We have some painted holiday "mice" as a chorus
created by an Uncle - very nice paintings...
They are 1/4" plywood - painted.
They are showing signs of "weathering",
and would like suggestions
on how to keep them in great shape ??
I would go to any marina or store that caters to the boating public and
buy some "Spar" or "Marine" varnish for your mice signs.
Spar (aka: Marine) varnish is intended to withstand exposure to the
elements as it's original purpose was in coating and sealing the exposed
wooden spars on tall ships. It's most important when protecting any
wood from the elements to treat the end grain of the wood. This is
because wood absorbs moisture through it's end grain 15 times faster
than it absorbs moisture across it's grain. So, weathering of wood
usually is the result of the absorbtion of rain water or snow melt into
the end grain of the wood. Where you have plywood, you have end grain
along the entire periphery of the plywood.
Oil based coatings typically will yellow with age when used in a place
with dim or minimal lighting. However, in direct or indirect sunlight,
the Sun's rays will remove that acquired yellow discolouration. So,
while you might a yellowish tint on the paintings from the spar varnish
itself, any further yellowing will be eliminated once the paintings are
exposed to direct or indirect sunlight for a few weeks. It would be
best to arrange the paintings somewhere in your yard that receives a
fair bit of sunlight for a few weeks before putting them on display for
the general public to see.
Museum curators, who typically have far more paintings (done in oil)
than they could ever put on display at one time will have sunny rooms in
the museum where they can put oil based paintings that they intend to
put on display in a few weeks. That way, the public sees the painting
the way the painter painted it, not in it's yellowed condition after
spending years in dimly lit storage rooms.
tnx all -
Hadn't thought about the "marine" aspect of coating the wood.
And yeah, it's probably the edges that are allowing the water infiltration.
I'll look around for some options to coat the edges, and the rest of the
To be perfectly honest, I expect the difference between one Marine
varnish and another are small compared to the similarities. Any place
that sells Marine varnish is always going to recommend a product they
sell, so how does one tell a good Marine varnish from a lousy one?
Recommendations from friends? What happens if your friends know less
about it than you do?
Mike is right, the last thing you want to use is a true spar varnish.
Spar varnish NEVER completely hardens since it is designed to flex
with the wooden spar when under load while sailing.
Haven't seen the signs, but if it was me, I would take some 100 grit
sandpaper and sand the raw plywood edges then coat with epoxy
from somebody like System 3, WEST systems, etc.
This will get you to System3.
Allow about a week and then apply marine varnish such as Epifanes
available from West Marine or Jamestown Distributers which will
the UV protection for the epoxy as well as the wood.
This will get you started.
Good stuff that Epifanes!
I had a few old cans of Minwax 'spar varnish' that I used on some
outdoor wood (only lasted a few months in the Southwest sunshine).
Bought a can of the Jamestown dist. 'Epifanes' and after several years
things are still peachy.
I used the System III on some wood clappers for giant wind chimes and it
bit the dust after about three years. Stuff that I sprayed with clear
coat automotive paint is completely unphased (gawd awful expensive
Epoxy should be coated with a uv protectant. It will degrade if left in
the sun. Generally epoxy followed by spar is a good finish, since spar
has uv protection. Also I saw someone in a mag recommended the clear
base from an exterior paint. It's clear until colored he said.
I think you folks are over thinking this. I have a salt water pontoon
boat with a plywood deck that is used 12 months a year. 25 years ago I
replaced the deck and when I sealed the plywood I just used Home Depot
house paint to seal the edges of the plywood (along with the faces). I
did soak it in as best I could. 2 1/2 decades later, the only place I
had any problem was an unsealed penetration that started going on me.
I cut out the bad part, sealed it and I was good to go.
One could ask you the same.. why didn't you read what I wrote.
I was responding to the fact that epoxy alone did not last.
Which is a given since it needs a UV protectant.
Spar alone is not perfect either. The two together are very good.
The spar contains the UV protectant and the epoxy keeps the piece water
proof. Another thing is the spar is sacrificial, meaning it will
degrade ... sand it off as it becomes chalky and re-apply. The epoxy
should still be good.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.