Latticino

Just love that term. Got out to the shop today for a bit. Forged up a Cable Damascus billet, third one ever and first forged completely in my residential pressure natural gas forge, all hand hammered with no striker. Worked great, with no chance of burning out wires, but took a bit longer than usual as I was attempting to forge the 1.25" cable to a 1" x 1" billet size. Did the whole forge ends, untwist and flux, heat and twist very tight, then forge weld, twist again, draw out to rectangle, cut in three, forge weld sections and twist one last time process. Does cable decarb...? Wanted to use this billet for an integral chefs knife, so plan on forging pretty thin.

2 second Google inquiry: http://www.brentbaileyforge.com/

It is a very large file, perhaps your carrier didn't allow the transfer.

There is an interesting, relevant, excerpt from the 1914 Machinery's Handbook (page 1132): http://www.woodworkslibrary.com/repository/machinery_handbook_for_machine_shop_and_drafting_room_1914.pdf It substantiates the brine solution/faster than water/faster than oil under typical conditions. This book was published when on site heat treatment was a more common part of a machinist's job and I would tend to believe it. My personal theory is that the elevated boiling point of brine has a lot to do with the difference as in an agitated bath (as recommended by most heat treat manuals I've scanned) the local vaporization of the quench media near the stock would be delayed longer. I can see this allowing better heat transfer.

Personally I like rectangular faces for all hammer faces that are not the ball on a ball peen, rounding face on a rounding hammer, or cross, straight or diagonal peen (though arguably these last are rectangular in crossection). I prefer rectangular because I find it easier to dress this kind of face to the profile I need for more or less aggressive forging.

Yes it is all about size, specifically BTU output per crossection area of burner outlet. If you look at the older furnaces you reference you will see relatively large banks of burners. I expect if you were to line the entire interior of a smaller forge with castable multiport burners you could get away with using residential pressure natural gas and NA burners. Of course that might provide a problem for insulating the chamber... By all means build one and try it out. Would love to hear back on your results.

Haven't been to Portugal in over 25 years (great place, went there on our honeymoon), but if I ever get back I'll have to take you up on that. Good luck with your swamp cooler.

Never got that hot here in upstate NY, but I am somewhat familiar with design for heat control from my glass blowing days. Of course the ideal solution is to build an insulated enclosure around the heat producing equipment that is exhausted to the building exterior. Since you need openings to access your forge area, size your exhaust for 100 '/minute air velocity at those openings (ie. if you have a 3' x 7' door size opening to get close to your forge, you will need 2,100 CFM of exhaust to keep the forge heat out of the rest of your facility). Needless to say this is easier with a gas forge than a coal one that you constantly have to tend. Then the next step is to replace that air in your forge with the coolest air you can source. When I had a glass studio in a large industrial building I was able to "steal" the cooler relief air from the rest of the building (large concrete thermal mass didn't heat up that quickly and gave me plenty of cooler makeup air). Other glass blowers thought my studio was air conditioned. Of course if you can mechanically cool the air that is even better. Assume that you will need around 56 BTUH of sensible cooling for each CFM to bring your 122 deg air down to a more comfortable 70 deg. Unfortunately that works out to quite a lot of energy cost (the 2,100 CFM from the earlier estimate needs around 10 tons of Dx cooling). If you have a local source of cold or cool water you might be able to rig up what they call a swamp cooler, where a water spray on the incoming air evaporates and cools the air, but the effectiveness depends on the ambient humidity. There are other options, but most depend on your resources and what you are willing to spend. Edit: cross post with Thomas, who has lots more experience in dealing with forging in hot climates.

Being from Hungary I wasn't sure that the baseball bat analogy would fly, otherwise I would certainly have used it . That is the term I was searching for... Thanks for reminding me.

If you look carefully at the entire burner assembly for your stove, I think you will find that there is a section at the back of the burner where air is induced into the mixing chamber to join with the gas prior to the burner face ("flame point"). These often have adjustable chokes to allow you to properly balance burner operation for stove configuration and burner size. See "air shutter" in the image below:

Think of the vibration as a sine wave moving along the length of your hammer, from the head down to the handle. Since the hammer is of a fairly stable construction (very stable in your case) with all parts tightly bonded and struck in the same place, during impact the typical vibration of the hammer should be also in a fairly consistent pattern along its length. If you are still picturing the sine wave you can see that there are locations of large amplitude of vibration and ones of relatively minor vibration (for the major resonance of the hammer, not the minor harmonics). The node that Thomas mentions is the location of a minor amount of vibration (where the amplitude of vibration approaches zero). This is a good place to locate your handle, as when the hammer strikes an object your hammer will not "buzz" with the vibration created, potentially hurting your hand. This is also a critical element of good sword and pole arm design.

I saw that as well. Also noticed that even though he was obviously young and fit that he struggled quite a bit with the effort it was taking him to forge the Viking sword. Made me wonder whether he could have done better with a more conventional anvil with some more mass under the hammer. If you looked closely you could see that he had both an "I-Beam" anvil for straightening(with no sound deading, bet they turned down the mike volume for that one) and a rail track anvil placed horizontally. Another time this found me talking to the screen, trying to get him to put the rail track anvil on end and used more efficiently. Don't disagree with the judges decision on this episode, but do think that Clarence could have made very good use of the prize money to upgrade his shop. Thought he said that he came from a family of smiths, or at least one relative was one. Don't know why his shop was so sparse regarding tooling. Seemed like a real nice guy, especially when they reprised his first appearance afterwards, and we saw him helping out one of the other contestants in "unwrapping" a particularly thick piece of spring steel. Still would have loved to see JD Smith's home shop though. Based on his work I bet he has a great setup.

You have gotten a ton of useful response from more accomplished smiths than I, but if I can still be of any help... If you want to practice your welding I would recommend using the spring steel to hardface mild steel hammer bodies. Several reasons for this: Difficulty of welding the presumed 5160 to itself to make a monolithic hammer due to chromium content Difficulty of upsetting the 1" thick 5160 stock to the 2" size needed for the style rounding hammer you describe Ability of a composite hammer to have the desirable hard face with soft eye without differential heat treatment (you will still need to temper the faces, but it will be a lot easier) Trust me this will still provide plenty of challenge getting successful forge welds for this specialized hammer making. Getting the two faces welded on (do it before punching and drifting, obviously) will test your speed, accuracy, forge atmosphere and temperature control skills. You will be welding fairly thick stock and will need to use a number of tricks to do that well also. Your welds will be tested in use with fairly severe shock loads, so they will need to be good. I have made hammers with wrought iron bodies and 1075 faces, 1045 and 4140 monolithic construction, and wrought iron and 56100 faces. The only style I would caution against is the last. I have to assume that a proposed mild steel with 5160 would behave most like the first. I like my wrought hammer with the 1075 face a lot and use it regularly for forging. For whatever reason it has a "thwack" sound in use rather than a "ping" (for want of a better description), while still having a hard face and good rebound. Works for me, but make your own and tell us how it goes...

Guess that dates me as well, since I remember that also...

Here is a view of Brent Bailey's cheek plate (or bolster) and hammer eye drift (on the right). Similar can be made for axes. I think he also sells hammer and axe drifts as well as other amazing quality tools...

Completely agree with Thomas on sizing for commercially available handles. I have several axes I forged still waiting for handles as I am so slow custom fitting them. Cheek plate is set below the item being drifted once the cheeks are drawn down. Keeps them from being crushed. They can be punched with an opening that will fit a drift. Aspery has details on making them in his second book. I think Brazeal uses some cylindrical supports set around the hardy hole and used under his fullered heads to accomplish the same thing.

Looks like you are on the road to making some very fine tools. Have you used them as yet (best test for functional tools)? Is the axe mild steel with a high carbon bit forge welded, or mono steel (and if so what kind)? Up to you, of course, but personally I like to see the axe cheeks drawn down a bit. Of course you will need a cheek plate to finalize your eye in that case. Might consider using a different drift for the axe rather than the same flattened oval you used for the hammer eye. I've certainly done the same, but these days prefer a thinner, wider eye for an axe head (more like a commercial axe eye). Just my personal aesthetics, these look very functional as is.

For the other point of view, I like classes, but for me it is my favorite form of vacation. I'd rather spend a week in a class, sweating away and learning new smithing techniques, than the same week in Vegas, lying on a beach somewhere, or off on a cruise. Each to their own, of course, and a lot depends on your finances. Joining a local group is typically a lot cheaper, and you can set yourself up to forge at home for a nominal investment. Just remember that the experienced smiths in your local group are not being paid to instruct you, and though they are usually very generous with their time and advise, a good show of respect, enthusiasm and careful attention (not to mention a periodic box of doughnuts) will go a long way.

I am hardly an expert in pattern welding, but the procedure I listed is one of the ones that is successfully used for exposing pattern welding "texture" on knives that are layered with high carbon and nickel steels (i.e. 1084 and 15N20). It may be for Cable Damascus you can get away with just an acid soak as Iron Poet indicates, but I would at least finish the surface to get rid of the scratches. Those will certainly reduce the effect of the pattern.

Might consider grinding blade section, at least, to a finer polish, oil hardening, tempering, then finish polish and light 30% ferric chloride etch. You probably have a very nice pattern weld hiding there. You did all the forge welding work, why not show it?

I'm with Thomas on surfing the unread content. Works great for me, and I love this site and all the great info I've gleaned from frequenting it. Only issue I have with the format is the irritation of having to refresh the page every time I try to follow a thread onto the following page (i.e. going from page 1 of 2 onto 2 of 2). This is minor, and most likely related to my using Windows Internet Explorer on a Windows 7 machine, but don't have that issue with other forums I frequent. Note that one of the other "good ones" is Bladesmith'sforum.com and it has an apparent similar structure to this one. I've also participated in some Facebook blacksmithing sites but found them extremely poorly structured, impossible to search adequately and full of misinformation, some dangerous. Might be my inexperience with Facebook though. Many thanks to the moderators and owner for setting up and maintaining such an excellent site.

@John, wish we had a like button for that comment. Going to have to remember that one

Casting aluminum and silicon bronze is one thing. Casting steel something else altogether. Please do more research, outside of youtube, and try to avoid a Darwin Award. I have no experience with foundries so can be of no real assistance, but do know the temperatures and atmosphere control involved are very different.

Why use hose and quick connects at all? Hard pipe right up to your burner connection with 1" schedule 40. If you need to be able to move it put in an isolation valve (full port) and downstream union. Make the final size reduction inside the burner body where you can adjust the orifice size iteratively to match your blower output to the maximum pressure you develop with the gas. Since you are developing your own burner design you had better expect to do some testing and optimization. With low pressure gas supply, my policy is to get as much into the forge area as possible. Can always turn it down, but if you don't have enough you are out of luck. Residential pressure natural gas forges definitely can work, as I have built several at this point. I am still struggling with getting my multiport burner to work up to my standards, but have successfully forged and even forge welded in the existing unit.

I am not aware of any design guidelines for the mixing tube configuration for forced air burners. I believe that there are too many variables for potential configuration to set them, but in my mind the only drawbacks for a mixing tube that is too long is the potential to "stall out" your low pressure gas entry by requiring too much static pressure to overcome the friction of the mixing tube and the backpressure of the burner outlet. I use commercial burner components currently, Inadequate precombustion mixing is not the issue. The issue is the potential for combustion in your mixing chamber. Believe me you will know if that is occurring. It will be loud and quite scary. The mixing tube will also get hot. Manifolds can be difficult to balance. Typically some sort of valving is needed to properly balance the multiple outlets. I prefer to minimize any potential leaks after the air and gas have been mixed (like valves with packing). Initially I would stick with a single burner if possible. I have no information on flame speed other than you need to strive for a stable flame. The stable flame should be burning just at the burner entrance to your forge, and not either lifting into the forge or burning back into the mixing chamber. I am not planning on performing the calculations to validate the proposed equivalence between the orifice and long tube run. It is certainly possible that there is one, but you will need to do some rather tricky calculations to confirm it (Reynolds numbers and the like). My residential pressure forge uses a 1" hard piped NG line, for what that is worth, but the line runs at 1.5" underground for some 100' to the main gas house regulator..