I'm working on a project that I'm hoping won't go up in flames... literally! It's a table top (made out of wood) for a fire pit. I planned on protecting the bottom with this High Heat Ultra Spray Paint, but I'm not sure what kind of finish to use for the top. Normally I would use Thompson's Water Seal for outdoor furniture, but I believe that finish isn't fire resistant. Is there a finish out there that would protect this project from catching fire when placed over a smoldering pile of ash?
-
3I believe the best solution would be to ensure the fire is completely out (including smoldering ashes) before placing any flammable object over the top of it.– FreeManCommented Jun 6, 2016 at 19:21
-
That paint is not going to keep the wood from reaching combustion temperature and going...Poof! Also, the moisture in the wood will heat up and delaminate the paint.– Ashlar ♦Commented Jun 6, 2016 at 20:05
-
Additionally, the paint will likely give off some nasty chemicals when it burns, and will also probably catch fire before the wood, increasing the likelihood of the wood catching.– FreeManCommented Jun 7, 2016 at 21:01
Add a comment
|
3 Answers
Use Cumaru hardwood (aka Brazilian Teak or Golden Teak). My internet searching seems to indicate that this wood has a Class A fire rating and is as resistant as concrete to fire.
This link includes a number of results from test data backing this up.
The type of testing that these hardwood decking and siding species were tested for is commonly referred to as ASTM E84-10 "Standard Method of Test for Surface Burning Characteristics of Building Materials". This fire testing standard was established by ASTM International (formerly known as American Society of Testing and Materials). A Class A fire rating using the ASTM test method is the equivalent of a Class A fire rating from the following test methods and agencies:
- ANSI/NFPA No 255 from the American National Standards Institute/National Fire Protection Association
- IBC 8.1 from the International Building Code
- UL 723 from Underwriters Laboratories
-
That might just work! Where would I find this Brazilian Teak sold by the board? I've done some searching, but I'm only finding tongue and grove flooring for sale.– NateCommented Jun 7, 2016 at 11:56
-
-
-
You'd only have to rip the tongue from one side and the grove from the other side of the top. You can use the T&G in the interior of your lid. Just don't glue the whole thing up tight - since it will be outdoors, it will be subject to a lot of temperature and humidity swings and will need a lot of room to expand and contract.– FreeManCommented Jun 7, 2016 at 21:03
In short wood is not the right material for this, I think you should re-think the requirements... coming to the inevitable conclusion that metal is very likely the way to go. Every fire-pit cover I can recall seeing was made from plate steel.
But if I'm reading the following right you already have problems you'll need to address!
a firepit made out of wood.
There's a reason barbecues and so forth are made from metal, brick or concrete, just sayin' ;-)
-
Sorry, I should have clarified in the question, this is a table top for a fire pit. So when it's not being used as a fire pit it can be converted into a small table.– NateCommented Jun 7, 2016 at 11:15
-
@Nate, simplest solution if you're going ahead is to douse the ashes with water. Not kidding. Assuming you can find cumaru or something similar and the cost is acceptable it's not a 100% solution since fire-resistant and scorch-resistant are not the same thing. Best thing to do if you need to convert the area from fire-pit mode to sit-around mode would be to damp the embers down.– GraphusCommented Jun 8, 2016 at 7:00
-
"Wood is not the right material". This, exactly. Although the water trick might still just work, of course "wood + water" is almost as bad as "wood + fire". I would personally be using a 3cm granite slab.– DamonCommented Jun 8, 2016 at 8:29
Even if you coated it with a thin sheet of steel - which you'll never get to burn with a wood fire - a wooden lid would char badly.
You need to keep the temperature of the wood low with a decent layer of insulating material if it's going to go over the top of glowing coals. You might be able to achieve this with a steel sheet against the wood, then an air gap, then another steel sheet, but long term I doubt it.
