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P Jones

New Forge Concept

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Beginner's Place seemed appropriate for this.

So I'm in the process of planning out my next forge. I'm not completely new at this game, I'm already made a small charcoal forge (which ended up failing) and a venturi gas forge (which works). All my tool and equipment before were mostly cheap tools or improvised, so now I'm slowly working at buying/making proper bladesmithing gear. The next on the chopping block is my forge. Now my other isn't bad, it's actually a pretty nice little forge, was even able to do some forge welding with it. The problem is that it isn't the most well-put together forges and internal temp isn't quite as high as I would like. I don't have anything put together yet, just some concepts drawn up on Paint. Beware, the photos are pretty high quality.

BurnerParts.pngFrontBackPlate.pngInternal.png

 

The body I'm making is from a steel tube I got from a buddy. A little overkill but its free. The rest of the dimensions are in the pictures and the burners I'm planning on making forced air this time around. I feel like I've got the main concepts down, but there are some questions I have that I can't seem to find after hours of searching.

-1 burner should be enough in this case to maintain forge welding temperatures, correct? I saw somewhere to make it one burner for every 350 cu/in, this one comes up to 340 (3" radius & 12 long chamber)(the image above in incorrect with the volume, that was before I planned on trimming the size of the tube down)

-Do I need the flair at the end of the burner for a forced air burner? Is so what size would I need from a 1" pipe or does it not really matter?

-for the fuel jet I was planning on using a brass plug with a hole drilled in it. It's a 1" pipe, and I've seen people mention using a #57 drill bit for the hole. Does this sound right? If not what size should work for this size burner?

So yeah. If anyone's willing to give me some direction with this, help's always appreciated. Also if anyone sees anything wrong with the design and is willing to point it out, I'm not the kind to disregard bad advice. And before I forget, I intend on using this forge mainly for making small and large knives and to do some forge welding, therefor its important for me to make a forge than can hold forge forge welding temps.

 

 

EDIT: Yeah, so as it turns out Photobucket charges users a premium for third party hosting. Anyone looking to share their images just use cubeupload instead. 

Edited by P Jones
Fix bad photo URL

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If this is a blown burner (fan driven, not venturi) then you don't want the the injector nipple.  There is a pinned thread on blown burners (which I wrote, no applause please) that has all of the info you need on the subject, or most of it, anyway.

You need a small hole injector to create the venturi effect, plus some high pressure on the gas line.  A blown burner need volume but not pressure to run correctly, I run mine at about 1 psi through a 1/4 " needle valve.

Geoff

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Welcome aboard!  Two things jump out at me: forced air does not require a small gas orifice, and the brick on the floor isn't really necessary.  Read the pinned thread "blown burners: the care and feeding" down in the Tools and Toolmaking forum here.  Most people just dump the gas in with a 1/8" line and needle valve.  The 350 cubic inch rule and flares are for venturi burners only, although a flare won't hurt a blown burner either.

Instead of the brick use a flux resisting castable or rammable refractory over the wool.  Something like Mizzou or Cast-o-Lite. Topcoat that with an IR reflective coating like ITC-100, Plistix, or Metricote, and with enough blower you will easily melt steel, not just weld it.

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Thank you for the quick replies. Good advice and the exact kind of information I was hoping for. I checked the forum one more time to see if there was already info pinned before posting, I didn't think to check outside the Beginner's Place and the forging forums. I'll be reading over that post a few times and make adjustments to my design.

Okay, that's one thing most material I've watched/read never really mentioned about the gas orifice. I figured the burner still needed it just because it was used in the venturi burner. Honestly it was the biggest question I had.

The firebrick is meant to be used as a surface to set the metal down on while the forge is in use, or do you think that could negatively impact the performance somehow? But yeah I didn't mention it in any of the diagrams, I planned on using some sort of refractory to coat the wool, however I've never considered using some type of reflective coating, so I'll definitely take that into account here.

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What the brick does is act as a heat sink until the forge comes up to temperature.  It will take around 20 minutes to bring that up to welding heat.  Compare that to 8-10 minutes without a brick.  

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Can everyone else see the pictures then? All I get is the old “photo bucket doesn’t share” images.

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I could see them yesterday, now they're gone.

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Photos should be good now. Photobucket apparently charges for hosting images, so I had to switch to a different site.

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From what I see from your schematics I would say the the 3/4" brass nipple should work.  Just drill and tap the cap for the T-fitting to receive it.  I would also put a pin valve on before the ball valve (or after it for that matter) to give fine adjustment to the gas flow.  I would replace the 1 1/2"X 1" reducer with a 1" black pipe for a burner tube.

Doug

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On 1/26/2018 at 4:37 PM, Jeremy Blohm said:

I took Geoff's instruction and advice... works like a charm.

"Brute force and dirt simple"... Amen.

 

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We are really lucky to have such a wealth of information here. Even when someone comes up with a new way to skin the cat (the cat doesn't like any of them BTW) it is based on logic, experience and trial, which they share.

Last night, for about one minute, I was sure that I had a great idea, that no one had ever thought of, for a forge burner. After due consderation the little voice in my head said,

" Uhh, Vern, are you aware that your idea is great for making a...what do they call it....uhm beachball???no, baseball?... biscuit?..no....Bomb? Yah that's it, you freaking idiot a BOMB, that thing would blow up sure as heck."

I won't even share where I was going with it. 

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On 1/31/2018 at 12:37 AM, Vern Wimmer said:

We are really lucky to have such a wealth of information here. Even when someone comes up with a new way to skin the cat (the cat doesn't like any of them BTW) it is based on logic, experience and trial, which they share.

Last night, for about one minute, I was sure that I had a great idea, that no one had ever thought of, for a forge burner. After due consderation the little voice in my head said,

" Uhh, Vern, are you aware that your idea is great for making a...what do they call it....uhm beachball???no, baseball?... biscuit?..no....Bomb? Yah that's it, you freaking idiot a BOMB, that thing would blow up sure as heck."

I won't even share where I was going with it. 

now we want to know

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6 hours ago, Ross Vosloo said:

now we want to know

If you are really curious, pm me. I don't want to even put it on the open net.

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2 hours ago, Vern Wimmer said:

If you are really curious, pm me. I don't want to even put it on the open net.

How many PMs have you got so far?

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1 hour ago, Charles du Preez said:

How many PMs have you got so far?

Zero, thankfully. I figured I'd have to write a boiler plate with a big disclaimer

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Thanks for the info so far. Did some reading (thanks for the thread Geoff), made some adjustments, and started ordering some parts. All of them are in, put together the burner since that's really just a matter of screwing in the pipe and testing the lines. Did a test burn and...

 

 

IMG0747.jpg

 

 

There's a gate valve on the other end of the hose just off the blower that isn't in the picture and a ball valve on the gas line. That one's visible, but the handle is flush with the line towards the ground. It took awhile to figure out the fuel/air mixture needed, and I gotta say I'm surprised at just how little air is needed to get the flame sustained. I thought it would be near full open, but 3 psi on the tank doesn't need much. I'll probably play around with it more tomorrow and paint the pipe black, but for now it's nice to know it works.

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