Buy, or Build?

[WELD]

Finally getting my shop setup to start hammering but need to address one missing item of my arsenal. The heat source.

I'm working inside a 20x24 shop with low ceilings and i try to keep the doors and windows shut for heat retention most days. So i am figuring a gas forge will be the cleanest and most efficient way for me to go. it also seems the easiest to stow.

I am a full time machinist/welder and have a full shop here at my disposal for building myself a forge so having the tools to do so isn't a question. But when i look around online I see lot of single and double burner forges i can purchase for only a few hundred dollars depending on sizes and brands. But then i start reading about the different styles, square edge vs round, insulation types and dangers of insulation fibers. brick vs clay etc. With all these options and variables and not knowing enough about it from experience i ask of those with more experience. 

Is it worth buying one over building one? if so what would YOU get/look for if you had a choice?

Is there a decent enough source for all the materials i need to build my own like stuff from Mcmastercarr? What design/dimensions would you go for? are there plans available somewhere that are worth copying? I read about certain burners needing certain cubes to work with or they won't burn clean. how do i know this if i build my own? 

Thanks in advance!

-Tony

[VaughnT]

Wayne Coe is a member here and is also a purveyor of all the stuff you might need to put a propane forge together.

Would I recommend buying or building?  Definitely building.

Even if you buy a top-shelf burner like the JF1 on ebay, you'll still save money and end up with a forge that suits your needs.  If you look at the commercially available ones, they're built heavy, but they also are built to a price point.  You don't need a heavy-wall pipe or old propane tank to make the outside of the forge.  This thing doesn't need to stop incoming fire from a howitzer, and can be made from the thinnest sheet metal that's cold-bent to shape.  By using a section of pipe, for example, you're automatically limiting yourself to the shape of that pipe.  Might be great if you're only interested in making blades and don't need the room, but if you're any kind of metal worker, you'll soon want to branch out into scrolls, stuff with big bends, etc.  If you have a wife, and she finds out that you're trying to blacksmith, you can expect all sorts of stuff added to your Honey-Do list.  I'm told that wives are really good at adding things to that list and need little provocation to do so.

I have a Majestic 3-burner that's 18" long.  Just about as bad a design as you could ask for and a real gas hog.  In all the time I've had it, I've never used more than one burner to heat up the front section of the forge.  No sense heating 18" of steel when I can't beat on it all before it cools down.  I really don't see the need for a 2-burner, either.

Definitely consider doing a blown burner rather than a venturi style.  Maybe even look into doing a Ribbon Burner.

2" of Inswool or Kaowool insulation on the inside of your shell.  Coat that with a light skim coat (.25") of refractory cement.  Paint over that with a bit of IR reflective paint.  That's how you make a propane forge.  What the shell looks like, well, that's the fun part.  Lots of ways to go, especially when you have a full-on shop like you do.  

 

[WayneCoeArtistBlacksmith]

Tony, check out the attachments  at the Forge Supplies page on my web-site www.WayneCoeArtistBlacksmith.com.  This will show the way I like to build a good long lasting, efficient forge.  You should also get a Carbon Monoxide detector.  Most will also detect flammable gasses incase you have gas leak.

 

Let me know if I can help you.

[WELD]

Thanks Vaughn, i never really researched the ribbon style. def seems the way to go. Wayne great link, thanks a bunch. lots of good reading on your website, good job. also thanks for the advise on the detector. I will def get one.

Let the build begin ha. But before i start a design I have a few other questions.

Any advantage to a round vs square chamber or flat bottom with rounded top(pizza oven)

What's a good size chamber to aim for? I would say the majority of what i would like to do is build axes. But blades and artwork type stuff are not out of the question. 

I've decided im going with a ribbon style, does the entry angle of the burner effect how it heats the metal? do i want flames directly at my workpiece or directed away? it seems most of the ribbon styles i'm seeing it is pointed away just a bit. 

Is it worth designing a pass through or back door for the forge, or will i most likely not need it? only thing i think of is if i were going to work the center of a long piece. 

How hot would you say the outside of the forge may get at its hottest? this will effect material i chose for the shell. i've got some cool stuff around i may use.

So,

Chamber shape

Chamber size

angle of entry of ribbon

one opening or pass through

outside temp 

-Tony

 

[Buzzkill]

For many of your questions there is no specific answer.  A LOT depends on what you want to do and the shape and size of stock you plan to work.  My first gas forge was way bigger than it needed to be.  What I'm using currently is a disposable helium tank you can get at party supply stores for blowing up party balloons.  I used 2 one inch layers of Superwool, which gives me an inside diameter of approximately 5 inches and it's about 11 inches long.  Using a single 3/4 inch T burner of Frosty's design I can get the entire chamber to yellow-white heat in just a few minutes.  However, I do think that for some things I do it would be better to have 2 one half inch burners instead.

The pass through door - definitely.  I can't imagine trying to work without one and unless you build a behemoth of a forge you will want one too. I welded a hinge and thin steel flap to cover the pass through when I'm not using it.  You lose some heat through the opening, but it's well worth the trade-off in my opinion.

I've tried a couple different entry angles for the burners, but all I can tell you is that for some things I prefer no direct contact with the flame and a more even heating in the chamber, and for other things I really like a "hot spot" to concentrate the highest heat in a small area on the metal.  I haven't worked with a ribbon burner yet, but it's on my list of things to build and try out when I get the time.

The chamber shape and size is really smith dependent and probably not even you knows what you'll end up wanting yet.  My advice is build something fairly small to start with and recognize that within a couple months of using it you'll probably already have a list of design changes that you want to put into your next build.  I can just about guarantee you that if you build one and you get the banging on hot metal addiction, you will build several forges within a few years.

As for the heat to the outside of the shell - obviously around the openings it gets very hot.  For the main part of the body mine is too hot to touch after a few minutes, but not hot enough to burn the original paint off even after several hours of use.

[Mikey98118]

Tony,

The guys are giving you a lot of good advice.

Mine is to hold your horses and do a little more research before you jump in and start building. No amount of questions and answers will set you up with all you need to know unless you plan to spend a couple of years asking them. You can buy books on the subject too, and they will help you ask the right questions in the first place. Try looking up gas burners or gas forges on Amazon.com in their book section.

If you don't have a very good idea what you want to do with a forge, I would like to suggest to either deliberately start small, like with  a knife making forge, or build a "forge cart" on which you can set up various insulated brick forge shapes, while making up your mind what you really want to work with. The advantage to these polar opposite pieces of heating equipment is that they both will get used even after you decide to build a particular forge for your own passions. The forge cart is also a usefull surface for doing welding, brazing, etc.

For general gas forge shapes, you should at least investigate oval forges, before making a decision. Don't forget to include a kiln shelf floor in your forge, because all the insulating materials and thin refractory coatings being recommended to you won't take a beating or stand up to flux attack, and hard brick becomes a heat sink. While two inches of ceramic fiber is a good standard thickness, you want to install it as separate 1" blanket layers to avoid rippling in the finish surface. Ceramic fiber products de-laminate so easily that they need to be rigidized anyway.

Then, of course we come to burners...:-)

As to buy versus build, if you're running a business already, buy a good forge. Otherwise, build; it isn't just about saving money. When you build a tool you learn a lot about it.

[GottMitUns]

I have a 3 burner whisper forge that is the least used forge in my shop.  it works great but entry and exit are a pain for the stuff I work on.  My main home made forge is on its 3 generation and less of a pain for entry and exit for the stuff I work on.  notice it always the "stuff I work on" that is the problem.  If you have a welding and machine shop available to you I suggest you build your own. Start with a small 1 burner and learn from there.  I have 1 store bought and 4 homemade in my shop  and sometimes the "stuff I work on" still wont fit. 

 

Russell 

[Frosty]

I have to go along with Mike with only a slight difference in terminology. What he's describing as a "cart forge" we  more commonly call a "brick pile forge". It's basically a refractory table top you can arrange bricks on to make whatever size or shape forge you need. This is the basis for my main shop forge with a few refinements. In the first couple years after the internet went public I haunted the ABANA email list, "theforge" list and hooked up with lots of smart people. One was Ralph Sproul and we started brainstorming improved brick pile forges.

Both are the same in principle and only slightly different in execution. I'll NEVER use a scissor jack for something like this again, I just had a pile available so that's what I used. Ralph used a trailer jack and it's a MUCH better component. The basic device is just a refractory table with a refractory lid on a jack. This lets a guy lift the lid and rearrange the partition walls as needed. I use light firebrick for partition walls and they are the most expensive consumable involved. A good kiln wash really lengthens the life of the floor and I use split 3,000f heavy use fire brick.

The first pic is mine, the second is Ralph's.

About the burners, mine are "Ts" and Ralph's are "sidearms". I don't know how Mike and I missed each other back then but. . .

Frosty The Lucky.

[Mikey98118]

Mine was built more as a movable hot-work surface where small welding and brazing projects could be done in a garage or off-site, but one of the abilities it has is to be used as a base for brick forges. It has UK style double gas outlets controlled by ball valves, twenty-five feet of 1/4" fuel line stripped from a torch hose, steel wheels, and a bottom shelf to store the five-gallon propane cylinder and a water tank; it also has a 3000 degree kiln shelf top supported by insulated fire brick over a layer of calcium silicate board, which "floats" on a thick layer of Perlite. The table top is 6" thick in all, and super insulated. There is a built in torch portal of 3000 degree castable refractory that can hold up to a 1" pipe burner. The whole thing could easily be lifted onto my truck bed as it doesn't weigh over thirty pounds stripped down, and all the "stuff" it carries can then be installed with it in place. The cart also features a built in variable height swinging insulated lid, so the forge can easily be used with brick for heating large scrolls and circular designs. That is the beauty of a configurable (brick pile) forge; endless accessories can be added to it for convenient heating of darn near anything, and it can be wheeled over to a corner of the shop afterward. The cart has been used for night classes at some working historical site in Maryland since 2006 along with all the other gas burner equipment that we demonstrated at the ABANA Conference in Kentucky that year. I now have a heavy duty hard fire brick work table, but then welding and brazing are more important aspects of equipment R & D than forging is; I do a lot more of that than wrought iron these days, being an old guy and all :-)

Frosty,

The way we missed connections was that you and Ron started out a few years ahead of me. I originally was gearing up to do wrought iron, after the shipyards in Seattle dried up and blew away, but health problems cancelled all that and left me with a lot of time for research. Originally, I started designing burners that would run completely clean in a gas forge, hoping to salvage some part of my plans, but never could recoup enough health for it, and drifted into writing instead. I imagine you felt just as stubborn after your accident, and Ron did after his long bout with pneumonia, but all three of us learned that we got old sometime while we weren't looking...bet ya every generation learns the same lesson, while "going down kicking and screaming" about it, yes?

Mikey

[Mikey98118]

What I like best about this group is the fresh ideas it inspires. This summer I will have to build another brick pile forge (in the heavy table this time), and install a fan-blown ribbon burner in it. Speaking of fresh ideas, its time to point out some advantages of oval forges over tube forges; they are built to provide additional width inside, but can be run with interior baffles to save gas when heating narrow stock. Yet oval forges are better than square forges because, like tube forges they will naturally shed heat from their bottom side as well as the top  side, so that there is reduced heat transfer to a table top.

So, why should someone claiming to have designed a powerful new kind of burner be interested in ribbon burners? Because I don't believe in an "ultimate" burner design, and don't even want there to be such a thing (Viva variety). At least one manufacturer claims interior equipment temps of 2700 degrees, and several sources claim excellent "hang time" for combustion gas,  along with low noise levels. Anyone primarily interested in equipment design, and claiming to have an open mind, should be willing to investigate such claims, whether doing so is personally convenient or not.

[Mikey98118]

 

tony,

It seems clear that the outside chamber and air feed system (fan, etc.) for a ribbon burner will require a fair amount of space and a rigid support structure, so you might as well build a small table for it to sit on. what kind of forge do you place on the table? brick pile or square seem the practical choices.

[WELD]

wow thanks, these are all some good points and thats why i ask now, because i I would like to get the design as close to what i want the first time around if possible.

I have a pretty good idea of what i will be using it for and time is precious and if i can eliminate the building several forges in a few years part i would like to do that. What I have in mind is a smaller ribbon style burner with about a 10-12" diameter(possibly more oval than round) chamber with a flat surface towards the bottom with good amount of insulation surrounding it all. 

I really like the brick table idea for figuring out a size i know which suits me best. And now I am thinking that Instead of building a one size forge or even a dedicated table to put the bricks on, maybe If i make a rigid/adjustable arm coming off my wall that will hold the burner and just use my workbench to stack bricks right on it would save some time and space. And at the least get me hammering sooner than later. 

 

 

 

[VaughnT]

Probably one of the best overall forge designs I've yet come across.  You can see that there's plenty of room in the chamber for a large 6" scroll, or a big stack of plates bound to become a damascus billet.  2" of blanket insulation with a skim coat of refractory cement.  The hard brick bottom even has good insulation underneath it.    The pass through is a good size, but still easily blocked off, and the front door makes getting your larger pieces in and out a breeze.

 

 

I keep coming back to this photo because I like the simplicity of the outer shell and how it illustrates just what's possible when you clear your tunnel vision.  Too many people automatically jump to using a pipe or cylinder because that's all they see on the internet.  They never stop to think just how much you can do with some sheet metal and self-taping screws!  When I make my next forge, it will be modeled off this one.

[WELD]

That's kind of what i was getting at for a shape, not sure what that would be called other than more oval than round. I wanted my height and width to be between 10 and 12" with that oval shape so theres no corners to disrupt circulating heat. It seems like a pretty efficient design. 

[ironwolfforgeca]

Frosty & Mike Thanks for the look @ you're brick pile forges !!!

I have built the bottom parts a year back or so then parked that forge project need a cart next

& started another P forge we use now LOL that is setting on the floor piece of the brick pile forge

& have a third P forge shell welded up 

but work keeps getting in the way LOL to finish those projects & I keep starting new projects / tools & eqt

[78sharpshooter]

Ribbon burner is the way to go. Just don't get too powerful of a blower otherwise you'll waste propane trying to get away from an overly oxidizing flame.

[Mikey98118]

Thanks, Sharpshooter,

I do love hearing specific details on a new (to me) subject.

[WayneCoeArtistBlacksmith]

With a Ribbon burner you should have a gate valve from the blower to control air volume and a needle valve on the gas to control gas volume.  Then you adjust for the reducing flame for fluxless welding and normalizing for general forging.  The blower needs to be a blower that will develop pressure.  Squirrel cage fans do not generally develop pressure.  www.kayneandson.com sells a smaller blower for about $125.00 that will work well. 

[Frosty]

Cool, I get busy for a day and look how far this has come! The half cylinder, quanset, mailbox, ? shape forges are about as close to a cylindrical forge as I personally want to go. I find a flat floor highly desirable while a cylinder or vaulted arch makes for much better flame flow.

Tristan, one of our Alaskan guys has mounted burners in the bottom of his forge aimed up and over at one side. This works WAY better than it sounds and no, crud doesn't fall in and plug the burner up. It also prevents heat from chimneying out the burners so he plumbs them with rubber rather than go through the conversion I do.

Ribbon burners are gun burners and adjusting the output or atmosphere is the same, adjust fuel and you have to adjust the air. This is the norm for any forced air burner though it's good to say it now and then so folk don't get to thinking a new burner type eliminates the rules of combustion.

I don't think Mike or I came up with anything we didn't learn in shop class in jr. high. The welding area always had a hot table or bench that was just a table covered with fire brick and a pile of brick on the shelf underneath. Almost every minute of every class had a student or two welding, brazing and or cutting on the table. As a matter of safety and courtesy you were EXPECTED to build a wall or box from brick around projects you were going to cut with a torch. If you didn't spatter would spray a long ways off the table and the kid might find himself doing classwork for a day or so.

So, anyhow, we grew up in a time where boys took shop while girls took home ecc and every boy took metal shop. Well almost, the glue sniffers took "crafts" or "Paint" where low yield solvents were common. Anyway, the concept of the brick pile on a hot table was every day in metal shop class so it's more than easy to stick a burner in the pile and do some forging.

Frosty The Lucky.

[Mikey98118]

Frosty,

I only took one metal shop class, and the only ting offered was sheet metal. This wasn't from lack of interest, and I did get to work summers, weekends, and holidays in my father's ornamental iron works from age twelve (mostly loved it), meeting old timer weldors and construction boomers; picking up a lot of general knowledge from them and from dad. Outside of sheet metal shop in junior high, all the shop classes offered in my school system at the high school level were electronic or automotive classes. I hope shop classes have improved in southern California over the last fifty years, but somehow doubt it. Blacksmithing, brazing, and welding would be excellent subjects for teenage boys to be exposed to. Trouble is they are expensive classes to run, as compared to baloney subjects that only cost for the light bill, and a teacher's salary. None of that hurt me, since all my education except simple math and writing skills was learned outside the school system (I learned to read before age five, along with my sister and brother; first from holding contests reading billboards and comic books, and later at the town library) Post grade school, everything I learned was in spite of school; not at it.

[Mikey98118]

Just when we all thought nobody was a bigger monomaniac than Dr. Frankenburner and his totally exhausting book on burners and heating equipment we find:  http://www.amazon.com/Digital-Temperature-Control-Blacksmith-Forge/dp/1449560105/ref=sr_1_5?s=books&ie=UTF8&qid=1450036500&sr=1-5&keywords=gas+forge

Where will it all end? Is nobody safe from these people?!?! Weren't hi/low gas switches complicated enough? Talk about "no rest for the wicked"!!!

[Dor]

I'm looking to get a gas forge, and rather than start a new thread, I'll ask in this one. I'm not sure I have the assembly means necessary to make my own forge, but if I was to buy one, does anyone know which one would be best? Was looking at the Majestic 3 burner, but I notice above everyone complaining about it. Plan was to spend about 500 dollars on a forge.

[Frosty]

Welcome aboard Dor, glad to have you. If you'll put your general location in the header you might be surprised how many of the gang live within visiting distance.

There is no such thing as the "best" forge and without at least developing proficiency and a product line you won't know enough to even make good guesses. I suggest reading the gas forge section here, this very question has been asked so many times I . . . Pull up a comfy chair, pack a lunch, the beverages of your choice and get ready to spend a few days reading and you'll have enough grounding to make a start.

Believe me unless you really like tinkering in the dark you'd much rather learn from other guy's mistakes.

Oh Mike: That's NOTHING compared to some of the splendiferously over complexstipated schemes proposed buy folk right here on Iforge! I can hardly wait till someone with more dollars than sense buys one and asks US to help make it work.

Frosty The Lucky.

[Mikey98118]

"Complexstipated"?

That deserves to be a real word. However, you know how much I love complexstpiations, so I'll try at least confusing him with some options; after all, you already gave him fair warning, Jerry.

Some commercial forges are better than others; usually becuase of the burners they come with. And although there is no ultimately perfect shape, oval forges are probably the best shape among the available choices. IMO the best commercial forge is a Chili Forge; you can Google their web site: this product also features the best NA burner on the Market; a fifth generation jet-ejector tube burner (commonly called a Mikey burner by home casting enthusiasts; you can Google those too). So, just what are oval forges? Well, they are actually rectangular forge interiors trapped in an oval body (shell). So, why not build them in a box shaped shell? Some people do just that; the problem with such a shell is that it needs to sit directly on a support structure; not just any kind of table though it has to be a refractory surface with plenty of insulation because of heat gain, or else a steel sheet thick enough not to warp from heat gain. By that point you would be better off with a brick pile forge, since it wouldn't be any more trouble to build and is the only kind of forge that can vary its size and shape. You can find more information on brick pile forges in another thread on this forum.

The point of oval exteriors is the same as that of tunnel forges (tube shaped structures); both kinds have round bottoms which invite ambient air to circulate beneath them, shedding heat gain, so that fairly short legs can separate them far enough above a supporting surface not to burn it up or warp it. You could sit the forge on a wooden or thin sheet metal work table with nothing more than a piece of cement board to protect it. But, inside the forge is a lot more available work area than you will find in a tunnel forge. Of course, there are times when you don't want to heat all that space, so internal barriers can be made with firebrick or high alumina kiln shelving backed by rigidized ceramic wool, with which to shrink that space; the beauty of such devices is that they are "add ons." You can make them at your leisure.

The next consideration is forge size; it isn't just a matter of  initial cost; the bigger the forge the more it will hold, but the bigger the forge the more it costs to heat. Most people automatically assume that "bigger is better"; an idea that has been carefully planted in our minds by advertisements all our lives, because the truth is that bigger costs more; a delicious idea from any huckster's viewpoint. Unless you have a specific use requiring a big forge, smaller is nearly always better; not least because, after you make that perfect forge you will start dreaming about while using the forge you bought or built, that first small forge will still get used quite often, but people don't want elephants as pets...

[Frosty]

But it is a real word MIke I made it up myself. Aren't ALL words made up? Lets put it in the glossary, I'll be justifiably immoralized!

It's easier to control  temperature in a bigger furnace. Every factor has it's up and down side. I usually advise new folk to NOT trying to build the perfect forge till they've been using one long enough to know what good enough is. That way they hopefully won't end up with as many unused old "perfect" forges as I have.

Frosty The Lucky.