Latticino

Yeah, MEK is awful indeed. Back in the day we used to wash our hands free of grease with solutions of either MEK or Trichloroethane. Worked great, but I shudder to think what it has done to my liver. Fortunately it wasn't a regular habit.

Virtually all blacksmithing items on e-bay seem to be overpriced these days. For hand cranked blowers, I would recommend tailgating at larger blacksmith gatherings, SOFA or ABANA gatherings as better choices. Of course there is always Craig's list and similar, but it does seem most online sources are way out of line. For a powered blower you have many more options, as Thomas noted.

Very interested as regards the "flat spot" discussion with regard to Chef's knives. I'm hardly a chef, but recently took an integral Chef's knife class with Nick Rossi at the New England School of Metalwork (great guy, teacher and facility). One of the things that he mentioned specifically is that he always includes an approximately 2" section of "flat" edge at the heel of his French style chef's knives. He mentioned that the chefs he consulted with liked the flat as a sort of a stop for the rocking motion they use in chopping. Here is a shot of a Kramer Chef's knife that appears to have this flat section (though it is hard to tell from the image):

Very nice Bob. Looks like you have the wrought stuff down pat. Going to etch the next one? Just had a failure trying to make an Austin style offset wrapped eye Viking axe out of wrought and 5160 over the weekend. Went pretty well until I got ready to wrap the eye for welding. My buddy, whose shop I was working in, had just walked away after asking if I wanted the torch setup to bend the ears in. I got impatient waiting for him and started to bend them over the bick. Let things get too cold and tapped one ear. Wrought cracked on me right at the back of the eye... May have made the cheeks too thin, but I think I'm just not that used to working with wrought. Guess I might try welding it back together, but in that kind of high stress location I don't fancy my chances.

Yes, all burners have a minimum fuel/air mixture flowrate that is at or just above the flame speed. However some have burner "end conditions" (flares, multiport burner outlets, flame retention ring nozzles...) that attempt to isolate the burner mixing tube from the flame front by use of a radical velocity change. To the best of my knowledge these extend the stable operating characteristics of a given burner. These are not in great favor typically on NA burners, as they invariably add a bit of flow restriction and consequent friction which reduces the ultimate capacity of the burner, but are not as significant for a typical forced air burner. No idea how they would impact yours.

But keeps running around for the next 15 minutes for some reason...

Personally I would contact the group you purchased it from to help you with tuning before making any major modifications. That being said, I see some potential issues: The location of your burner allows the forge heat and exhaust fumes to rise back up towards the burner (I prefer side entry burners for that reason). One could cause pre-ignition in your burner mixing chamber (does the burner mixer get very hot after it runs at correct working conditions?). The other could cause a flame-out condition by starving the burner of oxygen due to the induction of flue gasses rather than "clean" air. When you adjust your burner operation you will most likely have to adjust both the air and propane (using the inlet shroud for air and the regulator for the propane). It sounds like you are just adjusting the propane. At what you see as correct operation do you have a reducing flame (some "dragon's breath" exiting the front of the forge)? For most operations that is the target. I've built a similar type propane burner. During initial tuning, which took place outside the forge body, the location of the gas orifice and specific location of the SS flare on the end had a lot to do with maintaining a stable flame. It appears that you can adjust the orifice location with the set screws in the side. The flare on mine made small variations in the burner mixer length. I was quite surprised at how sensitive the assembly was to small changes in that length. Might be worth investigating with the vendors. Pressure variations in the gas can totally screw with the operation of a NA burner. So can any debris that occludes the orifice. A gage on the regulator is always a good idea IMHO, and a loupe can help you check the orifice (or maybe just some properly sized music wire).

One last caveat: I've never seen a successful NA burner run on low pressure (7-9" WG, residential) natural gas. I suppose you could make a really small one, but I doubt it would be very effective. So if you plan on running natural gas you will likely either have to have a special supply from the utility or go with a blown burner.

This is correct. Design of a dust extraction system is non-trivial. Velocities must be maintained for proper material transport, code compliance is required for the design (including the outlet location), spark protection and explosion relief vents may be required, and you can get into a lot of trouble combining materials collected (i.e. metal particles and wood dust). In addition to the ducting being the correct diameter, the fittings should be smooth and long radius, you should have cleanouts at all 90 deg. bends and some method of safely separating and collecting your dust. As noted by others, I've never seen one that could be termed quiet. Putting it outside or in a dedicated room is probably a good idea. High static is typically required to keep the velocity high in the ducting due to the extra friction that entails. You have a very nicely setup shop, I'd be careful about compromising with the dust collection. Cheapest option I've seen work fairly effectively is a bucket of water suspended below the grinder platen where the bulk of the sparks go.

Welcome to the site. Wonder why you think you need such a large forge. Unless you have a really huge fast power hammer or hydraulic press (or team of strikers) you are going to have a lot of trouble beating on anything more than about 6-8" of stock length before losing enough heat to be counterproductive in my limited experience. Might be different if you are planning on scrolling or twisting rather long or heavy stock in one go, but I do think you are overbuilding somewhat. Are you planning on industrial scale forgings or very large architectural construction? As a beginner I would certainly recommend starting with a smaller forge (see Wayne Coe's, Tim Zoada's or Dave Hammer's designs for good examples) If you are just planning on eventually making swords then a smaller forge for most of your shaping operations is a better, more efficient, recommendation (say 8-10" in length). Of course you will need something larger for easy heat treatment (though it is certainly possible to heat treat longer swords in a small forge), but that does not need to get up to forge welding temperatures and I've personally seen a 55 gallon drum heat treatment forge (Don Fogg style) get up to 1550 deg. heat treatment with a single NA propane burner (can't remember if it was a 3/4" or 1" burner). In fact you could use the same burner for the smaller forge and the larger heat treatment tank, just by switching them out. However, making a overly large gas forge does seem to be a kind of right of passage, so don't let me hold you back on that. I do think you will do better not trying to have one forge ( or even two similar forges) that you expect to perform all operations. One of the key benefits of making your own gas forge is that you can configure it to the expected operation. A bladesmith needs a different forge than a farrier or a smith who makes architectural screens and gates.

looks to me like you liner wasn't cured long enough before attempting to go up to full fire. Are you seeing any steam or liner co9lor changes? Most refractories benefit from a slow candling to drive out all moisture before setting. I don't think a single 1/2 brick should be a problem for a forge of that size if the burner is performing correctly and you allow the forge enough time to heat up. I've got two half bricks in mine and only 2" of wool and have no trouble getting up to temperature (different burner, needless to say, but still you shouldn't have that much trouble. My recommendation is curing the liner, checking the regulator to ensure you have at least 30 psi as a maximum setting, building some form of door and getting a steel support rather than the wood!

Biggest problem I see is that you appear to have used both hard firebrick and refractory for your forge lining. There are two different products that are both often (improperly I believe) called fire brick. One is relatively heavy, used for lining chimneys and kiln interiors and is usually called hard fire brick. This material is also a type of refractory, just brick shaped. The other is an insulating brick, light, friable and easy to cut with just about anything. If you have used hard brick, you have no insulation and your forge will be inefficient, a big heat sink and probably won't get very hot, unless your burner is greatly oversized. Of course if that is actually soft, insulating brick then you can ignore the previous.

I have been pretty happy with the Time/Life Home Improvement series of books. Presented for the novice with lots of good pictures. As regards use of a dimmer, there you do need to be careful. The best modern variable flow blowers are controlled by either a variable frequency drive (expensive, typically multiphase motors) or ECM (electrically commutated Motor). These vary the flow by adjusting the motor RPM. I'd prefer to have a electrician or electrical engineer clarify, but I think that conventional dimmer switches work by bleeding off some voltage into a resistance coil. Typically synchronous motors don't appreciate this method of speed control. Of course I could be totally off base, but I would also recommend a outlet blast gate or inlet shroud for volume control rather than using the dimmer unless you know your motor is rated for that kind of control.

You might want to consider wiring in a switch for the blower when you hook it up (or using a power strip with a switch). Kind of convenient to be able to just switch off your blower rather than pull the plug when you are done using it. Get some kind of basic electrical wiring book out from the library to make sure you wire the plug correctly. You want to switch in line for the hot lead (black wire in both the outlet you connect to and the lead on the motor). We have prominent, certified electricians on the forum who can give you better advise, but I'd bet that you can get by with #12 or possibly even #14 wire for such a small motor. Small wire nuts or crimp connections to make safe wire joints and keep those joints inside some sort of metal box.

No direct experience with these, but heard they may have plastic gearing. If so, I would be leery

Consider going to a hobby shop and getting a better grade of thin plywood (aircraft grade, multi ply) rather than the cheap 3 ply available at big box stores and the like. If you preseal the plywood with some form of paint or lacquer) and use contact cement to glue on the rubber it should not warp. Needless to say, don't stretch the rubber over the plywood when gluing on, just lay it on the surface. Sealing the plywood will help in any case as you don't want it to warp over time due to humidity fluctuations.

In addition to the golf ball trick (which I have also used to good effect) I have found that old wine or champagne corks make great handles for jewelers or needle files. After years of those darn things digging into my palm I can finally use them comfortably. My wife takes all the credit as I saw that she used something similar on her old copper plate engraving tools that were unearthed in a recent cleanup.

My recommendation would be an initial coating of colloidal silica to stiffen the blanket, then a final coating of refractory. There are many options for the final coating: 3,000 deg. F rated furnace cement: cheapest option and readily available at big box hardware stores. Apply in multiple thin coats to build up to at least 1/4" thickness. Down side is that it is rather fragile and prone to cracking away from the surface. Mizzou refractory: rated for the temperatures expected and fairly resistant to flux. Downside is that it is not as easy to source, more expensive than furnace cement, needs to be cast in place in one monolithic section, if possible, and may crack from thermal cycling. Also typically a minimum thickness of 1/2" will add more thermal mass to your forge, but if correctly installed and cured should last for decades. High Alumina castable refractory (Greencast 97 or similar). Same as Mizzou, but even more expensive, harder to source (go to industrial refractory suppliers and ask for a "sample") and flux resistant. "Bubble" Alumina Refractory: Lighter, flux resistant and even more expensive. I have limited experience with this material, but did use it in the bottom of one of my gas forges for flux resistance to good effect. A final inner coating of a IR reflective material (ITC 1000, Plistex, Metricote...) is reported to make the forge more efficient, but needs to be renewed periodically.

Goodness that's a cute little hammer. Would love to have one like that, but neighbors are too close.

Angled or curved handle is traditional on these hammers for a reason.

Just beware that you might have too much gas/air output for your burner outlet, but not for your forge volume/insulation/thermal mass. You might need a larger burner flare to get the most from your burner. It's all about relative velocity. 1/4 should be good for control authority provided you have enough pressure. Control valves are a tradeoff also. I'd try a larger flare first

From the video it appears that you have too much fuel/air flow for your nozzle diameter. The mixture appears to be moving away from the burner faster than the flame front is burning back. Visually it does not look like you are getting complete combustion, but you may be further in the chamber. I believe that you are right that you will get batter combustion as the forge heats up, but you will likely have some trouble turning down the system to low fire. I also agree that some form of metering valve is better for the gas line. Generally I would suggest a globe type valve at least 1 size smaller than your line size (for good valve authority) for the gas and a gate or butterfly valve for the air side.

Looks like you did an extremely professional job. Looks like you even have an SCR on your electrical circuit. Does the chamber maintain good stability at setpoint? I assume that you are planning on using it for melting non-ferrous metals. Most Nichrome wire heating chambers I've seen don't last long at the temperatures needed for steel/cast iron...

Most local codes here in the states are based on a version of the following International Codes: http://codes.iccsafe.org/I-Codes.html Of course your local may be different, but the link above is a good start to looking up info for yourself.

I think his stuff is very high quality and well worth purchase if you want to get right to hammer or axe making. On the other hand, if you are ready to forge large size stock of that nature, and don't mind making tools, forging a drift for yourself isn't all that difficult. Does go much faster if you have a striker or power hammer though.