Ronald Raygun wrote:
Wilbur Hubbard wrote:

"Armond Perretta" wrote in message
...
Armond Perretta wrote (on 25 April 2009):
I have been using Pettit Trinidad on my 28 foot sloop for many years
(1981 boat purchased new). When we haul, the boat is
pressure-washed, and then in the Spring the loose stuff is scraped
off and the entire bottom wet-sanded with 80 wet-dry. I use a foam
roller and about 3 quarts per coat on this full keel boat with a 22
foot waterline. At this rate every 3 years I've had enough paint on
hand to avoid buying a new gallon.
...
This year I have decided to honor the titans of Wall Street and what
remains of the financial system by "going cheap." I took a new
gallon of Trinidad, split it in half into a new empty gallon can,
added what appeared to be about one half quart of last year's paint,
and then thinned each can to bring the volume to about three quarts
in each one gallon can. This means the paint was thinned about 25 to
27 percent, which is well in excess of the manufacturer
recommendations. In fact just about any source I can find would
disagree with my approach and advise that I will end up with less
than adequate protection. The only advantage to me is, of course,
cutting my paint cost by half.
I suppose I will find out in the Fall if this plan is practical, but I
thought I'd throw it out there to see if anyone else does it this way
or has similar experience.
Last April I posted the above looking for comments and similar
experiences.
We hauled the boat yesterday and were able to determine how the highly
thinned bottom paint performed. The short answer is: "Very well."

I would have to say that this thinning method works for me, as I am now
going to get 2 paint jobs from one gallon on this 28 foot full keel
sailboat.

Stupid, stupid, stupid!

A bit harsh, though I must say his numbers don't quite seem to add up
or, as you would say on your side of the Pond, his "math" is suspect.

He needs 3 quarts per coat, and his old system therefore used 12 quarts
(3 gallons) of full strength goop every 4 years. His new system still
involves using 3 quarts per coat, but of goop thinned to 75% strength.
In other words he will now need 2.25 quarts of full strength goop per
coat, which isn't quite down to the 2 coats per gallon (which would be
2.00 quarts per coat) he claims, unless he's going to dilute it down to
67% strength (which he may well get away with, but I guess that's next
year's experiment).

3 gallons used to give him 4 years, and if he dilutes to 67%, then 2
gallons will give him 4 years. That's not "Half Price", it's 1/3 off.
And then only if the thinner costs nothing.

What you are doing is spending more on haul outs
than you save on paint. Your system requires an annual haul out and we all
know those aren't cheap. They call this being penny wise and pound foolish
across the other side of the Pond.

But he may well be hauling out annually anyway, for other reasons, even
in those years when no painting would be needed.

Well for what its worth, 5 litres of Jotun Seaguardian will do over 4
coats on a full keel 26 footer. That's two coats per year rolled on, +
extra coats near the waterline and on the rudder. Seaguardian is
supposed to be good for 30 months, but we haul annually anyway and might
as well freshen up the antifouling while we are out. The part tin will
keep a year if properly resealed with some butane gas in there to
displace the air and prevent it oxidizing. There is some thinners to
add to the bill but that's used at well under the 10% max ratio
recommended. Works pretty good as well, with no weed or barnacles
unless it's got rubbed off somewhere. Any spot that has got rubbed or
has to be taken back to the gelcoat for any reason gets underwater
primer followed by black hard scrubbable 'waterline' antifouling as a
'witness' coat and to prevent serious fouling if it happens again.
The same tiny can of scrubbable has been on the go for the last two
years and there is plenty left.

For all you mathematically challenged Leftpondians 1 litre is just under
a US quart.

This year I set aside half the big can as soon as I opened it as I had a
clean 2.5 litre tin handy. If you are keeping it, you want it well
mixed, as fresh as possible and to set it aside *before* mixing in old
paint.

I read it as every third year he avoided buying a new can so that's 2 US
gallons for 3 years and he's reduced to 1 for 2 years by diluting it.
How he got 3 quarts left after two years and reckons to save half by
thinning, I do not know, but unless he's measured what's left in the can
accurately I wouldn't believe his 3 quarts per coat.

Unless he's getting more paint on himself and the hard standing he's
slapping it on far thicker than we do as we are doing two coats. I
reckon I'd have had plenty from my half can to do a 28 footer at an even
two coats all over with a bit spare for the waterline and where the prop
wash hits the rudder.

The biggest saving would be buy a radiator roller handle and the *GOOD*
(i.e. EXPENSIVE) rollers to go on it. A fully loaded large roller is to
heavy and awkward and cheap rollers break up too much and waste paint.
The extra length of the radiator roller handle makes the job go much
quicker with less stooping.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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