Seeking ideas: Finishing Scorched Spruce (Exterior Grade)

[WLDOR]

Hi all, I came across this forum through a search on ideas for finishing some Adirondack chairs I'm in the process of making for outdoor use.

 

The chairs are all made from spruce, and have been lightly 'scorched' with a propane torch to highlight the grain/give the appearance that the wood is more exotic than it actually is!

 

My concern is with regard to finishing them with a suitable varnish. Here in Ontario, Canada our summers can be very hot (+30C & up), our winters very cold (-25C & lower). These chairs will remain exposed to the elements beside our fire pit year 'round. 

 

I'm assuming a marine-grade exterior varnish will be best (and if so, oil/water-based?), but my main concern is regarding the scorching - I really don't want to ruin the effect of the wood by making the darker colour bleed/run. i.e.: If I brush-on a varnish, am I likely to mess it up?!?

 

I welcome all advice/experience, please and thanks!

 

 

 

[Eric.]

 very hot (+30C & up)

 

LOL

 

I'd go with spar varnish.

[Guest]

-25 to +30 celsius  = -13 to +86 farhenheit, I believe.  who knew that Ontario was more temperate than chicago . 

 

Spar Varnish will darken the wood, but you so will anything that gives you protection. 

 

End grain is most important, that is where water gets sucked in and rot begins, so treat the bottoms of the legs with epoxy... keep them dry, flip them upside down it the winter so the rain and snow will shed off, if possible keep them out of direct sunlight but somewhere they can get dry after a rain.  All of those things will matter just as much as what you use the finish them.   

[WLDOR]

Thanks Woodsap - and agreed. I'm paying extra attention to end-grain, making sure the ends are sanded & sealed completely - especially at the base of the legs, where wood meets ground & tops of the back-rest, where water/air meets wood directly.

 

Unfortunately(??) we live on 3+ open acres of land (very little tree cover), and surrounded by +/- 1600 open acres of arable farm land on all sides... the fire pit is to the Southern-side of the house, and these chairs are too heavy & cumbersome to keep moving back and forth (It's not my first rodeo with this design - just this kind of finish!)

 

I appreciate the simple answer is going to be: "suck it and see, princess": apply varnish to a test sample and see how it works, but if anyone has any actual experience with applying finish to scorched lumber, I'd be very interested to hear their relative success with applying by brush, or whether spray is the more successful approach

[Bobby Slack]

Sealing the end grain with epoxy ... brilliant.

 

Call the guys that sell Sikkens. They have Cetol 1 for the first coat and Cetol 23 for second and third coat. I used this on my cabin in Colorado where is about 70 at the most in the summer and -20 in the winter.

 

No cracks, easy to re-apply

[wtnhighlander]

Don't worry, the scorched areas won't run. No matter what finish you apply.

[..Kev]

Wow! Those look cool!

[WLDOR]

It's been a while since the last post, but to 'close the loop', here are some pics of the finished chairs - scorched and shortly prior to finishing with three coats of semi-gloss Spar urethane:

 

 

 

My bride loved the look, so did some friends, but they asked for benches too, so I adjusted the plan accordingly and made a few of these as well - these are the 'finished article', with 3 coats of oil-based Spar Urethane:

 

 

As an aside, I had a couple of old decks lying around, so re-purposed those into horseshoe pits, and added a scoreboard for good measure:

 

[wtnhighlander]

Awesome!

[wdwerker]

Looks great! If you use a coarse wire wheel before torching you get amazing 3D grain that looks old and weathered.