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13824Re: latex paints

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  • dcraig@westelcom.com
    Aug 22, 2001
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      Richard, I would suggest going to Dave Carnell's Boat Building Page
      and reading his article on Latex Paints For Boats - I would give him
      some credence since he is a chemical engineer.

      > i have a quick (i hope) question about latex house paints. I have
      been reading some propaganda
      > (advertisements) that talk about letting the wood "breath." i know
      that proper moisture content wood
      > should not need to "breath", but does this mean that latex house
      paint is formulated to be porous?

      That's pretty much exactly what it means. In an earlier life, I was
      making carved wooden signs for a living and I did NOT want paint
      blistering. These signs were going to be exposed to sun and elements
      24-7-365, year after year. I researched the literature from
      experienced sign makers and learned that the best protective coating
      was not oil paint but latex. Oil paint had the best reputation
      because it had been used for centuries - it was all that was
      available, not counting shellac and lacquer, milk paint etc. - and
      latex was new and crappy at first, but excellent today.
      The proper moisture content of wood is not worth bothering about,
      for our purposes, because kiln dried values are worthless as soon as
      you stack the wood in an open air warehouse - and that's where most of
      us find our stuff.
      All wood, seasoned or not, has moisture in it to a greater or
      lesser degree. Depending on the moisture content inside the wood and
      the outside climatic conditions, oil paint can be a great coating for
      many years or it can start to blister in a few years. The reason for
      blistering is that the moisture wants out and the oil paint won't let
      it out, so the wood and paint separate. Oil paint is not porous for
      the passage of moisture.
      I recently scraped and repainted a fancy fence that had been
      painted with oil six years ago. In places the paint pulled off in
      strips. Underneath, the wood was green with fungus and wet; wet, even
      after five weeks of hot dry weather. There was nothing wrong with the
      paint, it was thick and the strips were strong - but there was a
      failure in the bond between paint and wood.
      Latex paint, in my humble opinion based on research (reading) and
      experimentation, is porous to the passage of moisture and will not
      blister (that doesn't mean it won't strip off epoxy that has not been
      properly prepared). The best paint I found for signage was Pratt &
      Lambert exterior acrylic/latex house trim paint. It has a high level
      of pigment content, so color retention lasts longer under weather.
      Signs I painted six years ago with acrylic/latex have still not
      blistered.
      Honestly, I do not know, or have an opinion, on how latex would
      perform on the bottom of a boat that sits in the water all season. But
      for a dry sailer, I would use it.

      how
      > do i tell an intentionally porous latex house paint from a good one
      for a boat.

      For a boat, I would consider an acrylic/latex 'deck and porch'
      enamel - paint that is intended to be walked on should be the most
      durable.
      I've had this discussion with so-called house painters who do this
      for a living, and I hear things like 'latex paints on a fence or sign
      are good, but you still have to prime it with an oil base primer.' Go
      figure.

      Don Craig



      - To order plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester,
      MA, 01930, Fax: (978) 282-1349
      > > - Unsubscribe: bolger-unsubscribe@y...
      > >
      ----------------------------------------------------------------------
      --
      > >
      > > There are 5 messages in this issue.
      > >
      > > Topics in this digest:
      > >
      > > 1. RE: Re: Centerboard pivot
      > > From: "Chuck Leinweber" <chuck@d...>
      > > 2. Re: Sharpie Pounding
      > > From: raymcquin@y...
      > > 3. Re: Sanding Latex Primer?
      > > From: dbaldnz@y...
      > > 4. Re: Re: Sharpie Pounding
      > > From: "Harry W. James" <welshman@p...>
      > > 5. An article to salivate over . . .
      > > From: William Samson <willsamson@y...>
      > >
      > >
      ______________________________________________________________________
      __
      > >
      ______________________________________________________________________
      __
      > >
      > > Message: 1
      > > Date: Mon, 20 Aug 2001 22:55:54 -0500
      > > From: "Chuck Leinweber" <chuck@d...>
      > > Subject: RE: Re: Centerboard pivot
      > >
      > > Richard:
      > >
      > > I like the UHMW idea. You may remember that I used it for parrels
      on my
      > > Caprice. Also for hatch glides. You can get extruded bushing
      stock from
      > > McMaster-carr with 1-1/4" ID and various OD's.
      > >
      > > Chuck
      > >
      > > >
      > > >
      > > > Ah, that would make sense.
      > > >
      > > > Googling shows quite a few references to "uhmw bushings aluminum
      > > > shaft"... Even a couple of marine ones.
      > > >
      > > > For the low load, slow speed application of rudder, centerboard,
      and
      > > > tabernacle pivot, think I could get away with 1 1/8" aluminum
      > > > shafting and uhmw poly bushings?
      > > >
      > > > I suspect the bushings and shafts would last quite a few years
      of
      > > > normal trailer sailing use. I'd be sure to design the setup so
      it's
      > > > easy to dissassemble for inspections and/or replacements.
      > > >
      > > >
      > > > --- In bolger@y..., kwilson800@a... wrote:
      > > > > Why doesn't aluminum make a good bearing? The reason bare
      aluminum
      > > > > doesn't "rust" in normal use is that it forms a very thin
      coating
      > > > of
      > > > > aluminum oxide on the surface which inhibits further
      corrosion. In
      > > > a
      > > > > bearing application, this coating is continuously worn off and
      > > > > renewed. Well, guess what, the aluminuum oxide left inside
      the
      > > > > beaing is quite an effective abrasive. You could probably
      hardcoat
      > > > > anodize it, or "hardlube", which is hardcoat anodizing
      impregnated
      > > > > with teflon. There are also several proprietary processes to
      make
      > > > > aluminum into a decent bearing surface, "Nituff" is one of the
      > > > better-
      > > > > known ones, but by the time you've gone through all that
      trouble,
      > > > why
      > > > > not just use bronze or stainless steel in the first place?
      > > > >
      > > > > Keith Wilson
      > > > >
      > > > > --- In bolger@y..., richard@s... wrote:
      > > > > > UHMW poly has a pretty low melting point. Wonder if I could
      cast
      > > > > > parts out of it?
      > > > > >
      > > > > > Also, why doesn't it work well with aluminum?
      > > >
      > > >
      > > > Bolger rules!!!
      > > > - no cursing, flaming, trolling, spamming, or flogging dead
      horses
      > > > - pls take "personals" off-list, stay on topic, and punctuate
      > > > - add your comments at the TOP and SIGN your posts, snip all you
      like
      > > > - To order plans: Mr. Philip C. Bolger, P.O. Box 1209,
      > > > Gloucester, MA, 01930, Fax: (978) 282-1349
      > > > - Unsubscribe: bolger-unsubscribe@y...
      > > >
      > > > Your use of Yahoo! Groups is subject to
      http://docs.yahoo.com/info/terms/
      > > >
      > > >
      > > >
      > >
      > >
      ______________________________________________________________________
      __
      > >
      ______________________________________________________________________
      __
      > >
      > > Message: 2
      > > Date: Tue, 21 Aug 2001 04:49:23 -0000
      > > From: raymcquin@y...
      > > Subject: Re: Sharpie Pounding
      > >
      > > Bryan,
      > >
      > > I've searched for info on Phil Theil with no luck. Can you
      provide
      > > any links to his designs?
      > >
      > > Thanks,
      > > Ray McQuin
      > >
      > > --- In bolger@y..., king@c... wrote:
      > > > My wife and I just spent a weekend on my Escargot, a bolger
      > > inspired
      > > > design by Phil Theil.
      > >
      > >
      ______________________________________________________________________
      __
      > >
      ______________________________________________________________________
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      > >
      > > Message: 3
      > > Date: Tue, 21 Aug 2001 05:11:04 -0000
      > > From: dbaldnz@y...
      > > Subject: Re: Sanding Latex Primer?
      > >
      > > Glen, I am nearly through re-painting my Micro with latex. I
      sanded
      > > the previous enamel paint back to the epoxy, touched up some parts
      of
      > > the epoxy and scrubbed down with a scotchbrite plastic pad. Then
      > > started again with a latex primer, which has stuck really well, as
      > > the paint manufacturer said it would. It's filling capacity was
      > > about the same as the previous enamel filler. I only applied 1
      coat
      > > of primer, then sanded it lightly with 180 grit on my
      > > random/orbital. The paint sanded really well, much like enamel
      > > primer. Between finishing coats, I hand sanded lightly with "wet
      &
      > > dry", again very similar to enamel. Masking tape applied as
      firmly
      > > as I could by hand for boot top etc has not pulled away any of the
      > > paint. I always pull the tape off as soon as I finish
      > > painting...never leave it on for longer.
      > > These newer latex paints are a very different animal to earlier
      > > versions, reflecting the huge amount of work that has gone into
      > > development. All in all I am very happy so far, but I guess the
      > > final test, sun, salt and time has yet to come.
      > > DonB
      > >
      > > --- In bolger@y..., "Glen Gibson" <glen@i...> wrote:
      > > >
      > > > I'm in the final countdown for getting my Micro finished (down
      to
      > > the
      > > > last 5 items, so maybe this week) and am contemplating the
      painting
      > > > process. You guys have pretty much convinced me of using a high
      > > quality
      > > > latex paint, and a Latex primer like Kilz 2.
      > > >
      > > > By the way, the boat is BS1088 marine mahogony, coated and
      > > fiberglassed
      > > > with Raka epoxy and 3.5 oz cloth.
      > > >
      > > > Question: Does this primer provide any build up for filling
      small
      > > > scratches? Is there another product I can paint on and sand off
      to
      > > fill
      > > > small imperfections (besides epoxy/microlite filler)? Or does
      the
      > > latex
      > > > paint fill small imperfections by itself (it is thicker than
      some
      > > of the
      > > > other finishes, like LPU, etc).
      > > >
      > > > Any advice would be appreciated, as well as general boat/latex
      > > painting
      > > > tips.
      > > >
      > > > Thanks
      > > >
      > > > Glen Gibson
      > >
      > >
      ______________________________________________________________________
      __
      > >
      ______________________________________________________________________
      __
      > >
      > > Message: 4
      > > Date: Mon, 20 Aug 2001 22:36:51 -0800
      > > From: "Harry W. James" <welshman@p...>
      > > Subject: Re: Re: Sharpie Pounding
      > >
      > > Use plastic screen and it probably won't scrape.
      > >
      > > HJ
      > >
      > > >
      > > > He has mentioned somewhere that WW I torpedo boats used a
      > > > window screen two or three inches in front of their glass
      > > > windscreens in order to reduce the likelihood of the glass being
      > > > shattered by wave action. Screen might work to reduce sharpie
      > > > slap. I have in mind a loose roll of plastic window screen big
      > > > enough in diameter to reach from the bow to an inch or two
      > > > underwater, and long enough to extend a little beyond the sides
      > > > of the boat and to make a place for light cord lashings to hold
      it
      > > > in place.
      > > >
      > >
      > > >
      > > > This may scrape the bottom paint a little, but what is a good
      > > > night's sleep worth to you?
      > > >
      > > > Vance
      > > >
      > > > Bolger rules!!!
      > > > - no cursing, flaming, trolling, spamming, or flogging dead
      horses
      > > > - pls take "personals" off-list, stay on topic, and punctuate
      > > > - add your comments at the TOP and SIGN your posts, snip all you
      like
      > > > - To order plans: Mr. Philip C. Bolger, P.O. Box 1209,
      Gloucester, MA, 01930, Fax: (978) 282-1349
      > > > - Unsubscribe: bolger-unsubscribe@y...
      > > >
      > > > Your use of Yahoo! Groups is subject to
      http://docs.yahoo.com/info/terms/
      > >
      > >
      ______________________________________________________________________
      __
      > >
      ______________________________________________________________________
      __
      > >
      > > Message: 5
      > > Date: Tue, 21 Aug 2001 09:11:10 +0100 (BST)
      > > From: William Samson <willsamson@y...>
      > > Subject: An article to salivate over . . .
      > >
      > > Hi,
      > >
      > > Pleasant surprise this morning. Postman arrived with
      > > the new Water Craft mag.
      > >
      > > Big article (5 pages) on Micro by Peter de Boer, with
      > > mouth-watering pics of his gold-plater Micro. Not for
      > > him luan underlayment - Oh no! - Genuine Bruynzeel
      > > ply! Brass portholes, too. Fantastic finish with
      > > more than the usual amount of brightwork.
      > >
      > > I wonder if this is the first Bolger boat ever to be
      > > built out of Bruynzeel?
      > >
      > > Apart from the wonderful pics, there's a good honest
      > > appraisal of how she performs.
      > >
      > > A 'must' for Micro enthusiasts!
      > >
      > > Bill Samson
      > >
      > > ____________________________________________________________
      > > Do You Yahoo!?
      > > Get your free @... address at http://mail.yahoo.co.uk
      > > or your free @... address at http://mail.yahoo.ie
      > >
      > >
      ______________________________________________________________________
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      > >
      ______________________________________________________________________
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      > >
      > > Your use of Yahoo! Groups is subject to
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      >
      > --
      > To invent, you need a good imagination and a pile of junk. --Thomas
      Edison
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