cement block, did i get the wrong kind?

[lisound]

I bought solid cement block 16x4x8. I thought it would hold the heat better instead of the ones with holes in them.
I'm now thinking the wider ones would be more stable and hold up to the heat better. I'm going 3 courses high. My plan was to use a little gorilla glue to hold them in place. I dry fitted them today and there was not much movement.
But once i get the steam pans in there, it may go all wrong. I fear a cracked block or something worse. Should i attempt to return them for the larger blocks? Which were mostly frozen on the pallets.

[briansickler]

Some of the blocks will crack from the heat. We used a block arch our first year. The wider blocks would be more stable. Ours was 8" block and stayed very stable even with numerous cracks. You can line with fire brick and possibly avoid the cracks. We had a 2x4 raised flue pan and a 3x3 syrup pan on it. The arch was 2 courses tall laid up dry...no mortar.

Brian

[happy thoughts]

I also think the wider hollow blocks would be more stable. This is the second year using ours and so far not much cracking though we have lined the firebox with red brick (not fire brick). Whatever size you use, one thing I would not do is stick them together with gorilla glue. The MSDS for it says not to expose to prolonged temps above 320F. You'll reach that easily. One of the products of it's combustion are traces of cyanide. You probably don't want that in your lungs or in syrup.

Good luck this year! Hope it's a productive one :)

[lisound]

I also think the wider hollow blocks would be more stable. This is the second year using ours and so far not much cracking though we have lined the firebox with red brick (not fire brick). Whatever size you use, one thing I would not do is stick them together with gorilla glue. The MSDS for it says not to expose to prolonged temps above 320F. You'll reach that easily. One of the products of it's combustion are traces of cyanide. You probably don't want that in your lungs or in syrup.

Good luck this year! Hope it's a productive one :)

Yeah, don't want that. Can I use a quick set mortar to put the flue in?

[happy thoughts]

Yeah, don't want that. Can I use a quick set mortar to put the flue in?

Yes, that's what we used.

[Spolcik]

I used the hollow eight inch block first time this year. I just dry stacked them did a test boil with water seemed to hold up fine started with about 25 gallons in the pan.

[emo]

69096908I am on my fifth year on a concrete block arch, 8x8x16 with two open cells. Everything is just dry set, no mortar or adhesive. Lined the arch with a layer of standard red brick that we had laying around. Some of the red brick have cracked, have not checked the inside of the cement block. Made a form out of wood and made a solid block for the stack. Used unlined cement block thesecond year I boiled and when I went to move them, all of the block fell apart from the heat. Mine is three courses high with a row of the 16x4x8 as a top.

[lisound]

69096908I am on my fifth year on a concrete block arch, 8x8x16 with two open cells. Everything is just dry set, no mortar or adhesive. Lined the arch with a layer of standard red brick that we had laying around. Some of the red brick have cracked, have not checked the inside of the cement block. Made a form out of wood and made a solid block for the stack. Used unlined cement block thesecond year I boiled and when I went to move them, all of the block fell apart from the heat. Mine is three courses high with a row of the 16x4x8 as a top.


Funny emo, i am modeling mine after yours.
do you have half blocks mixed in on the side walls?
I've never built anything out of stone, but want it as solid as possible.
thanks

[emo]

There are a couple of half blocks on the sides, middle row at the front. I tried to make sure the joints for the rest of the block do not line up. I did not worry about the top block overlapping as I used them more for a work surface than structural. Have to re-adjust a couple of the top block every boiling season, but have not had any known structure issues in 5 years. Good luck on yours, it is all trial and error.

[ren46]

Definitely use fire brick to line the inside as much as possible. This will help protect the concrete blocks from the heat. I also keep my arch covered all year to keep the blocks dry thinking maybe moisture getting into the concrete may expand when heated cracking the block? Just a thought.

Block arch w/3 pans
22 Taps 2010
33 Taps 2012
40 Taps 2013
Kubota 3430
Husky and Stihl saws
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