Slabwood as Boiler Food

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Mushroom Man

Member
Sep 6, 2008
183
Eastern Ontario
A local mill owner (and recent social acquaintance) has an abundance of slabwood from white cedar production. He'll deliver a large dump trailer in 12' lengths for $50 (no tax). The trailer appears to be 12*5*6=360 cu.ft

I've been paying $1000 for 10 cords of good hardwood in log lengths

I am wondering if slabs are a viable fuel for an EKO 60 with 1500 gal un-pressurized storage. I am not trying to go for long burns, just trying to get lots of heat into storage fast. I ordered one load to try it. I guess if it has poor results I'll have lots of kindling

I have a radial arm saw that might facilitate cutting.

I was thinking about storing cut slabs in apple boxes (4'*4'*2') and then fork lifting those into the boiler room (garage) to reduce handling. I find that this method has reduced handling of hardwood appreciably.

For those of you who have tried slabs...how'd it go?
 
I don't run a boiler, but we tried Slabwood this year. Guy claimed 3/4 cord per bundle for 40.00. We ordered 2 bundles and in the end after cutting and stacking ended up with less than a cord. I've never burnt cedar. Our Slabwood was oak, maple, beech and some cherry. While it burned okay, I will never mess around with a bundle again. For me I wasted alot of time processing the stuff and cleaning up the bits and pieces left behind. Things may be okay for a gasification boiler, but I would rather process logs anyday.
 
Glad you brought this up. I have been thinking of trying this as well. We have several Amish wood mills around. I am going to see how cheap I can get a truck load of the hardwood slabwood. Even if it is just used as kindling and fill for a fire. If it is good hardwood it should make for some good btus. If I cut it to length, split it into 2-4" wide slats it should dry stacked neatly in the basement. Anyone have any experience doing this?
 
My dad buys oak slab wood for his indoor stove. It is debarked and costs $25 for a 3'X4' X 8' bundle. It is getting harder to buy because demand is going up. I have more wood than I can burn but will try to get some for starting fires.

I burned some in my OWB but it was tricky because the air mixture was off with so many pieces burning, smoked like crazy.

gg
 
Not sure about an Eastern Cedar, Western Red Cedar is toxic when burned however. Maybe something to check into for your species. If it checks out ok I see no reason not to burn it. Tremendous labour savings, plus you should be able to pack it really tight in the fire box.

Make a huge cube, light & drive all those btu's into storage. After a few test burns of course. ;-) Don't want to wind up chasing a run away train so to speak.
 
Local sawyer has 3.5 to 4 foot diameter by 12 foot bundles of hemlock FOB for $20, call it a cord each. Got two bundles and hauled them home. They were stacked three bundles high it the yard and had been there over a year, but with very little air flow they were quite wet. And heavy.

So I stickered them early last August out of the rain and facing the south, and being so thin it had dried out enough by October to make some pretty good fuel. Looks like the stack will carry us out to the end of December, so it will be nice to have a surplus of hardwood on into the heart of the heating season.

It was tedious to stack the stuff so it would dry, a slab or two at a time by hand off the trailer onto the stack, but in the end it was comparable in what the time would be to buck, split, and stack a similar amount of cordwood. I've been going out and cutting the pile in boiler-length pieces and loading them into the wheelbarrow. It's more handling for all the little pieces, hardly worth the effort, but cordwood is no picnic either.

Seems somewhat difficult to burn to me. If put too much in too soon it all tries to burn at once and will even extinguish the gasification jet with smoke at times, but with a decent bed of coals I can pile it full and it will burn hot and steady.
 

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I burn lots of hardwood slabs . Great to pack and dries very fast, not to mention 70.00 / cord
 
Mushroom Man said:
A local mill owner (and recent social acquaintance) has an abundance of slabwood from white cedar production. He'll deliver a large dump trailer in 12' lengths for $50 (no tax). The trailer appears to be 12*5*6=360 cu.ft

I've been paying $1000 for 10 cords of good hardwood in log lengths

I am wondering if slabs are a viable fuel for an EKO 60 with 1500 gal un-pressurized storage. I am not trying to go for long burns, just trying to get lots of heat into storage fast. I ordered one load to try it. I guess if it has poor results I'll have lots of kindling

I have a radial arm saw that might facilitate cutting.

I was thinking about storing cut slabs in apple boxes (4'*4'*2') and then fork lifting those into the boiler room (garage) to reduce handling. I find that this method has reduced handling of hardwood appreciably.

For those of you who have tried slabs...how'd it go?

Cedar is extremely light and burns up almost like cardboard. It will burn hot, but very fast if its dry.
 
Thanks for the info EW. I think I am going to try to get a load if it is cheap enough. Process it 24" long and split it 2-4" wide so it will dry fast. We'll see how it goes. Mushroom man. Does your aquantance have any hardwood slab? I will bet that cedar will burn fast when it is dry. Real fast.
 
I'd get as much slab wood as I could at the prices I'm seeing here. No splitting, will dry in no time, and burns like crazy. Piece of cake to split if you do need to split it for firestarting.

Typical no-brainer?
 
My guy only has white cedar but the price was better than first indicated. He delivered the load for $35. It is nice and dry but likely won't stay that way. It is outside and staying there. I am trying to conceptualize a template to use for cutting it to boiler lengths that will sit atop the apple boxes. Minimizing handling is the objective. I know it will burn fast but I don't see a problem with that as long as I can transfer most of the heat to storage without idling the boiler. Idling is just a waste of wood.

I will try to burn some waste mushroom substrate along with the cedar slabs. The intense burn may dry the mushroom substrate better than hardwood. We'll see!
 
Mushroom Man said:
My guy only has white cedar but the price was better than first indicated. He delivered the load for $35. It is nice and dry but likely won't stay that way. It is outside and staying there. I am trying to conceptualize a template to use for cutting it to boiler lengths that will sit atop the apple boxes. Minimizing handling is the objective. I know it will burn fast but I don't see a problem with that as long as I can transfer most of the heat to storage without idling the boiler. Idling is just a waste of wood.

I will try to burn some waste mushroom substrate along with the cedar slabs. The intense burn may dry the mushroom substrate better than hardwood. We'll see!

I use slab wood for kindling and the best thing I have use to cut it is my circular saw and someone feeding them to me. I have tried a table saw,radial arm saw, chop saw and the fastest by far is my hand held circular saw.

Rob
 
One of the hard things about slab is getting it cut to length. But I found sliding severeal boards forward on the pile to get my prefered length I could use my chainsaw to cut the wood. Odds and ends lengths can pile up though and make the work tedious. Splitting, cutting and stacking cord wood makes you sweat too though. In my gasser it worked well once there were coals and I burned without storage. More for an attendance fire than an all nighter though. Enough of the slab was wafer thin and lent itself well to kindling others were so odd and bulked shaped some splitting had to be done. I have an OWB right now and I have about 2.5 cord of mostly oak slab. Stacked right (which can be a real challenge) I can probably get a 12 hour burn. The gasser was 8-10 hours in medium cold and 6-8 in hard cold weather. I never got more than 6 hours with pine or spruce in the gasser. Never had cedar for the gasser but would probably not get any better or worse times than spruce. I might be healthier having worked with slab when I was pushed for firewood (instead of watching tv after tossing wood for five minutes with the gasser) but I did not feel as productive. Made it through the winter though and for less money.
 
I've heard before slab wood is hard to cut with a chainsaw. Why is this?
 
maple1 said:
I'd get as much slab wood as I could at the prices I'm seeing here. No splitting, will dry in no time, and burns like crazy. Piece of cake to split if you do need to split it for firestarting.

Typical no-brainer?

Dunno about the "no time" bit, and oaks take their sweet time. (2-3 x other woods.) Might wanna separate the oak- not hard to ID.
 
If someone offered me slabwood at a cheap price, I would take it but it would have to be real cheap. As far as I'm concerned there is alot more handling and sweat per BTU than logs. One other thing to consider is that it is all bark and sap wood. The good part goes into the lumber. I find it difficult to buck up, difficult to stack and difficult to handle when loading into a boiler.
I have access to cheap slabwood and cut offs. I tried it once and haven't been back to get more.
 
bpirger said:
I've heard before slab wood is hard to cut with a chainsaw. Why is this?

The slab wood i get is not just the outside round of the tree, it is thin strips, short chunks,ect so cutting it is a pain because your chainsaw trys to pull it back at you.


Rob
 
That's right! The chain snags the smaller pieces because they don't have the mass to stay put when saw is put to them. What does work are the old belt driven buck saws they used to attach to the old Farmall (you know, the ones with the rocking table) but I don't know where they all went.
 
CTYank said:
maple1 said:
I'd get as much slab wood as I could at the prices I'm seeing here. No splitting, will dry in no time, and burns like crazy. Piece of cake to split if you do need to split it for firestarting.

Typical no-brainer?

Dunno about the "no time" bit, and oaks take their sweet time. (2-3 x other woods.) Might wanna separate the oak- not hard to ID.

Well, I guess that was a relative term. Compared to buying the same type of wood in its normal form (whole) and just cutting each as received to length, that is. Even after splitting normal wood, the large cut surface area of slabwood lends itself to drying much faster. So yes, it does still require some time.
 
Fred61 said:
That's right! The chain snags the smaller pieces because they don't have the mass to stay put when saw is put to them. What does work are the old belt driven buck saws they used to attach to the old Farmall (you know, the ones with the rocking table) but I don't know where they all went.

Stickering gave me a tall, stable, and fast drying stack. It's quite easy to cut to length right from the stack since the stack holds everything in place. It's been taking me five or ten minutes to process a week's worth. [See post and photo above.]

--ewd
 
i tried some free slab wood and got so frustrated with it i burned the last 1/3 out in a brush pile. wasnt worth it for my set up
 
Mushroom man,

Today I had time in the afternoon to get to an Amish wood mill. I thought I would go to the closest one and ended up six miles from the house. Unfortunately the only wood they use is pine because they only make storage sheds. But I stopped and talked to the owner and asked them if they sold the slab wood. He said yes. If you want the long stuff in that pile it is free for the taking. Or, if you want the stuff from that pile it is cut to 14-16" already. We sell that for $7 a truck load.

Now the free stuff was tempting. But I do not have a lot of time on my hands and I thought at $7 a truck load, that is cheap and a lot of time and labor saved. So I told him I would take a load and if he provided me a helper to load it I would give him $10 a load. He said he could do that. So we loaded up one heaping load in about 20 minutes. I brought it home and threw it off the truck. As I did I seperated the small stuff that was literally 2-4" and various sizes, already cut square or rectangular, and about 14-16 inches long. Dry as could be at that size and sitting in the sun in that huge pile. That stuff, about 4'x4'x14-16" worth went right in under the covered porch.

Next step was to put some used o.s.b. sheeting that was just the right size into the back of the truck. This would protect my back window and make some temporary sides that would stand four feet tall and allow a lot more to be loaded into the truck. Back I went and bought another load for $10. After getting it all stacked, I ended up with about 2 1/4 face cords of the larger slabs. These pieces, which is 90% of the load, range from 1-4" thick and 4-14" wide. Lengths went from 12-16" with most being 14-16" long. I was able to get all of this wood loaded, brought home, and stacked from 12 - 3:30 PM. Being pine, the wood will burn fast. But I think it will work well being mixed in with the Ash that I burn. Once it is dry. So most will be for next year. I stacked that outside on pallets adding it on to my Ash stacks. At that price and not having to do any cutting, I am going to go back and get more. Since I am already set for this year and just looking to add to next years stacks, it was easy to get antoher 2 cord this way. But first, I am also going to go to a couple of other mills that are close enough and see if they have hard wood.

That will be on Saturday. I had to promise the wife one day of shopping, that is Friday. No working with the wood Friday. Oh well, I will get a nice lunch and dinner out of it. I will make certain that the food establishments will have beer on tap. ;-)
 
Gasifier:

Wow! At that price, your slab wood supply is one of the cheapest fuels I know of, even if there is some work entailed. I was happy with my cedar slabs and the price until I heard of your find ....all cut to length.

My slab wood is wet/green so to test it properly I'll have to dry it; but it should dry fast. If I can get it cut up to length and deposited into the boiler room (insulated garage); it will dry really fast.

That is one really compelling feature of slab wood as a resource when your wood supply runs short during the season. That happened last year to me and I had to burn freshly cut ash. Fortunately for me, ash will burn when green. If split small enough it will even gasify.
 
I picked up two loads on Thursday and two more on Saturday. I stand in the back of the truck and stack all the wood the same way while he hands it to me. With the O.S.B. sheating to protect the back window and make the sides taller we get a lot of wood on the truck. With my 07 Toyota Cremax, I found a nice used one last year, the box is short, but with the sides built up I figure I am getting about 1.5 face cord per load. I did some measuring and it worked out to 6 face cord I have stacked now. And about a half face cord of that is already dry because it is in 2x2, 2x4, 2x6 and varying size pieces. Because the wood is so thin, being the outside of the tree and averaging 1-4" from bark to sliced side, the wood stacks tightly as well. My seven year old son has really taken a liking to helping dad with the wood over the years. And he is getting bigger every day. It works out great when we get home and he stands up in the truck and hands it down to me to do the stacking on the pile. Nice to be able to back right up to where we stack it. So nice to not have to do any cutting or splitting. I am going to go back the next chance I get and get two more loads. I will try to get a picture of a truck load and some piles posted.
 
Mushroom Man said:
My slab wood is wet/green so to test it properly I'll have to dry it; but it should dry fast. If I can get it cut up to length and deposited into the boiler room (insulated garage); it will dry really fast.

Be careful when dumping a couple tons of green or wet wood into a heated and insulated space. You will need some sort of ventilation in that space in order to prevent condensation which may cause mold to form. You will be putting a hell of a lot of water in that space.

It reminds me of the time at my old place that I had a couple oaks sawn out and I stickered and stacked most of it in the hay loft which had plenty of ventilation. For some reason I decided to place a stack in a heated and insulated area adjacent to my office which at one time held some production machinery. The stack was about 4'X4'X12'. The humidity stayed extremely high in that area all winter and the acid in the air pitted every metal item in there. Lucky for me it was only a few hand tools. The most damage was done to some magnesium drywall tools. They were pitted so badly they were unusable
 
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