Salem Posey

I am wanting to start erecting my firebrick “J” tube using clay slip as sealer/mortar. Freezing temps are expected overnight for the next few nights. Will this have a negative affect on the clay slip? Do I need to try to keep it from reaching freezing temps in my little cabin?
Never worked with clay slip so any help would be appreciated!

Glenn Herbert wrote:No, the usefulness of a bypass is that it gives a lower-friction path. A bit of air might still go through the bench, but it would be negligible, especially if the bench is cold.

People have tried multiple-duct routing, and reportedly found that even if you try to make them identical, one path will hog much of the flow. A bypass compared to a whole bench run will be no contest.

Ok. Thank you for the help. I have another question. I was about to start building my firebox and heat riser with clay slip. I just checked the weather and we are supposed to have freezing temperatures starting tonight. Will it cause a problem if that clay slip sealing off the firebrick isn’t completely dry and it freezes?

Glenn Herbert wrote:With your situation, the option of a quick fire that does not heat the mass sounds good. What you would want is a bypass from near the bottom of the barrel to the chimney, so that the whole barrel gets hot. Exiting from the top of the barrel would leave much of it cold. The high bypass idea is strictly for difficult starting situations.

A bypass inside the mass from near the barrel straight to the chimney connection would also work fine, if your layout makes that easy.

Glenn, if I put the bypass at the bottom of the barrel with a damper in it, would I still need a damper in the pipe where it enters the mass after exiting the manifold?

It looks much like sand. It has trapped water in it. When they heat it above about 1200 degrees it melts the outside and that is the point at which the perlite expands, becoming less dense. I thought that maybe I could use the non expanded perlite in the mass since it shouldn’t be reaching anywhere near that temp. But, I am completely new to this RMH thing.

I live in New Mexico at 9300 feet elevation. In the fall the early mornings are pretty chilly but the days often warm up nicely. I am about to construct my first RMH and am wanting to install a bypass in my system so that I can light a quick fire in the morning and not overheat the house all day. My exit pipe will will come up very close to the bell. Is it better to install the bypass in the ducting inside the mass or would it be ok to come out the side of the top of the bell and tee directly into the exit pipe? Any thoughts and or design ideas/pictures/drawings would be very appreciated! Thanks in advance!

Hello all.
 I have been given about 1000 lbs of unexpanded perlite. Would this be good to use in the mass of the heat exchange?