RMH for Dummies! Please help guide me through my first build!

Hi!  I don't think I ever posted a"FINISHED" pictures, so here they are!
She's going to start her third season shortly!

Staci that looks totally amazing!  What a great finish.
I love your barrel tree. A great way to disguise it during the off season.

I was wondering if you could give a few tidbits of your experiences in regards to some of the things I remember you having problems with over the years and how you solved or lived with them: smoke back, plaster cracking etc. and also things you may change or recommend to others.

Gerry Parent wrote:Staci that looks totally amazing!  What a great finish.
I love your barrel tree. A great way to disguise it during the off season.

I was wondering if you could give a few tidbits of your experiences in regards to some of the things I remember you having problems with over the years and how you solved or lived with them: smoke back, plaster cracking etc. and also things you may change or recommend to others.

Sure thing, Gerry.  Might take a week or so to get it out- but will do!
Thanks!

Absolutely marvelous!  Well done Staci!

I managed to read through pretty much this entire thread. You did great work and helped a lot of us along the way! Did you ever figure out what the issue was with smokeback and flames coming back on you?

Hey Staci, I'm just getting to the point of considering plasters and finishes.   Did you end up using boiled linseed oil to seal it?  I'm wondering about the dust from a dried clay plaster?  I'm considering going with lime plaster if I can't work out the details of the clay plaster.  Thanks!

Hello!  It has been a while since I have posted.

This RMH has been running successfully for years and one of my proudest achievements. :)  
I believe this is my 4rth year running it.  I have not fired it up yet in 2023 due to a warmer fall here in the PNW.  She will get fired up later this week.

There have been cracks developing over the years.  I have attempted to fill/patch them, but without much luck.  I knew that the cob up around the barrel was destined to crack, yet the cracks running down the front    were a surprise.  There is one on each side.  There is also a crack on the back side.
Anything to worry about?

Also in cleaning out the system this year, I noticed that the ducting pipe exiting the manifold is degrading and has holes.  Is this a concern?


Thank you!

Staci

Hi Stacie;
Nice to hear from you again!
Cob and cracks just seem to go together, I would not let them bother you.
Once your mass is warm they sure are not going to leak gasses back into the room.

The deteriorating metal should be buried under the cob, if so then no worries.

Yep, when you have a thick masonry mass that is getting heated intensely on the inner surface, that will expand more than the outer surface and cause it to crack. The upper part of my  firebrick bell where it is exposed against the future chimney area has a verticalish hairline crack running down several feet (generally following mortar joints) even though I built it with refractory cement mortar as code requires. There might be similar cracks on other sides, but I can't see those with 6" of cob covering it.

A way to reduce or eliminate cracks on the exterior (which is in the masonry heater building code) is to have a separation - air space, layer of corrugated cardboard, etc. - between inner and outer skins so that the inner shell of the heater can expand from heat without stressing the outer skin. This requires both skins to be independently structural, so not just a plaster layer on the inner structure.

Thank you, Thomas!!

Thank you, Glenn!