Seal the stone mantel?

[LRCRUE08]

Hey guys,
After lurking around here for about a year now, I have found a ton of great information that I must thank all of you for. Since I am new to the wood game I bought the Jotul F3 CB this year to supplement my oil situation. I converted a gas fireplace back to wood. When I bought the house, the brick was painted and there was a wood mantel. I replaced the wood mantel with a stone slab for clearence and scrubbed the paint off the brick with a variety of strippers. There is now 20 inches between the top of the stove and the bottom of the stone mantel.
I worry that this unsealed mantel will be heat stained? Is this something I should worry about or am I just being over anal? I am just afraid to seal the stone as this will change the color of the mantel. Thanks again for all of your advice.

 

[kd460]

There are sealers out there that once that are applied and allow to "dry", you can't even tell they were sealed. I must clarify, my knowledge of sealing stone and grout is from the floor covering end of it and not from the fireplace end of it. Why do I mention that? Because my concerns about the sealer and heat.

One of the best sealers I have ever used is called Silox 8, made by ceramaseal company. It is a sealer that is designed to be absorbed into the stone and does a great job of repelling liquid type stains. It is not a surface coating, those will always fail and look bad after awhile. Water will actually bead up on the surface of the stone if you use it. Good stuff. I have no idea what it will do for smoke or heat. It is also a petroleum and silicone based product, but the petroleum "carrier" evaporates after a few days. Like I said, once it is applied and dries, you can not tell it is on the stone. The only way to tell it is on there is when you get it wet, the water will bead.

Another product is made by aqua mix company and they have a few different items. One is called penetrating sealer, the other is stone sealer, and the other is stone enhancer. Once again, they are all below the surface type of sealers designed to be absorbed into the stone. It is not a coating on top. Once again, after it dries, you can not tell it is on the stone unless you check it by getting it wet and watching the water bead. The last item, stone enhancer actually brings out some of the more natural tones in the stone, or it "enhances" the colors. The aqua mix products are a water based sealer, so they may be more user friendly for the fireplace situation. How they work is kind of cool.

The way it was explained to me by the manufacturer is the sealer gets absorbed into the pores of the stone, then as it dries, the sealer forms crystals in the pores. The pores are now partially plugged by the crystals. The holes are now so small that a water molecule can not pass thru them, thus repelling the stain, or the liquid (stain) just sits on the surface.

This is good in a floor situation in a home because it will still allow moisture vapor transmission because a vapor molocule is smaller than a water molocule, so it allow for the vapor transmission, but still repels water (kind of like gore-tex). Why is this important? Ever see a tile or stone floor that had a floor wax or a coating on top? After awhile the grout or stone will turn dark or change color from the moisture getting locked in (the coating is a barrier to the vapor transmission from say a cooler damper basement to a warmer dryer living area).

So, in a round about way, I would reccomend one of the above type of sealers, but, I will also say that I have no idea how the performance would be for a mantle. At least you have a little more info to make this decision. The stone sealer is what I have used on my limestone hearth and surround, and it has not changed in appearance in 2 burning seasons, and I will use it again when I change out the stone again. I stayed away from the silox 8, just because of the heat, but I use it on floors in wet areas and kitchen counter tops. KD

 

[Gooserider]

I think sealers are a good idea, but it might not be a bad idea to contact the tech support folks for the different brands and ask about the product reaction to heat. I seriously doubt that any would be a safety issue once dried, but it could be that a product wasn't intended or suited for high temperature use and would change color or fail in some other way. OTOH, if you read labels and find one that says it's suitable for hearths and mantles then I'd think you had a winner.

Gooserider

 

[begreen]

To the uneducated, what is heat-stained? I can see being concerned about smoke staining, but heat staining is a new one on me.

 

[senorFrog]

Not sure if you've used the stove yet, but why not monitor how hot the stone get's over a month of real use? You could just put your hand on it if it' not too hot. Or put a stove thermometer on it if you want to be precise. Then you should have some info to determine if it's too hot for a sealer.

I wouldn't worry about it discoloring under normal conditions. I've sealed stone bathroom listello with no discoloration. I used TEC Guard All Invisible Penetrating Sealer and it was expensive. In bathrooms the sealer is supposed to keep the moisture out of the stone along with their related mold and mildew problems. My tile guy recommended once/year on the seal. Not sure if you'd have to do it that often or at all for a hearth application.

Nice looking install. With 200 year old home, I know all about the pains of stripping paint.

Good luck!

PS - THere are products to clean stone and they do a pretty good job. So if you see a problem developing you could always clean then seal.