High 30's at night ... 60-70 ! during the day.... Valley snow gone ! YEE HA ! life is good, time to play in the mud and get dirty! I rebuilt my rmh last spring, switching from a M.W. cast core to a firebrick core. My observations so far are that the cast core is hotter, way faster but had durability issues in my feed tube and burn tunnel roof. The firebrick core has had no issues with durability, but just won't get as hot as a cast core and it takes its time heating up. When I did that rebuild last year I experimented with a much longer burn tunnel . However I neglected to do my math and did not lengthen the riser at the same time ! Big mistake , it actually worked seemingly well, +1000 F top of the barrel, mass heating nicely. I was very pleased with myself..... Untill ... late january or so when it just seemed to be struggling....OH NO ...yup .... ASH BUILDUP ! Dang it anyway ! Well as anybody on the west coast knows this was the warmest february in years , so I was able to do a mini rebuild . Suck out the ash , shorten the burn tunnel 5" and back together and relit in just over 4 hours ! I LOVE COB ! Crumble it up add water and walla fresh cob ! Now that warm weather is here I've torn the core all apart again, my walker cast riser in the 16 gal grease barrel again just lifts off and gets set aside ready to be set back on when i'm ready (gotta love that riser.) Doing my math this time and going with a 12" burn tunnel roof and a 50" riser. I have mentioned in other posts about locating used firebrick that is used in sawmill boilers. As anybody in timber country knows , sawmills open and then they close... boilers get built for the dry kiln then they get dismantled , put on pallets and sold at auction,usually to another sawmill as part of a bigger lot. Many times those pallets of brick get set off to the side not needed and slowly get covered up by debri.... prime time for me to show up....I have been very lucky and have not had to pay a penny for well over a hundred FB ! Most are the heavy dense ones in great shape some are the insulated ones in not so good a shape. They all work just fine. I had so many that I did a brick surround of my core using firebrick ! Last fall my neighbor called and said pile of old red clay bricks here if you want them... they were in the back of my truck within hours of his call. This spring the same guy calls (he scraps for a living) He says got a pile of them thare firebricks you like so much! Come and get them and oh yea got you a couple of sacks that say "refractory" on them !!! Might have broke the speed limit getting over there! Yes two sacks of insulating refractory !!! and then another surprise, quite a few of the firebricks are 6" instead of 4.5 ! never saw any this size before. 6" x 2.5" x 18" ! sadly none were 18" anymore most were 11" or so but still 6" tall is nice,would be perfect if I had a 6" core. There was even one 4.5" x 2.5" x 18" that was in perfect condition !,( its now part of my burn tunnel). So now I'm in the middle of my rebuild, removing the firebrick surround and replacing it with the red brick I scored last year. Taking lots of photos as I go. Not to many people posting right now so my mini novel may make enjoyable reading.
Thanks julie: The old saying what goes around comes around is certainly true. The neighbor that gave me most of this is almost 75 , trying to get by on social security and scrapping. I do all his mechanical work for the cost of the parts. I'm hoping that in 20 years or so some young person will be around to help me... Meanwhile play, or ah ,work goes on with the rebuild. Brick core sure is massive compared to a cast one, but its all mortored up! Having a grand time pretending to be a brick layer! Remembered belatedly why you use a trowel and NOT your bare hands... when playing with concrete instead of clay.
Ok . playing with the new refractory this morning, as I ran out of concrete mortar yesterday to be able to finish the brick surround. This stuff is nice, similar to working with fireclay & perlite doing cast cores & risers. Speaking of risers... after bragging about moving mine several times... lifting it back this morning a rust spot on the barrel broke and allowed the casting to shift and now it has cracks ! I could still use it as its all there BUT murphy,s law says replace it or you'll be sorry. So... even though the fireclay / perlite worked, because I have it I am going to try the new refractory mix. Off to the store to get a sack of type S mortar mix for the brick and an 8" sonitube to cast a new riser.
Back on the job, new 16 gal barrel has the paint burning off , finished the brick surround. Because I want to use my other free bag of refractory on my new cast riser , 1/2 my core will have refractory around it and the other half will have reconstituted fireclay / perlite around it ,saved from my first cast core! Making the new cast riser next. Thinking I will fill it halfway , lift it into place and finish it. After that its mount the 55 and light it off !!! I can cob the barrel as time permits over the summer.
Progress continues, Finished filling surround with castable mix , ash pit and transition area vacuumed out, riser barrel burned off , 8" hole cut in bottom, sonitube cut to length , riser barrel fireclayed on top of core.
Today I got the new riser cast. One bag of refractory supplemented with fireclay will make apx 1/2 of a riser ! Good thing I had 2 sacks of fireclay and a new 4 ' bag of perlite to make up the rest of it. Final height of riser is 51". burn tunnel roof is 12"
Well , not much accomplished today. My new riser form tried to buckle from too much moisture soaking thru the sonitube and I had to slap some clay around the 55 and light the stove off ! Hottest day so far this year (of course) . Lighting the stove off even just for a little while was enough to solidify the riser and stop the slumping. Next I can take the 55 gal barrel loose again and get it level and cob it properly. Once I have a good cob seal started on the 55 , then I can really try this rocket out ! From its initial performance with a cold wet core and a sopping wet riser I have great hopes for the performance of this one.
Disaster averted yesterday. Today I'm cobbin... cob is really cool stuff , it lasts forever ! crush it up , add water , do the happy dance and new cob appears on your tarp ... quite the improvement on concrete. Cob is also HARD work! Note the 10# sledge . I am going to try something new this time (OH NO) and use fiberglass mesh to wrap the barrel after i get my first lift done. Each year the vertical cob on my barrel starts to crack and want to pull away. This time I am going to wrap it with fiberglass mesh before applying my finish color coat in the hope that it will hold together better.
Cobbing progresses slowly. Vertical cobbing is a slow process. I will start coloring the cob after I have a nice even coating. I used a drywall mesh tape on the lower half of the barrel ,over apx 2" of cob ,there is another inch of cob over top of that. I'm hoping that it helps the cob not pull away from the barrel over the next burning season.
Little bit of smoothing and the base coat of cob is done! Now onward to coloring. Last year I discovered that concrete dye mixes easily with cob. A mix of red & a small amount of black creates a nice brick red color. My plan was to do the same thing this year.....but....... I made a discovery ! If I take the powder color for concrete, mix it dry and add water, I can PAINT directly on my cob/barrel! Any color or if I was an artist, any scene.... This means that you don't have to have a mud covered barrel in your living room but instead you can have an original art piece! This seems so obvious after the fact , that I don't know why I or anybody else didn't do this sooner! The artist in my life says no way is she painting that barrel! Says I tear it apart every time she turns around! lol ... guess I do ! So , I will give it a try ... worse could happen is it's so bad I cover it over.
Not all who wander are lost... J.R.R. Tolkien
posted 4 years ago
That you can use those dyes that way is so cool to know! Thanks!!! I will have to use it on mine. Oh, since I am building outside without a roof (at the present anyway) can I use a cement type slip coat to protect it all?
You can always trace or stencil a design on before you "Paint" if that would be easier....
Everything looks great!
He puts the "turd" in "saturday". Speaking of which, have you smelled this tiny ad?
A rocket mass heater is the most sustainable way to heat a conventional home