RMH heaters precast components

I remember hearing in a Paul Wheaton podcast with E&E that they we working on a project to sell precast parts for RMH's to make the build easier. I can't find anything on them yet. Any news?

- Dustin : Ernie And Erica Wisner who are both Stewards here for the wood stoves thread are working towards that goal. Their short term goal is is find the right combination of products
that they can personally test and prove the longevity of the product, product combinations to exceed one year ! This needs to result in a stable product that can be built by D.I.Y.ers
and give good repeatable results. Price (at Volume) will be important too!

All This is on top of all the other 'spinning plates they have up in the air ' , - 24/7/365 - !


I would like to see a lot of people sign in here and leave comments , this should be a ''HOT TOPIC ''! PYRO Magic-ally Allen L. be safe keep warm !

Best of luck to them, It would be a great item as the burn chamber poses lots of tricks to the newcomer. Hoping mine works out!

I agree. A good pre-fab "core" ready to be placed and piped could take RMHs to a HNL

Prefab would be awesome. That would get many more folks interested.

I world love to buy a starter kit. I got 65 hour work week this week, so sadly I have more money than time.

I just finished the burn riser for my daughter's new house with diatomaceous earth (bentonite) and perlite, mixed per the Wisner's new info and crammed between two stainess steel tubes I almost gave up bending into a tube from stainless sheet metal 24ga because I couldn't find snap lock tubes 26 ga or 28 ga. This was terrible. For experiment, I crammed some of the stiff mix into a brick let it dry and left in in my existing RMH firebox where it's hottest. Out came a cute very light brick, really quite strong. This light firebrick insulating material sure could be made commercially, so we don't even need those hard-to-get stainless steel tubes, run down the perlite and bentonite to build our own. Right?

David Graber wrote:diatomaceous earth (bentonite)

ahhh....i'm pretty sure these are two different things:

Diatomaceous Earth, or silicon dioxide, is very specific. It is made from the skeletons of the smallest creatures on earth, of creatures that have skeletons-- diatoms. It's sold as a bug killer, slug repellant, desiccant, pool filter coating/medium, and a mortar additive. The cheapest way to purchase it is as 'food grade diatomaceous earth' at a local pool supply place, or as 'sharp sand' from a masonry supplier.

It doesn't really do that good of a good job holding substrate (perlite) together since it is also considered a substrate itself. You would have to get it really really really hot to actually fuse.

Bentonite, is quite a general term for clay that is dug out of the ground from many different regions and may contain any number of different elements. The cheapest way to purchase this is as generic, grocery store brand, unscented clay cat litter.

It's much 'stickier' than DE and will do a great job of holding all kinds of substrates together-- fired or unfired... but it usually contains a lot of organic material and can't take the heat that DE can.

Do you possibly mean that you mixed the two?

and perlite, mixed per the Wisner's new info

ahh...what info would that be?

For experiment, I crammed some of the stiff mix into a brick let it dry

first of all: what mix? 1:1? 2:1? 9:1?
second: dry for how long?

and left in in my existing RMH firebox where it's hottest. Out came a cute very light brick, really quite strong.

If you did use just DE and perlite, how the heck did your cute little brick hold together? how long did you 'fire' it? you mean to tell me that you got this little brick hot enough to fuse the silicon of the DE into a matrix around the perlite? how much did it shrink?

I'm a bit unclear on your methods and results...

...could you elaborate?

Bentonite, here in MT, is the brand name for the type of diatomaceous earth used for sealing oil well casings, around the perimeter of basements, and incidentally in health and gardening. The two mines in the area are near Belle Fourche, SD and near Worland, WY. I bought 4,000 lbs from Worland to line an irrigation pond and have kept about 100 lbs cause it's cool stuff. The Worland mine is closer, and they crush it to a finer powder. It's also higher in calcium than the bentonite near Belle Fourche. Whatever the reason, I started mixing it with water like I would powdered joint compound (drywall) and was VERY impressed how much water it wanted to get a reasonable slump in the slurry, mixing with my industrial drill in a 5 gal pail. I then hired my grandsons (grandma cookie payment) to help me pack in the perlite in mud pies,to a breaking consistency, and cram in between my two layers of SS 24ga sheetmetal for the burner. That's when I decided on the experiment making a brick in my first RMH. I let it dry about a month before firing it. Does that help? I haven't figured out how to post picts in the place.

Yes, David, your explanation helps a great deal...but I'm afraid you are still muddying together two different terms for two different things as if they were the same, when they are not. I'm only sticking on this point because someone might track down this thread while doing research for their own RMH, and mistakenly think that you mixed diatomaceous earth and perlite when, in actuality, you mixed clay and perlite. From what you describe, it sounds like you are using sodium bentonite because it is the type that is predominately used for sealing well casings, filling gaps in foundations, and lining ponds. It sucks up a ton of water and then creates an effective water barrier after it dries. This is because when dissolved in water, bentonite forms a colloidal fluid because the dissolved particles are small enough to be suspended in the water without settling out. The particles 'trap' the water in between each other until it evaporates. This process slowly pulls the particles back together until all the water is gone and you are left with a contiguous mass. DE would not behave in the same way as it is mostly made up of silicon and does not dissolve in water. However, it does absorb a ton of water as well, but in a different way. DE is made up of diatom skeletons which look like little hollow geodesic balls under a microscope. These little hollow silicon structures quickly suck in water, but then retain it due to surface tension, until it finally evaporates. When mixed in water, DE will clump together, but it is not considered a colloidal liquid because the particles are too large-- much larger than dissolved bentonite. Subsequently, when a DE slurry dries, it simply falls back to dust. This is why DE is popular to use as a desiccant because it can be used over and over.

I seriously hope you don't take my picking on this point the wrong way. I'm just trying to prevent future confusion. Mistakenly mixing DE and perlite for an RMH and expecting it to hold together could have disastrous results.

Thank you Chris! I was misinformed about diatomaceous earth being a generic term for the bentonite material I hauled on my big trailer! What I got worked very well, and I have the brick to prove it, but as you so well point out, it's bentonite, and a VVEEERRRY sticky clay. Not diatomaceous earth. Thanks.