Burners 101

[Mikey98118]

I hope that any of you who are interested in building blacksmith-450's Mongo burner, will also questions about it, and encourage him to popularize his burner design, and his insights  about how he does such a fine job of tuning his burners to make "the magic flame."

[Square Nail]

On 8/16/2017 at 3:49 PM, blacksmith-450 said:

My Mongo Burner

I started with the recipe of the mongo burner found on the WEB and adapted it to a 3/4 format.

Parts List :

• 3/4 to 1 inch reducer
• 3/4 X 8 inches nipple
• 3/4 to 3/4 connector
• 3/4 cap
• 1/8 NPT nipple 2 or 3 inches
• 2 X Fitting 1/4 NPT 1/4 tube
• Mig Tip .023 (brass welded on fitting)

I drilled 4 X 1/2 inch holes at 1/2 inch from the threads.

When I had a neutral flame, I welded the 1/8 nipple in place rather than using a set screw... yes, I lose the possibility of adjusting it but.... ?  If my flame is steady, why play with it ???

Just curious if it would be feasible to thread the 1/8 NPT nipple the length of the nipple and use that as the adjustment instead of a set screw? Thread the cap and screw it in or out as needed! 

 

[Mikey98118]

Square Mail,

Thanks for including building instructions. I look forward to lots of smiths choosing to build your version of Mongo burners. As I never felt that the original Mongo burners were worth looking into, the joke is on me

[Square Nail]

On 8/19/2017 at 4:21 AM, Mikey98118 said:

Square Mail,

Thanks for including building instructions. I look forward to lots of smiths choosing to build your version of Mongo burners. As I never felt that the original Mongo burners were worth looking into, the joke is on me

Just for the record, this wan't my post. I was just asking the question at the end of the quote.

[Frosty]

3 minutes ago, Square Nail said:

Just for the record, this wan't my post. I was just asking the question at the end of the quote.

Let the record show it is now YOUR end of the post. 

Frosty The Lucky.

[Mikey98118]

You're right. My apologies to both Square Nail and blacksmith-450 for that completely senior moment 

[kander54]

On ‎5‎/‎8‎/‎2016 at 0:56 AM, Mikey98118 said:

Darious,

And you are the vary sort of pupil I was hoping to give the advice to! First, I would advice you to obtain a copy of my old book "Gas Burners for Forges, Furnaces, & Kilns. No, this isn't a sales pitch; it has been pirated to the net for yes, so you can obtain a free copy. Because there has been a lot of water flow under the dam since publication, I can update you and others who read this. This is IMHO  your best pass, but far from your only one. We can speak  about burners from other designs; there are a number of worthy designs floating around; it makes no difference which one you want to go with. My first burner was a Ron Riel linear design, which was quickly  modified, and we where off to the races. With  the MIG tip modification and a step style modified combustion "flare" (burner nozzle) it is still one of the best burner out there, as is the Frosty "T" burner, for a lot less work and money invested then either mine or Ron's. Next we come to the Modified Side-arm burner, which has been around for many years; you can find a lot of knowledge about it on the Larry Zoeler Forge site, but he isn't available to give you personal input on the material, and my knowledge about it is a little weaker than is available than Jerry's and mine on the others burners.

Pick your poison and let the questions begin. 

 

 

 

Sorry about all those typos; they'll be around for a while. Also I don't mean to imply that you cant start with whatever questions are already on your mind. Please begin.

Mike is there any other places to obtain your book, I have attempted to find it on the "pirated" sites but they all appear to be scams and the print books are out of my league in cost. 

[Mikey98118]

A couple of the guys on IFI have gained my permission to display any part of my book on this forum, which they may care to; what is preventing them, I don't know. In the meantime, thetr is one pirated version of the book, which I run across now and then, that doesn't come with strings attached; next time I run across it, their URL will appear on this thread. That is the best I can do while the book is out of print.

[Irondragon Forge ClayWorks]

I found it on scribd.com free download, not a scam site.

https://www.scribd.com/doc/155973901/Gas-Burners-for-Forges-Furnaces-and-Kilns-Michael-Porter

 

[kander54]

Thank you Mike, I have give a special thanks to BuzzKill, he hooked me up with a copy.

[Mikey98118]

The best way to become savvy enough to tune an air-fuel burner, or is to look at as many flame [hphotos as you  can, and study them until you understand what you are seeing

Start by discounting any sales ad for a burner that doesn't include a picture of its flame in action. It is becoming commonplace for burners to be shown running, in order to produce some proof that their burners are worth buying. dare anyone claiming to have a good burner to "show you the beef." Either they will change the oversight, or they really have nothing worth showing.

Nearly all butane blue flame lighters, and air-fuel torches have perfect flames. Ignore their needle flame shape, which is due to a much lower fuel pressure than propane torches. Concentrate on the total fuel combustion in a primary flame envelope, and on their shade of blue; never blue-green, which means a reducing flame; and never dark blue, which means an oxidizing flame; they are always a light to medium blue, which is in the ballpark of neutral flames.

You will find faked up photographs of imported blue flame torches, but they shortly become easy to identify as the frauds they are.

Finally note their lack of secondary flames throughout half of their pressure range, and very small secondary flames, even when turned up to wide open.

[Mikey98118]

Faked up photos? Yes, but they are of no concern. Some importers of butane-air (blue flame) hand torches will re-color their secondary flames, so that it matches the blue of the primary flame, making the torch look reminiscent of a junior light saber, which doesn't prevent you from, using the photos to learn from; just don't get all exited and buy their junk.

[Mikey98118]

Reality check

I place a lot of emphasis on getting every last erg of usable energy from a burner, so that the forge doesn't have to be built perfectly, knowing that it is just as easy for people to fall short in the forge build, as in the burner build. The idea is to offer more than one chance to "get it right." Right means hot enough to do the job-not to work perfectly. All the winners get from building everything just-so in a burner and forge, is the ability to turn the burner down lower, and save more gas. Well, okay; some of us get a lot of personal satisfaction out of the deal, too. Saner people make saner decisions 

[Mikey98118]

To err is human. Supposing you get too darn "sane" in your burner and forge build, and it does not get hot enough?  You still have two parts that you can improve. Just decide which of them is easier to modify, and try again. No; it doesn't have to be the burner. Half the parts people get wrong on a forge are external. What I call an add-on, which is just as easy to change as the burner.

[Mikey98118]

Future burner size confusion is inevitable

On another thread, Frosty noted "Not to be picky but those are 1/2" burners NOT 1 1/2". The burner size and output are determined by the narrowest part of the burner, the throat. Most modern burners are made with plumbing pipe so it works out to the same as the whole tube."

By common agreement, burner size have been connected to common water pipe call-out sizes, even when the burner's mixing tube was made of steel tube; this has work well, even though its application was restricted to naturally aspirated tube burners; not fan-blown, or wasp-waist burners (ex. Ransom burners).

Zirconium silicate based refractory opens the door to all manner of shaped burners, and so we might as well get used to using "narrowest part" for the bases of burner sizes. Unfortunately, pipe call-out sizes are smaller than actual pipe inner diameters. There will be some confusion over this.
 

[MonkeyForge]

I built 3 T burners (3/4) and I took picture of the flame before trimming the MIG tip so don't expect a perfect flame .  I misaligned the MIG tip on one of them, it is off centre relative to the mixing tube. I thought I would at least post the pictures. The opening in the insulating brick fits the 3/4 pipe exactly, I used the burner pipe to cut it out so it is not much for a flare.

Brick pile for testing:

Off centre orifice:

Not as much off centre orifice:

[Mikey98118]

That is Frosty's burner design...so he is up to bat.

[Latticino]

I'm sure Frosty will have plenty more detail, but there are a few fairly obvious issues here:

1. flame is lifting off the burner outlet, therefore the air gas mixture is moving at a higher velocity than the flame can burn.  Can be any of the following: too much gas pressure, too large a propane orifice, too much air entrained (mig tip not the right length), burner outlet too small (add flare, multiport burner, or flame retention nozzle)
2. Don't see either a regulator or 1/4 turn propane safety valve in your gas train.  Without the former you can't adjust the pressure effectively, without the latter you can't shut off the gas in an emergency
3. Alignment of orifice is critical for a stable, high quality flame.  I'd dump that one or use it for experimentation on improving the gas inlet mounting with a locking slide of some sort.
4. At times you can get a flame to be more stable closer to the burner outlet after the forge interior heats up a bit.  Try candling at a lower pressure for a few minutes before turning it up to full bore.

Just suggestions from my experience with gas forges.  Remember to change only one thing at a time and check results.

Good luck and be safe.

[MonkeyForge]

Agreed with all suggestions. I have an adjustable regulator and cut off at the tank. As I stated these burners are not tuned and I know one is misaligned. Pictures are merely to demonstrate the difference between flames. The brick pile is my test bed. Just want to share my failures in a visual way.. And, as always thanks your advise is valuable info in stuff I did not think about yet

[Frosty]

Not bad Maarten good enough to tune. First point is how you have your gas hose attached. The wall of a pipe T isn't thick enough for the threaded section to hold a brass fitting very securely so you can't have that much hose hanging from it and keep the jet aligned. This is another reason I like copper tubing for the final connection. I don't move the burners without taking the gas lines off either and sometimes find I've bumped the jet anyway. You can adjust alignment by GENTLY prying with a small screw driver or similar. Remember GENTLY.

The flame is too rich and the pressure looks to be too high in the pic. A too rich flame blows off the end of a burner easily so in this case it isn't necessarily an indication of too much pressure. Neither is a problem once you get the jet trimmed. Remember trim and test in small increments. Once you have the ratio right you'll find you have a surprising range of pressures it'll work at.

Frosty The Lucky.

[MonkeyForge]

I will start trimming the tips tonight, more pictures to follow. I f I cannot get a stable flame with the misaligned one I will not use it as Latticino suggests (it is off center but still points straight into the mixing tube) . pressure is between 0.5 and 0.9 bar so around 7 to 12 psi. I will make sure to support the hose during testing.

[Mikey98118]

Gas pipes for saddle mounted linear burners

A 6" long schedule #80 1/8" pipe nipple, that is cut in half, is the most convenient form of burner gas pipe in the USA, because of the pipe thread left ready  for mounting pipe connections to. If you have British or European parts available, you would simply recalculate the inside and outside diameters needed on the gas pipe.

Also, by stopping the outside thread short of the end with the MIG tip, you gain more leeway in gas pipe diameters.

There are some European MIG tips available, with small threaded ends.

Finally,  silver braze alloys, common solders, or thread locker, can be used to seal threaded parts together, so pipe thread need not be used at all. What parts you use is only a matter of convenience.

[Mikey98118]

On 9/5/2017 at 11:31 AM, Latticino said:

'm sure Frosty will have plenty more detail, but there are a few fairly obvious issues here:

Thanks, Latticino,

Thosefour excellent points for anyone trying to tune any kind of gas burner to keep in mind.

[Glenn]

It was suggested that a post be copied to this thread for informational purposes. 

 

I'm planning on building a small gas forge with a single burner and would really appreciate some advice.  Ideally I'd like to use a propane torch as the burner but I'm struggling with working out which one will work best. Would something like this be suitable? 

Like I said, advice really appreciated. 

======

Reply by Timgunn1962

Assuming from the link that you are in the UK, I would not advise using a torch unless you have (or need to buy) one anyway.

The Sievert stuff is quality, but it's worth checking whether the burner on that one is brass, steel or stainless steel.  There's a pretty good chance that brass will become a dribbly mess when trying to get useful forge temperatures.

You can buy a 1/2" long-Venturi Amal Atmospheric Injector (a commercial Venturi mixer) for around £50 delivered. Either the 354/12BLV (with a 60 jet) or 354/12PLV (with a 70 jet) will work. If you are mainly working hot, with welding the priority, the 60 jet is probably best. The 70 jet might be slightly better if precise temperature control down at Heat-Treating temperatures is important to you.

You'll also want a 6" (or longer) 1/2" pipe nipple for the burner. The injector incorporates a 1-in-12 tapered section and you don't usually need anything else on the end in a forge.  

You'll need a regulator, hose and fittings to get you into the 1/4" BSPF port in the injector. A gauge is optional and will fit in the other 1/4" port in the injector if you want to use one. The regulator should be a 0-30PSI (0-2 bar: adequate) or 0-60 PSI (0-4 bar: overkill).

Don't get a 0.5 bar-minimum (8 PSI) regulator, they are horrible to use in a forge.

The Amal burners turn down well and provide for exceptionally fine adjustment of the mixture/temperature. 

Fire bricks come in 2 main types: "Hard" and "Soft" or "insulating Fire Bricks". You'll almost certainly want IFBs. Hard bricks do not insulate to any useful degree and you'll probably need to step up to a 3/4" burner if you use them.

IFBs are not flux-resistant. Read the stickys for ways to protect them. 

Bricks are expensive to ship so we tend to get different ones over here to those in the US. My preferred IFBs for forges are marked LW23GRD. They don't seem to break up as badly with heat cycling as others I have used and, despite the 2300 degF rating, do not melt at temperatures I can readily obtain with the Amal burners. They also insulate better than anything else I have tried except the JM23s from Thermal Ceramics. I once used a JM23 to reduce the opening of a forge built from LW23GRD and the JM23 melted to a puddle. JM23s are my first choice for electric Heat-Treat ovens but I avoid them for forges.

I weld up a frame from 1" angle, rather than a sheet metal box.

I also take the burner in the side to reduce the chimney effect on the burner when the forge is shut down.

===========

Reply by Mikey98118

I recommended that burners be positioned vertical down at a tangent for the last eighteen years; this was because I liked the flame to impinge on high alumina kiln shelf floors, as the most durable position in the most energy efficient forge designs.

But circumstances alters cases. With better insulating and reflecting materials having recently become available at sane prices, it is time to turn away from the vertical down position.

[Mikey98118]

Thanks, Glenn.

In the past, thin heat rective coatings, painted on a semi-insulating high alumina refractory, was the most practical "thermal" armor," which people of modest means could find to act as a hot face over high priced ceramic fiber boards; these were use rated at only 2300 F. Now Morgan is making an equally high priced ceramic board; but one with has a higher use limit, and more mechanically sound. EDE, who lives in Texas, has has found a retail source of this board.

Morgan is also marketing a HIGHLY INSULATING, and much tougher semi- hard brick, which is use rated at 2600 F, for about the same price as the standard 2300 F bricks that we all know to fall apart under thermal cycling. Only their bricks don't; you can by them singly or is small quantities of eBay, with reasonable shipping prices, because they are very light.

Use rated 2600 F ceramic blanket remnants are starting to appear on places like eBay at reduced prices.

Veegum, bentonite clay, and bentone can all be used, in very small quantities, as a binder/plasticizer to turn zirconium silicate into very tough heat reflective coatings; they can also be used to turn zirconium silicate into a very high end refractory thermal armor; you can read more about that in recent pages on the Forges 101 thread.

But this is the burner thread, so getting back to the main point; these materials now make it practical to aim your burner in the most effective direction, without need to protect weak forge walls.