That's just Grate!

[oneoldbanjo]

The way the current wood loading and burning system works in my Woodmaster is that after I load the wood it stays together and burns for a while until the wood loses it integrity and it falls apart and forms coals, then the coals fall to the bottom of the furnace and they lay on the previous layer of coals and ashes. If you don't stir things around the coals get smothered and never do burn.

I have often thought that the use of a grate in my Woodmaster would sure make dealing with the ashes and coals easier. Instead of having to rake the coals and ashes back and forth......the coalswould just stay up on the grate until they turned to coals...then when the coals burned up they would just fall through the grate. I had a piece of heavy woven wire that was made from wire about as big around as a pencil, and I decided to use it to try building a grate system without spending any money. I cut the woven wire into two pieces that were about 24" square and wired them together to make a hinge. I stacked up two bricks at the back and middle of the OWB and placed the rack on top. Then I put some logs on the rack and shoveled a few coals onto the wood and closed the door.

Everything worked well for about 3 days.....however the rack was starting to show some sagging from the heat. On the 3rd day the outdoor temperature was going down to 10 degrees and we were going to be gone all day until late at night.....so in addition to stacking wood on top I put a few pieces of wood in the bottom of the firebox in front of the grate. The result was that the grate got too hot and lost all of it's strength.....and ended up sitting on the bottom of the OWB firebox.

For a few days it was pretty nice.....I just needed to shovel ashes and did not have to do any raking of coals. I am not sure if heavier materials would solve this problem......if you have fire on both sides of the grate it just gets too hot and sags.

 

[Metals406]

I've heated the small cast iron grate in my stove to the point it sagged, and cast iron (not cast steel) is far more heat resistant than mild steel.

I've also made several custom grates for wood heaters/fireplaces. . . I always use 3/4" bar stock (sometimes 1"). And yes, they're heavy when done. 3/4" hot-rolled is 1.91 lbs per ft.

Even at 1400-1800 degrees, that 3/4" bar will take a lot of weight -- esp. with a good grate design.

 

[savageactor7]

My Dad said remove old ash daily and 'never ever' let the coals and ash touch the grate. If you didn't do that bad things would happen to the grate...wish I played closer attention to 'why' back then. Unfortunately for me that ship has sailed.

 

[leon]

thats just grate

You need to bite the bullet a do a few things.


First to help you with the ash problem:

In you case I would buy some fire brick-not the thin pieces from TSC

the standard fire brick will help you keeep the heat in, hold the heat in and

burn hotter to a fine white ash.


Line the bottom of the combustion chamber with fire brick as far as you wish to stack the fire brick around the bottom of the chamber.


You can add fire brick to fill the bottom of as high as you want to do it-


Please understand I am not trying to get you to spend money frivolously-

By filling it with fire brick you do several things

1. you insulate the inner fire box-wait i am getting to that part

2. you are creating thermal mass- I am getting to it

3. you use use wood for fuel.



The firebrick insulates the firebox which concentrates the heat and also absorbs the heat created by the burning of the firewood.

The firebrick also protects the fire box from the potential overheating of the fire and possibly causing damage to the firebox.


The extra firebrick is a thermal storage mass that holds the heat from
the fire to keep it burning hotter and and holds the heat longer for you.


As the firebrick stays hot the fire is hotter and there is much less smoke which means you are burning much much hotter.


The heat energy created by the fire is absorbed and stored in the fire brick and if the fire cools down the heat stored in the fire brick rediates from the brick into the boiler and absorbed by the interior of the boiler.


So can save a huge amount of wood fuel by purchasing fire brick-


I filled my wood and coal boiler half full with fire brick (half the physiacal volume of the combustion chamber is filled with fire brick) and I have not regretted it as I burn less wood and less coal at a hotter temperature with less smoke and ash.


I bought a 12 inch by 12 inch piece of channel iron to cover half the length of the coal grates which are held in place by angle iron and I can still shake them with little effort.

If you lay fire brick in the boiler you will not regret it. You will not have to cement it in place either as it is only holding in heat as the fire box is holding the smoke and gasses.

When you lay down the first layer of fire brick you can cover the bottom of the combustion chamber fully and you could lay several layers of firebrick longways to back up the rear of the boiler and create a wall of fire brick with the long side facing the loading door one brick deep.

part 2


If you buy some heavy stamped grating from a fab shop-the grating is a very common item you will have a very stable piece of metal to build a fire and keep one going.


I can candidly tell you that the fire brick solution works and works well,


leon

 

[jbighump]

the grate in my stove is made out of about 1 1/2" cast iron and has held up fine, at least for the 3 years ive been using it.

wonder if some one was able to obtain a old storm sewer grate and cut it down would that work

 

[Biker Dude]

Excellent idea Leon! I have the same problem in my Taylor with coals being smothered by ash but my solution was to drill holes in a scoop shovel and sift the ash out while returning the coals to the boiler. It works, but if you are standing downwind while sifting you get a face full of ash.

Where do you get thick ceramic firebrick from? My firebox is flat on the bottom so firebrick would lay in there nicely and I'm always looking to make my setup more efficient.

 

[hardy steve]

I dont know the size of your fire box,but if you really want a grate.You can buy Hardy replacement grates and use firebrick to hold it off the bottom.Just my2cents.

 

[CrappieKeith]

We carry 2 sizes of 2700 degree fire brick.
They are 2" thick and are 9"x6" or 12"x6".

We also have heavy duty 30 lb. cast iron grates that are 8"x24".
I'll give 25% off to you guys here at AS.

 

[boltonranger]

Well maybe it'll work...

First I'll say that I don't have a OWB.
But hear me out.
I have a fireplace with a standard Lowes log grate. The kind with about 3/8" iron.
My trouble was that all the coals fall through the wide gaps as the wood breaks down. So I went to the hardware store and found a sheet of steel grating, looks like very thick wire and is woven. Anyhow I placed this over my iron grate and bent it to kind of form fit over the iron.

The result is that the only thing that falls into the bottom of my fireplace is ash.
Very fine like powder. While the screen has sagged a little - mostly it's in the same shape as when I put it in. And the result is that all my wood burns completely. I do not know if this would work for you but for 20-25 bucks I would try. My actual iron grate is much thicker and heat resistant than what I see in your picture. I will post a pic for you when I get home.
-br

 

[leon]

stuff and firebricks

Excellent idea Leon! I have the same problem in my Taylor with coals being smothered by ash but my solution was to drill holes in a scoop shovel and sift the ash out while returning the coals to the boiler. It works, but if you are standing downwind while sifting you get a face full of ash.

Where do you get thick ceramic firebrick from? My firebox is flat on the bottom so firebrick would lay in there nicely and I'm always looking to make my setup more efficient.

You can buy them from Crappie Keith or any firm that sells
cut stone or engineered stone pavers, flagstone, tumbled engineered paving paving stone if it is too far to travel to visit keith


The issue of how much is simply volume required I bought almost enough firebrick to fill half the volume of my fire box being 12 by 12 by 36 L*W*h


I can tell you that it works and works very well well and keeps it hot for yuo.

simply decide how much of the fire box you want to fill and go from there using


the math formulas for volume of a cylinder

3.14 X the radius X the radius X the height.

3.14 times half the distance of the width of the boiler chamber so if you have a cylindrical boiler chamber that is 36 inches in diameter the radius is 18 inches. the hieght would be the length from front to back.


and a rectangle


the length times the width times the height


If you take the volume of the cylinder and subtract two thirds of it it would give you the volume of fire bricks required to fill a third of the fire box in one solid mass.

take the volume of one fire brick 9 by 6 by 2 or 12 by 6 by 2 and dived that volume into the remainder of the volume of the cylinder to get a ball park figure for bricks.

Buying the grates from keith would save you the aggravation of buying punched metal decking and the handling of it while cleaning and the eventual sagging.


I had the back wall lined with brick sveral years ago having a firm come up and weld angle iron to the back of the boiler(the back wall to stack brick has no water contact) and two years a go I bougth nearly enough brick for the boiler when I was in Syracuse NY for the winter farm show at the fairgrounds.



I will tell you that I wish I had done this 32 years ago and when I buy the outdoor boiler to replace this one I will do the same thing with the bigger outdoor boiler. the fire burns hotter and cleaner and the shortcoming of having a bigger chimney and a smaller boiler flue was no longer a problem as the fire as hot and huge with a small fire.


leon



Leon:chainsawguy:

 

[CrappieKeith]

I would add that brick is not equall.There are different densities and or temp ratings.The more dense a brick is the better heat retention you'll gain when it comes to thermal mass. 2700 degrees is about as dense as you'll find.
We actually buy our brick from a manufacturer that makes these bricks for bread or pizza ovens.

 

[leon]

fire brick

I would add that brick is not equall.There are different densities and or temp ratings.The more dense a brick is the better heat retention you'll gain when it comes to thermal mass. 2700 degrees is about as dense as you'll find.
We actually buy our brick from a manufacturer that makes these bricks for bread or pizza ovens.

I agree with you keith, my dad had to rebuild the after burner in the incinerator twice when he used it in his grocery business before he retired.


I was certainly surprized to see how thing the fire brickk is that tractor supply is handling in my area anyway.


leon

 

[olyman]

the grate in my stove is made out of about 1 1/2" cast iron and has held up fine, at least for the 3 years ive been using it.

wonder if some one was able to obtain a old storm sewer grate and cut it down would that work

this be wayyy good idea--but to get new--might be salty--and depending on the cast makeup--whether it will stand weight--and heat--weight of traffic,yes---with heat added,maybe not------

 

[leon]

thats just grate

this be wayyy good idea--but to get new--might be salty--and depending on the cast makeup--whether it will stand weight--and heat--weight of traffic,yes---with heat added,maybe not------

No you do not want a sewer grate as it will attract a lot of the wrong attention from the local authorities, unless you buy it directly from the distributor of manholes or the company that casts them- the newer type of grates/basin covers are too thin anyway.




No I did not!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :deadhorse:

 

[motoman3b]

Curious what you guys do with the firebrick when it comes time for end of season clean up?? Just take it out I would presume... My firebox on my OWB is round has anyone had any luck lining a round one? Thanks

 

[leon]

fire brick

Curious what you guys do with the firebrick when it comes time for end of season clean up?? Just take it out I would presume... My firebox on my OWB is round has anyone had any luck lining a round one? Thanks

I do not bother taking mine out and have had no problems.

If a fire box is round its not problem as you are simply building
a thick wall of fire brick.


You could simply weld some long pieces of angle iron to hold the brick in place either for the entire cercumference or part way.

Spacing the angle iron far enough apart to allow the sliding of the individual brick along the channel created foir the long side of the fire brick and you can do this for the entire circumference of the fire box-but planing is ket to fully cover the interior of the fire box by measuring the corcumference and the thickness of the angle iron with a bit of fudge factor to allow easly sliding of the fire brick in place

If you want to add more brick it simply a matter of stacking brick to fill the fire box which was half full in my case.

The round fire box is no problem where the brick is simply built up row upon row of fire brick laying the bottom course along the side until you want stop the brick level by laying the brick longways from front to back.

Laying the brick across the back is no different where you can simply lay the brick up to the point where you want to stop or simply fill it up with fire brick until it is filled to the point you want to stop.

In my case I filled the combustion chamber half full except for the area around the flue pipe.

Creating a running bond length ways with half the fire brick covering the lower half of another fire brick is simply time consuming but it is rewarding.


The themal mass keeps everthing hot and stays hot.

leon

 

[Justsaws]

If you can find them, the old cast iron window weights make great grate cross bars when stacked on something to raise them to the appropriate height. Old small rail or heavy angle with some locators welded on works great.

Fire brick can work but it is my experience that the brick(hard only in this app) will not hold up well to being heated and jostled much.

 

[Metals406]

If you can find them, the old cast iron window weights make great grate cross bars when stacked on something to raise them to the appropriate height. Old small rail or heavy angle with some locators welded on works great.

Fire brick can work but it is my experience that the brick(hard only in this app) will not hold up well to being heated and jostled much.

Those weights are indeed rare. . . I've saved some from remodels of old homes, and you can find them occasionally at an auction. Most folks don't know what they are when they see them.

In all actuality, it's an old wives' tale that you can't use a steel grate in a wood burner. It takes a very long time for even 1/4" steel to erode away in a fire.

If a person has good stove cleaning habits, and keeps the ash cleaned out (the way it should be anyway) a 3/4" grate will last for years. A BBQ grate is a fine example. . . I've never seen one that didn't outlast the BBQ itself.

Most stoves are made out of mild steel, and some are very thin. I've seen barrel stove 20 years old, that were unlined and going strong. 55 gallon drums are pretty thin.

I remember dads double-barrel stove when I was a kid in the early 80's at his blacksmith shop. . . He'd get that baby humming where the sides would glow red.

I could be mistaken, but it appears the OP used a piece of hog-fence panel for the grate. IMHO, he could double it, and have a few more supports on the bottom. I saw only one brick supporting the first one that sagged.

I'm also a proponent of him lining 1/3 (or better) of his burner with firebrick. . . It would make his burner better no doubt.

 

[Nosmo]

Simple Grate

My Englander TR-18 is lined with firebrick but had no grate. So what I did was to cut 2 pieces of 2" pipe and lay one on each side of the stove's floor.
These run from the front to the back on each side.

I can lay 2 or 3 pieces of wood across from side to side and a couple smaller pieces on top from front to back. Starting up a fire is no problem because air flows all around each piece of wood.

Nosmo

 

[oneoldbanjo]

Sorry to be away so long.....the recent snow got the best of me. The Cincinnati area has set a new record for February Snow totals.

I am not sure that Fire Brick is going to be much help for me. My OWB burns fine and managing the coals/ashes is not too much of a problem when I am burning big rounds. The problem comes when burning wood that are limbs. I have cut them 36" long and they are mostly 3" in diameter.....and it takes a bunch of them to keep the house and garage warm.

I load in the morning before I go to work and then again when I get home from work, and then again before I go to bed. Once or twice a week I have a meeting that starts at 7:30 and I don't get home until about 10:00...so I have to load up a lot of wood to last 16 hours. When I throw in a lot of the smaller limbs they burn up and collapse very quickly and they leave a thick bed of coals that can sometimes be 6 inches or more thick - while only the top couple of inches get enough air to burn. I do rake before I throw in any more wood - but it takes several hours and several rakings to get the coals all exposed and burned into ashes. My goal in building a grate was to have the burn work more like a fireplace - where the coals are exposed to air and when they burn up and turn to ash they just fall through the grate.

I did build a wire mesh scoop and it does work - but it is a bit messy and it still requires several hours and several "turnings" to get the coals to burn up. If I don't get much of a chance to turn the coals/ashes during the week I can spend an entire day burning up coals and never adding any wood. On Saturday I can start turning the coals/ashes over every half hour and burn almost the entire day just burning up coals that built up over the week.

Finally....the grate I made was a temporary attempt to see if the system worked and I did not expect it to be permanent ....but I did expect it to last more than 3 days. I had stacked 2 bricks on top of each other in the front and the back and they were in the middle of the OWB where the two panels were wired together to make a hinge. The metal grate has 2" openings and the wire size is 3/16" in one direction and 1/4" in the other. The smaller wires were the ones that were oriented in the direction that took the load and it may have lasted a bit longer if oriented the other way - however the size of the scrap metal I had fit better the way I installed it. I did like the way the system worked as the coals did tend to stay up with the fire and the ashes fell to the bottom of the stove. The 2" openings may have been a bit large as there were coals about the size of a marble that would fall through.

I will attempt to make another grate now that I know it has some potential. I will probably make a 24" wide platform of thick metal that may be spaced every 4 inches or so - with a smaller 1" mesh on top. The sides will angle up as before to that the wood tends to bunch together as it burns. The system can be made in pieces so that it is possible to lift it into place without getting a hernia. I have learned that it is very important to keep the coals and ashes away from the bottom of the grate......or it starts to work like a blacksmiths' forge and get the metal grate very hot.