Building a fire grate

[craigwade2005]

I’m in the process of tying up some loose ends on my new (to me) 2x5 oil tank evaporator. I’m adding AUF to it and am building a new fire grate from leftover sign post parts. With the holes in them already should I still space them apart around 3/4” at the seams or run them right together? See the two examples below. Both pictures are at the 19.5” width I need.

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[red/one]

My backyard opinion tells me the holes are enough and butt the pieces tight to contain the ashes and keep the grates from warping. The only issue would be you would have to empty ashes from the wood door.

[tcross]

my guess is you'll want a little bit of space between them. maybe not 3/4" since you already have holes in them... but some to let in more are. i'm not sure you'll really know until you try each way and see how it goes?!

[raptorfan85]

I would say gaps in between but not that large. Maybe half that would be fine. I would also put them in with the open side up so they can fill with Ash to keep them from warping.

[craigwade2005]

Sounds like some smaller gaps and the channel up. Once I get the rest set up, ill update everyone on how it goes!

[DrOriginal]

Interested to see how this works for you. I agree with everybody else, you want some space but not quite 3/4". I used angle iron in my oil tank last year. I had it oriented so it looked like a V. And I should have made the gaps smaller. I felt like too many coals fell through the openings. If they stayed on the grate they could have provided more heat. Those coals also may have burned down finer and protected the iron. Because my grate also ended up warping like crazy. By the end of the season it had the same curve as the bottom of the oil tank. Hoping the sign posts hold up for you. If they do I may have to steal it for next year :) Ran out of time to make a new grate this year. Just squished my angle iron flat again and threw it back in the tank.

[berkshires]

I made a fire grate out of signposts as well. You definitely need space between them. I built mine with insufficient space between posts and the holes got plugged with ash and coals, and my fire starved. Not right away, it took a few hours. But then it was a downward spiral, because the wood started making more and more coals, which plugged the holes more, etc. I'd leave a good half inch between them.

Cheers,

Gabe

[berkshires]

Oh, and yes, holes down.

GO

[TapTapTap]

I am rather surprised that sign posts should be used for grates.

First, I expect and it appears that your steel posts are galvanized. Normally, I avoid heating galvanized steel since the vapors are harmful. I think you'd be safe but I don't like discharging any heavy metals into the atmosphere that we all breath.

Secondly, I'm surprised that the posts hold up to high heat. My Leader Vortex has very heavy cast angle pieces with rounded edges. I considered using some heavy 3/4" thick angle for replacements to the stock grates. I decided against it since I thought that even the heavy sections will warp severely. And, i have plenty of the heavy angle in a scrap pile.

[TreeTapper2]

I used sign posts before. They worked great for a couple years then it went downhill. They are in a heap of bent up mess next to my evaporator. This year I made a grate with strut. Will see how they work out.

[Super Sapper]

I made mine out of strut in 2013 and they are still as good as the day I put them in. I first had 3/8" spacing but went to 3/4 as the spaces filled up too much. I used the solid strut so the ash could fill the inside. As far as how hot I run, I used to use 3/16 thick 304 stainless sheet to protect my insulation but that only lasted 2 years until it burnt up.

[For_the_kids]

If you use the sign posts with holes in them they wont be able to fill with ashes to protect from heat will they?

Has anyone considered filling the channels with sand ahead of time so that they are protected from the start right away?

[berkshires]

If you use the sign posts with holes in them they wont be able to fill with ashes to protect from heat will they?


In my experience, yes, after a short time they do fill first with coals, and then with ash. That's why I needed to expand the space between posts - that's where the air gets through.

I have not used AUF, so if you're blowing hard from underneath, your mileage may vary.

GO

[In da bush]

I scrounged a storm grate from a scrap yard,if you can warp that I want pics