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Gas Forge Design Progress - Critique please!


Jeff Tervo

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I’m new to blacksmithing, well I WANT to be new. I haven’t started yet lol.

 

Anyway, I started designing what I’d like my forge to look like this past weekend. It isn’t finished as of yet, I plan to hinge the end doors so they open to the side and I will add a door to the side to hinge down flat.

 

What advice can I receive from the pros out there? Should I tweak anything? Also, what would be the best burner to use that requires the least amount of specialized fabrication?

6E323F18-6CF5-4C56-9634-CA43B85910B0.jpeg

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Welcome aboard Jeff, glad to have you. You can be a new blacksmith. . .  I give you leave. :rolleyes: 

Have you checked out the Illustrated T burner instructions in the gas burner Section? That's as easy as I could think to make the things though I keep finding tweaks every time I build one.

I don't like that much threaded pipe on top of burners it has too much leverage and tends to knock the jets out of alignment. I use 1/4" copper tubing for the final fuel line between the burners and the manifold.  In your drawing the "manifold" would be right after the T in the fuel line. I put the manifold off to the side of the forge and lower to keep it out of the heat. I mount the individual 1/4 turn valves on the manifold. Copper tubing is flexible and doesn't have enough strength to  bump the burners or jets out of position. It'll take more heat than it'll get even mounted over a door so it's not a fire hazard. 

I put the main 1/4 turn fuel valve directly after the regulator on the tank. In that position you don't have to reach through a fire to shut the fuel off fast. Being able to shut the fuel off FAST in an emergency is why I put a 14 turn ball valve on the main line the tank valve can take several seconds to shut off even if you're pee your pants scared. Seconds can count a LOT where an uncontrolled fire and compressed flammable gas are combined. Yes?

Your concept drawing looks good, could use some tweaks and dimensional details to get right but all in all it appears to be a nice working forge. It's a BIG boy though, probably bigger than you'll use. If it isn't crazy too big for what you intend to do there's something disturbingly wrong with you. (JOKING! Everybody overbuilds equipment, even when we've been doing this long enough to know better.)

Frosty The Lucky.

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Pretty much what frosty said.  We need to know the dimensions to give advixe on burner size.  His t burner is the easiest to make.  The one thing i would suggest is to rotate both t's by 90 degrees so that the air intakes dont line up and they arwnt "fighting" each other for the same airspace

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Jeff,

What Frosty is implying, "This will not be your forever Forge". Everyone has a "First" Forge, very few have their "Last" Forge, most have their "Current" Forge. The process is called 'Learning'. Learning what/how much you really need and what/how much you don't really need. You will end up with a number of Forges, One you will use for this job, One you will use for that job. Sometimes you will just grab a Rosebud and get a job done. Coal, Coke, Charcoal, Propane, Natural Gas, Mapp Gas, Personal Gas, all have their place. The only Purrfect is when you are not cooking your cat, You let the Cat out of the Bag.

Neil

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1 hour ago, Frosty said:

Welcome aboard Jeff, glad to have you. You can be a new blacksmith. . .  I give you leave. :rolleyes: 

Have you checked out the Illustrated T burner instructions in the gas burner Section? That's as easy as I could think to make the things though I keep finding tweaks every time I build one.

I don't like that much threaded pipe on top of burners it has too much leverage and tends to knock the jets out of alignment. I use 1/4" copper tubing for the final fuel line between the burners and the manifold.  In your drawing the "manifold" would be right after the T in the fuel line. I put the manifold off to the side of the forge and lower to keep it out of the heat. I mount the individual 1/4 turn valves on the manifold. Copper tubing is flexible and doesn't have enough strength to  bump the burners or jets out of position. It'll take more heat than it'll get even mounted over a door so it's not a fire hazard. 

I put the main 1/4 turn fuel valve directly after the regulator on the tank. In that position you don't have to reach through a fire to shut the fuel off fast. Being able to shut the fuel off FAST in an emergency is why I put a 14 turn ball valve on the main line the tank valve can take several seconds to shut off even if you're pee your pants scared. Seconds can count a LOT where an uncontrolled fire and compressed flammable gas are combined. Yes?

Your concept drawing looks good, could use some tweaks and dimensional details to get right but all in all it appears to be a nice working forge. It's a BIG boy though, probably bigger than you'll use. If it isn't crazy too big for what you intend to do there's something disturbingly wrong with you. (JOKING! Everybody overbuilds equipment, even when we've been doing this long enough to know better.)

Frosty The Lucky.

Well let me start off by saying that I feel honored to have Frosty, the man himself, comment on my thread the first day here! After the countless hours of research I’ve been doing these past few weeks, I’ve seen your name and your burners a LOT! Lol.

 

So here is what I gathered from your reply. Correct me if I’m wrong.

 

1. Eliminate the excess piping before the T’s (where the mig tip goes) and mount them as well as the shutoff valves off to the side and down low. With the main shutoff right after the pressure reg?

 

2. Provide dimensions for a preliminary review.

 

3. Design it smaller :( lol.

 

If I missed anything, let me know. Can you provide some photos just so I am clear as to what you’re trying to tell me?

 

Thanks again!

 

edit: yes I have viewed the T burner instructions. I actually used them for my design, which I’m sure you noticed lol.

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Stop bowing Jeff, I'm just another guy who likes to play with fire and hit things with hammers. :rolleyes:

What I do and what you end up doing is just that what we do or did. Just cutting way back on the threaded pipe eliminates the main concerns. Just because I like copper tubing doesn't make it THE way to go. Following is my variable volume shop forge release .1 as an example of my gas supply method and of WAY more forge than necessary. The scissor jack lifts the lid and I can arrange the walls as needed to make the forge chamber. Each burner heats approx 350 cu". In the years since I built this I've only ever used all 4 burners at once maybe two times when there were a bunch of guys working. I've never needed to heat anything that wouldn't fit under two.

5a1e6bae799d1_PhotoMoto0035.jpg.d822bb1daca27c160d163b67c3814cd5.jpg

By dimensions you need to calculate the flame contact volume of the forge to provide enough burners to reach the temperatures you need. Remember it's easy to turn the gas down, turning it above maximum . . . not so. If those are 3/4" burners in a balanced chamber that'd represent 600-700 cu". forge. Having one wall wide open spilling heat, would make it more of a brazing hearth than a proper forge.

Frosty The Lucky.

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17 hours ago, Frosty said:

Stop bowing Jeff, I'm just another guy who likes to play with fire and hit things with hammers. :rolleyes:

What I do and what you end up doing is just that what we do or did. Just cutting way back on the threaded pipe eliminates the main concerns. Just because I like copper tubing doesn't make it THE way to go. Following is my variable volume shop forge release .1 as an example of my gas supply method and of WAY more forge than necessary. The scissor jack lifts the lid and I can arrange the walls as needed to make the forge chamber. Each burner heats approx 350 cu". In the years since I built this I've only ever used all 4 burners at once maybe two times when there were a bunch of guys working. I've never needed to heat anything that wouldn't fit under two.

5a1e6bae799d1_PhotoMoto0035.jpg.d822bb1daca27c160d163b67c3814cd5.jpg

By dimensions you need to calculate the flame contact volume of the forge to provide enough burners to reach the temperatures you need. Remember it's easy to turn the gas down, turning it above maximum . . . not so. If those are 3/4" burners in a balanced chamber that'd represent 600-700 cu". forge. Having one wall wide open spilling heat, would make it more of a brazing hearth than a proper forge.

Frosty The Lucky.

I swear I replied this morning. Apparently not haha.

 

I’ll throw some dimensions on it sometime this week and figure out the cu” of the internal surfaces. Would you say to not go any larger than 700 cu” with two 3/4” burners?

 

Also, this design is still in process. I plan to add a third door to the side (the gaping hole in the side) and have it hinge downwards.

13 hours ago, WayneCoeArtistBlacksmith said:

Check out the Build a Gas Forge attachment on the Forge Supplies page of my web site.

You can get the url and e-mail addy on my Profiles page.

Let me know if I can help you.

Wayne

Will do! Thanks!

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Jeff: Iforge is a world spanning forum with 45,000+ members, last I heard, a lot don't have high speed connections some are dial up. So please don't quote posts you're replying to unless it's necessary to make a point, ask a question, etc. You can delete unnecessary text and pictures  or if you highlight what you need, a tag will pop up saying "quote this" click on it and it'll be added in the text window. I'm on a broad band connection and bandwidth can slow things down, I can't imagine trying to download a few meg on my original 96kb connection! :o It was a hot rod computer but dial up could slow even a 386 way down. 

Okay, back on topic. Whatever you do don't get in a hurry, rushing only makes our mistakes permanent more quickly. If you do some reading in the "Forges 101" and "Burners 101" threads you'll get a handle on how these things work, the jargon, characters in play. No need to study it but the more handle you get on the subject the smoother the learning curve gets.

One last piece of what I think is important advice. If you pick a set of plans do NOT mix and match features from others. That is for after you get the hang of the things.

Frosty The Lucky.

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Be my guest Mike. Gas brazing hearths are common British tools or maybe European. I ran across them back in the make a working burner days right after the interwebs went public and I could go shopping. If you look at chip forges you'll run across brazing hearths my the same companies.

If I take the partition walls out of my variable volume shop forge it becomes a 4 burner brazing hearth you could heat a square 2' on a side of a car hood in. Not sure why but you could.

Thinking about it I need a T shirt that says something like, "Overbuilt it AGAIN!" or, "Overbuilt that one didn't you?" something like that.

Frosty The Lucky.

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You're basically building a Majestic forge.  After running one for awhile, I'd go a completely different direction.

 

The side door sounds like a good idea, but I've found it more of a pain than its worth.  The gap lets a ton of heat out, the door warps from the heat, and scale/grime gets down in the hinge gap and prevents it closing back up when you need it closed.

Does it allow you to get larger pieces in there?  No, not really.  Think about it like this:  your chamber is only so wide.  as such, you're only going to be able to fit a portion of the larger piece in there.  that means the door has to remain open.  and that means you're burning a ton of fuel to basically turn your forge into a pair of torches.

You'd be much better off to make the chamber an inch or so shorter and an inch or so wider.  Then rely on the short side being hinged so you can open it up, slide a wide piece in, and then close the door behind it.

I almost never use my side door simply because it's such a pain to manage everything..... only to have to leave it open while I'm forging whatever just heated up.

Insulation is your friend.  While fire bricks sound like a great idea, hard bricks don't insulate well at all so you end up burning a ton of fuel.  Soft insulation like Kaowool, covered in refractory cement and an IR reflective paint....  now that will get you cooking and cut down on how much fuel you're burning.

2" of insulation is good.  If you go with 3" of soft insulation, you're upping the cost, but I don't know if you're getting a lot of bang for the extra buck.  Maybe.  It certainly won't hurt performance.

The forge chamber should be sized such that you can fit bent pieces in there to heat.  A lot of people say they're only interested in making blades, but everybody branches out here and there.  Being able to heat a 6" scroll for your Mother's Day present.... that's a win!

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  • 2 months later...

Well, I made some changes finally. Life got busy and this was put on the back burner.

@Frosty, sorry for replying the way that I was. Every forum I am involved in has different rules and that is one I will remember here.

 

I want a 2 burner forge because I don't want to be AS limited as I would be with a single burner. I want to forge weld eventually and I think I will be working with larger pieces in the future when I get that far. @VaughnT you're right, I don't want to focus on one thing (knives), I want to learn how to do everything from knives to scrolling to architectural pieces. I scrapped the side door idea for now. If I get the urge, or need, for something like that in the future, I'll figure something out. But for getting started, I don't need it. It wasn't going to be a wide open wall, as mentioned earlier in the thread, I just wasn't finished with my initial design when I made the rendering.

 

I have attached a (very rough draft) PDF of a 2D drawing of what I changed the size to. Frosty, you mentioned that those burners heat ~350 cubic inches each. This revision has 729 cubic inches. How far apart should I place the two burners? I've heard 7" O.C. apart from each other, but this design doesn't allow that amount of spacing. It has 2" of kaowool insulation around the perimeter and 3 K-28 bricks.

FORGE DRAWING.pdf

I just realized I had a brain fart in the previous post. Of course there’s room for two burners on this. I was thinking I needed 14 inches for the burners lol. Disregard that burner placement question.

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Don't sweat it Jeff,  everybody has to get used to a new neighborhood, it's not a rule it's more of a consideration thing. Iforge is mostly self governing and members started asking folk to trim replies when folk on slow dial up started complaining. Some were so slow they couldn't get more than one med res pic per post. Anyway, folk just started asking folks to trim extra stuff.

You are going to fit right in here, we all have forges collecting dust that were just too darned big :huh: and that's nothing compared to my variable geometry forge, now THAT one's too big.

What kind of heat spread do you want? If you use two, 3/4" burners they'll get it to welding heat but you'll likely have two HOT spots or a larger HOT zone with temps tapering down as the distance increases. Not a lot maybe but with experience you'll start to notice. That isn't necessarily a bad thing though, I like having a hot spot it makes it easier to isolate temperature in pieces, say riveting or tweaking a spot without effecting the surrounding area  as much.

It's not so good for heat treating though, for that you want even temp in the forge chamber. If you want even temp then I'd suggest four, 1/2" burners in a pattern that spreads them evenly. I'd have to think and do some sketching to speculate about measurements. Maybe another time. The spacing you proposed is good to start with, you have the idea.

Another thing to think about is NOT trying to build a long term forge to start with, I think most all of us have made that mistake. It's sheer luck if a person actually gets THE forge in the first couple tries. Brick pile forges are good for experimenting with size and shape without committing to a permanent structure right off but bricks have their downside. Personally I think it's cheaper to build permanent than try using a brick pile long enough to properly evaluate one. However, you're using K-26 so my down checks for long term brick pile forges are no longer part of the equation.

If you don't like the K-26 forge you build you can just take it apart,  rearrange it and try again. Just do NOT cement them together! The cement isn't necessary and being able to move things is a BIG plus.

I don't think you're forge plans are bad I just don't know how likely it is they're be long term good for you.. I've been building the things for years and the last two I built are fails, though the NARB forge is close. My next NARB forge will I think be much better and that will be a one feature prototype. I have to force myself to NOT put a whole bunch of Oooh!! super duper ideas I have into each forge I build. Of course it keeps the space under my benches and shelves from becoming cluttered with stuff I use.

Frosty The Lucky.

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What kind of spread do I want? I’m not sure I understand what that means. I was thinking I’d want an even heat throughout? That’s why I changed the dimensions to be as close to 350 cubic inches per burner. Or is that not beneficial to have an even heat with both burners running?

Hot spots: they’re bad right? They can cause burns in the steel if the material is left in the same spot for too long, right? How do I get away from having hot spots?

Whats an NARB forge? Lol. Sorry I’m new to all of this haha.

I’m a design engineer by day, so I think I’m using that and over engineering/using too much theory and math to make it as efficient as I THINK it will be lol. Why reinvent the wheel, right?

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13 hours ago, Jeff Tervo said:

I want a 2 burner forge because I don't want to be AS limited as I would be with a single burner. I want to forge weld eventually and I think I will be working with larger pieces in the future when I get that far. @VaughnT you're right, I don't want to focus on one thing (knives), I want to learn how to do everything from knives to scrolling to architectural pieces. I scrapped the side door idea for now. If I get the urge, or need, for something like that in the future, I'll figure something out. But for getting started, I don't need it. It wasn't going to be a wide open wall, as mentioned earlier in the thread, I just wasn't finished with my initial design when I made the rendering.

Focus on what you will be doing the most of right now.  Wanting to do XYZ in the future is great, but you can burn up a lot of fuel in the mean time if your forge is over size for what you'e making until you get to the point  you can do XYZ.

Ribbon Burners are way more efficient than naturally-aspirated burners, but they also require electricity and a fan - both of which add to the cost/aggravation for a lot of people.

The side door, in my estimation, is just a bad idea all the way around because it opens too much, allowing out too much heat, without giving you a ton of benefit.  You already have a hole on the short side, so if any side is going to be hinged to open, that's the side that makes the most sense.  This allows you to keep the most insulation forming a solid wall.

 

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Heres my advice to you.  You are overthinking and over engineering this entire thing.  You are a beginner that doesnt know how blacksmithing works and have no idea what you will need or what you will want to do.

Follow a set design for a simple forge so you can get to blacksmithing and figure out the answers to what you want to do and get an idea of what you will need to do it.  

You can find easy forge plans on waynes website google waynecoe artist blacksmith

He also sells everything you will need to build it.  For a burner look at the frosty t burner instructions pinned on this site.

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Building a large forge at the outset of your smithing is rather like buying a 15 passenger van as your first car because you expect to get married and have a large family in a decade or two...Forges, like vehicles, should be chosen to suit your needs *now*, fully expecting that you will buy/build others as those needs change.

Even coal forges are like this;  I'm about due to build another one to meet my current needs, it will be the 4th? forge body for the same firepit and designed for easier breakdown and travelling. Since I'm over 60 I'm starting to avoid heavy awkward loads as much as I can...

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