2x4 arch build questions

[tbear]

Hi Everyone,
Brother is going to weld me up an arch! Good brother, eh? (1) What gauge steel should we use for the floor of the ash clean out? We talked over 16 gauge and worried that might be to light. (2) What would be a good door size for a 2x4 with a firebox roughly 22wide x22deep x19high? (3) Any problem putting louvers on the sides of the firebox, towards the front, versus have the air intake on the front of the arch? Also, what size of louvers (square inch openings) should we use for a 2x4 with an 8" stack? Thanks, Ted

[Bucket Head]

When I went to forced draft on my homemade arch I made the ash box out of 1/8" steel. I figured I didn't want to do it again any time soon and it has held up well. It won't need replacing any time soon! There's almost no such thing as too thick when it comes to mild steel being exposed to fire.
As for a door, maybe 16-18 wide and 14-16 high? The size of the fire wood you plan on using, and personal preference will dictate the final size I think.
Not sure what to suggest on the louvers. I have no experience with air entering the arch from the sides. Mine comes up through the grate, with the forced air entering at the rear of the ash pit.
Steve

[tbear]

Thanks Bucket Head! I appreciate the input. Ted

[RileySugarbush]

Best air flow for natural draft is up through the grate. Air inlet below the grate can be on any side, but most put it on the front.

Firebox should be bricked, and optimally insulated behind the brick. That will cut down the size of the firebox, but that's ok. My firebox has 1" ceramic blanket insulation behind full firebrick, so the width of the firebox is 24-2x(1+3) = 16" Works fine! Our door is roughly 12" square and that works fine too. You don't want the door any bigger than necessary. Every time you open the door a big slug of cool air comes in over the fire.

Our arch is skinned with 16 gauge over a light angle frame. No problems there either.

[tbear]

Thanks RileySugarbush! I misspoke in original post, I should have said on the sides of ash cleanout, under the firebox. Our firebox will have 1 inch ceramic blanket and bricked with splits, so will be roughly 22x22x19. Maybe instead of having cleanout door the width of the firebox we could make it smaller with a circular air intake in the front on each side of cleanout door. Wondering how large of an area we need for air intake. Is there a formula we should follow, or should we just guesstimate? Ted

[Super Sapper]

You will need at least as much opening as the area of your stack. Before I added AOF I made a door on the back of the ash pan.