Starting build with 30 gallon barrel

Great idea! Perfect, since I also have a 16 inch concrete form as well

 

I guess. But this guy is so much more entertaining. He builds the exact same burner. But, it looks like he's using 2×2 structural tubing.

 

Glumpy again!! LOL

 

Sure why not.....As his saying goes, it's as cheap as chips. LOL.

But, as far as foundrys are concerned, why use a external combustion chamber when you have refractory?

 

Fiberglass resin, available at most auto parts stores will waterproof the outside of a Quick-Tube form. Surface the outer paper of the tube w/ light sand paper or scuff w/ 3M pad to make smooth. Two light coats of resin worked well for me.

More details later as I hafta work tomorrow.

 

If he can melt iron with that particular burner, I'd be way more impressed: it's a rich orange flame in a cool steel tube rather than a nice pink/blue flame of Nobox7's burner.

 

I should frame this statement and hang it in my foundry as a general principle.

Of all of the builds I've read about the removal of the forms seems to be the most common unplanned pain in the ass of the whole job. When I used the HVAC duct I was able to use a screwdriver to pry open the assembly channel the length of the duct, grab the exposed corner with pliers, and spiral the thing right out. If using sonotube wrapped or coated in some way as described above I'd still pre-cut it along the length and duct tape it back together. I've seen others burn it out afterward as well but if you've used epoxy or something like that to coat it I'd probably reconsider burning it.
Having the form impermeable is also important so it doesn't rob the moisture from the refractory. Adding water to the refractory isn't just a means to get it to flow, it sets off a chemical reaction that's been precisely formulated and is predictable. Clean potable water is important too. If you wouldn't drink it don't use it. It was also suggested to me to dump the whole bag and mix it dry to assure that the fines haven't settled out in transport, then mix it in portions as Kelly described above. This isn't always practical but I understand why it's a good idea.
A mask is an extremely good idea when mixing any refractory dry, or any sand product for that matter, and get the heavy green rubber gloves. Whatever you think refractory is, remember it's simply a dry chemical mixture and it's kinda nasty, so protect your skin, lungs, and eyes.
Figure out what your drying/firing schedule is going to be before you start as well. Patience is the watchword. The initial dryout is very important and the manufactures recommendations are important although most of us take some liberties with the firing schedule because strict recommendations are just not doable in our home environments.
Some of this may seem like minutia but I assure you it's not and it may prevent your future thread titled "What Happened?"

Pete

 

@Tobho Mott, Thank you for passing this info along. Really helpful seeing how you set up form. I had considered using aluminum flashing. I have some in the garage. Not sure if I'll cut down a larger form or use aluminum, but nice to know that both are good options!

 

@Petee716, Great info. I've only used plastic refractory in past, so tip about remixing dry refractory is really useful, in particular. Never would have thought of it myself!

 

I used this fiberglass resin kit to waterproof the outside of my Quik-Tube form: https://www.3m.com/3M/en_US/company...Fiberglass-Resin/?N=5002385+3293241081&rt=rud
There was no water or moisture intrusion. Minimum two coats, block sand to smooth.


Cut the cardboard discs for centering and reinforcement w/ an Allpax circle gasket cutter kit. Punched the center hole on a shop press w/ a reamed and sharpened 1" pipe nipple (ID). Discs spaced about 2" apart, doubled at top and bottom, glue gunned in.

Form removal was easy-peasy, like tearing apart a cardboard box.

It held the center really well also, form OD to keg wall ID.

 

@Al2O3, just made plinth. Making this first was great advice. Took 2 lbs of dry refractory, which should require about 84 ml of water.

So, I mixed everything up and I’m thinking that there is no way on Earth that 84ml of water is even close to enough. Learned that magic happens when the vibration starts. Hrmmm, that just sounds so wrong, but you all understand what I mean.

Makes a for a great demo of the process of liquefaction!

I was surprised that the plinth took 2 lbs of refractory. Given it’s a 5 x 3 inch cylinder.

 

Yeah, hit home despot earlier today for mixer paddle. It occurred to me that mixing more than a couple lbs by hand would be unpleasant.

Read some good suggestions in forum on topic if setting up larger scale vibro platform, which will be helpful!

 

One more question. A lot of videos show people creating insulation for lid. Instead of cutting wool in circles, they stack up chunks of wool like books on a bookshelf. Is there a big upside to this approach?

On a slightly unrelated topic...

So, I cut off top 11 inches of 30 gallon drum with angle grinder and diamond cutting wheel. Did a pretty good job. Better than expected.

Bonus was that cut edge was knife sharp, so I used it as a giant cookie cutter to cut out two 1 inch thick pieces of ceramic fiber wool for furnace floor insulation.

 

Yes, take a scrap of your insulation, pull it apart in various directions and you'll notice it has much more structural integrity across it's length and width than it does across its thickness so, if you stack the like books, it's less likely to pull apart and separate from the lid.