The Amazing, Economical Crawford 40 Base Heater

I know you want videos and as soon as I am not working 6 days a week for 16 hour, overnight shifts; I will get them made.
Here is a brief report on how well the Crawford is doing. It, like the little Glenwood No 9 and the Glenwood 6 is simply amazing in it's performance. I decided to post this off the cuff, at the spur of the moment to show you how this stove is performing.
I loaded it a around 6:30 yesterday evening with about 20-25 pounds of coal or about a little more than a third of a 5 gallon bucket's worth. I set the dampers and off to work I went. When I got home this morning at 11:00 AM, all I did was shake the fire and it settled down about 6 inches in the fire pot. That's it. I took a little nap and now it is around 1:15 in the afternoon. I took these pictures at around 1:30. The stove is at 475 and there is still a full fire with blue flames 19 hours after I put just that small amount of coal in it.
Even after several years of using these, they still amaze me. Here are the pictures.

William,

Very nice! Lovely stove and amazing performance!

dj

That's looking wonderful William.

But how big is that stove ?
".............. all I did was shake the fire and it settled down about 6 inches in the fire pot. ............"

Dropped 6 inches ? That's the total depth of the firebox on my range !

If I may ask, what are the dimensions and capacity of the Crawford's fire pot ?

Reason I ask is, those pictures you posted of the #6 fire ring have got me intrigued and kicking around some ideas for when I get to making the firepot liner of my 118.

I'm trying to figure ahead, if I want to make a thicker cast firepot for my 118, that incorporates small secondary air channels up from the ash drawer area, or make an air distribution ring like your #6 has. If I make a ring that sits on top of the liner, I can go with a thinner liner, therefore, a little more coal capacity.

It's looking like a one inch thick liner will give me just over 10 cubit feet of firepot capacity.

Just for grins I measured the kitchen range. With the original, thicker firebox liners, it has 3.5 cubit feet.

Paul

Edit to correct my math. Just redid the numbers and skipped one, the range is .31 cubic feet and the 118 is somewhere around . 9 cubic feet.

Note to self. No more doing math during happy hour !!

Paul

One inch is what the original bricks were. I would not bleed off primary air for secondary function. Keep it separate.

The fire pot is 12 inches across by 16 inches deep. I estimate it holds around 50 pounds of coal.

franco b wrote:One inch is what the original bricks were. I would not bleed off primary air for secondary function. Keep it separate.

My reason for considering feeding from the two primary dampers in the ash door is that, if I use small, vertical channels cast in the liner, say about 1/8 inch, there would be more resistance to flow. More so, than the primary air feeding through the grates.

By only having to change the primary air setting, I keep the air feed before and after the fire pot more proportional with no additional setting require for the secondary.

More air into the grates equals more heat and gas volume above the coal bed, raising the draft (pressure drop) at the secondary outlets thus increasing their flow by speeding them up. Slow the fire down and draft pressure drop is reduced so the secondary feed volume automatically slows down. Those liner secondarys will work exactly like high speed air bleeds in carburetors. In other words they will automatically change their air flow proportional to the pressure drop above and below the firepot.

And drawing secondary air from the hot ash drawer and letting it pick up even more heat as it travels inside the walls of the firepot will preheat that secondary air even more.

Maybe I can get a 118 to have those dancing salamanders William spoke of.

Least, dats me tinkin' on it.

Paul

wsherrick wrote:The fire pot is 12 inches across by 16 inches deep. I estimate it holds around 50 pounds of coal.

Thank you.

Ok, so that's a bit more then what I figure the 118 is, . . . with a one inch thick liner making it 16 inch at the top, tapering to 12 inch at the bottom, but it's only about 10-11 inches deep.

Paul

Sunny Boy wrote:And drawing secondary air from the hot ash drawer and letting it pick up even more heat as it travels inside the walls of the firepot will preheat that secondary air even more.

Nothing ventured, nothing gained and it will certainly be interesting to learn the result. A proportional feed might be best. I would be concerned with fly ash blocking the upper holes.

franco b wrote:

Sunny Boy wrote:And drawing secondary air from the hot ash drawer and letting it pick up even more heat as it travels inside the walls of the firepot will preheat that secondary air even more.

Nothing ventured, nothing gained and it will certainly be interesting to learn the result. A proportional feed might be best. I would be concerned with fly ash blocking the upper holes.

True. And if it doesn't work, there's more refractory to close off the passageways.

Yeah, right after I posted that, I went out and shook down the range to get ready to cook dinner. It hit me that small passageways with a pressure drop leading to the ash drawer will likely draw in ash, . . . OH-DUH !

Then I remembered, "metering rods".

If I make larger passageways, I can down -size them but dropping a smaller diameter drill rod in each with a short 90 degree bend at the top to keep it from falling through. If a passageway becomes plugged, just lift out the rod and drop it back in. And I can fine tune the feed through each passageway by changing to drill rod of different diameter.

Paul

It's going on 24 hours and everything is the same as when I put this up here. I am sure it will last until I come in from work tomorrow morning. It's one thing for a stove to hold a fire for a great length of time. It's quite another to have it maintain the same high out put for that length of time.

Will you post more pictures of the stove tomorrow. Please !

Paul

wsherrick wrote: It's one thing for a stove to hold a fire for a great length of time. It's quite another to have it maintain the same high out put for that length of time.

And that is what some people cannot seem to wrap their head around when it comes to BB's. I knew when I purchased the Crawford I was buying a great stove. What I didn't know and understand was not only how good it heats but for how long and with so little coal all while maintaining the same consistant high output.

I am still amazed that after 36 hours the Crawford still holds the temperature. Even after giving "Joan" a shake a poke or two and adding coal, the stove holds its temp. They are truely amazing. Now I am on the hunt for a Glenwood #6.

Baseburneritis... The only cure is getting another one.

SunnyBoy-
Whats wrong with using the original secondary air setup on your 118? Is it that much less efficient than the secondary design of the #6 base heater?

PJT wrote:SunnyBoy-
Whats wrong with using the original secondary air setup on your 118? Is it that much less efficient than the secondary design of the #6 base heater?

PJT,
Location.

Unlike what I've seen with some of the base burners, the Glenwood Modern Oaks get their secondary air up higher from the "gas burner" damper casting built into the loading door.

The damper is the same tri-opening round type damper as the two in the ash door, but there is an inside casting with holes in a circular pattern to diffuse and disperse the secondary air up higher than at the top of the firepot. And it only lets air in at the very front near where the tops of the blue flames would be, as opposed to feeding air more uniformly around the perimeter of the firepot at the base of the flames. I think that difference of firepot ring vs door secondary air, is why the base heaters can do a better job of getting closer to 100% complete combustion than the Modern Oak models.

I think the secondary in the door may have been done that way because these models were a compromise. Unlike the base burners, the Modern Oak models were made to burn either wood or coal. The higher placement of secondary air probably works better with wood ??????

As part of this experiment, I'll be casting a removable firepot, or casting the firepot as separate bricks, either way it will be 100% reversible without changing, or risk of damaging, any original parts.

Paul

I look forward to seeing the experiment works. Removeable bricks might be easier. Just a thought.