Burner orientation - is sideways effective?

[Drunken Dwarf]

Hi all,

 

I'm relatively inexperiences with gas forge design. I've forged for years with both coal and induction, but for various reasons I now use gas in my shop. I'm using a commercial forge right now but I don't like it so I'm planning to build a new quick little brick built forge.

One of my main problems with my current forge is that with the burner coming directly vertical from the top, there's a lot of rising heat and the gas hose gets a lot more mot than I am comfortable with. So I want to change the burner angle.

I was noodling around youtube and found "Essential Craftsman's" brick built forge where the burner comes in the side. (https://www.youtube.com/watch?v=TS7wumQt0s8)

I've never seen this before, only ever seen burners pointing down, either vertically or at a slight 30-45 degree angle. Is the sideways burner effective? It's exactly what I would like in terms of layout if its viable as a production forge (for full time use, not hobbyist use) and reasonably fuel efficient.

It's worth noting that I work pretty much entirely in mild steel, so dont really care about the whole "keeping out of direct burner path" and associated issues that happen when unevenly heating knife steel for example.

 

Thanks for any guidance

Danny

[Frosty]

hey Danny, good to see you posting again.

Yes, putting the burner on the side works better than straight down. This video is a good example of why I don't watch and especially don't recommend this website. 

His is an over designed poor copy of my no weld forge and a poor but expensive copy of my T burner.

I have to apologize, I don't seem to have control of this computer I can't reduce file size or my old standby do a save as. This is the only pic I have of my no weld brick pile forge. It's 4 pieces of 2" x 2" angle iron about 12" long and 8 pieces of all thread rod. I take NO responsibility for the way the burner is mounted, Dad would've yelled at me for that when I was 10! We built 30 of these at a club forge and burner clinic and it was chaotic.

The fire bricks are IFB (Insulating Fire Bricks) "Morgan Thermal Ceramics, K-26" by name. They are rated to 2,600f sustained working temp, are resistant to molten borax welding fluxes and are not susceptible to the rapid thermal shock of a propane forge heating up. This forge comes to yellow heat in under 4 minutes. The burner is a 1/2" T burner which has half the output of the 3/4" T in the video you linked. Provided it is a well tuned burner. 

    

 

I posted detailed instructions to build a T burner, it's in the IFORGE propane burner section, it might even still be pinned. 

To answer your question, I'm in favor of mounting burners in almost any orientation than straight down. Oriented downwards at an angle so it impinges on the floor at an angle causes the flame to swirl in a uniform manner. We stopped calling it cyclonic when it was pointed out the term refers to a very different kind of circulation. 

Circulating in a cylindrical swirl helps keep the fire IN the forge longer giving it more time to transfer energy to the forge flame contact layer so it can be re-radiated into the chamber to heat your work. 

While Morgan K-26 work well, they will do MUCH better with a high zirconia kiln wash, flame face. Zirconium is chemically VERY inert, nearly diamond HARD and a very poor thermal conductor. What this means is your forge welding flux will have ZERO effect on it. It will continue to absorb energy from the flame but conducts it to the insulating fire brick VERY slowly. That means the zirconia kiln wash becomes to incandescent heat quickly. 

The trick is a good binder to make the zirconia stay where you want it. Some commercial refractories contain zirconia flour. The best home brew I know of is IIRC 97% Zircopax flour and 3% Bentone a type of Bentonite clay. I've used bentonite drill mud and found it satisfactory.

I hope this doesn't cause more confusion than it solves. The short answer being YES, a bolt together IFB propane forge works well to VERY WELL. Just not the essential guy's from what I've seen.

Please feel free to ask me questions though there are a number of outstanding propane forge builders on the forum. 

Frosty The Lucky.

[Drunken Dwarf]

Hiya Frosty, always a wealth of information!

 

That news is perfect, once I came across a sideways burner orientation I really hoped it would be viable, it's perfect for the way I want to build mine. To be fair, I wasn't really planning to follow the design of Essential Craftsmans, hes never really struck me as a blacksmithing authority  I was just going to weld up an angle frame for the basic square brick pattern and had picked up on his use of the burner coming in the side of the forge.

I had planned to use soft brick for the sides and top (https://shop.vitcas.com/products/fire-bricks/insulation-fire-bricks.html) and hard brick for the floor (https://shop.vitcas.com/products/fire-bricks/refractory-fire-bricks.html). I don't klow if Morgan are a brand we get much in the UK, but Vitcas seems to be our standard for thermal stuff. Interesting that you'd used grade 26 bricks. Do I not need to shell out for full grade 30 ones? (I do like saving a little money)

 

Thanks so much Frosty

[Frosty]

I don't know how the Morgan K-26 matches up to the Vitcas IFBs. Morgan has a division in the UK, I'll PM the link it's not allowed on the open forum, we gotta be sneaky.  Morgan makes higher rated refractory (bricks are only one of many available shapes) I forgot to finish this thought. The K-26 have met and exceeded everything we need in a propane forge or the caster in the club's bronze melter and the petroleum coke fueled cupola melter he uses at the annual iron pour.

I have no experience with Vitcas products. From what I saw skimming the links you sent I HIGHLY recommend you not get refractory mortar or cement of any kind. It's good for setting refractory brick but degrades rapidly in contact with flame. Propane flame is VERY chemically active.

You might need to shop at ceramic equipment suppliers for a zirconium kiln wash. Washes are used in ceramics kilns to prevent glazes, pigments, etc. from sticking and firing to the kiln furniture. Almost nothing sticks to zirconium. Zirconium flour is made to fire to furnaces, kilns furnaces, etc. by encasing it in a binder that fires hard trapping the zirconia. The finer the zirconia the better, it takes less binder and less is better so long as it fires hard. Make sense?

Frosty The Lucky.

[Mikey98118]

You will notice that the Frosty forge has the burner mounted so that the flame enters horizontally toward the top of his forge. The other guy had the flame entering at the bottom; giving little room for the fuel to combust before impinging on the work pieces.

I have nothing against innovation. However, everything has a reason behind it in good forge and good burner design!

The main point of horizontal positioning is to allow more room for flame combustion to complete before impingement with work pieces, than top mounted down-facing positioning provides. Placing the flame right next to the work does just the opposite.

[Drunken Dwarf]

Yeah, I did notice that the burner was higher up. The guys video showed him putting his in the bottom slightly angled up and that really didn't seem right to me. I was working out mine for the burner to go in maybe 2/3 the way up the wall? (as pictured).

May have to work on brick layout though, I don't know if standard brick size in the US is different to here, but ours as standard are 9" x 4.5" x 3" which only gives me a 3"wide forge chamber. I may have to rething that, I want to keep it nice and small for fuel efficiency, but my candle holders are 4" once finished and I need to be able to at least fit one of them in

[Frosty]

So make your forge wider, it's just stacked brick after all. Putting the heavy 3,000f fire brick on the bottom doesn't make things better, I put split heavy brick on the floor of my way too large shop forge and the whole forge comes to working temp before the floor starts to show color. 

A good kiln wash will armor the floor just fine and it's easy to repair.

If you place a heavy hard brick on top of the roof bricks directly above the wall the roof will cantilever and be stable. Soooo, you can do the same on the other side and make a forge chamber 9" x 9" x 4 1/2". When there were two of us working a demo I'd make my brick pile this way. I don't have a number of bricks for the floor, I use my fire brick welding, hot work table. It makes for nice porches at the ends so I can lay long work in the forge without having to prop it up.

9" x 9" x 4 1/2" makes a 365 cu/in chamber, this is barely over sized for a single 3/4" naturally aspirated burner. Partially blocking the ends makes up for it nicely. Mike's thermal baffles work far better than doors.

Frosty The Lucky.