Kako95

Help and tips requested

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Hey everyone! Newcomer to blacksmithin, just got done building up my forge. Just some firebricks stacked and a Devil's Forge propane burner. (see video attached)

One thing that i noticed is that it seems that my burner tip seems to get Red Hot, kinda looks like it's burning too early in the flare and im not sure about the flame noise (Never seen a proper forge in my life, no one forges in the island where i live)
I've spent about an hour fiddling with different pressures and air intakes, to no avail (maybe the tip was so hot that it was messing with the tuning)

I was wondering what tips do you have and if you think the tip getting hot  and the noise. is normal

Thank you

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It's burning rich and under too much pressure in the video. Try opening the choke more and turning the psi down. Devil forge burners are pretty good burners you may have it too far into the brick. Pull it back till only about 1/4" is in the brick. 

You'll have a much faster heating economical forge if you use insulating fire brick rather than hard fire brick. Morgan Thermal Ceramics, K 26 IFB take the heat and rapid thermal cycle speeds our forges generate well. 

Hard fire brick has about the same insulating properties as an equal thickness of limestone, R1= 1 foot of limestone, that's the basis of R value. Anyway, it takes a lot of fuel and considerable time to bring to forging temperature and radiates a lot of heat right through the brick.

There's nothing wrong with a brick pile forge, they work well it's just new refractories are a SWEET improvement over the ones available just a few years ago.

Frosty The Lucky.

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As always, quick and helpful community, honestly one of the best forums I've been part of. 

Anyway, at the time of recording I was using 0.1 mpa, which I already thought it was low, as I've seen people being successful being around 0.15mpa

I can't really remember but I believe that when I lowered the pressure I would get orange flames shooting out the entrance and the choke would not prevent that. My assumption was that there wasn't enough venturi effect to draw air in. I'll do more testing tomorrow. 

Also, do you think I'll have any problems with the flare getting red hot? I'd think that that would just cause the flame to burn earlier, don't know if it causes any major long term problems. 

Do you recommend closing the back? 

I'm actually impressed with the insulation of the bricks, I could get a 1cm square bar into forging temperature in less than 4 minutes, I don't think they'll be a problem, for now at least. Could also be because, as you said, I was running too rich. 

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So, I had to look up what an mpa is, not gonna lie. If my conversion-fu is working that works out to about 14 psi. 

I am just as new as you are to all this, but, for what it's worth my forge runs happiest at 4 or 5 psi (.027-.033 mpa, again assuming correct conversion) and that's on 2 1/2" burners. 

Long story short I suspect your psi may be a touch high, but if I were you I'd wait on one of the old salts here to confirm or deny, please dont change anything just based on my word alone. 

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15 hours ago, St.patty said:

 

Yeah, it's the measurement used o their gauge. 

But I can see how that makes some sense as my forge is on the smaller size. I guess I got a bit scared of going lower pressure as there were huge orange flames shooting out, guess I panicked a bit and didn't adjust my choke. Again, more testing needed, just wanted to see if there would be a merciful God who would enlighten me. 

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Yeah, from the scale of it I think our forges may be very similar in cubic inches. Mine is simply cylindrical rather than a rectangle, and has 2 small burners vice your 1 larger one. 

At any rate, lots of wicked smart people here, I'm sure with some help from these guys you'll have it running like a top in no time. Good luck with (the last 10% of) your build!

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Did you try my suggestions?: Pull the burner OUT till only maybe 5 - 7mm of the flare is inside the brick. Open the choke and turn down the pressure. (I'll link myself a conversion chart so we can talk the same pressure numbers)

If you would like a little grounding in how burners work and what I'm talking about I suggest you spend a little time reading up on the subject. The most current discussions can be found in the Iforge section, "Burners 101" and similarly, regarding forge: construction, materials and performance can be found in "Forges 101."

If making the adjustments I suggest don't help give me a shout. Once you make the broad changes I suggest, only make ONE at a time, then test and take notes. If you start changing more than one thing at a time you can't tell what did what. I'm suggesting 3 change because I've been messing with the things for a couple few decades.

Don't worry, we'll get you working right in no time.

Frosty The Lucky.

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4 hours ago, Kako95 said:

I guess I got a bit scared of going lower pressure as there were huge orange flames shooting out, guess I panicked a bit and didn't adjust my choke. Again, more testing needed, just wanted to see if there would be a merciful God who would enlighten me. 

The only difference between you guys and us "old salts" is we had our moments of panic decades back. All of us go through similar learning curves :rolleyes:

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Ain't that the truth Mike. How long did it take for Kathy to stop complaining about you smelling like burned hair? I got over that phase before I met Deb. What is it with girls and aroma? :huh:

Frosty The Lucky.

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Actually. she was very good about that. On the other hand, she would through out all my work clothes after every Alaska contract ($$$); said they smelt of fish!

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11 hours ago, Frosty said:

Did you try my suggestions?:

I do have some understanding of the science behind it, as I've done my research to build a burner of my own. Couldn't manage mostly due to the lack of the right materials. I like doing my homework before doing anything to make sure I have the best chances of success, I obviously lack the experience tho. 

Thanks a lot for the help, I'll try all of the above later today and give you some feedback, I'm confident it'll work. 

Also, as I said, the forge I have I think will suffice for now, as I gain more experience and love for the trade I'll obviously upgrade. Just didn't want to spend too too much on entry level. 

Again, Thanks a lot and fingers crossed

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Made the changes, this is what I have, what do you think? Tip still seems to get red hot

On 2/28/2019 at 9:48 PM, Frosty said:

Did you try my suggestions?: Pull the burner OUT till only maybe 5 - 7mm of the flare is inside the brick. Open the choke and turn down the pressure. (I'll link myself a conversion chart so we can talk the same pressure number

 

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The flame appears to be closer to neutral and is shorter. A picture of the choke and a walk to an upside down gauge wasn't helpful. The problem with videos is not being able to take a long look or zoom in to see details. 

How far did you back the burner out of the forge? How tight does it fit the hole in the brick? It needs a little space between the flare and forge liner so it can induce a LITTLE additional air. This cools the flare and burns the small amount of unburnt propane in the outer flame sheath. However, it's not uncommon for the outlet end of propane burners to get red hot. 

Please take still pics, they provide better information than videos. I can see from the shape and color of the flame you opened the choke and turned down the pressure. A still pic of where the burner enters the forge might be helpful. 

Seriously it's looking a lot better, have you heated steel in it now? What do you think?

Frosty The Lucky.

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That gauge, if it's accurate and my chart is correct (I'm using the same one), converts to 5.8 psi.  Here's a little chart I hope you find useful.  It converts the MPa to psi.  Where the numbers are correspond with the numbers on the dial.  Where there are just dashes, corresponds with the lines between the numbers.  Basically, the last image in the video, of the gauge, shows that you're at about 5.8 psi:

MPa - psi 
 
0.0 -  0.0
    -  2.9
    -  5.8
    -  8.7
    - 11.6
0.1 - 14.5
    - 17.4
    - 20.3
    - 23.2
    - 26.1
0.2 - 29.0
    - 31.9
    - 34.8
    - 37.7
    - 40.6
0.3 - 43.5
    - 46.4
    - 49.3
    - 52.2
    - 55.1
0.4 - 58.0
    - 60.9
    - 63.8
    - 66.7
    - 69.6
0.5 - 72.5
    - 75.4
    - 78.3
    - 81.2
    - 84.1
0.6 - 87.0

 

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On 3/1/2019 at 1:31 PM, Frosty said:

The flame appears to be closer to neutral and is shorter. A picture of the choke and a walk to an upside down gauge wasn't helpful. The problem with videos is not being able to take a long look or zoom in to see details. 

You're absolutely right, but I wanted to show how the flame was doing and thought 'since I'm here and filming, might as well show the rest.' will take pictures tomorrow. 

The burner isn't as far back as you recommended, need to so some changes to the rig I setup to hold the burner, but I was just too excited to do that today lol

The hole in the brick is 55mm wide, which is huge, I know, but I was planning on doing something different before I bought this burner, gonna drill another brick with the appropriate size, just not looking forward to almost an hour of drilling to get through that thick SOB. To counter that for now, I just drilled a hole on a sheet of stainless still that rests over the hole and is kinda snug to the burner. Obviously not air tight so some air does pass through. I did notice that the flare would not get red where it protrudes the brick so I see what you mean when you say to pull it back. 

Again, going to take detailed pictures tomorrow. 

Yes I did, I managed to get the steel to quenching temperature (magnet check) and tried my hand at one of those leaf Keychain things that alec steele reccomends for practice. Obviously didn't come out as expected but it was a huge and great learning experience. Not too shabby considering it's my first time swinging at steel. 

 

Thank you all for the great help, especially you Frosty, I've noticed you're a dear member of this community. 

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You're welcome Kako, It's a pleasure to help, especially folk listen give suggestions a try and come back with better (more advanced) questions. The new video of your burner put a big smile on my face. 

What don't you like about the leaf? It looks darned good to me. Sure it needs a good vigorous wire brushing to clean the scale but that's a minor thing. Nice leaf, well done.

For veins you can gently strike with an edge of your hammer or make a veining tool. I blunted then rounded the edge of an old cold chisel and incise veins in leaves. Leaves come in thousands of shapes and make terrific learning projects. What you make from a leaf is much less important than making the leaf. Yes?

Frosty The Lucky.

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On 3/1/2019 at 2:27 PM, Frosty said:

 

There's a couple of errand hammer blows, which showed me I need better control, a couple of delaminations which I noticed was from when I made the shoulders, not hitting on the same spot and I couldn't get the main vein in, again, better control. Also, couldn't get the hoop done, from not tapering enough

The scales is probably from my excitement to see my work that I quenched in water because I didn't really notice any scales forming when forging, and I did brush it from time to time. I know, never quench in water, but I figured this was just a mild steel practice piece so I didn't bother

Exactly, that's why I said it was a great learning experience! 

It makes me really happy and excited to hear encouragement from experienced smiths

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That kind of burner, with that kind of choke can benefit from the choke being closed down a little more. There is a learning curve involved, because that kind of choke on a linear burner should have a "sweet spot" where it draws the maximum air and give that air the maximum swirl to mix the LPG and air together properly. I think you will find that sweet spot with an space between the tube edge and choke plate of around 1" wide. I could be wrong, but it won't take much time to find out...

If I'm right, your flame should stop pulsing and become staight blue, with no greed tinge.

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On 3/1/2019 at 1:31 PM, Frosty said:

The flame appears to be closer to neutral and is shorter. A picture of the choke and a walk to an upside down gauge wasn't helpful. The problem with videos is not being able to take a long look or zoom in to see details. 

Pulled out the burner to about 7mm in the forge now, and as promised, here's more detailed pictures 

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That's much better thank you. With the size hole you've drilled in the brick it's more like part of the forge chamber than a burner port. Everything in there is likely to get really hot. The brick is beginning to break up now so you'll need to replace it before long. When you do try drilling it a couple/few mm larger than the burner flare. This will help prevent the burner getting as hot and help refine the flame. 

I only ever look at the pressure gauge on my forges when I want a specific heat range when I light it. I never use the gauge pressure as an indication of how to tune a burner. Too many folks focus on some magic pressure to aim for. There is no "right" pressure, there are too many variables, where mine run best doesn't mean anything where your burners are concerned. This is where Youtube "experts:rolleyes:" are so very wrong.

The only reason I mentioned psi when I first posted about NARB is how stable it is at all pressures. Naturally Aspirated burners typically have a relatively narrow range of operating pressure.

Forget the propane pressure, focus on a good flame. Then maybe look at the pressure in case you need to replace something and have to set a new regulator. Otherwise it's not very important. Once the tuner is tuned all the pressure does is turn the heat up and down.

What I'm seeing in this picture is a SLIGHTLY rich flame, maybe open the choke a little more. Start playing with the choke while it's running. When you hit the sweet spot you'll know it, the forge will get HOT. Note the color of the flame it will tell you if it's oxidizing. (running lean) However until you know what that flame looks like you'll need to watch for the other indicator, what happens to steel in the fire. If steel scales IN THE FORGE, the flame is lean, close the choke SLIGHTLY and test a clean piece of steel.

How do you like it's performance now?

Frosty The Lucky.

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48 minutes ago, Frosty said:

 

That's what I was thinking after I looked at the picture, the hole is definitely huge and in messing with th whole forge. I'll get to drilling tomorrow, as that needs to be resolved asap

I noticed the flame was rich as well after the picture and did some fiddling with the tuning again. Once the forge was hot i wasn't seeing any orange flames. What's happening now is that the stainless plate is gating red hot, again, due to the huge hole, must fix that. 

I noticed that today there was a bit more scaling, like what in used to seeing in videos, so maybe I'm starting to get to the sweet spot. We'll see once I redo the hole. 

Tried my hand again at a leaf, still somethings that I don't like but hey, for a learner I don't think its too bad. (wire brushed it afterwards to look shinier)

Also, still can't get the little roll when separating from the bar, it keeps 'breaking' on me

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You're getting it. ;)

Close off the openings some, the circulation of the flame will draw ambient air into the forge. It's entirely possible to have a rich flame and scale in the forge at the same time. You can move the "thermal baffles" Mike's term for the bricks blocking the opening. The brick blocking the opening get HOT and return radiant energy while allowing exhaust gasses to escape. 

That's a much nicer leaf! #2 right? Take a look at where the leaf blade transitions into the stem. See those sharp cuts? Those are caused by setting the shoulder over a sharp edge on the anvil and are known as "Cold Shuts" or "Stress Risers." They act just like scoring glass to snap where you want. Force conducts uniformly through material until it comes to something that obstructs it.(a Stop) Sharp corners are notorious for this as are scratches in glass and ceramics. You've maybe noticed how easily a chipped coffee cup breaks? When force encounters a stop it stops the has to jump the stop to continue. The stress riser (stop) is hit from both sides by the same amount of force, virtually doubling it.

After that windy description. The cure is to set shoulders over a radiused edge. A smoothly curved change in profile allows force to conduct smoothly without undue stress on the parent stock. Make sense?

Another thought would be let the stem stay straight a little farther from the leaf so you're not bending it right ON the transition. Yes?

If you tilt the hammer slightly, low to the edge of the leaf it'll forge thinner edges for a more natural look. 

There's not a thing wrong with that leaf, it's darned attractive. Well done.

Frosty The Lucky.

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Oh, on the way home is was trying to figure out how to keep that little edge from happening, now I understand. Thing is, my anvil edges are in mint condition so I'll have to figure something out hehe

 

Thank you so much frosty, your help has been invaluable, I wouldn't have managed all of that on my own, specially with no one to help around these parts. 

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You can radius the edge of your anvil, they come from the factory with sharp edges, expecting the smith to radius them to suit jobs. Or make a hardy block with a different radius on each edge.

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You're welcome Kako, I enjoy helping, it makes me feel good.

You need a right angle disk grinder Kako! If your wife hesitates tell her it's an emergency, your anvil is eating forgings and you need to blunt it's teeth!

Gently grind a small radius in one section of one edge. Wait till you determine what radii work best for you, more than one radius is handy depending on the effect you need. New anvils come with sharp edges so the smith can radius it as s/he prefers. 

I usually set shoulders on the close edge but have radii on both sides that change radius every couple inches. 

Frosty The Lucky.

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