Robert Simmons

That would invert the situation and the shop would have a higher ambient presure than the surrounding air. As a result, the air will seek any crack it can to escape. It might go under a toor, through a small hole, you name it. It wont, however form a cohesive flow to the vent unless the shop is absolutely air tight elsewhere. Dont get me wrong, it can work but it wont be as good as negative flow. Instead I would supplement the swamp cooler with a roof fan that can pull more air than the cooler can put out and a secondary louvred vent to make up the difference. Having the fan be able to pull more means that no matter what order they are turned on, the shop will quickly reach negative pressure.

Wow, looks fantastic. Great job. I have been trying to locate good forging hammers that dont cost an arm and a leg. At the local farrier they want 100 bucks for a 2# hammer! Any suggestions on where to find them, other than your obviously accomplished hands?

[quote name='Geoff' date='25 July 2010 - 03:25 AM' I used 8mmx10mm stock cut a piece off and welded it to the reign. I used high amps so that I got good penetration. Then I forged to shape, drilled and riveted.

I personally love vice grips but I came from welding and fabrication and am new to smithing. Perhaps there are better ways when smithing. I have probably 50 pairs of vice grip clamps with all manners of jaws welded to them for holding things like round stock and square stock securely. In fact I was trying to think the other day if blacksmith tongs could be altered to use some vice grip style mechanism without being inconvenient in using them.

Yes. Silly typo that I didnt catch, thanks. I have one of the following in the roof of my garage: http://www.homedepot.com/h_d1/N-5yc1vZ1xhf/R-100073799/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

One more tip I thought of. If you have a wall AC unit, it may or may not deliver enough air to compensate for what is being drawn out yet you may not want a normal open gable vent because warm air might be drawn in in the summer. One solution to minimize the warm air is to get a gable vent that opens depending upon air pressure in the shop. There is no motor driving such a vent, it opens via the low pressure in the shop and closes by gravity. The louvred vent will supply only the extra air that you need to supplement the AC. A friend of mine has his weld and fab shop set up this way and it stays comfy and fume free.

Hmm I tried to read between the lines. Since you didnt mention it, I assumed it was a rejection of the idea. Thanks for clarifying.

Just a note, DO NOT USE an acetylene regulator unless it is specifically rated for propane. That would be dangerous. Propane can cause the parts in a pure acetylene regulator to degrade.

I have a cheapo regularot from a dealer of propane tanks. I want a Victor Edge regulator but alas it is not in the current budget.

Ya can snag an exhaust fan from home depot for 50 bucks. All you nneed is a bir of roof mastic and a reciprocating saw and it will take an hour to install and wire.

So you dont think taking the flare off and flaring with castolyte would work ? I wonder what a solid Tungsten flare would cost :)

I have read a few comments from people who, after feeling dizzy, decided to purchase a CO detector for their enclosed shop and were surprised at the high numbers that the detector would have even though their garage door or shop door were wide open. At the same time my CO detector remains at 0 without my garage door open but only a roof vent fan on. Now I cant stress enough the importance of a CO detector. Whether working with coal or propane CO buildup can send you to the morgue. Your body detects that you need to breathe by the amount of CO2 in your body but CO will push out oxygen WITHOUT triggering a gasping response. This is why pooled gasses like Argon from welding and CO have killed people that haven't even thought there was a problem. Back in the dark ages of my youth, over 17 years ago, I was a volunteer firefighter and I learned something important about air and heat and thought it would be interesting to pass it on. One large open window or door does not make airflow. To achieve airflow you must have an entry point and an exit point and something moving the air. So two doors open on opposite sides of the shop wont do it either because there is no driver. One fan in one of two openings in the shop is only marginally better because the air blown in can pool and back pressure and go back out the same door it came in. So setting a box fan in the door of your shop will do little more than keep you cool. The optimum setup is a large, powerful fan mounted high (on the roof if possible) and an opening on the other side of the shop as LOW as possible. If you have a door to your shop, install a roof fan that moves 1000cuft of air or more per minute opposite the shop door then make a little quarter door by cutting your shop door near the bottom and hinging it so the quarter door can be open when the main door is closed. A better alternative is keep all doors closed and put in a gable vent as close to the floor as possible. Gable vents made for the roof of the house usually have bug screens and can even be louvred for automatic open and closing. What happens when the fan is on is that there will be negative pressure in the shop generated by the air being pulled out of the shop so the atmospheric pressure in the shop will drop. The air must come in from the other side so it is sucked in strongly. Now you have air flow. You place the vent near the floor so gasses that are heavier than air can flow back out the vent (such as argon) and cant pool high enough to be dangerous (think of a glass with a hole cut in it so it cant overflow and drown what is inside of it.) This configuration will keep your CO meter pegged at 0 while you have all doors closed. You can even run the AC just make sure the AC isnt the only inlet for air in the shop. If you open the garage door much at all, the low pressure zone will be compromised and the air flow will again become chaotic and ineffective at getting rid of the nasties. Incidentally it works for the car as well, isntead of all windows open, open only the front driver's side and rear passenger side and note the massive difference in air flow. The dynamics are the same for the house and so on. Anyway, just thought Id offer that tip.

That is a common misconception. A huge open door doesnt necessarily mean you have airflow. Without air flow there is no ventilation of gasses.

Greetings, I am working on a forge designed from a 30 gallon barrel with 3 inches of ceramic blanket (coated with castolyte) and 2 inches of cast castolyte on the sides and top. The bottom will have three inches of castolyte cast. I had planed to make my burners enter so that they come in about halfway up the arch that will be in the center and then point up at the roof of the arch to promote a swirling effect in the forge and reduce back pressure. I also didnt want them comming in at the top because I dont want heat backing up into them if possible. I had even thought of having them come up not through the floor but just above the floor pointing mostly up. Anyway, my test torches have cast iron flares on them to hold the flame and reduce the gas pressure enough to retain the flame on the torch. What I am wondering is if I should include the flares when I put the torches in the forge. The problem of course would be melting or other deformation of the flares. I had already decided to have the torches stop one inch short of the inside wall of the castolyte to protect them from the heat. Perhaps even 2 inches would be fine. I could cut the torch holes so that the holes are only a very small amount larger than the actual burner pipe. In this manner perhaps I can make a cone out at the end of the cast castolyte tube to act as a flame holder in the forge itself. Imagine the pipe has only a 1/4" tolerance with the tunnel in the cast wall and at the interior side of the tunnel the 3/4" flares to 1" cone. I have heard that some poeple use stainless steel flares. However, I dont understand why when stainless has a lower melting point than black iron. What am I missing here? Do they put the flares all the way in the forge? Thanks a lot for the feedback. -- Robert P.S. On I have a cool test showing the effect of gas jet placement in a venturi driven burner. If people are interested I will record it and post a vid.

Thanks. Can I coat my forms with something so that they will release from the castolyte? That way I can make solid wood forms out of thin plywood and still get them out of the middle without burning them out or risking damaging the castolyte. Perhaps wax coated wood where I can melt the wax? What kind of firebricks should I use on top of the 3" thick castolyte floor? Insulating, soft or hard? Other suggestions? Thanks a bunch.

Yeah, it works in my brick pile forge well. As for the new one I am building, we will see. My question would be what is the distance between the burners and the piece in the forge or the opposite wal the burner is pushing into. The back pressure may be causing problems for you. I am not an expert or anything but I know the orientation was important. When I had it firing down into the brick pile, it had a hard time, when I fired it sideways and a tiny bit up, it did fine. It was angled to hit the roof, just before the wall opposite the burner so that the gas would bounce around and not merely reflect back. Maybe tinker with your angles and see what you get? Took me a bit to get just the right spot.

I am considering buildign a forge with a 12" x 12" interior floor that has a 4" straight height and ends in a dome that extends up to 7" in height max. Think of it like a cut arch design. I can easily make sheet metal do this for me without a problem One sheet of 1/8th, a torch to heat and some angle iron will bend the sides up and a dome is pretty easy with bent sheet metal welded to front and back forms. The problem is when we get to insulation design. The forge would be powered by two 3/4 inch with propane burners with 1" flares entering from the right side along at the top of the flat rise off the floor. Finally I want the inside 1/2 to 1 inch be catalite 3000deg refractory and that would be wrapped with 3" of kaowool on the top and sides with 2" to 3" of castalyte on the floor. The problem comes in trying to fugure out how to put the KAO Wool on the outside ad castalite on the inside without compromising either. I had thought about starting with the KAO Wool and then wrapping that inside with a 2" tube cutouts for the burners. Then I would tip the shell on its end (so the two open ends are up and down and then take mixed castalite and put a half inch layer over one end, flip it over and put a half inch layer over the other end and then line the walls with it and finally line the tubes welded for the burners with half an inch of castalyte as well. Finally the entire interior would be lined with ITC-100 coating. The problems and questions start there. First of all would I be damaging the KAO wool blanket by placing castalite right up against the KAO Wool? I dont know what the water content in the cement would do. Naturally I would let the whole thing thouroughly dry and SLOWLY fire it the first time but I wouldnt want to damage the blanket with the moist cement. I also dont want to crush the blanket and lose its insulation powers. When it comes to the floor I thought about putting another inch or two so of kaowool under the floor and cutting holes in the KAOWool and filling the holes with castalyte. When it dries the holes would form pilars that would hold up the floor from crushing the KAO wool. I could then weld the bottom on after all has dried. Questions: 1) What do you think? Am I nuts? 2) Do I have to worry about water or crushign the KOA Wool when forming the roof? 3) How logn will I have to work with the castalyte after mixed? Will I be able to mix it like putty and hand sculpt it or is it a pour type material? 4) Any tips for getting a good smooth cast wall? I had thought of inserting a final heavy cardstock wall to the inside shape after the cement is on. This wall could burn away in the forge if needed. Also another material like super thin sheet aluminum was considered given aluminum's low melting point. 5) Anythign else I am missign? One other thought I have would be to pull off the current flare on my torch and replace it with one lined with 1/2 inch of castalyte and have that be the flare rather than some metal. I dont know how well that would work.

I dont want to rehash the gloves debate. As for OSes, I just cant be bothered messing around with Linux when off work. Id rather things jsut work. If I want to spend dozens of hours screwing with a config file, I will go to work and get paid for it. Mac OS is BSD unix with a slick UI and easy administration. best of all worlds. Once you go Mac, you cant go back.

Thomas, not trying to be a snipe or anything but I have had my regulator so far down on my regulator that you cant see the diff between 0 and where it is at and my regulator goes down to 1 psi markings. The burner was still stable and the flame was still neutral. So I can run it at vanishingly small amounts of propane. I was trying to test how low can the burner go and it only flamed out when I had the gas completely off.

This is something of a religion debate in most smithy circles. There are advantages and disadvantages to both. However, the atmospheric forges are safer. If there is a power failure or the failure of the blower on the blown forge, the flame will soon go super rich and then blow out from lack of O2. The propane will then pool in the shop and wait for someone flicking on a light or throwing a grinder spark to make the evening news. An atmospheric forge is aspirated via the venturi effect and requires no electrical help. You can walk away from it for 20 min if you want, I wouldnt walk away from a blown one. Just make sure you have lots of airflow in the shop with either, they both eat oxygen like candy and thats oxygen not available to your lungs. On the other hand there are advantages to blown forges. I just prefer to err on the side of safety and simplicity. My personal opinion only, not to be taken as gospel on anything.

I appreciate the various encouraging posts. I was feeling a bit like a skunk at a perfume trade show. Well anecdotal with a lot of evidence at the very least. But I ask where would we be as a culture if we said "that works, dont change it" rather than, "what if I ....." Anyway I am not passing judgement on anyone and any design. I was only trying to share mine. Thats all. Two sets of three brass set screws. One set in the far back, one set in the middle of the coupler. Brass so they dont mar the jet tube. I could try to build a straight line burner but I read (from Reil himself and others) that the burner was unstable at low pressures and prone to flameback. That is why I went with the side ported design and it works well. I can crank my propane WAY down to barely on and the burner holds. It even seems to self choke as I never had to adjust air flow at any point in the drop from 20 to 1 psi or lower. I think If I back the jet up maybe 1/4 of an inch the flame will be perfect. I am a mac guy. Its just the standard Preview image viewer that comes with any mac. I have been programming computers professionally for a long time and cant be bothered wrestling with windows when I dont have to.

You know somehow I still think handling potnetially burning hot metal with potentially extremely sharp edges is better done with a good pair of gloves but I am not allowed an opinion because I am new here. I think it is, yes, crazy, to be tossing around hot metal bare handed. I am not allowed that opinion either because I am new here. I grant that great points have been made about gloves around rotary machinery. I am not credited with that either. Sorry, I have trouble genuflecting to the "vetrans" when 7 years of welding an fabricating, and all the classes I have taken in metal work go to the opposite. But again I am not allowed my opinion because I am new here. Sure I havent smithed nearly as much but I have been around metal shops most of my life. But again, my opinion doesnt matter. I really suck at discussions that involve people saying "I cant justify an argument but you suck because I have been doing this longer." Am I perfect? Oh god no!! Am I a complete asshole? I dont think so but of course it is possible. Do I know it all? Definitely not. Can I be swayed by rational argument? Absolutely! Do I do well with "veterans" that lack empirical arguments? No, must be a character flaw of mine - never put too much creedence in authority or position. Clearly I am a poor fit for the forum. Good luck to you all. Even those flaming me for expressing an opinion. I wish you the best.

Thanks for the comments on the burner. As for the rest .. BAH nevermind. I shouldnt have come here. If the simple act of discussign the science or having the gall to question the "genuflecting" vetrans is offensive then the forum is not conducive to discussion and I wont fit in. I like to discuss thinge empirically and I really suck at dealing with people that say "Well I have been doing x for so long so you suck newb." I really dislike that. I prefer to discuss on scientific or empirical basis. It just seems I am not a good fit for this site. I tried posting a couple threads and people jumped down my throat. Am I perfect? No way! Am I a complete asshole. I dont think so but anything is possible. Heck, even this thread which I expected would be pretty cool and took the time to label my picture and so on ends up offending? What a waste. My disappointment couldnt be higher. If the goal was to drive away, it has succeeded. Good luck to you in the future.

Well there have been some good points made in the thread and I rad every post. The points about lathes and rill presses and gloves are definitely worth the thought. At least peopel are talking aobut safety. It seems people have varying levels of comfort and that is cool, that is why we live in a free country. My intent wasnt to anger people but to ask and to probe and to question the very essence of what we do. Do you value the empirical discussion or is the potential blow to the ego too severe to even countenance a debate? I love the other points made on the thread about rotating machinery and gloves or the hazzards of non gauntlet gloves or even the "hey its my personal choice and I take the risk." All of those are great comments. Yours, Sam Thompson, just came across as arrogant, spiteful, condescending and elitist.

I really dont see how I could have written it otherwise. How is saying particulary offensive or pushy? How would you have written it short of not writing it at all? If its not written at all then what is the point of a discussion forum where one cant discuss? I am not trying to agitate anyone, just discussing things scientifically. I would NEVER presume to give advice or discount advice on smithing as I dont know jack xxxx compared to many people about that. However the design of a burner doesn't have much to do with smithing other than being one application of the burner. Now I am no albert einstein or anything but I did manage to pass my physics and fluid dynamics classes in college. I could be wrong about 5 dozen things and Id love to hear where I am wrong but scientifically and not just "yeah you suck newb" or words to that effect. If someone says, "Well Robert, actually turbulence in mixing isnt necessarily a good thing because ... " then they will have my rapt attention. I am just not very good at saying, "Worked for me, you must be wrong" especially when Reil himself in his own pages didnt stop with the cross tube open burner but progressed to a design upon which I based mine (namely the mongo). He himself identified several of the issues that I apparently xxxxxx people off talking about. I am afraid I dont get it. I dont think I am below average inteligence but I dont get how what I have said in this thread is particularly offensive. Even in the safety thread, there were good points made on both sides and I learned some things but I dont see how that thread was offensive either. If we reach a point where we no longer question what we do on a day to day basis, then havent we stagnated? If we do things merely because others have done so, without being able to justify them empirically, arent we falling into a trap? Well again, my intention wansnt to xxxx anyone off, just to share thoughts with others of like mind. If I offended anyone then that wasnt my intent. I will shut up now and move on. I will just accept that my design is xxxx and I dont know anything and have no business even trying to work on something or share and be done with it.