timgunn1962

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About timgunn1962

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  • Birthday 03/15/1962

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    Lancashire, England
  1. Gameco (alec steel) burner

    I don't think I've denied that a photo is important or useful, particularly when trying to understand why a burner is not doing what it is intended to do. If you can show me a thread where I have done so, I'll gladly post a retraction. The point I am trying to make is that a video is basically just a large number of photos in rapid succession and that he has posted quite a lot of video showing these burners in use, achieving temperatures that pretty much any smith I know would consider adequately hot. To date, I have not seen any evidence to suggest that any conventional forge, however good, can provide a working temperature in excess of the flame temperature provided by the burner itself.* It therefore seems to me that achieving welding temperatures absolutely requires a "hot burning" burner. Yet it seems they are indeed hot-burning. It's fairly hard work going through his youtube videos, but it may prove instructive. Hint: I found that judicious use of the mute button helps, as does skipping through as much as possible of the face-to-camera stuff (old age and intolerance comes to us all). He does make the point (in a video where he builds a forge) that he had used the Gameco burners when he was in Australia and was so impressed by them that he brought them into the UK. Corinkayaker's youtube videos probably have a rather better signal-to-noise ratio when it comes to showing the capabilities of the Gameco burners, though I've not found one that shows the burner being used for welding. His "Heat Treating Blades at Home Accurately Aiming for Minimal Scale and Decarburization" video was about the only thing I could find online that demonstrated the relationship between mixture and temperature, back when I started building forges using very similar "Amal" mixers (I'd mistakenly thought all smiths would already know this stuff). The thing that really impressed me was the precision with which temperature can be controlled with a threaded choke adjuster. I'm not 100% certain, but I think the commercially-made burners with a classical Venturi (reduction, very short throat, 1-in-12 increasing taper) provide a much greater air pressure reduction at the throat than the fixed-diameter tube designs, allowing much smaller air intake areas. They certainly look different to any of the shop-built designs, all of which seem to be variations of the long-throat, fixed-diameter-tube design. * Caveat: The Sandia recuperative forges are the only forges that I am aware of that might be considered to do this. I'd not consider these "conventional" and I very much doubt that the burners used in them would be considered mediocre.
  2. Gameco (alec steel) burner

    I'm struggling to understand your point, Mikey. The guy may not be your preferred youtube viewing. He is not mine either. Being irritating is not the same as being wrong (or, as you seem to be implying, dishonest). Why would he want to back up his claims with pictures? He seems to have a reasonably successful business posting youtube videos and there is quite a lot of that video showing him working with those burners, achieving welds which most of us would be entirely happy with. On that basis, he does seem to be backing up his claims. If you are seeing burners that you consider "unlikely to be hot burning", despite the considerable evidence to the contrary, it may be time to re-evaluate what you "know" about burners.
  3. Metric T-Burner

    Many of the mini-migs take an M5-threaded tip (14K) and these are widely available. M5 is also a standard thread for pneumatic fittings. I used a 1/8" BSP to M5 hex reducing bush to fit these mig tips into Amal atmospheric injectors when I was experimenting with jet sizing a few years ago. I never came across a fitting that would make it easy to build a T-burner though. I wasn't specifically looking, but I'm pretty sure I'd have bought a handful if I'd seen anything. The MB360 MIG torches use an M8-threaded tip, available in 0.6mm (which surprised me), 0.8mm and 1.0mm There are also bigger sizes (1.2mm and 1.6mm, maybe others), but they are bigger than "we" are likely to use. There won't be enough meat in the 1/8" nipple to tap out to M8 (tapping drill size for 1/8" BSP is only 8.8mm), but you'd probably be able to find a 1/4" BSP fitting with enough wall thickness to tap M8.
  4. Vanturi burner blowing out with to much air?

    It's not really what I had in mind as a flame retention cup. I'm not entirely sure what the "flare" actually does in most of the burner designs I see out there. In the "classic" Venturi design, there is a reduction to a very short "throat", followed by a 1-in-12 tapered diffuser. As I understand it, this diffuser is intended to slow down the fluid flowing through the Venturi while the flow is still primarily laminar. In the designs where the "throat" is extended to become the full length of the burner tube, the laminar-to-turbulent transition occurs within the extended throat and there does not seem to be a mechanism by which the 1-in-12 taper can work as an effective diffuser. That is not to say that it does not provide some benefit, just that I don't understand the mechanism. When a burner discharges into a forge, the relatively fast-moving mixture causes a slight pressure reduction in the forge atmosphere immediately adjacent to the exiting mixture. This draws the surrounding atmosphere in, just like the fast-moving gas exiting the gas jet draws in air at the Venturi, albeit to a lesser extent because the mixture speed at the burner tip is much lower than the gas speed at the jet. Because the forge atmosphere is effectively all flame, this means that flame is being drawn to the emerging mixture and this stabilizes the flame on the burner nozzle. It makes a huge difference to flame stability and is why it is pretty pointless trying to tune a forge burner in open air. A flame retention cup is usually a sizeable step-change in diameter (typically to twice the diameter, 4 times the area) and, as I understand it, works rather like a miniature forge, setting up a toroidal (donut-shaped) ciculating flame on the step of the retention cup and stabilizing the flame. When a flame retention cup seems appropriate, the flame design I tend to use is more-or-less as shown in the Amal atmospheric injector leaflet. http://amalcarb.co.uk/downloadfiles/amal/amal_gas_injectors.pdf Though I don't use a burner port nozzle as shown in the Amal drawing and I tend to weld something up from whatever is to hand. For a 1/2" burner, I'll slip a 1" length of 3/4" pipe over the end and then slip a 2 1/2" length of 1" pipe over that to get a 1" id retention cup about 1 1/2" long. I've not found the dimensions to be critical, but I've always stuck to a cup of twice the burner ID. About the only time I use a retention cup in a forge is when I am aiming for very low temperatures for heat-treating (around 800 degC, 1572 degF or a little less). In this case, the flame is extremely rich and I want to give it all the help I can. For forging or welding temperatures, I don't use a cup. It's the only pic I have that shows the retention cup at all.
  5. Vanturi burner blowing out with to much air?

    I don't think there's a problem with that flame, unless you intend to use it as a torch. How does it fare in a forge? That's the only thing that matters with a forge burner. There are certainly things you can do to make a burner work "better" in open air (a flame retention cup, for example), but they tend to adversely affect performance in a forge.
  6. Jay Hayes Clamshell Kit?

    I think the correct spelling is Jay Hayes, for anyone else googling it.
  7. Forges 101

    To be fair, Mike, "solved that problem" is over-egging it a bit. I get the strong impression that most beginning smiths want to build the ultimate forge straight off, thinking that it'll allow them to do everything immediately. The reality is, of course, rather different. I'm in the UK where we don't have the Wayne Coes of this world selling small quantities of high-performance refractories at prices most hobbyists can justify to themselves or their significant other. If I want 1400 degC/2600 degF blanket, I have to buy a full roll. If I want Kast-O-Lite 30LI, I have to buy a 55 lb bag. The "cheap fire cement and a double wrap of blanket" approach is just the cheapest, easiest way I have been able to come up with that allows a beginner to get started with forging over here. It approaches the cheapness of the truly abysmal sand-and-plaster-of-Paris constructions seen on youtube, whilst actually working quite effectively (given an appropriate burner) and lasting beyond the second or third use (given reasonable care). Body-Soluble fibre blanket is available by the metre from ebay dot co dot uk and fire cement is available at every DIY store. I've played about with forges a bit and built versions that range from distinctly meh to pretty good (at specific things), though they have all been aimed primarily at various aspects of knifemaking. I've played with various other things too, including home-brew rigidizers using both fumed-Silica-in-water and Sodium Silicate solutions. I've tried porcelain clay-and-Zirconium Silicate surface coatings, IFB forges, modified-torch burners, a couple of homebuilt burner "designs", burners built around commercial Venturi mixers and electric Heat-Treat ovens. Results have been mixed, but interesting. I'm not good at write-ups and the few I have done have disappeared along with the British Blades forum. If I can dig out some of my notes and pictures, I'll try to get some of the more useful stuff on here over the next few weeks.
  8. T Burner Illustrated Directions

    The sputtering is usually* caused by the flame speed through the mixture becoming faster than the flame speed along the burner tube. It is usually a sign that you need more gas pressure. The flame speed is a function of several things: the air:fuel ratio, the temperature and the pressure are the 3 main ones. With the burner design you have, the tuning is what determines the air:fuel ratio and you have no real way to adjust that once the burner is running. The pressure that affects the flame speed is the pressure of the mixture, not the feed pressure of the gas. It is not really something you have very much control over, as it'll be within one or two percent of atmospheric pressure whilst the forge is running normally. The temperature is the big variable. As the forge heats up, the temperature increase causes the flame speed to increase. At some point, the flame speed through the mixture may become faster than the mixture speed along the burner tube and the flame will travel down the tube. As the flame-front moves down the tube, it radiates heat ahead of it, heating the mixture ahead of the flamefront and increasing the flame speed. The accelerating flamefront causes a pressure wave, which moves ahead of the flamefront. The mixture just ahead of the flamefront is now hot and at higher pressure, so the flamefront accelerates down your burner tube until it runs out of mixture to burn and goes out. At this point the burner tube is full of burnt gases. Some of the heat released as the flame ran down the tube will have been absorbed by the burner tube, so it is now a little warmer. The gas is still being fed, still drawing in air, mixing with it and moving along the burner tube. When the mixture reaches the hot forge, it ignites and the whole thing happens again. It may be quicker this time because the burner tube is hotter. If the operator reacts quickly enough to turn up the gas feed pressure and thereby increase the mixture speed in the tube, the problem will usually go away. If the operator does not turn up the pressure before the burner tube has got hot enough to stabilize the flame at the inlet end of the burner tube, it's a case of shut down, let things cool and try again, preferably at higher gas pressure. Do you know what gas pressure you were running at the time? What is the range of your regulator? The mixture speed is proportional to the speed of the gas through the jet. The gas speed through the jet is proportional to the square root of the gas pressure, up to "around" 30 PSI where the flow becomes choked (it reaches the local speed of sound). Above the choked pressure, increasing pressure still increases the gas flow, it just doesn't follow the same relationship. If you have an idea of your gas pressure when the problem occurred, try again at higher pressure. I'd aim to double the pressure (which will give about 41% higher mixture speed) and if it works, maybe reduce the pressure in small steps with the forge at temperature until the problem starts to manifest itself again. That way you can establish the minimum running pressure for the hot forge. You are quite likely to find it difficult to light a cold forge at high pressure. If so, light it at lower pressure and increase the pressure as the forge heats up. * "Usually" is used here, essentially as a weasel word, to cover the possibility of your having done something really outlandish that I've not previously encountered.
  9. Devil Forge use for a newbie

    Refractory coatings are not particularly easy to give good advice on, at least over here. I gather Kast-O-Lite 30 is very highly thought of, but it's not very easy to get hold of here, particularly in small quantities. The same tends to be true of Mizzou and most other hard castable refractories. The blanket is relatively easy to get in "our" quantities, though it's become difficult to find anything less than a full roll of the 1400 degC (2600 degF) stuff since the body-soluble fibre started to become popular. The body-soluble stuff is only rated to 1200 degC as a rule. My advice is to accept that you are not going to build a forge-for-life anytime soon. You'll need a fair bit of actual forging under your belt before you are in a position to decide exactly what sort of work you are going to need to build it for. From the OP, it doesn't sound like you'll need welding temperatures for a while yet ("does this seem adequate to heat and shape metal with?") I'd buy some extra blanket: enough for a couple of reline jobs on the forge you have. You'll want 25mm thick, 128 kg/m3 (1" thick, 8 lb/cu.ft). The body-soluble stuff can be found by the metre on ebay. I'd then go to the nearest Screwfix, Toolstation, B&Q, etc and buy 2 or 3 x 2 kg kg tubs of cheap fire cement. If you can find some that look like they've been on the shelf since Noah made landfall, get those and don't move them more than you need to. While you are there, get one of those long-handled, angle-head, cheap, nook-and-cranny paintbrushes. You'll need some containers to mix stuff in. I tend to use 1L yoghurt containers. Whatever you use needs to be sealable, disposable and you'll want a few of them. If you can find a really fine seive, it's useful too. You'll also need some stirring sticks, and something to apply a coating of fire cement with. I tend to use bits of 1" x 1/8" steel flat bar because it's what I have. Take that bit of hard fire brick out of the forge and put it to one side. I’m not sure what the spec is on the blanket Devil Forge use. If it’s better than the blanket you’ve bought, take it out and save it for a reline when you are likely to need welding temperatures. Whatever you get should be fine to forging temperatures.. I usually cut blanket with a knife on a sacrificial wooden board to minimize fibre release. I usually scarf the ends at 45 degrees where they join, though I’m not sure it really helps. I usually cut the burner hole through the blanket with a holesaw, turning fast and feeding slowly, outdoors and upwind of any fibre release. Open a tub (container 1) of the fire cement carefully. If you are lucky, there will be a layer of viscous liquid on top that has separated out while it has been on the shelf. Decant this into another container (container 2) and save it for later. Take about 1/3rd of the remaining contents of the tub (container 1) and transfer it to another container (container 3). Add tapwater, mixing to get a an even consistency until you have about 1/2-3/4 litre (1-1 1/2 US pints) of milky liquid. Let it settle for perhaps 30 seconds so the bigger (sand-sized) solids settle out. Decant off the milky liquid (through the sieve, if you have one) and add it to the viscous liquid in container 2 that you decanted off earlier. Keep mixing so it doesn’t settle out while you slosh it onto the blanket in the forge with your angled brush. You'll need to rotate the forge as you do so. The idea is to get the fine clay-like stuff and the resin-like binder soaked into the blanket to work as a rigidizer. Don't skimp; you want the blanket properly wet to a depth of 1/4-3/8" (6-10mm), but retain some for later if you can. Some of the solids will almost certainly stay on the surface. Return the sandy solids and any remaining milky liquid from container 3 to the reamaining 2/3rds of the fire cement in container 1 and mix. Add tapwater if needed until you have a spreadable consistency. Spread this onto the blanket to get as even a coating as you can manage. Aim for about 3-5mm (1/8” - 3/16”). Thicker is not a problem, but try to save some for later. Do not coat the end faces: you’ll need a route out for the water vapour. Put the lids on the 2 containers with stuff still in them and put the forge somewhere to dry. Where you put it will obviously depend on what’s available. I suspect an oven set on really low would be ideal: like you’d use for making jerky. I tend to leave things in my unheated shop and it takes weeks to dry there. I doubt Derbyshire is very much better than Lancashire in this regard, so indoors is obviously better. It’s a case of doing the best you can without causing undue domestic disharmony. You don’t want to get it hot enough to flash off steam in the fire cement, so a hairdryer is ok to help move things along, but a hot-air paint stripper probably isn’t. Once it seems pretty dry, you can set about reducing the openings. A 1” wide strip of 1” blanket, soaked in the runny stuff and coated with the thick stuff can be put inside the ends. You can also peel the blanket apart to get a further 1/2” layer if the type of work you intend to do will let you use a smaller opening. Don’t go smaller than your nook-and-cranny brush head, as there’s a good chance you’ll need to patch up the fire cement at some point. Most of the stuff you’ll see online talks about numbers of burners for forge volume. My experience suggests that the size of the openings has more effect on the amount of burner needed than the volume. Use the smallest openings you are sure will be big enough for your immediate needs. Put the forge back to dry. The reason for not reducing the openings earlier was that the reduced openings reduce the airflow through the forge and slow the drying. Once the interior seems dry, you can fire it up at the minimum pressure and choke opening it’ll run at for brief periods. The heat robbed by the drying liner and the water vapour produced will mean that you’ll need more pressure/choke opening than for a dry forge. You can increase the duration of the on periods as things progressively dry. You don’t want to flash off steam in the fire cement. It causes bubbles to form which dry quickly and break off, thinning the layer.. As the lining dries from the hot face, it’ll get to the stage where there’s no danger of damaging the lining and the water still in the blanket will be driven out through the unsealed faces. While the blanket is drying, you can turn up the burner pressure and open the choke until you have the temperature you’ll need for normal work. Don’t be tempted to give it the beans just to see what it’ll do. Make yourself a work support to go in front of the forge. The lining will last much better if it doesn’t have to take the weight of the workpiece. If you are doing stuff that doesn’t need a rear opening, it can be temporarily closed up with a piece of untreated blanket. Put your spare materials somewhere safe so that you can reline as and when necessary. Keep the blanket in a sealed bag. Separate marked, sealed bags if you saved the original blanket. This procedure and these materials will not give you a particularly good forge. What it will do is give you a forge that works well enough and lasts long enough for you to develop the skills and knowledge to decide what your next forge needs to be like. It is cheap/easy enough to reline that fear of damaging it to be unlikely to limit your activities.
  10. Devil Forge use for a newbie

    I can't see the end of the burner where adjustments are made, so it's not clear whether it's a DFP or a DFPProf burner. I'm guessing it's a DFP? You have 2 adjustments with the DFP. The first is the amount of gas being burned and this is controlled by adjusting the gas pressure. The second is the flame temperature and this is adjusted by varying the choke position (the disc on the back of the burner that screws up and down to vary the air gap between the bellmouth and the disc). If you've run with the choke closed, that'll explain the sooting. I bought a DFP burner only off ebay, just to see whether they'd done a good job of it and I was impressed. It seems they've got the gas jet (which looks to be a drilled hole) about right, IMO. Mine seems to get hotter as the choke is opened while remaining on the fuel-rich side of stoichiometric even with the choke fully open. I only did my initial testing in a purpose-designed Heat-Treat forge, so I've not tried for maximum temperature yet. I still need to try it in a "normal" forge to see if it'll get to welding temperatures and it's something to get around to in the next few weeks: I prefer to do in the dark so that I can see what the flames are doing and it is best done in the the dark winter evenings. Operating pressures are likely to fall in the 0-0.2 MPa range (0-30 PSI). For a given gas jet, gas flow varies with the square root of pressure. If you burn X gas per hour at 30 PSI, you'll burn 0.707X at 15 PSI, 0.5X at 7.5 PSI, 0.25X at just under 2 PSI and about 0.18x at 1 PSI.
  11. Kaowool and refractory

    Effectively none. The thermocouple was a type S removed from a Landfill gas burner I decommissioned. Type S is generally considered stable and an uncalibrated type S is a lot more useful to me than no type S. The readout was the cheapest thing I could find which would take types K, N, R and S. I did check it against the "calibrator" at work, but even that does not have traceable calibration back to National standards. To be fair, I don't get the impression many of us on IFI are working to ISO9001 or similar and most of us understand that there is an uncertainty in any measurement. For example, the chamber dimensions I gave above are based on nominal 9" x 4.5" x 3" IFBs and I'd expect most smiths to be ok with that.
  12. Kaowool and refractory

    I've had a measured-with-photos 1545 degC, 2813 degF from a forge. The forge was a quick, dirty IFB construction made from some very cheap (probably Chinese) grade 23 bricks and a 1" burner based on an Amal atmospheric injector. I was experimenting with jet sizes and this was using a 0.6mm MIG tip (.024") with an actual ID between .029" and .031". A #69 drill would go but a #68 would not. Propane pressure would have been at maximum on a nominal 0-30 PSI regulator. No gauge. The chamber was 6" x 6" x 13.5" with the opening only about 3" x 3" at the time. It was built with a 5"H, 3"W front opening and a 3" x 3" rear opening and I'm pretty sure the rear opening was plugged with kaowool when the photo was taken. The front opening was reduced with a bit of JM23 IFB and the bottom pic shows how it melted. I have no doubt a forge temperature of 2900 degF is achievable, though I'd consider it unwise.. If the refractory hangs together at the temperature, the Kaowool behind it should survive ok. It doesn't actually melt until 3200 degF and only needs to retain enough strength and rigidity to keep the refractory in place. Always keep in mind that forge linings are consumable items. http://www.barteltinsulation.com/pdfs/CERAMICBLANKET.pdf
  13. Gas torch as a burner?

    Assuming from the link that you are in the UK, I would not advise using a torch unless you have (or need to buy) one anyway. The Sievert stuff is quality, but it's worth checking whether the burner on that one is brass, steel or stainless steel. There's a pretty good chance that brass will become a dribbly mess when trying to get useful forge temperatures. You can buy a 1/2" long-Venturi Amal Atmospheric Injector (a commercial Venturi mixer) for around £50 delivered. Either the 354/12BLV (with a 60 jet) or 354/12PLV (with a 70 jet) will work. If you are mainly working hot, with welding the priority, the 60 jet is probably best. The 70 jet might be slightly better if precise temperature control down at Heat-Treating temperatures is important to you. You'll also want a 6" (or longer) 1/2" pipe nipple for the burner. The injector incorporates a 1-in-12 tapered section and you don't usually need anything else on the end in a forge. You'll need a regulator, hose and fittings to get you into the 1/4" BSPF port in the injector. A gauge is optional and will fit in the other 1/4" port in the injector if you want to use one. The regulator should be a 0-30PSI (0-2 bar: adequate) or 0-60 PSI (0-4 bar: overkill). Don't get a 0.5 bar-minimum (8 PSI) regulator, they are horrible to use in a forge. The Amal burners turn down well and provide for exceptionally fine adjustment of the mixture/temperature. Fire bricks come in 2 main types: "Hard" and "Soft" or "insulating Fire Bricks". You'll almost certainly want IFBs. Hard bricks do not insulate to any useful degree and you'll probably need to step up to a 3/4" burner if you use them. IFBs are not flux-resistant. Read the stickys for ways to protect them. Bricks are expensive to ship so we tend to get different ones over here to those in the US. My preferred IFBs for forges are marked LW23GRD. They don't seem to break up as badly with heat cycling as others I have used and, despite the 2300 degF rating, do not melt at temperatures I can readily obtain with the Amal burners. They also insulate better than anything else I have tried except the JM23s from Thermal Ceramics. I once used a JM23 to reduce the opening of a forge built from LW23GRD and the JM23 melted to a puddle. JM23s are my first choice for electric Heat-Treat ovens but I avoid them for forges. I weld up a frame from 1" angle, rather than a sheet metal box. I also take the burner in the side to reduce the chimney effect on the burner when the forge is shut down.
  14. just built my first forge.... so many questions

    The Vids show a LOT of Dragons Breath. For a hotter flame, you'll want more air for the same gas. In a Naturally Aspirated burner, the speed of the gas out of the jet (your mig tip) is effectively what draws the gas in. If you make the jet smaller and the gas pressure higher, you'll have more speed out of the gas jet for the same gas flow and you'll draw more air in, giving a hotter flame. Try a .023" MIG tip and let us know what happens.
  15. How dry is your rigidizer? It needs to be properly dry. If it is not, it can take so much (latent) heat out of the flame and produce so much water vapour that the burner struggles to stay lit. Make sure it's really dry and try again before you start messing with any other variables. If I've thoroughly soaked the blanket, I generally give it at least a couple of weeks to dry off in the shop before trying to run the burner. This is obviously climate and time of year dependent: I am in Lancashire, England. Mine is not generally considered a warm, dry climate. I don't normally heat the shop, but usually run a dehumidifier in there. Once I've got the rigidizer properly dry, I'll apply a coating and leave it at least another week or so before running the burner again. I've tried force-drying a few times. Taking it into the house speeds things up quite a lot, but does not exactly promote marital harmony. Apart from the spousal disgruntlement, this doesn't seem to cause a problem and it cuts the drying time from weeks to a couple of days or so. I have tried leaving small forges on top of an oil-filled electric radiator in the shop with less success. I think rigidizer should be fine at perhaps 20 degC (38 degF) above ambient, maybe more. For a surface coating, I have mostly used a 2:1 mix of Zirconium Silicate and Porcelain clay powder, made into a slip and painted on. Although not ideal even when dried slowly, this seems to crack much more when dried fast. If it is not fully dry when the burner is lit, it tends to flash off steam which lifts a paper-thin layer. This fires quickly and breaks up, then it seems to happen again. The result is a very fragile surface coat of varying thickness. I fully appreciate that nobody is going to wait weeks for their first forge to dry. However, it's a good idea to run your first forge for a few weeks, maybe even months, to work out how the next one can be built better, but to build the second before the first fails completely and ensure it has thoroughly dried before firing. If I really need to build and run a forge in a single weekend, I use IFBs and bypass the whole drying issue. I don't see any realistic way of building a long-lasting, flux-tolerant forge on such a tight timescale in my climate and using conventional materials.