Andy98

Hi, So my 1/2" Frosty T burner has frankly been fantastic, and it barely sips from the propane tank - but I'm thinking of moving to NG since, you know, it's piped right into my house and it should also be cheaper (I'll save $15 per equivalent 20lb BBQ tank of propane). With the T-burner, I'd run at 6psi for (the one and only successful attempt at) welding, and 2psi for forging. Per the BTU calculator on Ron Reil's site, that's 40000BTUs and 18000BTUs respectively. I've acquired an old (mid efficiency) gas furnace for $0. I intend to take the draft inducer off it - I'm under the impression that it'll make a pretty good blower, and that I can modulate the intake air with a gate valve of some type. Is there anything else that would be good to keep before I toss the rest of the furnace? Gas valve? Flame sensor? Pressure/flow switch? Thanks!

If you have abandoned the idea of a london pattern, then check out the anvil design used by GSTongs: Its hardened and flat all over, with the sides being swage blocks and forms for the various work he does (eg, his hammer heads fit nicely in the half round cutout on the top of the left side so they don't go flying as he punches and drifts them). It keeps most of its weight right under the hammer, and has a minimal/reasonable amount of removed material from the base block shape. Probably still not worth making rather than buying. I'd miss having the horn. Here is his video on it:

I like it! Reminds me of the quote "In English, any word can be verbed" except in this case...adjectived? Adjectivized?

Sorry if this is a hijack, but can anyone contrast how easily O1 is forged vs (say) 1084 or 1095. I haven't tried any 10xx steel yet, but did work some O1 and found it super hard to move. Will 1084 be any easier on me?

Well you can order both from Pottery Supply House. That said, I did not use ITC-100 in my forge and I was able to successfully weld in it (exactly one time, and I haven't tried again since but I don't see why anything would have changed....) Are you sure sounding stone doesn't have rigidizer? That seems odd to me - I'm under the impression that one always uses it when they use the blanket. In any case I think any clay wash would work (they for sure have clay wash - you use it to protect your kiln shelves if I understand correctly).

Why am I just getting this advice now?

I thought I'd update my progress in this thread for posterity's sake - it's based on advice given to me on another thread (here) I went ahead and modified the forge. I cut back the forge "hood" to make it possible to block up the front and back with firebrick, see here: The forge interior now seems quite cozy: That's it running with the 1/2" T burner at approx 6psi, ambient temperature was around 10C. That piece shows a joint that was about to be successfully forge welded. With the regulator down at around 1-2 psi, it was still easily hot enough to forge, but not forge-weld.

I didn't weld or even screw down my forge body. I made it out of sheet metal (from metal supermarkets, which has a Winnipeg location) and bent metal tabs to join the two parts (I made a top and bottom separately). Details are here. It looks a little funny but seems to work just fine. I bought my refractory from The Pottery Supply House - which is in Ontario and they ship. You can probably buy all the refractory, rigidizer, and high-alumina tile at The Sounding Stone in Winnipeg (I just found them on the Internet searching for pottery supply). They repair kilns, so they should be able to supply you with anything you need. I wouldn't want a smaller forge than I built, but I don't feel the need for anything bigger. I'm quite sure a coffee can would have been too small for me. I'm using a 1/2" T burner that I built. I think if you buy a burner, it'll likely be 3/4" and be too large for a forge my size... Actual construction time, for the forge and burner, was probably less than 8 hours. NB: This is my first forge, and I probably have less than 35 hours of total lifetime forging experience - so you might want to consider that when listening to anything I say.

Ok - so I finally got back to the forge. I bricked up the back and most of the front and saw what I thought was a nice improvement. I can now easily forge mild steel with the regulator set almost as low as it can go (1-2 psi at @10C). So that's great! I went and tried a forge weld again. Took three attempts, but I got it. I think the first two attempts were just not hot enough. I "cranked up" the forge to around 6psi which got the steel into a yellow/white colour (as judged in the sun by my eye) and it just worked. You could tell with the first two setting blows that it was together. Very encouraging. Photos below (gallery is here if the embedded photos don't work http://imgur.com/a/iUKxn) 3rd attempt, I waited for the weld area to uniformly get up to that lemon yellow colour. ...likely not the prettiest weld. I forgot to wire-brush the sides as I was doing this. Ground away about 1/2 a mm - you can still see the line between them. I presume that is scale and oxidization? Does that bind the two pieces at all? Ground away about a full mm now in the center, and the steel there is fully welded. Hard to tell in the photo, but the line is gone and the metal appears solid and uniform. Super cool! Thanks everyone for the help!

I think I'll try both approaches, actually, should be interesting. I'm happy yo try, but I'm still at exactly zero successful forge welds - admittedly not one of them was ever done properly (I've always started with heavily scaled stock). When you do this (fold the steel over) how do you prevent scale from building up while you're doing the bend? I presume the process is: Heat Brush, foldback and hammer the pieces so they are firmly together, flux, back in forge Let heatup and soak until...? The flux is bubbling? Out of the forge, several light (but not that light) quick taps, flux, and back into the forge. Let heat and soak again Out and hammer for real Thanks everyone for the comments.

As usual, I think I'm confused. You're saying that if the jet orifice is the right size, the air/gas velocity in the mixing tube is roughly at the flame-propagation speed so lighting it inside the burner creates the risk that the flame stays right there. A burner with too-small a jet orifice will have a higher air/gas velocity in the mixing tube and will basically blow the flame into the forge, but will be logically injecting less fuel making the burner net lean and needing choking. Did I come close on that explanation? I'm surprised that the air/gas velocity inside the mixing tube is that close to the flame-propagation speed. I always assumed it would be faster because the air/gas is considerably cooler in the mixing tube, plus I thought part of the roll of the forge-body/flare was to allow the gas to slow down to balance with the flame-speed. I believe I did read a comment you made that the point of the flare isn't to "hold the flame" but instead to improve air induction, which confused me, but I guess that's because of the same misconception on my part here.

Hi, I'd like to make a long handled shoe horn, as well as a BBQ fork, each out of just mild steel but would appreciate some starting stock size suggestions. I'll be buying the stock to work with, not re-purposing something else. For the BBQ fork, I thought I'd start with 3/4" round? For the shoe horn, I really don't know. I feel like 3/4" round won't spread out enough to make the horn. I'm tempted to start with a flat bar roughly the width I want in the horn, but then making the rest of the handle round will be a chore (likewise, I think drawing out 3/4 or 1" round will also be a chore, but good practice I suppose?). I will be working only with hand tools. I do not have any fullers, "just" a basic anvil (I figure I can shape the shoehorn reasonably will on the anvil horn?). Thanks in advance.

Ah ok - I'm trying to get a frame of reference so that I can tune it. I thought I knew what rich looked like, but wanted to confirm that I wasn't totally off base. So now I'm pretty sure I can recognize rich. Once I have a chance to run the forge again, with the brick doors/baffles, I'll try to get to neutral and get a photo of that. Does temperature affect the atmosphere? I feel like 5-10 minutes is enough for the burn to steady out. Should I be letting it run longer before I bother trying to tune? Thanks for the explanation on the steel coupon scale test. Again, I don't have a frame of reference and I had assumed that the scale wouldn't begin to form until the metal was already incandescent (at which point, I believe, I wouldn't be able to see it). So now I understand that, if I'm oxidizing, I would see it scale even before it gets to those temps.

So now I'm excited to make that change! ...BUT: In the photos and video, am I correct in my belief that the forge environment is reducing? And how do I go about judging that based on the scale buildup (i.e., if I can't see the scale when it's hot, and taking it out of the forge guarantees scale buildup, how do I know whether I'm reducing or oxidizing?)

I came across this discussion on reddit: https://www.reddit.com/r/Bladesmith/comments/4wmdhf/first_forge_question_chimney_bricks_or_some/d6fc3cm ...the poster there runs a NG forge off a BBQ line with regular residential pressures. It's a blown forge, and he uses a furnace air-inducer motor that can be speed controlled with a simple dimmer. He has some details and photos in his post, but what it seemed to boil down to is for him hooking NG into a regular blown burner config worked great, no extra-special high pressure NG line, not even plugged direct into a 1" pipe.

Yes, for sure. In fact, I'm expecting to get the bricks today for this very purpose. I also intend to cut back the kaowool "hood" I built in so that I can better place the bricks without forcing all the hot exhaust down onto my table.

Apologies in advance, I fear I'm about to ask a dumb question but I want to make sure I have this right. I'm working away with my small propane forge and having fun. I'm still not confident about how oxidizing / reducing my forge atmosphere is. I've read that: I can learn things from the rate of scaling of metal in the forge I should be looking at the dragon's breath For #1: Rate of scaling When we talk about scale do we mean the thicker black flakes that get left behind on my anvil? Or the thin black coating (not soot)? Or both? I believe we mean both. When we say that a reducing atmosphere will not create scale on metal - how can I even tell? When the metal is hot in the forge, the scale is also hot, so at high temperature how do I tell if scale is building up? Then of course, once I remove the hot metal from the forge it'll scale in the open atmosphere as it cools - so I guess I don't really know how to conduct this test at all. For #2: Dragon's Breath I think I am making some progress here, but would like to double check a fact: Here is my forge running almost fully choked. The work piece in it has borax on it. I believe this is a good reducing atmosphere suitable for welding: (More photos here: http://imgur.com/a/P9vf6) Can anyone let me know if I am right? I believe I need to get the temperature hotter (turn the forge up) but that I'm not too far off. Am I? I'd like to get a photo of what I think is neutral and what I think is lean - but I ran out of propane and time, so that'll have to wait for a bit. You can see the "cold" end of the work piece is, to my eye, very heavily scaled - but that piece had been through probably 15-20 forge heats, and quenched in water several times too - so that doesn't seem like an unreasonable amount of scale. Is it? Here is a video of the forge take around the same time as the photo: Thanks in advance for any advice offered.

FWIW, I find that I can generally light my forge by putting a flame to the air intake of the burner.

Ok thanks. I don't feel irritated. My principle concern is not wasting your or Mikey's time.

I'm pretty sure I'm going to flunk this test. Unfortunately, I'm not confident that I am remember the details of what I did accurately. I do believe I remember what I thought at the time,and those thoughts were: "The dragon's breath suddenly seems more orange, and at a lower velocity" "Is it suddenly running more rich? I don't think I have done anything that would have caused this." "I wonder if there is a fuel flow problem?" "I wonder if this is related to high temperatures?" I do believe that approx 15 minutes earlier I had increased the propane pressure substantially and that is why I suspected a fuel flow issue (icing due to higher flow) or a temperature phenomena. It did not make sense to me that higher fuel pressure and temperatures would lower the intensity of the dragon's breath, and I didn't see any ice forming on the tank (admittedly I did not inspect it thoroughly, I just glanced at it and looked at the tank-side pressure gauge which was reading ~500 psi). When I say that the dragon's breath "suddenly" changed I mean that I had just removed something from the forge, worked on it, then turned back to the forge and noticed it was different. It's possible it was slowly changing all along and I just noticed it at that moment - again, I'm not 100% confident (or even 50% confident) in my observations. I'm not 100% sure whether this happened before or after I tried my weld, honestly, but I am pretty sure it was before. If I were to take a guess, I would guess that it was either due to the forge interior being at a higher temperature than I had operated it at before (I do not understand this causality) or there was a flow issue (either in fuel flow, or the burner had gotten obstructed because it slumped). As I said above, I did do a cursory inspection and had dismissed these two concerns at the time but that doesn't mean I got it right. Honestly, when all this happened I wasn't in an experimental mode so I really wasn't paying attention. I will start keeping a log at all times now. I did not notice any damage or erosion to the forge liner. I didn't see anything splatter while it was in the forge, and I was really careful to get the fluxed part of the work piece right on the kiln tile. I used very, very, little flux. The whole attempt was unplanned - I had made a mistake and saw the forge-weld as the only option to remedy it so I decided to wing it. I'm looking forward to making a more organized attempt per your instructions - that likely won't be for a few weeks (late Oct) as I don't believe I will have another opportunity before then. Can you tell me how you draw this conclusion? I'm not questioning the conclusion itself, I'm trying to better understand what I should be looking for so that when I do try again I won't fret over temperature. Note that I've never seen any of the metal I'm working with actually spark from heat. Ah - ok, got it. That makes sense.

...ok, so I didn't understand most (possibly any) of that... I believe you are suggesting I add an IR coating (ITC or similar), block up the front (what would a baffle look like? I mean, I know what a baffle is I just don't know what one at the front of a forge looks like...) and presumably block up the back (should I just seal up the back completely, minus a small passthrough door? I only really left it fully open because I was worried about backpressure.) Note that my "hood" idea (where the arch insulation extends 1" in front of the forge) also means it's hard to actually block the the openings up with bricks (it just forces all the hot gasses downward). Should I ditch the hoods (trim them back to make everything flush?) Note that I've now run the forge for approx 15 hours, and it seems to be doing fine getting (mild) steel to forging temperatures (admittedly, I'm not sure I'm forging at the right temperatures). To my eye, in sunlight, the steel definitely gets to orange and some lemon-yellow, but I don't think I get light-yellow or white hot. I would like to attempt forge welding in this forge at some point, but I feel like I'm a fair bit away from that? Here is another video of the forge running. It was fully at temperature (probably had been running for over an hour) and I choked it back a lot (was really trying to make sure the environment was rich as an experiment: https://youtu.be/S1Oz7a3IcOE Also, separate from the choking, I do feel like something weird happened to the forge after a few multi-hour runs - suddenly the dragon's breath became really orange even when I had the chokes removed. I was also getting near the bottom of my tank (although still reading several hundred psi on the tank side of the guage), and I had just put some borax into the forge in an attempt to weld something. It just seemed different all of a sudden... Finally, you can see that the T-burner is slumping downwards. I believe the conduit mount is getting hot enough to flex a bit... ...exactly what I was thinking when I did it - I had grander dreams for it, but they didn't materialize. I'm confused as to whether I even need the flare. Now that I have a forge running, I have a better shot at making one. Should I bother? Yes, I really see now that more oval would really have helped. As far as the the burner tune - do you see it as being too rich? I haven't cut back this mig tip at all (it was waaay too lean originally as far as I could tell, so I overcorrected...)

FWIW he said above that he's actually got the solenoid valve wired into the alarm output on the PID, so it's basically just working as a temperature switch. These seem like really, really good ideas. Poking around for proportional regulators lead me to the "home-roasters" community (wow, there are a lot of hobbies out there..) and apparently those guys build PID controlled, gas-fueled, coffee roasters. Here is one guy's experiment: https://www.youtube.com/watch?v=X75Rx_mezHs ...he found an inexpensive proportional solenoid valve (not a proportional regulator) which was interesting (to me).

Sorry it's taken so long to reply - I'm not sure what happened, I actually typed up a full reply quite a while ago and just noticed that it went missing. Oh well. Ok, just to get some terms out of the way, there are On/Off valves (aka shutoff valves, or digital valves) which are meant to be fully open or fully closed. Then there are modulating valves (also known as control valves) which can be adjusted to between 0 and 100% open. I think you're asking, how can you control a modulating valve from an electronic output. In industry, the answer typically is you use air pressure to actuate the valve, and you have another device that controls the air pressure in response to your output signal (typically a 4-20ma signal). Here is the wikipedia page on Control Valves. It's less common, but motorized valves do exist. They are usually for special applications (I've only ever seen them for very large valves). Note that when you do motor controlled valves, you also generally have a position sensor as well. None of the above falls into hobby-level pricing. With some quick googling I did see that some people go about building stepper motor controlled valves. I'm not sure I'd be super comfortable with that, myself, for dealing with propane. For PWM, you'd have the actual pulse output going into the solenoid (or perhaps you'd put a relay between the two). So the solenoid might open for 30 seconds, then close for 30 seconds, then open for 30 seconds etc... depending on how you configure the duty cycle. In your application that would mean you'd have 30 seconds full heat, then 30 seconds idle heat, etc.. representing a 50% control output. Note that you need to control the blower as well as the fuel - so, using the above example again, off the top of my head I'd wire the PWM into a relay and have one contact from the relay wired to the blower to kick it into full speed, with another contact going to the gas solenoid. Again, I've never automated a forge so there might be better approaches. I haven't even researched the topic. If you want to use the arduino, I'd be tempted to just ditch the PID controller and find an open-source PID arduino project. I'm sure there are dozens - I know that home brewers do that sort of thing a lot to control fermenting tanks. I would NOT write a PID controller from scratch - the basic idea is straightfoward, but there are bells and whistles that would be annoying to replicate. EDIT: Interesting, found some options on Ali Baba. This one includes open and close position switches, so you could home it against the close to figure out the position. This one just has an "open" command input and a "close" command input, so you'd need your ardunio to home the device and track what % open it is. https://www.aliexpress.com/item/5-wires-CR05-DC12V-Electric-motor-valve-1-4-Brass-2-Way-Motorized-valve-DN8-Electric/32432458325.html?spm=2114.10010108.1000013.3.M3NzwY&scm=1007.13339.33317.0&pvid=ef2793c6-7f93-44cc-914d-1dc74d7be792&tpp=1 This one actually takes an analog 4-20ma input - so it must be doing the position tracking itself: https://www.aliexpress.com/item/4-20mA-or-0-10V-AC-DC24V-control-1-1-2-proprotion-Modulating-valve-for-flow/990932550.html?spm=2114.10010108.1000010.2.IvmCiH&scm=1007.13438.37934.0&pvid=3eff91a9-1121-4d3b-8c78-d806d6a411b2&tpp=1 ...that last one there says it's proportional, but the flow graph isn't linear. Basically if you open the valve twice as much, you want to be getting twice as much propane otherwise your PID will get confused (it wants a linear system). Anyway, these would all be a shot in the dark. I did not evaluate them at all for this application other than to note that they are control valves. They are probably totally inappropriate for fuel gas or forge use - I'm just pasting the links to give a sense of what is out there.

There is a coffeeshop near me that has a sign up: "Unsupervised children will be given a shot of espresso and a puppy" ...Hopefully squeaking in under 1hr is considered rapid enough. The pottery supply I used is called "The Pottery Supply House" (creatively enough). I'm not sure how helpful that will be, since they are up here in Canada - but they do accept online orders, and they do have a rather extensive inventory (including all kinds of alumina tile, 1/4" and 1/2"). Here is the alumina kiln tile link: http://www.psh.ca/index.php?cat_id=211 Prices will be in CDN, so remeber to factor in a 20% discount due to exchange rate. I did read some article somewhere about making your own alumina kiln tile with alumina and veegum (?). Just mentioning in case that is interesting.

EDIT 1: I keep trying to post the forge videos I sent to Mikey, but the forum keeps eating my work. Frustrating. I'm going to keep trying... EDIT: 2: It seems that the forum is rejecting posts with youtube clips embedded, but is accepting them as regular links.... Certainly! The video below shows the forge running at a variety of exposures. The forge would have been running for only a few minutes at this point: https://www.youtube.com/watch?v=cRuXz102jqw I then decided to wait until it got darker out, and I turned off the forge and returned approx 40 minutes later. The forge had obviously cooled off, and this is what it looked like when I restarted it. I see a lot of white flame at the beginning, which might be partly due to exposure on the camera, but it seems to go away so perhaps that was just due to the forge being cool? https://www.youtube.com/watch?v=FG-JC_JXQoo ...and finally the last video of the night. The forge only ran for a total of about 5 minutes really: https://www.youtube.com/watch?v=fIapN5f7K38 On a side note, just in case it's interesting to you, I build the forge aiming for a D shape based on various suggestions, but my first light was disappointing. It looked like the flame just curled down the one side, and then turned 90 degrees to head straight out the front and back. I added some extra kaowool and satenite to the side the flame hits to make that more of an oval, and to create a curved transition onto my forge-floor. That seemed to give me a good swirling effect that you can pickup in the videos above. Here is a video before I made that modification: https://www.youtube.com/watch?v=YiG8nSvtxmo Some additional notes I did not include in my original message to Mikey: The forge interior is approx 4.75" wide by 3" tall, with the forge floor being 10" in length. I made the forge ceiling insulation extend forward thinking it would act as a hood to protect the metal enclosure. The longest part of the insulation is approx 12" long. The insulation is 1" thick 2600F kaowool as the inside layer, and 1" thick 2300F for the outside layer. The floor is coated with bubble alumina, the top is satenite. The floor is two pieces of 4.5"x4.5"x1/4" high-alumina kiln tile. That was the best fit that the pottery store sold. The fact that they are two pieces is a problem - I was reluctant to try cutting a larger piece since I didn't know if that would be harder than I anticipated. I'll have to do something about this. Advice and feedback is apprecaited. Thanks in advance.