Need a good design. Show me your forge, please

[SomeGuy]

I need a good forge for general blacksmithing. I see so many forges and burners, and I need a good design. I need something that is super efficient. Please, if you don't mind, show me your forge and burner, and tell me how much gas it uses on average, Thank you

[WayneCoeArtistBlacksmith]

Check out the attachments at the Forge Supplies page at www.WayneCoeArtistBlacksmith.com.

Let me know if I can help you.

[bigb]

Wayne, I am leaning toward your forge design but I have a question about step #7, why only one layer of insulating blanket on the top?

[SomeGuy]

9 hours ago, SomeGuy said:

 

 

5 hours ago, WayneCoeArtistBlacksmith.c said:

9 hours ago, SomeGuy said:

 

.

5 hours ago, WayneCoeArtistBlacksmith.c said:

Thank you. I'm sorry about muti quote stuff. I am having trouble understanding this website. I accidentally added muti quotes but cant figure out how to remove them. I also already replied to you once, but I don't see my response below, so something must have gone wrong. anyway, I'll retype it again.

About the link you provided, I have seen that webpage before and found it useful, and I'm considering a ribbon burner. Ultimately its about fuel efficiency for me. Are ribbon burners much more efficient in conserving fuel?

I'm also wondering about forge opening size. I know that many people say that its good to have proper ventilation and that forge openings must not be too small for that reason. However I see this topic discussed here on IforgeIron, and this gentlemen seems to say the opposite. I'm in agreement with Grant Sarver that the only efficiency I'm concerned with is fuel cost. What is your opinion of his advice given in the topic below? (see link below) I would ask him directly but its an old topic and I'm not sure he is on this website any longer.

 

http://www.iforgeiron.com/topic/13239-gas-forge-quotefficiencyquot/?page=1

 

[WayneCoeArtistBlacksmith]

You do not gain that much more insolating value for the smaller interior size.  1" of blanket and about 1/2" of Kast-0-Lite and a coat of infrared reflective product (Plistix or Metrikote) will provide a long lasting, efficient forge.  If you use a 20# Propane tank with 1" of blanket and 1/2" of Kast-0-Lite you will have a 7 1/2" chamber.  You can then block up the openings as needed. 

I run my Ribbon Burner forge with about 1/2# of pressure at the regulator.  Before, with a venture burner I ran from 5 to 7# pressure.

[Frosty]

Glad to see you joining in Wayne. I've been intending to ask you about naturally aspirated ribbons but am still messing with a test unit. I do have a little bone to pick here though, just saying one burner type uses .5psi as opposed to another type using 5-7 psi is kind of misleading isn't it? The temperature and BTU output of a forge is determined by how many cubic inches of fuel is burned in it per second. A NA burner has to force that amount through a jet around0.035" dia where a gun burner putting out about the same BTUH is what a bit larger than 3/16" dia.?

I'm not getting picky to be picky but we have a new fellow trying to understand these things and I can't think of a better time to keep the basics straight. It's also another reason I never tell people at what psi my burners run only general numbers. There are just too many location determined variables for what my burner at aprox. 450' elevation needs as opposed to an identical one at 8,000'.

Oh, back to the ribbons how'd it work as a NA?

Frosty The Lucky.

[WayneCoeArtistBlacksmith]

If you are using less pressure isn't that less gas?

I have seen some information about non blown ribbon burners but no detail.  I think that you need the blower to get the gas and enough air through the many holes and aid the disbursal. 

Let me know what you find out.

[Andy98]

1 hour ago, WayneCoeArtistBlacksmith.c said:

If you are using less pressure isn't that less gas?

No.

A high-volume flow at low pressure can move as much gas as a low-volume flow at high pressure. Think of a slow moving wide&deep river vs a fast moving narrow&shallow river.

Ultimately, a burner is simply releasing the energy stored in the propane (by burning the fuel). So if you want 60k BTUs of energy, you will consume 60k BTUs of fuel (plus some extra due to inefficiencies) whether you deliver that quickly through a thin tube, or slowly through a fat tube.

I'm thinking (and would love to be further educated on the topic) that basically all the burners are equally efficient (e.g. no burner is producing a lot of unburned or incompletely burned propane). The forge itself might be inefficient (some burning might take place outside the forge, it might be poorly insulated and not retain the heat, etc...)

[Frosty]

9 hours ago, WayneCoeArtistBlacksmith.c said:

If you are using less pressure isn't that less gas?

I have seen some information about non blown ribbon burners but no detail.  I think that you need the blower to get the gas and enough air through the many holes and aid the disbursal. 

Let me know what you find out.

The size of the orifice is the other half of the equation to determine the flow. Twice the volume will flow through a 3/4" pipe as a 1/2" pipe at the same psi. OR velocity. It's a function of the area of the cross section, all other things being equal.

PSI change only effects the volume through the same size orifice, pipe, etc. It's only half the equation.

Oh yeah, I'll be posting the results of my NA ribbon burner experiments. I'm thinking the basic ratios for inducers should apply. It shouldn't require high pressure in the plenum to get a proper flow velocity to prevent backfiring.

I recall you saying something about Kast-O-Lite 30 breaking when you made a ribbon from it. Where and how'd it break? Pattern, location, time temp, etc.?

Frosty The Lucky.

[SomeGuy]

23 hours ago, WayneCoeArtistBlacksmith.c said:

You do not gain that much more insolating value for the smaller interior size.  1" of blanket and about 1/2" of Kast-0-Lite and a coat of infrared reflective product (Plistix or Metrikote) will provide a long lasting, efficient forge.  If you use a 20# Propane tank with 1" of blanket and 1/2" of Kast-0-Lite you will have a 7 1/2" chamber.  You can then block up the openings as needed. 

I run my Ribbon Burner forge with about 1/2# of pressure at the regulator.  Before, with a venture burner I ran from 5 to 7# pressure.

Wayne, you have a ribbon burner. Excellent. I wanted to ask about those. I know theese type burners are said to heat the forge more evenly, but what about fuel consumption? How much fuel does your forge use?

Also, how big are your forge openings? How small can I make them if I use a ribbon burner?

10 hours ago, Andy98 said:

No.

A high-volume flow at low pressure can move as much gas as a low-volume flow at high pressure. Think of a slow moving wide&deep river vs a fast moving narrow&shallow river.

Ultimately, a burner is simply releasing the energy stored in the propane (by burning the fuel). So if you want 60k BTUs of energy, you will consume 60k BTUs of fuel (plus some extra due to inefficiencies) whether you deliver that quickly through a thin tube, or slowly through a fat tube.

I'm thinking (and would love to be further educated on the topic) that basically all the burners are equally efficient (e.g. no burner is producing a lot of unburned or incompletely burned propane). The forge itself might be inefficient (some burning might take place outside the forge, it might be poorly insulated and not retain the heat, etc...)

Andy, The theory concerning BTU output seems logical. However, it also seems that if we are using more BTU's than is necessary then we are wasting fuel.

This is exactly the question I'm searching answers for. If we have a lot of energy (dragons breath) escaping from the forge openings then that's wasted energy and wasted fuel. I know a forge must breath properly, but I'm looking to make it as efficient as possible. If that means finding a burner that I can use at lower BTU outputs then that's what I want. But I'm not sure what is needed to accomplish this goal though. I want to limit the amount of energy that is wasted as it escapes out if the forge openings. This is my whole search in a nutshell.

[IanOhio]

Frosty/Andy, going back to high vs low pressures; given a NA burner that is the same in all respects except whether it is setup to run high pressure with a smaller orifice or Low pressure with a larger orifice/lines/etc, will the high pressure be able to draw more air in? Am I correct in that assumption?

[Andy98]

On July 18, 2016 at 6:51 PM, SomeGuy said:

Andy, The theory concerning BTU output seems logical.

It's not a theory - it's the first law of thermodynamics.

11 hours ago, IanOhio said:

Frosty/Andy, going back to high vs low pressures; given a NA burner that is the same in all respects except whether it is setup to run high pressure with a smaller orifice or Low pressure with a larger orifice/lines/etc, will the high pressure be able to draw more air in? Am I correct in that assumption?

That's an interesting question that I am completly unqualified to answer. Ultimately you want the right amount of air, not necessarily the most air possible. But then don't listen to me, I've never even built a forge or lit a burner before.

[SomeGuy]

Thanks Andy.

[IanOhio]

Maybe I should rephrase, would a higher pressure flow be more efficient at "grabbing" air?  I have built several, all of them "mikey" burners, and really I assumed that was the reason for the larger range of adjustment. Lower pressures=lower air flow. Higher=higher. I do use sliding chokes, but for the most part once set, unless you change pressure drastically they seem to make little difference. I'm just wondering if I've got the right idea going or missing some other variable. 

Also maybe I should've asked this on the burner 101 thread rather than hijacking this one. Apologies. 

Edited July 22, 2016 by IanOhio
added 2nd thought

[Andy98]

9 minutes ago, IanOhio said:

Maybe I should rephrase, would a higher pressure flow be more efficient at "grabbing" air?

Again, noting that i don't really know, what does "more efficient" mean? Grabs more air per unit of...what? And what is the consequence of that inefficiency?

Again, I'm still trying to figure a lot of this out - and the dynamics of a burner seem quite complicated.

[IanOhio]

3 minutes ago, Andy98 said:

Again, noting that i don't really know, what does "more efficient" mean? Grabs more air per unit of...what? And what is the consequence of that inefficiency?

Again, I'm still trying to figure a lot of this out - and the dynamics of a burner seem quite complicated.

Units of propane. The inefficiency being that the lack of pull would require the burn to inherently be rich to get enough air to burn at the temperatures required, thus less efficient. I may be completely off. And probably am. I was actually just reading in another thread started by Mikey about this exact principle. I'm doing the exact thing you are, trying to figure all this out

[Andy98]

1 minute ago, IanOhio said:

Units of propane. The inefficiency being that the lack of pull would require the burn to inherently be rich to get enough air to burn at the temperatures required, thus less efficient.

...but all the burners can be tuned to get the ratio you want, therefore by that measure they are all equally efficient...?

I must be missing something because the "induction ratio" of a burner gets a lot of talk so it must matter. Perhaps none of the (non-commercial) burners actually induct enough air for complete combustion? That would create an inefficiency (require air be drawn into the forge from the openings and create lower-temperature combustion zones?)

Fluids  + combustion + heat transfer = voodoo.

[IanOhio]

1 minute ago, Andy98 said:

...but all the burners can be tuned to get the ratio you want, therefore by that measure they are all equally efficient...?

Fluids  + combustion + heat transfer = voodoo.

Well that's kind of what I'm wondering. Can they all?  Can a burner designed for lower pressure pull enough air on its own to be leaned out? I don't even know if it's a question worth asking. But I've asked it already...

Voodoo Indeed!

[swedefiddle]

Good Morning,

Andy, you haven't built a Forge? It's time to start and learn what works and what won't work.

There is no magic secret formula, other than by starting and learning what works and what won't work. Start simple, Keep it simple, try a atmospheric burner, then try adding a little fan to it. You can control the air from the fan. There is NO ONE DESIGN that is perfect. There are too many variables. This is why Frosty isn't talking a specific pressure. How many Propane Tanks are you going to have hooked together, are they vertical or horizontal. Try Natural Gas?

I have tried Ribbon Burners without a blower, they work better with a blower in the forges that I have, at sea level (not the Dead Sea).

If you haven't cooked your whiskers yet, get started.

Neil

[IanOhio]

1 hour ago, swedefiddle said:

Good Morning,

Andy, you haven't built a Forge? It's time to start and learn what works and what won't work.

There is no magic secret formula, other than by starting and learning what works and what won't work. Start simple, Keep it simple, try a atmospheric burner, then try adding a little fan to it. You can control the air from the fan. There is NO ONE DESIGN that is perfect. There are too many variables. This is why Frosty isn't talking a specific pressure. How many Propane Tanks are you going to have hooked together, are they vertical or horizontal. Try Natural Gas?

I have tried Ribbon Burners without a blower, they work better with a blower in the forges that I have, at sea level (not the Dead Sea).

If you haven't cooked your whiskers yet, get started.

Neil

I've built 4 versions so far, I run 3 of the 3rd design on my large forge, and the 4th design on my smaller guy. Definitely lost some whiskers ...and eyebrows... it's a secondary addiction to forging

[Buzzkill]

Hopefully Mikey or Frosty will join in here, but I'll get it started.   The diameter and length of the jet and the burner tube as well as the air inlet openings are "matched" fairly well in a good design.  The result is that, once tuned, the NA burner will pull very close to the "right" amount of air in with the propane anywhere in the functional operating range of the burner.  So, if you tune your burner to be a little on the rich side (slightly less air than the amount for complete combustion in the forge), then raising or lowering the propane pressure a little should affect the heat output, but not the relative ratio of air to fuel - you'll stay with a slightly rich flame at 3 psi or 12 psi.  The bottom line is guys like Frosty and Mikey have already done the hard work for us.  They've figured out the correct diameters, lengths, and general design so that all we have to do is initial tuning and then raise or lower the propane pressure to get the desired temperature.

[Andy98]

10 hours ago, swedefiddle said:

There is no magic secret formula...If you haven't cooked your whiskers yet, get started.

Hi - fear not, I'm working on it. I just like to understand what's going on - I'm not paralyzed trying to make a decision or anything. I've got a plan, and am working towards it (with unfortunately very limited time to dedicate) 

10 hours ago, IanOhio said:

Well that's kind of what I'm wondering. Can they all?  Can a burner designed for lower pressure pull enough air on its own to be leaned out? I don't even know if it's a question worth asking. But I've asked it already...

Voodoo Indeed!

For sure you can build a non-functional burner. But the common burner designs are all functional, and all have at least some operational range in which they, you  know, work.

What I've concluded from all the conversation on the topic is that the real difference between the burner designs is:

• Ease of tuning (ability to get the flame characteristic you want)
• Ease of construction
• How wide the operational range is (expressed by input propane PSI)
• Stability: Once tuned and running, how likely is it that the burner will continue to deliver the desired flame when confronted with wind, backpressure, etc.

I've decided that burner engineering is an efficiency trap: It's easy to get obsessed with making the most "efficient" burner but the actual improvement in performance is small. While I would have fun pursuing the "most efficient" burner, it's not necessary to run an economical forge.

I've also concluded that I'll get more efficiency gains by improving the forge itself, than I would by worrying about the burner: Keep the forge interior small, well insulated and IR reflective. Possibly add an idler circuit. Don't have too much dragon's breath.

These are my personal conclusions - they may be totally off the mark, but that's how I'm proceeding.

To @SomeGuy (the OP):

You've mentioned a few times that conserving propane is a big deal for you. If you have access to natural gas, you might consider following this person's lead: http://www.flemingknives.com/ribbonforge.htm - I don't know if he is a user here, but he is a user on bladeforums: http://www.bladeforums.com/forums/showthread.php/934512-Table-Forge-with-Ribbon-Burner/

...he built a natural gas forge, using a blown ribbon burner, that he runs off his residential NG supply. It runs (and gets welding heat) using 1/4 psi NG (I have no idea what volume of gas it uses - but he says it is so little he can't even notice it on his monthly bill).

 

[IanOhio]

2 minutes ago, Andy98 said:

I've decided that burner engineering is an efficiency trap: It's easy to get obsessed with making the most "efficient" burner but the actual improvement in performance is small. While I would have fun pursuing the "most efficient" burner, it's not necessary to run an economical forge.

I've also concluded that I'll get more efficiency gains by improving the forge itself, than I would by worrying about the burner: Keep the forge interior small, well insulated and IR reflective. Possibly add an idler circuit. Don't have too much dragon's breath.

These are my personal conclusions - they may be totally off the mark, but that's how I'm proceeding.

I don't think you're off the mark at all Andy, I agree with both points.  Following proven plans as everyone here advises is the smartest way to go, in both burner and forge construction.  I built my large forge before finding this website.  I have nearly a week's worth of labor in it, well over $500.  Used it for awhile, works very well but is 4 times the size I need for most of what I've been doing.  I can heat 20" of a 1" bar in no time at all.  Which, is sometimes useful I guess, but most of the time wasteful.  So after I did the research I should have done in the first place, and found this site, I built a small 8" long single burner forge based off of a video David Hammer(if memory serves me correctly) has on youtube.  I built it in under an hour. with scraps I had from the larger burner for under $40. and have been using it for a couple weeks now.  Even managed to accidently melt a firebrick!  It is far from perfect, but much better suited for my everyday use. 

So in short; I am, without any shadow of a doubt, the poster child for the "Newbie building a forge 9 times too large" lesson. 

My advice.  Keep it small, basic, and definitely add the idle circuit. 

[IanOhio]

1 hour ago, Buzzkill said:

Hopefully Mikey or Frosty will join in here, but I'll get it started.   The diameter and length of the jet and the burner tube as well as the air inlet openings are "matched" fairly well in a good design.  The result is that, once tuned, the NA burner will pull very close to the "right" amount of air in with the propane anywhere in the functional operating range of the burner.  So, if you tune your burner to be a little on the rich side (slightly less air than the amount for complete combustion in the forge), then raising or lowering the propane pressure a little should affect the heat output, but not the relative ratio of air to fuel - you'll stay with a slightly rich flame at 3 psi or 12 psi.  The bottom line is guys like Frosty and Mikey have already done the hard work for us.  They've figured out the correct diameters, lengths, and general design so that all we have to do is initial tuning and then raise or lower the propane pressure to get the desired temperature.

Buzzkill, I missed this earlier.  Thanks for the reply.  I've noticed that exact principle in mine.  Once I got the choke tubes set I could adjust up and down with pressure and not need to adjust the choke much, if at all. I found Mikey's burner plans early on and later, after I'd built a couple,  that is what led me to this forum.  And then any confidence I had in my relatively small understanding of how these worked was crushed by the amount of information I found here. 

[Frosty]

Ian: As you can tell reading this thread there is a LOT of commentary by guys who are barely figuring out how to make one work let alone actually understanding what makes them work. If you've been making Mike's burners then you know how to make one his take a higher level of shop skill than many, the T burner especially.

A naturally aspirated burner is an induction device that has been tuned to induce the right ratio of air determined by how much primary (propane) pressure is supplied. They work on a relatively flat curve making tuning in operation unnecessary.

Frosty The Lucky.