The RMH Builders guide build-pic heavy

Good tip about the mass, I do intend on casing it in.  I have tons of limestone here, basically my only rock and more then I could possibly ever need.

The next layer I'm working on consists of the the bridge over the burn tunnel, for this course 2 bricks have to be cut.   That's why I bought 2 extras.  I laid everything out and found my two bricks needed to be trimmed off at 7 1/8 inches. I sketched it out on my bricks.



I do not have the proper equipment to cut bricks.  I'm not going to buy the proper equipment to cut bricks for only two bricks.  I tried it two ways, and both proved successful.

First attempt, I have an angle grinder with a thin metal cutting blade on it.



I clamped the brick to my trailer and scored the brick with the metal cutting blade.  Lots of sparks were coming off and I assumed (incorrectly) that the sparks were from the blade and that I was destroying the blade rather quickly.  So i just scored the surface at this time to conserve the blade( I only have one currently)





The trailer rail is built out of angle iron, I loosened the brick and slid the scored line to match the edge of the angle iron.  I clamped it again, hit it with a hammer, and VOILA!  The wrong end of the brick broke off.....



This was an insightful experience.  As it turns out, the strongest edge of the angle iron to beat against would be the corner edge......I clamped on the wrong side...

The next attempt, measured, scored and clamped the brick again, but this time matching my line up with the strongest area of the angle iron as depicted here.



This time, instead of a hammer, I broke out an air hammer.  Basically a pneumatic chisel with interchangeable bits.



I hit my line with the chisel and the brick popped apart, not cleanly, but at least on the correct side of the line this time.



About 20 seconds of careful clean up with the air chisel and I had a pretty straight brick

Now that I only had one brick left to cut, I decided to just give er hell with the cut off wheel.



Actually went really well, didn't consume much of the blade, it was apparently the brick that was throwing sparks...



Fully mocked up with cut bricks



Then mortared together





At this point I performed some clean up.  Used a putty knife to scrape all the surfaces and clean with a sponge, vacuumed up little bits with the shop vac and mopped the floor.  Let the whole assembly dry before proceeding.

The next course was then mocked up and laid.  This finishes out the full size bricks, and finishes the wood feed completely.  While it looks good, there are a few minor issues.





The wood feed came out short at 14 3/4 inches



As did the height of my burn tunnel at 6 1/2



I was making sure each brick that was laid level and plumb with each other on two planes.  I did that well.





I never checked the third plane of level for how the bricks tipped in and out and it was off!  It never crossed my mind for two reasons.  1) the clay squishes out between the courses of bricks and placing my level on the clay would not give a true reading.  2) I thought by making sure the inside edges of the bricks were flush with each other, that the brick was "square" on it's pad.  This turned out not true.  The chamber started out as 7 inches by 7 1/2 inches NOW the chamber is at 7 x 7 1/4"

I lost a 1/4 inch in just 3 layers of brick!





I didn't immediately panic about this.  But I did start to think If I don't pay better attention for the next 8 courses of brick for my heat riser, I may have a very small opening.  I went ahead and continued on as I was.

Starting on the heat riser with the split fire bricks,  I mocked up each layer and mortared them in place again leveling and making sure they were plumb.



The first few layers were not fun, you set the first brick down and line up the edge but it's never in the right spot, requires a bunch of taping around. I found a trick to it.

Mock up each layer so that the inside edges are plumb



Remove two of the bricks



Mark each edge with a pencil this will ensure two of the bricks are laid correctly, so when the final two are placed, there is very little tapping around to get the bricks in the right spot.







Butter each of the side bricks and lay them into place matching your lines up and keeping the inside edge plumb.



Then place the last two

After the second layer for the heat riser was laid, I measured the opening of my bricks and found it was now 7 1/4 by 6 7/8.  I decided at this point I could not continue without doing something drastic.  It may have been a mistake, but a decision was made.  I spaced two bricks out on the third layer to make the dimension 7 1/4 by 7 1/4.  You can see my repair here.  I was able to keep this dimension the rest of the way up until the heat riser was finished!



I finished 7 layers as shown in the book, ran out of split bricks, but did not have the overall correct height.  It was only 43 1/4 inches from the floor of the burn tunnel to top of the heat riser.



I had to run back to Springfield and purchase 6 more split fire bricks.  4 for the next level and 2 to control air flow into the wood feed as the stove is running  That brings the correct total of bricks to 56 full size ( 58 if you want to practice cutting) and 34 splits

After finishing the 8th layer of splits I now have the heat riser height at 47 3/4, the book calls for 48 or higher.  I'm going to call this good.  I'm afraid if I made it one layer higher it would be tough to remove the barrel for maintenance and clear the ceiling.



After the whole thing has had time to set up and dry, I'm starting to see some cracking in some of the joints.  It looks a little concerning.  The whole structure SEEMS super solid.







At this point I kind of wished I would have ponied up the cash for the actual refractory thin set, because I doubt I would have this problem.  I don't actually suspect IT IS a problem, but it bothers me none the less.  I know deep down, soot and ash will plug the crevices on the inside.  My plan its to take a squirt bottle, re-wet the joints, and paste some thinned out clay slip over the cracks.   What do you guys think about that?

Hi Eric; Everything is moving along for you.  Add some sand to your slip it will help with the cracking.  Also, do you not have a 55 gal barrel with a removable lid ???  Way way easier to inspect/ clean  if you just pop a lid. removing the barrel should only need happen during a core rebuild.  One of my removable lid barrels I purchased at a farm and ranch store (BIG R) $30.00 the others were located for free by checking county shops , mechanic shops , farmers , someone has that barrel and doesn't need it ... you do.  Only as a last resort would I use a barrel without a removable lid.

thomas rubino wrote:Hi Eric; Everything is moving along for you.  Add some sand to your slip it will help with the cracking.  Also, do you not have a 55 gal barrel with a removable lid ???  Way way easier to inspect/ clean  if you just pop a lid. removing the barrel should only need happen during a core rebuild.  One of my removable lid barrels I purchased at a farm and ranch store (BIG R) $30.00 the others were located for free by checking county shops , mechanic shops , farmers , someone has that barrel and doesn't need it ... you do.  Only as a last resort would I use a barrel without a removable lid.

Hey Thomas, let me show you what I've found as far as barrels.  I wanted two barrels with lids like you said.  All I could find locally was TONS of solid barrels or barrels with open tops, no lids, no clamps.  I got on craigslist and found some barrels an hour away advertised with this picture for 20 dollars each.  I kind of thought that was high, but I went ahead and called him to make sure he had two.



I drove up there, but the barrels he had did not match the picture.  They look like this instead:



I went ahead and bought 2, the barrels were used for tomato paste and the lids are galvanized metal.  I can't risk heating up the galvanized and releasing fumes into my house.



The coolest feature is that the top tips in just a bit, and the barrels are made to stack on each other perfectly.



To check how good the barrels fit on each other, I rolled up a few balls of clay and placed them around the edges.









With a thin piece of fireplace gasket I could seal these barrels easily.  My plan was to weld brackets to each barrel and use 3 of these to clamp the barrels together



By using the top barrel upside down I could get rid of the galvanized And utilize my barrels taper.

After I brought them home, my neighbor called me an found these in the trash.



but these lids don't fit because of my barrels tapered top uses a smaller lid.   I would need to purchase another lidless barrel or trade one of my barrels to make it work.  If I welded handles on a barrel I don't think it would be too terrible to take on and off, but I do like the idea of a removable lid, because I'm very very lazy.  What do you think?

I think ensuring the gasket fits correctly is the trickiest part of removing and replacing either a barrel or a lid, and there would not be much difference in the time and care involved. It would just take some more muscle to lift the whole barrel over the riser. Another factor: if you want to closely inspect the riser or other parts or make any repairs, it will be easier to do with the whole barrel off.

You mentioned dimensions being a bit smaller than they should be by the book... I have found that there are the standard commercial firebricks exactly 4 1/2 x 9 x 2 1/2, and a skimpier version about 1/4" smaller in each dimension. At least you don't have a mix of the two - that would be a real hassle to work with (don't ask me how I know).

It's not ideal for the burn tunnel to be only 6 1/2" tall instead of 7", but that is the one place in the system where a slight constriction is said to be okay. I think if you just add a layer of splits laid flat around the top of your feed, after building up the surrounding material so they can be well bedded, you will get a nearly exact 16" height which will work fine. This would give a nice flat hard surround to your feed. If you are custom cutting all of your firewood and want to make it all about 14" long, that would work too.

Now I literally go several years before popping my lid. But I have a tried and true fireclay perlite riser that performs flawlessly (even though I would like to upgrade to  ceramic fiber). I also have a huge transition area with an ash pit  that gets cleaned each spring . When my system was new (5+ years ago) I checked the riser monthly, so a removable lid was essential. Your going to want to inspect yours often in the beginning as well.
In regards to your question ,I understand very lazy (I think of it as smart)  I would locate a free lidless barrel and use the lid and clamp you have in your photo.  That style removable lid ,you will want some wood stove door gasket to replace the plastic seal that usually comes on them. Lifting off the barrel is just more work than I would want to do. admittedly your riser is brick so its less Likely to have issues than a home cast one... but still .  

Glenn Herbert wrote:You mentioned dimensions being a bit smaller than they should be by the book... I have found that there are the standard commercial firebricks exactly 4 1/2 x 9 x 2 1/2, and a skimpier version about 1/4" smaller in each dimension. At least you don't have a mix of the two - that would be a real hassle to work with (don't ask me how I know).

It's not ideal for the burn tunnel to be only 6 1/2" tall instead of 7", but that is the one place in the system where a slight constriction is said to be okay. I think if you just add a layer of splits laid flat around the top of your feed, after building up the surrounding material so they can be well bedded, you will get a nearly exact 16" height which will work fine. This would give a nice flat hard surround to your feed. If you are custom cutting all of your firewood and want to make it all about 14" long, that would work too.

Your right Glenn, my receipt from ACME lists the brick as 8 3/4 x 4 1/4 x 2 1/2 for full or 1 1/4 for split.....but measuring with a ruler......even THAT is a generous number.  They measure smaller. Its so weird that they would make different sizes.  I'm glad you think the height of the burn tunnel will be ok, it was bothering me in the back of my mind, but there really was nothing I could do about it with the materials I had.  I've proceeded on and will find out what happens.

I had thought about your suggestion for splits surrounding the wood feed, if two of us thought it, it must be a good idea.

thomas rubino wrote:Now I literally go several years before popping my lid. But I have a tried and true fireclay perlite riser that performs flawlessly (even though I would like to upgrade to  ceramic fiber). I also have a huge transition area with an ash pit  that gets cleaned each spring . When my system was new (5+ years ago) I checked the riser monthly, so a removable lid was essential. Your going to want to inspect yours often in the beginning as well.
In regards to your question ,I understand very lazy (I think of it as smart)  I would locate a free lidless barrel and use the lid and clamp you have in your photo.  That style removable lid ,you will want some wood stove door gasket to replace the plastic seal that usually comes on them. Lifting off the barrel is just more work than I would want to do. admittedly your riser is brick so its less Likely to have issues than a home cast one... but still .  

I'll go ahead and do that. It might put me a day or two behind.  No local places around here seems to be open on Sundays or Mondays

Well I found a place open today(Monday)  and I did a little horse trading.  They had a barrel with a lid but no clamp, and traded me straight across for one of my barrels.  With the clamps I found it should have been perfect



Should have been is the key phrase.  I went to stack the new barrel on the my old barrel and they didn't fit......super close but just not quite.  I have a tiny pair of pliers that have a 10-1 ratio of force, very strong clamping power. I went around the barrel and crimped the edge tighter.  For reference Knipex makes the best pliers in the world.





Here's the difference, left side not crimped, right side crimped



After crimping the barrels fit perfectly!



I repeated the clay test

I needed to cut the bottom out of my green barrel.  There was already a good mold line in the barrel for a reference.  I decided, cut to this line would still give me plenty of space to glue wood stove gasket.  I don't know why this picture doesn't look green, but I swear its the green barrel.



I decided the best attack would be to cut out the bottom with an oxy acetylene torch a touch big, and then grind it down to that line.



It's really hard to take a picture while cutting with a torch......



Boom, hole in barrel



Too hot to work with.....



I used an angle grinder to get clean up the edge and to grind down to the mold line in the barrel



This made for some really sharp edges, so I cleaned them up with a die grinder and a 35 grit sanding disc.



Finished barrel with bottom cut out and lid clamped on

Thomas, I'm SO glad I took your advice.  Just lifting the barrel into place for mockup was a heavy terrible experience.  I do not want to do that very often!

Per the book I need 2 inches of clearance between the top of the burn chamber and barrel lid.   You can use whatever you have to create this space.  What I had on hand is way way overkill.....These are machinist 1-2-3 blocks.  They are precision ground to be 1 inch 2 inch or 3 inches depending on which way you lay them.  I placed them on the 2 inch side.



I then placed the barrel on top....it's not super heavy but a very awkward lift to clear the heat riser.



I then measured the bottom of the barrel to the brick pad the bottom barrel will rest on.  This gives me a preliminary measurement so I can calculate how tall my bottom barrel needs to be.



It ended up at 15 3/4 inches.

Since my top barrel and bottom barrel fit together, I needed to calculate my loss of height and add that to my bottom barrel to maintain the correct height.  I measured each barrel and then measured them together.





Then did some math stuff....



My calculations do not include the thickness of the stove gasket between the barrels, or thickness of the mortar of the barrel to the fire brick pad, but I assume the 2 inch measurement is not like life and death critical and erring on the side of slightly too large is better then too small......you'll also notice I just rounded up 1/16"

I measured out my 16.5 inches all the way around the barrel



Then I played connect the dots



Cutoff disc back on the angle grinder to cut the barrel



Barrels in two pieces



Again, clean up the sharp edges





Barrels fit together



As a lot of you know, I live off grid, so my air source is this:  A 300 gallon propane tank aired up by a 5 hp Honda motor and a belt driven air compressor.  Kind of redneck, but works really good and is surprisingly efficient.  Takes about 45 minutes to fill up to 150 psi from empty.   I split a tractor apart to put a clutch in it and I'm still working on the same tank, almost down to 100 psi.

I made a little more progress today. I measured out all the dimensions of the bricks for cutting my bottom barrel.



I ground a reference edge in my barrel to hook my tape measure to



Then measured and layed everything out.



Remember the old saying measure twice, cut once?  It's because somehow the first time you measure is WAY WAY off.  Thank goodness I took this prescription.



Cutout barrel



Installed onto bricks for test fit.....perfect

For my transition/manifold, I decided to stray from the book.  There is a thread in this forum about this subject.  The one that makes the most sense to me, is the one presented by Ralf Siepmann.  You get to eliminate the first "T" and from everything I read on the donkey boards, the transition really should be massive, its a major problem for new builder not being large enough. Ralf was kind enough to send me his program for calculating the pipe angles, however this poor Missouri boy had a tough time with it.  This is the show me state, so unless I see it in front of me, it's doesn't work well.  I went with the only way I knew how.  I practiced twice on my extra scrap of barrel to make sure this was going to work. I figured the biggest transition would be with the pipe half in and half out of the barrel, so I went ahead and cut an 8 inch groove 14 inches long and then marked each end with the pipe to see how it would all fit at first.  I chose 14 inches simply because that was the length of my ruler





As you can see if fits in the barrel like so...



The cut just isn't close enough to weld together



Using a super lame, but effective method, I marked the barrel where it was closest to my 8 inch tube.  This ended up being 10.5 inches. I then cut some paper to match the contour of the pipe and made a template out of cardboard.








I went ahead and laid everything out on my manifold barrel using my new template and new length at 10.5 inches



And then cut to fit



Plenty close for welding



I'll get it all welded up tomorrow!