Brick Bell Laid as Shiners

Would you hesitate to build a brick bell by laying the bricks as "shiners" where they stack on the narrow side?

By my reckoning, laying shiners saves weight and space, and would make the heater more responsive. I figure this is an acceptable compromise and the 2 & 1/4 inches of brick thickness is stable enough for the job since a bell is not a load bearing structure. I DO intend to add a second skin of either tile or cob. Not sure of final dimensions but it wouldn't be much more than 4 feet tall.

Hi Matt;
My first thought is it will lose heat faster.
My next thought is, if you are using a cob mortar any good bump will tip the bricks.
My last thought is after you cover it with cob, it should hold up just fine and have a fair amount of heat-retaining mass.

If it were me I would want the most mass I could get.
Supporting the floor is in most cases is not a big job.
It takes a bit longer to heat up but holding that heat is really what you want your mass heater to do.

I think the cob would do better on the inside of the brick, protecting the shiners from the heat.
I wonder if you could use a 'mortar" that will set fairly stiff, the bell will hold together long enough to be skinned.
For the tile over brick it looks like the recommendations are to use a concrete primer, and a leveling coat of thinset.
No mention of any mesh , not even on fireplaces,which surprised me.
A lot of cob ovens seem to include a layer of mesh to discourage cracking, but thinset is different a beast.

At this point I'm gonna suggest some alternatives.
-You could build a form from scrap wood and forming the cob in that.
Line the insides of the form with tile before you begin.
Instead of cob, make soil cement.
-You might build the bell from cement block and tile/cob over it.
-You could even build the bell out of old file cabinets and cob or tile over them.

Matt Todd wrote:Would you hesitate to build a brick bell by laying the bricks as "shiners" where they stack on the narrow side?

By my reckoning, laying shiners saves weight and space, and would make the heater more responsive. I figure this is an acceptable compromise and the 2 & 1/4 inches of brick thickness is stable enough for the job since a bell is not a load bearing structure. I DO intend to add a second skin of either tile or cob. Not sure of final dimensions but it wouldn't be much more than 4 feet tall.

1) With so many "terms" being used as bricks being called shiners,  and I would agree with the above  "laid on the narrow side" Generally with the longest face exposed to the layer of bricks- horizontally speaking.  This goes fairly fast, with the tier height going up 4.5" per row.  I am guessing your 2.25" could be be really  2.5" But there are so many kinds of bricks out there if your not talking about standard fire bricks.

2) Mission- for most mass these would be laid flat with the 4.5" width down,  Simple math calculates the difference but for simplicity sakes  laid flat increases mass by 1.8 times and of course to do this, increases the number of bricks required.

2b)  your mission will dictate what you want/need but as Tom pointed out, going for the most mass gives you the most heat retention time, but as you all know this is NOT a increase or decrease in efficiency. Simply storing heat for a longer period of time. Still takes X amount of wood, to produce X amount of BTU's

3) It appears to me, that your making a single bell, and if so, your Internal Surface Area, is fairly well calculated by Peter, thus you should be able to calculate exactly how tall, based on wall length and width.  

Best of success.
Scott

Using string lines once square corners are set, greatly helps keeping things in order and straight.

Matt,

If you are intending to cover the bricks with cob I would recommend laying them ON shiners without any additional covering with plaster. You will have:
-more stable structure
-better heat accumulation (bricks are denser than cob, especially true fire bricks)
-plaster may be peeling off if not applied correctly

I would even do it if I wanted to plaster it with cob for aesthetic purposes. Regarding tiles - Vitcas manufactures heat resistant adhesives or maybe they could be inset in the cob layer.