Finish on Fireplace Mantel

[Rich Riddle]

What types of finish do you recommend on an oak fireplace mantel? I have never seen one "shiny" but more like a finish similar to that found on Stickley furniture. Your advice is appreciated.

[Kent A Bathurst]

Use whatever you want - isn't a "fireproof"question. If it is, the varnish ain't the thing that will save the house.

Use a oil-based varnish like W'lox - satin if you like that; if not, rub it out to your preferred gloss.

Or, one traditional finish was the old standby [everyone's recipe is a bit different] - 1/3 BLO, 1/3 oil varnish, 1/3 turps.

Flood on, and just before it gets tacky, wipe it off and buff it. Wait a day. RInse. Repeat. 3 - 4 coats shoudl do it.

[Rich Engelhardt]

Anything is fine.
There are specialty coatings called intumescent" that react to heat/flame and "puff up" to form a protective barrier between the flame and the wood, but, you don't need or want that on a mantel.


If it is, the varnish ain't the thing that will save the house.
Actually old buddy, that's just exactly what they do!
Anyone with a timber frame house that doesn't coat the timbers with an intumescent coating is foolish.
Same goes for wood shingles on a roof.

[Kent A Bathurst]

Actually old buddy, that's just exactly what they do!
Anyone with a timber frame house that doesn't coat the timbers with an intumescent coating is foolish.
Same goes for wood shingles on a roof.

I concede the point. Had the question been about timber-framed houses or wooden roof shingles, rather than a piece of indoor furniture, I would not have posted. ;)

But still - interesting point - knew nothing about either of those.

[Rich Riddle]

It wasn't meant to be a fireproof question at all. At least it wasn't intended that way and hopefully doesn't need to be that way. I have Waterlox but thought that might be too "shiny" for lack of better terminology. Thanks.

[Rich Engelhardt]

Rich,
Any regular clear finish should work fine - satin, semi gloss flat or gloss.
The heat from the fireplace shouldn't be high enough to bother anything.
Most coatings will stand up to 200 degree F temperatures just fine.
Oil base materials may discolor a bit faster, but, other than that the finish isn't bothered.
As I mentioned above - you don't need or want an intumescent coating for a mantel.

An intumescent is a "one shot deal" just like the brake on a saw-stop.
Once the coating "triggers" it gets all puffy and swelled up, sort of like one of those snakes you light and they grow and grow, or the expanding foam.

The dead air space created insulates the substrate and starves it of oxygen.

Cleaning the stuff off is a nightmare.
However - if it saves the structure and the contents, the cleanup is worth it.