This is typical for professional finishers in the wooden boat business, for
initial coats. The first coat would be diluted 50% (the pros I know use
turpentine, not mineral spirits), and the second coat would be diluted 25%.
After that it's full-strength coats for most spar varnishes, except for the
Epifanes product which is too thick as-shipped for brushing. For that
product they continue to reduce it with a little turps and maybe a splash of
Penetrol for better brushing and wet edge retention.
We tend to think that we get better penetration by doing this, and it's
probably true for soft woods, but teak - used a lot for exterior woodwork on
boats - is so oily that I doubt if it penetrates very much. It does make a
nice base for the later coats, though. It would be interesting to do it on a
scrap piece and then cross-cut it when it's dried and look at it with a
loupe to see if you could actually identify any visible penetration.
If you're counting coats, we count the first two thinned coats as just one.
Tom Dacon
"walnutlvr" <[email protected]> wrote in message
news:[email protected]...
> If I dilute 50% spar urethane and 50% mineral spirits will I get a deeper
> penetration.
> I am using it on ply and would like to get as much moisture protection as
> possible.
> Thanks In advance
> Lee
>
Tom Dacon wrote:
> This is typical for professional finishers in the wooden boat
> business, for initial coats. The first coat would be diluted 50% (the
> pros I know use turpentine, not mineral spirits), and the second coat
> would be diluted 25%. After that it's full-strength coats for most
> spar varnishes, except for the Epifanes product which is too thick
> as-shipped for brushing. For that product they continue to reduce it
> with a little turps and maybe a splash of Penetrol for better
> brushing and wet edge retention.
> We tend to think that we get better penetration by doing this, and
> it's probably true for soft woods, but teak - used a lot for exterior
> woodwork on boats - is so oily that I doubt if it penetrates very
> much. It does make a nice base for the later coats, though. It would
> be interesting to do it on a scrap piece and then cross-cut it when
> it's dried and look at it with a loupe to see if you could actually
> identify any visible penetration.
I did (years ago), I couldn't (10x triplet)
--
dadiOH
____________________________
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walnutlvr wrote:
> If I dilute 50% spar urethane and 50% mineral spirits will I get a
> deeper penetration.
> I am using it on ply and would like to get as much moisture
> protection as possible.
> Thanks In advance
> Lee
All you'll get is something that is easier to brush.
--
dadiOH
____________________________
dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico
"walnutlvr" wrote:
> Lew
> Brother has rv and there is moisture in a small area of one of the
> walls. Really hard to replace wood but have removed wood panel and
> was thinking of replacing it with 1/4 cdx with min wax spar urethane
> .
Since this is in an RV, I'd use 1/4 A/C ply with all surfaces,
including edges, sealed with 2-3 coats of laminating epoxy.
(Doubt anybody stocks anything but A/C in 1/4)
Since this is inside away from the sun the epoxy won't be exposed to
the sun's UV rays so no need to protect epoxy from sun.
Sand with 100 grit after 48 hours cure time to prep for next coat of
resin.
Buy a dozen, 2" chip brushes on sale @ HF, then use one time and throw
away.
Costs more to clean them than they are worth which is about $0.25
each.
The RV will be in the dump and those epoxy coated panels will still be
in service.
Have fun.
Lew
"walnutlvr" wrote:
> If I dilute 50% spar urethane and 50% mineral spirits will I get a
> deeper penetration.
> I am using it on ply and would like to get as much moisture
> protection as possible.
All you will get is a mess.
BTW, spar varnish is the wrong choice.
True spar varnish never truly hardens.
What are you trying to protect?
Lew
dadiOH wrote:
> walnutlvr wrote:
>> If I dilute 50% spar urethane and 50% mineral spirits will I get a
>> deeper penetration.
>> I am using it on ply and would like to get as much moisture
>> protection as possible.
>> Thanks In advance
>> Lee
>
> All you'll get is something that is easier to brush.
And fewer solids left from the same applied volume when the solvent dries.
--
Lew
Brother has rv and there is moisture in a small area of one of the walls.
Really hard to replace wood but have removed wood panel and was thinking of
replacing it with 1/4 cdx with min wax spar urethane .
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> "walnutlvr" wrote:
>
>> If I dilute 50% spar urethane and 50% mineral spirits will I get a deeper
>> penetration.
>> I am using it on ply and would like to get as much moisture protection as
>> possible.
>
> All you will get is a mess.
>
> BTW, spar varnish is the wrong choice.
>
> True spar varnish never truly hardens.
>
> What are you trying to protect?
>
> Lew
>
>
Thanks Lew Looks like epoxy it is
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> "walnutlvr" wrote:
>
>> Lew
>> Brother has rv and there is moisture in a small area of one of the walls.
>> Really hard to replace wood but have removed wood panel and was thinking
>> of replacing it with 1/4 cdx with min wax spar urethane .
>
> Since this is in an RV, I'd use 1/4 A/C ply with all surfaces, including
> edges, sealed with 2-3 coats of laminating epoxy.
>
> (Doubt anybody stocks anything but A/C in 1/4)
>
> Since this is inside away from the sun the epoxy won't be exposed to the
> sun's UV rays so no need to protect epoxy from sun.
>
> Sand with 100 grit after 48 hours cure time to prep for next coat of
> resin.
>
> Buy a dozen, 2" chip brushes on sale @ HF, then use one time and throw
> away.
>
> Costs more to clean them than they are worth which is about $0.25 each.
>
> The RV will be in the dump and those epoxy coated panels will still be in
> service.
>
> Have fun.
>
> Lew
>
>
"walnutlvr" <[email protected]> wrote in message
news:[email protected]...
> If I dilute 50% spar urethane and 50% mineral spirits will I get a deeper
> penetration.
> I am using it on ply and would like to get as much moisture protection as
> possible.
> Thanks In advance
> Lee
Varnish is sometimes diluted for the first coat for better adhesion to
porous surfaces. Not really a question of penetration but yes, it probably
is good practice but not really for penetration and not exactly to form a
moisture barrier.
The last coat is sometimes diluted too, to get a better finish, like dadioh
says it is easier to brush out.
tim W