Minwax Spar Urethane 3rd has serious white haze : help H2O


B

bent

Pine outdoor picnic table:

The 2nd coat had a little bit of white haze, and I assumed it was because it
rained on it a few hours. So I sanded, washed, recoated, and I think it
would have been ok. But, the humitity was very high - for the 3rd coat. I
could see a mist building as it dried.
This morning, after the 3rd has "dried" it is white - almost as if I had
white paint in the mix. Now I still asssume I can fix it. I assume the 3rd
would have been fine if not for the humidity.

What is the right thing to do:

rubbing compound, steel wool, sandpaper?

The original fix was a combination of sanding, washing, recoating. But I
do not want to keep recoating.
 
P

Phil Scott

bent said:
Pine outdoor picnic table:

The 2nd coat had a little bit of white haze, and I assumed it was because it
rained on it a few hours. So I sanded, washed, recoated, and I think it
would have been ok. But, the humitity was very high - for the 3rd coat. I
could see a mist building as it dried.
This morning, after the 3rd has "dried" it is white - almost as if I had
white paint in the mix. Now I still asssume I can fix it. I assume the 3rd
would have been fine if not for the humidity.

What is the right thing to do:

rubbing compound, steel wool, sandpaper?

The original fix was a combination of sanding, washing, recoating. But I
do not want to keep recoating.

Outdoor in the rain on a horizontal surface with soft wood
like pine is virtually impossible. if water sits on the
surface..if water runs off because the surface is at a slight
angle then there is some faint hope...but not for long with
any of the oil based materials you are talking about.

I think you will do modestly better with "Diamond Hard" a
water based outdoor rated wood finish... I put three coats on
a yellow ballau deck a year ago and most of it still still
looks like new...some of the boards have soaked water through
in spots and some grey is starting to show up... no lasting
white spots.

There is probably not a solution to your current dillema other
than to strip and refinish...if you want the best outdoor
finish try 'sun frog' an oil, it takes a while to dry, you
recoat the table ever two years or so and it will look great
forever.


The problem with finishes that dry hard over wood that expands
and contracts in the humidiy and sun is that the finish
delaminates from the wood... and as you noticed water gets
under it via permeation and causes the finish to turn white.


Thinner is better sometimes..

Phil Scott
 
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B

bent

hoping for more info; going to see
15 yr old table; 40 coats of same material: never before this prob. Always
been good
 
P

Phil Scott

bent said:
hoping for more info; going to see
15 yr old table; 40 coats of same material: never before this prob. Always
been good
40 coats of varnish would be nearly an 1/8th of an inch
thick.... sounds like smoke. you need about 3 days drying
time between coats or it never dries if you go beyond 3
coats... 3 coats is a practical maximum for that
material...you can stretch it though with 3+ days drying time
between coats if the relative humidity is under 60% or
so...forget it if it is over 80%...... serving no really
useful purpose though.

also none of these materials is made to work over anything
but real dry wood.. any moisture is the kiss of death to those
applications, that caused the finish to turn white in your
example.

With laquer, hand rubbed you might see 20 coats of on some
jobs...or actually an unlimited number of coats. Not with
any of the varnishes though in particular... some urethanes
you can get more coats with less drying time if you an
accelerator.


Some tables get flooded with acrylic resin though, a dam is
built around the table then the resin is poured on it to
achieve whatever thickness you want...and a dead flat flawless
finish without much effort.

....that would hold up against water in the outdoors.

You may wish to call the manufacturer of your product and ask
how it will hold up on a flat surface in the rain..also ask
about the maximum number or coats before problems develop.


Phil Scott , who made $45,000 one time touching up the wood
work in a 300 room hotel... $1,500 per day. .. took 30
days...about 6 hours a day.

Never repeated that trick though. For a while I thought I had
struck the mothah lode.
I did develop my own magical almost instantaneous drying low
odor finish though.. a real tricky little combination of
products. and with that able to achieve some nice stain and
dye effects.
 
B

bent

that was quick math (wrong)
12 yr old table; 3 coats stripped ~ every other year.
block wet 400, rubbing compound - better, not gone. its like glass though -
what a diff!
i'll be back
 
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finished picnic table with spar urethane-weather very moist-had milky white surface when it dried-solution :spray on shellac-worked great!
 

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