Water Based Varnish Outdoors?

[anwalt]

I made a white oak table for my son for outdoor use.  Location: Indiana so there is winter here.  

First a dark-brown, pigmented, water-based stain will be applied.  He would like the stain covered with a clear smooth coating.  

Lacquer should work, maybe spar varnish, but water based varnish would be good if it tolerated uv, rain and snow.  

Thanks for your advise and suggestions.  

tom

[jteneyck]

Don't use any product not rated for exterior use.  Many products rated for exterior use aren't very good; trying to use any that aren't so rated will soon lead to disappointment.  

Putting a dark stain on the table is going to make it even harder for whatever clear coat you apply to survive.  The longest lasting clearcoat system is a catalyzed polyurethane, like automotive clearcoat, followed by epoxy primer + marine varnish like Epifanes.  The waterbased exterior poly I've seen, GF's Exterior 450, didn't look too good after one winter on a planter box at my local Rocklers.  I wouldn't recommend it for a table.  

Any finish is going to require routine (read yearly) maintenance to stay looking good.  The exception is if the table is under a porch roof or is covered except when being used.  The sun and especially the snow and rain during winter really takes its toll.  

John

[anwalt]

Don't use any product not rated for exterior use.  Many products rated for exterior use aren't very good; trying to use any that aren't so rated will soon lead to disappointment.  

Putting a dark stain on the table is going to make it even harder for whatever clear coat you apply to survive.  The longest lasting clearcoat system is a catalyzed polyurethane, like automotive clearcoat, followed by epoxy primer + marine varnish like Epifanes.  The waterbased exterior poly I've seen, GF's Exterior 450, didn't look too good after one winter on a planter box at my local Rocklers.  I wouldn't recommend it for a table.  

Any finish is going to require routine (read yearly) maintenance to stay looking good.  The exception is if the table is under a porch roof or is covered except when being used.  The sun and especially the snow and rain during winter really takes its toll.  

John

John,

Thank you for your response, and wisdom.  I will pass it on to my son.  

tom

[Alan S]

Whether it can stand up to weather is not the only consideration.  It must also be compatible with what you put it on. 

System Three WR-LPU is catalyzed water based finish that is very durable and UV resistant.  It works very well over epoxy-coated wood in marine applications, but is not appropriate for direct use on wood.  For that you need something like the Epifanes spar varnish that remains flexible enough to cover wood that expands and contracts.

I have stretched things a bit.  I once made an outdoor table painted in many colors, only some of which I had in exterior paint.  I used some interior paint, then covered the entire thing with a couple of coats of exterior deep paint base (with no pigment).  This worked well, and held up.  If you try it, check to make sure your paint base dries clear and colorless.  But I tried the same paint base directly over cedar, and it peeled in a year.

[jteneyck]

Whether it can stand up to weather is not the only consideration.  It must also be compatible with what you put it on. 

System Three WR-LPU is catalyzed water based finish that is very durable and UV resistant.  It works very well over epoxy-coated wood in marine applications, but is not appropriate for direct use on wood.  For that you need something like the Epifanes spar varnish that remains flexible enough to cover wood that expands and contracts.

I have stretched things a bit.  I once made an outdoor table painted in many colors, only some of which I had in exterior paint.  I used some interior paint, then covered the entire thing with a couple of coats of exterior deep paint base (with no pigment).  This worked well, and held up.  If you try it, check to make sure your paint base dries clear and colorless.  But I tried the same paint base directly over cedar, and it peeled in a year.

Alan, thanks very much for your post.  I've been looking for just such a product and had not been able to find one.  Strange since I used System Three's epoxy to glue the joints in exterior projects, but I hadn't seen the WR-LPU.  Definitely on my list of candidates for exterior doors.  Thanks again.

John

[Alan S]

Alan, thanks very much for your post.  I've been looking for just such a product and had not been able to find one.  Strange since I used System Three's epoxy to glue the joints in exterior projects, but I hadn't seen the WR-LPU.  Definitely on my list of candidates for exterior doors.  Thanks again.

John

John:

I'm delighted to be able to contribute.  I have learned many things from your posts over the years.

Alan