A Cherry table?

[Tinker]

I was having a discussion with one of my landscaping contractors yesterday.  She told me she had a large slab of Cherry at the local saw mill.  The mill owner told her he could make the slab into a picnic table for her. 
She asked:#1 Is cherry durable as an out side table.
My answer was that i did not think so.

#2  The builder of the table was going to use urethane for the finish.
I am not so sure about that either.  My suggestion is to use a spar varnish meant specifically for outdoor use.

Were my answers correct? Of course my first reply should have been to let me do the build  :
Aside from that, I can think of a lot of other woods more suitable for out door use.
The area where I am most lacking in knowledge to any degree is a finish.  Is urethane suitable?  What wood be best finish?
TIA
Tinker

 

[Tyler Ernsberger]

Your right, cherry is not the best choice for a exterior table.  Spar varnish will fail over time with the cherry.  Slabs will crack and moisture will get it the wood.  She should find a better wood choice and put on a Sikkens product or Penofin.  If she can find some black locust that would be the best local option.  There are fence post cut from locust still in the ground from 100 years ago.

 

[Tinker]

Thanks Tyler.
I will look into the finish products you mention.
She told me the slab of cherry is about 3"s thick.  I can think of a lot of other projects for that piece. I have only used cherry on one project, and that was this past winter as a border for a table top. I have other projects in ind for the leftovers, but NOT for out doors.

Years ago I used Spar varnish for some of the trim on a boat i had built.  It worked pretty good over ash.  But we re-did it every spring.  The kids who wanted to go water skiing with me were put to work on that project [big grin]
Tinker

 

[Tyler Ernsberger]

Cherry is a very pretty wood but its soft.  My only fear with spar varnish is that it only coats the surface.  The slab is going to split and or already has.  Sikkens/Penofin is a penetrating oil and is made for exterior uses. 

 

[clark_fork]

The answer is simple per Fine Woodworking May/June 2009.

Seven coats, thinned per instructions of Epifanes High Gloss Marine Varnish

www.epifanes.com

or

Three coats Smith & Company, Penetrating Epoxy Sealer Under Five Coats Epifanes Marine Varnish

www.smithandcompany.org

I hope you like to wield a brush. That is a lot of coats.

 

[msweig]

UV will destroy pretty much any finish, so outdoor projects are going to need to be refinished regularly.  Getting something like a marine grade (from a marina, not a "marine" finish from Home Depot, etc.) will hold up better, but you'll still need to refinish it.

At least that is my understanding based on all of Flexner's books.

 

[nickao]

American Cherry is soft, and I assume this is what we are talking about. BUT I am not so sure many people work with cherry much becasue if they did the first thing they would ask if its all heartwood. A pure heartwood slab of cherry would be from a huge tree. If its heartwood it can be most likely be used outside. Walnut is the same it's very soft, but the pure heartwood in a slab can, if tis the right piece, be used outside as well. The heartwood won't be hard, but like soft cedar it will be rot and decay resistant. If cedar can be used cherry and walnut can be. Cedar is softer than cherry and walnut.

I suspect if this is coming from a mill the miler knows this and would only provide and suggest a wood he knows would work outside. The sawmill guys go through and see more wood in a season than most of us will in a lifetime. They learn a lot about wood even if they cant build a house or cabinets from it. They know what sits outside for years and what lasts.

I suspect everyone that has commented has given their thoughts based what they learned and most likely haven't actually used a 3" thick slab of heartwood Cherry in an outside project. I know I have never used it for an outside project and I know I was taught it was crap outside. After many years in the shop and with pallets of lumber sitting outside in Chicago weather I have had a change of hear from what I was taught, I would use cherry or walnut if the slab was just right for an outside project. I just keep thinking of all the cedar I have used outside and 5 years later it's there, but cherry just couldn't look any worse.

Anyway, there are plenty of respected people in the trades you can Google to see how they used cherry and walnut for outside projects. Some say no way, these are guys that haven't tried the woods outside to even give it a chance, but those that took a chance found it did hold up.

Here is a person with experience with cherry and loads of other woods. His business is wood:
https://wunderwoods.wordpress.com/2013/08/25/walnut-and-cherry-are-great-exterior-woods/

 

[Tinker]

@ Dovetail65 I read the attachment.  Very interesting.  It seems the writer has used both Walnut AND Cherry for outdoor projects.  The slab my friend has is from what she described as a very huge cherry tree that had fallen down on her sister's property.  I don't know if it is live edge, but I am assuming it has both heartwood and sapwood involvement. 

Thanks to all advice from other responders as well.  I have been educated once more.  I will pass all the info on to my friend.  I have no hand in the production, but will stash the info for my future use.

Thanks
Tinker

 

[JimD]

Interesting point of view indeed.  I would not have guessed cherry would hold up.  But I do know that sunlight affects cherry quite  bit.  It darkens when exposed to sunlight.  So if you don't want that, you should use a UV blocking finish.  (Walnut, by the way, fades in sunlight)