taken into
consideration when transporting it.
It is somewhat pricey (ca. USD 25 for one kg, FOB Tallinn,
Estonia, Europe). Depending on the hardness chosen, you
would need 0,25 ... 0,5 kg/m2 for one coat.
Apparently there are no similar products available, or at
least I don't know of them. Then again, I don't know
everything (oh how hard it is to admit this !-)
I am planning to use Topium to build a small boat during the
summer. I'll let the group know how it goes.
---
And a third alternative could be epoxy but I don't know
whether it sticks to concrete as well as the a.m. products.
But if you'd use Vosschemie's G4 or a similar product as a
pre-coating I think you could get good adhesion for epoxy.
G4 is also used for preparing wood for covering with
polyester resin so you might be able to use poly instead of
epoxy. Epoxy is however better in terms of preventing water
ingress as we have read in those wonderful threads, thanks
Dave and Kern et al.
As for the question of longevity of any coating system I
doubt there is a coating that will last forever. Maybe you
are better off using some common two-part system for
concrete floors, might be cheaper as well. Maybe folks who
have ferrocement boats have solved this problem already?
Pekka
scow
something right. Blast it, fixes cracks with epoxy, prime with waterbased
Zinser 1-2-3 and top coat with expensive house paint, like a waterbased
acrylic high gloss porch and deck paint. Unfortunately f-c hull boats
aquired a bad reputation in the US back in the late '60's, when a lot of
people tryed building them without the required skills or budgets. It
looked easy and wasn't.
----------
In article <7ebq90$gl3$1...@reader1.reader.news.ozemail.net>, "Andrew Darroch"
Eearleyone
done rite it will pock the hull and require much fairing. My boat bottom was
blasted and the craters looked like a moon scape.
Mike Johnston
<city...@ozemail.com.au> wrote:
>Any suggestions on where I could find information on the preparation and
>painting of a ferro-cement hull would be appreciated. It is 20 years old
>and well cured. I am planning to grit blast the accummulation of paints
>which currently cover the hull and would like advice on whether an epoxy
>base and two pack paint is appropriate or if I am wasting my time. Is it
>simply going to peel again in time?
>
>Up until now it has just been regularly covered with a cheap house paint
>which peels in around a season or two. It has never been completely
>stripped, just a bit of a scrape and rub between coats.
>
>Andrew Darroch
>
>
Andrew....I tried to reply to your e-mail but the address bounced.
there is a ferro-cement boat assoc. in your area. Try
ian.mc...@netinfo.com.au
I'll try again privately to respond....mj
D.Moore
can buy ,purchase brushes and rollers then and only then....throw away the
boat...
It ain't worth it man
Mike Johnston <mjoh...@recorder.ca> wrote in message
news:3709e6ed....@news.recorder.ca...
> On Tue, 6 Apr 1999 12:05:05 +1000, "Andrew Darroch"
> <city...@ozemail.com.au> wrote:
>
> >Any suggestions on where I could find information on the preparation and
> >painting of a ferro-cement hull would be appreciated. It is 20 years old
> >and well cured. I am planning to grit blast the accummulation of paints
> >which currently cover the hull and would like advice on whether an epoxy
> >base and two pack paint is appropriate or if I am wasting my time. Is it
> >simply going to peel again in time?
> >
> >Up until now it has just been regularly covered with a cheap house paint
> >which peels in around a season or two. It has never been completely
> >stripped, just a bit of a scrape and rub between coats.
> >
> >Andrew Darroch
> >
> >
> and still looks great
> (see her at http://eisboch.webjump.com)
Gerrie Warner
onlt draw back here is that if you have to have filler or such you can't use
epoxy bsed stuff on top.
Otherwise two part marine coatings are preferable but pricy.
> > >Any suggestions on where I could find information on the preparation and
> > >painting of a ferro-cement hull would be appreciated.
Gerrie Warner, Östhammar, Sweden
Viking Boats and Magazine
http://www.lp.se/gerrie-warner/boat.htm
A.S.S.; http://www.algonet.se/~gwarner/webtaxi.htm