Buzzkill

Frosty, I learn something new every day on here. That's what keeps me coming back. Well, that and I love to see what the next play on words or pun will be. MonkeyForge, it is normal that the burner will not burn outside of the forge without a flare on it. There are a lot of factors that go into what the "right" pressure is, but I will say that 21 psi sounds really high to me. On my 3/4" Frosty T burner I usually forge around 8 psi, but my elevation, humidity, etc. is likely different from yours so don't try to match what works for me or anyone else. If the burner is functioning correctly, you want it to heat your forge to the desired temperature without blowing a bunch of excess heat out the openings. My guess is that at the pressure you mentioned you are burning more fuel than is needed, which just costs more money in the long run.

Weird. I saw the pictures yesterday and it's gorgeous, but today the pics are gone and just a string of alphanumeric characters instead.

Mikey, It appears as though the orifice size for the jet is approximately 0.06 times the inside diameter of the tube used in the burner and the tube length is about 9 times the inside diameter. Out of curiosity was this discovered through trial and error or was this a specific calculation that you found when working with burners? If that's a decent way to determine jet orifice size for a given tube then it would be as easy for those using the metric system as it is for those of us using imperial measurements to relate the two without any conversions involved.

I made something quite similar. I used fire clay, white (silica) sand, styrofoam, and Greenpatch 421. This was nearly 3 inches thick in my forge and it would take over an hour of operation before the outer shell got too hot to comfortably lay your hand on it. However, as I look back on it now, I would recommend just buying a quality insulating blanket material and a good refractory for the hot face. You'll save yourself a lot of time, effort, and probably money in the long run. My refractory mix worked, but was very heavy (my forge weighed as much as my anvil), and after use it took a couple hours to cool down to the point where I was comfortable handling it. There is a reason that some things have become a standard. This usually happens when lots of people try lots of ideas and a large number of them come to the same conclusion after the experimenting is done. Take it for what it's worth.

All of this discussion should be in the context of the original post. He's clearly NOT going to have a storage tank with thousands of gallons capacity. I agreed that there is danger and continue to do so. I questioned, and still do, whether in the context of a small forge the danger is any greater from diesel fuel than it is from propane or the fact that glowing steel is repeatedly struck with a hammer. A diesel or kerosene burning forge functions nearly the same as a torpedo heater with the notable exception that we try to keep the heat in rather than blow the heat out. Those devices have the fuel tank mere inches from the business end that is glowing orange and has open flames behind it when running and they typically hold about 10 gallons of fuel. I've never heard of one exploding that was properly functioning and using the designated fuel. I tried to think of a scenario (again in the context of a small forge and consumer quantities of fuel in storage) where your expressed concern is likely to occur. The only thing I could come up with is a hot forge with fuel going in and the air shutting off. That could create the situation as the oxygen in the forge would quickly be consumed, but the temps would still be high enough for some time to quickly vaporize the fuel after the flame was out. Other than that it's a highly unlikely concern. Perhaps I did mistakenly make the assumption that the OP would know enough to operate the forge outside or in a well ventilated building and to store the fuel in closed containers. Is there danger in burning a fuel oil in a home forge? You bet there is. Is it significantly more dangerous than LPG used for the same purpose? Not in my mind, but each to his own.

I'm not looking to pick a fight Frosty. I work with diesel fuel every day. It's not an assumption it's fact. Vapor pressure and vapor temp are not the same thing. Diesel simply doesn't evaporate quickly enough to saturate the air at normal temperatures in anything other than a small enclosed place with no air movement.

True enough Frosty, but the main difference is it has a very low vapor pressure. It's not going to evaporate much unless significant heat is applied without a direct flame. If there is a direct flame it will burn as the vapor is created as long as the oxygen exists to support combustion. The point of a fuel oil boiler, forge, furnace, etc. is to burn the fuel as it enters. I guess if you had it up to temp and for some reason the forced air stopped but the fuel kept going in you could create the scenario you warn about, but that would pretty much require someone to leave the setup unattended (or be inattentive). Technically it's not a true explosion either; it's a rapid burn, but that's of little consolation if it happens. The same statement can be made about fine particles of anything flammable in the air as well. There is a ratio of air and fuel for most things that will burn that only needs an ignition source to create a rapid burn and effectively explode if there is any containment such as building. One of the local coal-fired power generating plants has had at least 3 coal dust explosions that I can remember over the past few decades. Not that I suggest anyone ever try this, but I have put cigarettes out in a small container of diesel fuel just to make a point to someone. As you point out it's the vapor/air mix that's really dangerous, but in general the scenario to create the problem you describe is fairly rare. If it wasn't then there would be a nasty *whooomp* every time a torpedo heater kicked on and it would probably blow apart. I guess while I agree there is some danger there and it should be taken into account, when we're talking about a practice involving pressurized flammable gases and/or hitting heavy pieces of incandescent steel with hammers I'm not sure this danger rises significantly above the others.

That sounds quite similar to a blower I got for Christmas. In the end I took it all apart, cleaned it up, polished the shafts on the buffer, put a thin layer of grease on all the shafts and put it back together. After I did that the vibration, noise, and extra resistance went away. I put the appropriate amount of oil in the case after that and haven't had any more issues with it, but I've only used it for a few hours. My impression was that one or more of the holes for the shafts were worn a bit to allow a small amount of movement. That coupled with a dry shaft essentially allowed for a chatter effect of sorts. Without hearing your blower I can't tell for sure if it's exactly the same thing as mine, nor am I 100% sure that my diagnosis is correct. All I can tell you is what I did and that my problem went away as a result.

Another tip. If you're trying to move steel that thick you need to concentrate the force into a small area. If you use your radius edge with the hot steel hanging over a bit and the back edge lifted off the anvil and then strike so the hammer face is half on/half off the anvil when it lands on your piece, you get all that force right on the corner. Move the piece a little and repeat. This will create waves in your hot steel, but it moves the metal much faster and it's fairly easy to flatten the piece back out by laying it flat on the anvil face after you get it thinner and/or closer to your desired dimensions. Even with that technique you'll probably want a heavier hammer to do that work, but regardless of the hammer size you want to get the maximum effect out of each strike and that will help with thick pieces.

Here's my 2 cents: It can be done. Whether or not it is worth it to you I can't say. I built a home made siphon nozzle system which used compressed air to pull and mist the used oil and a blower from the power vent of a hot water heater for the forced air. The benefit of that is it only pulls fuel while the compressed air is flowing, so you're less likely to end up with a big puddle of oil like you might with a gravity fed system. It was a bit difficult to start sometimes, so I usually fired it up on kerosene or diesel and switched to the used oil once it got hot. Here's the down side: Used oil (motor or veggie) changes viscosity significantly with temperature. In order to maintain a certain temperature over time you have to have the same fuel and air ratio. This can be done as simply as a drip system and a blower with an air adjustment or some kind of pump to deliver a constant stream of oil under pressure. For my siphon nozzle system the change in hydraulic pressure from full to nearly empty in the container I was pulling from was enough to require frequent adjustments to the fuel/air ratio. It was different from day to day as well since the ambient temperature affected the thickness of the oil and the ability of the siphon nozzle to pull in the oil. I probably went too complicated, but in the end I figured I was spending more time fiddling with the controls than banging on hot metal so I converted it to propane and haven't regretted the decision. I'm sure there are others who had a more positive experience with a used oil forge and maybe one of them will chime in.

One other side note. The holes for the air on your torch are very near the burner tip. It's quite possible that you are at least partially blocking/restricting the air that is supposed to be mixing with the fuel. From what I've seen the recommendation for using a torch is to get one (like the one in the picture you linked to) which has the air ports further away from the burner tip to avoid that problem. I have only personally built 3/4" Frosty designed T burners, but he has stated many times that 1/2" burners work fine. You drop down to a .023 mig tip for those and use a 3/4 to 1/2 T IIRC. The burner tube length is shorter as well, since it is a multiple of the tube diameter. I believe the factor is 9 (roughly) so that would give you a 4.5 inch tube on a 1/2 inch burner. If I've gotten any of that wrong hopefully Frosty will correct me.

Nice work Theo. The green/brass combination always seems to work out well for some reason. Personally I'd rather see scale the entire length of the spine or not at all, but that's just me. I do like it and when I see those designs I wish I had the setup to make brass pieces like that.

The forum goblins keep eating my responses. Search for this on the forum : BP1048 Side Draft Chimney

5 gallon buckets tend to be around 10 1/2 to 11 inches in diameter if I remember right, so in principle it would work, but cutting the bottoms out of a half dozen or more and fastening them together in a way that you don't have a lot of air gaps which would reduce your draft at the forge seems like it could be a problem. You could do the whole thing with stove pipe. Zip 2 5" pieces together for a 10" diameter or a couple 6" to get 12" diameter. Put a T where your fire pot is and you're golden. Easy to break down and set up as needed.

Good point John. It makes me wonder if I could forge some stainless san mai that thin and get the best of both worlds. It's a bit on the expensive side for experimenting though... Anyone ever try that in a filet knife?

Thanks for the responses. Based on what I see for the heat treat on L6 it's out of the question. I probably should have added that I don't have any equipment to accurately hold temperature or raise/lower temps in steps over time. So far I haven't done anything more difficult than O1. I guess there's always the option to send out for heat treating, but I prefer to do everything myself if I can. I'm a little surprised that the 1084 could get the needed flex and still have decent edge retention, but I may have to give that a shot.

I've had a request for a filet knife, which is far thinner and more flexible than anything I've made to this point. While I consider it beyond anything I can reasonably accomplish right now, I'm wondering if anyone who has forged a filet knife can suggest a good steel for the project so I can get some practice materials. I'm fairly sure the heat treat is critical to get the desired results, but I don't want to start with a steel which doesn't lend itself well to a thin and flexible blade. If you have pics I'd love to see those as well.

The magnets and chains are for noise reduction. It quiets the ringing a bit.

Stormcrow, if you don't feel compelled to watch the show when it airs you can stream directly from the History Channel later. I'm not sure what the delay is though. BTW I'm a fan of your work and always look forward to seeing what you'll post next.

How about a drift of blacksmiths?

No eye protection either. That guy is just asking for a painful woodchip to the eye. It is hard to beat that one. I didn't know whether to cringe, cry, or laugh .............. so I went with laugh.

See if you can spot the safety issues in the following photos:

I respectfully disagree. If the protection restricts your movement or vision to the point where it crosses the liability/benefit threshold then it is too much protection.

Thanks for the response. I too was building on a budget and I managed to get the 1hp agricultural motor from HF for under $100 and the only other motors they had at the time were compressor duty so I thought I'd try it. Now I think I'll get a 2 hp from WayneCoe and move the 1hp to an old table saw whose motor quit on me a while ago. I went so far as to make a wooden drive wheel which was a bit of a challenge without a lathe, but it works. I also used skateboard wheels and bearings for the flat platen and tracking, but I can't really recommend that. I've only had to replace one set of bearings and I do like the way the steel feels on the wheels when I do direct grinding, but it's just not heavy duty enough for long term use. I also tripped the breaker on mine once before I realized the lights and another outlet, which was powering halogen work lights at the time, were on the same circuit. It's an uneasy feeling when everything goes dark and you have to try to remember where everything was between you and the door or breaker box. Now I use a different circuit. I also only have a single 220v circuit which my buzz box Lincoln is plugged into, but since I'll never be using both appliances at the same time I will probably go the 220v route on the next motor. I tried babying the belts some, but it didn't seem to pay off for me. I've read on here to use the belts as if they are free and replace them as needed. From my limited experience I have to agree. I wasted more time and effort trying to get a little more life out of a belt than if I had just switched to a new belt, and if I was trying to grind too lightly to "save" the belt life again I would end up wasting too much time to justify it. YMMV. I do keep partially worn belts to start grinds that would strip a lot of abrasive off a new belt and I hang on to some broken belts that have life left to use like emery cloth for handle shaping and such, but in general for me it works best to use 'em hard and toss them when they stop cutting well.