My home made arc, ash grates in question though

[J&A maple]

first time Here, What a great Forum, I am in the middle of a build and want to say that I believe this grate system may be doomed to fail, I will try to post pictures of it. The perimeter is of 1.5 x 1.5 x 3/16 angle, Same as the horizontals for the grates, The slopes to the ash pan is 10 gauge steel which I need to fully weld, The question is I believe they will not hold up to the heat and I believe the entire ash pan should be bricked correct?, I do have a dial on the ash door to let in air. Thanks everyone and have a great day. May go into backyard sales if this works.
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[RileySugarbush]

Nice arch!

Here are some comments for you:

The grate looks good but should be the other way around, with the angles pointing down so they fill with ash to keep them from burning up. The key is to let them self insulate that way and let the incoming air on the bottom of the slopes of the angles keep the steel cool. Mine are that way and have worked for years with no distortion at all. They are 2 x 2 x 1/4 though. Also, you want air flow over the whole bottom area, so a couple more slots would be good.

Your draft vent is far too small. That would be good for a wood stove, where you want to regulate burn rate for long overnight burns. What you are after here is to burn an arm full of wood in 10 minutes or so, so a big draft door is needed to let lots of air in. That air is what allows the hot fire for a good evaporation rate. You will likely want to add on blower in the future, so maybe add a port in the back for that now if you want. No need to brick the area under the grates.

[J&A maple]

Thank you Very Much John, I will add more air holes to the Door for now or figure out how to utilize what i got to expand. as far as the ash pan not being brick I really appreciated that advise, I will modify the angles pointing the other way also, I was also thinking of filling them with mineral wool and capping them, I thought that they would work as well. I'm retired from 30 years of sheet metal H.V.A.C . And seriously thinking of building and selling a few. Just bought a tennsmith 6 ft brake and shear for the stainless, It's a great pastime. Again, Thanks for the advise, all advise welcome. Have a great day. Jerry

[maple flats]

The air might well be big enough, if you open the entire hinged door. The adjustable draft you have is way too small. On my 3x8 the draft door is about 6" high and 14" wide. I no longer use natural aspiration, as I have high pressure air under fire (AUF) and air over fire (AOF) but when I did, that draft door was full open. You need lots of air!!! If you have an ash pan inside the door, get rid of it, the leading edge will block too much air.

[J&A maple]

Thanks Guy's For your solid advice, I will start the re-modifications tomorrow, I appreciate the great feedback you have givin me. need this prototype done asap. I will post pictures soon as I get the stainless pans on top. One Question though if you have time, I was thinking of encapsulating the reworked angle grates with the v facing down with mineral wool or arch insulation blanket, A little more work but maybe Better?. Again, I appreciate all the sound advice.
thanks Dave . Nice setup you sure have. Jerry

[RileySugarbush]

not needed and it probably wouldn't hold up with all the wood on the grates. Let them fill with ashes and they should be fine, though they would be better if made of a bit thicker steel.

[Dennis H.]

Nice looking fab work.
Do not worry about filling the grates with blanket material, do like what was mentioned before and let them fill with ash. The bigger the angle iron the better.
I used 1"x1/4" angle for my homemade barrel evap and they warped not long after firing the 1st time. There was just not enough room for enough ash to insulate the grates.

As for the draft door, go big! You have some really nice looking fab work on the adjustable draft control and all but when it comes to a maple syrup evap that fine of control over draft is just not needed.

What size smoke stack are you planning on using? 6", 8" ?
What will be the size of pan that you are going to make? Is it going to just be a flat bottom pan or do you have the ability to make a drop or raised flue pan?

Nice build, keep the pics flowing.