Robert Simmons

Just thinking out loud but couldnt you cannibalize a Diesel injector off an old engine and use that to atomize the fuel?

You Must be going to get it really hot! I use it in my forges and have never had any issues with it. As for the expense 120 bucks for a 2 foot by 4 foot piece is not bad in my book. considering that will build a lot of forge. Good luck and keep us posted on your progress.

Are you asking about this because you already have these materials? Because if it was me, I would use the refractory board. It is rigid enough to stand up to your design. In fact I would use 2 layers for better insulation factor. Just a thought.

As I understand it, tool steel is basically high carbon steel with chromium and some other elements in it to inhibit corrosion. So I was wondering if it would be possible to take high carbon steel from perhaps a car coil spring and add chromium content to it. What I was thinking is that you could measure out the elements you want by weight and then pack it into a container in the manner you do to add carbon to steel and then bring it up yellow to austentite and hold it there for a while. I was hoping that the diffusion would absorb the chromium into the steel.

Do you guys think that is possible and safe (toxic substances wise)?

P.S. Here is a distributor of chromium powder.

http://micmet.com/chromium.htm

I was thinking of a way I would put a castable roof for the variable volume forge I am adapting from Frosty's design and I was trying to think of a way that i could make a lighter weight roof than simply casting the whole thing. Frosty use Pleated kao wool but it doesn't seem that he would do it again from our conversations. So my idea was kind of simple.

Basically I would build a box the Size of the roof out of angle iron placed one on top of the other so that it makes a T or perhaps a piece of a small scrap i beam. The idea is that the angle iron would extend into the castable and help hold it in place giving it support. Then I would put the frame over a piece of hardboard coated with oil for release agent and fasten it down. I would then pour a 1" thick layer of castable. After that (and while still wet) I would place in firebricks separated by about 1/2 an inch channel between the bricks. Then I would fill up the channels and put another 1" of castable on top of the soft bricks and smooth off then let the whole thing harden.

So what do you think, would that possibly work or am I kind of nuts here? If so, then why?

Thanks in advance.

Your nozzle/flare/what ever should not extend past you refractory. In fact it doesn't usually hurt for it to be recessed 1/2" or more from the inside of the refractory. Again, how long are you giving it to heat fully? It may seemto heat quicly to a orange but take a while to come up fully. Once to get your propane refilled (many will recommend a larger tank or manifold mutiple 20#ers. You regulator is NOT a BBQ regulator is it? They don't have the volume required. One design I have seen is to use and gauged needle valve in favor of a regulator. You can get more volume that way. I think your on the right path. Don't give up.

Well frosty's burner seems to be working much better than all others i have tried. I have welded up the start of a table to hold my brick pile so I can get it off my fabricating table. My fabricating table could hold a car if you could get it up there but it is overkill for the brick pile. I thought about getting some lockable casters, putting some expanded metal over the cross supports (because since they are there we might as well have a shelf, and putting in some other things. It could be the beginning of something great. However, the heat of the forge is still task number 1.

I had thought of putting the burner through the roof in a downward manner as frosty did but I still have to solve the problem of the flare that would melt in there if I give it a chance. I thought of devising a flame holder since the flame for that originates outside the burner tube but I dont know if that would help. Even the flare coming from the side was absolutely red hot. I am wondering if a flare with a piece of female threaded pipe embedded in a cast flare of castolyte refractory would work.

I have completed one of frosty's burners and it certainly is working great in the forge but it still isnt getting super hot. I can get it to a bright orange to beginning yellow fairly quickly but getting up to bright yellow or welding temps, I dont know what it would take. I upped the PSI to 15psi but then I started running out of propane.

I wonder if one of the problems I am having is the propane bottles themselves not letting me pull propane out of them fast enough.

Oh there was one issue. With the frosty burner the flare which was a piece of 1" ID pipe slipped on the 3/4, turned bright red and I imagine if I got the forge to welding temps, it would definitely melt.

Greetings,

I am looking to get a gas forge to be hot enough to forge weld in the forge. The problem is that nothing I try has managed to accomplish the task as of yet. I will detail my attempts and then let people comment on what could be wrong or whether i am just barking up the wrong tree and should find another hobby until I can get a coal forge and move out of the city so I can use it.

I started working with an atmospheric burner and I had a hell of a time getting the burner to function properly. When I built my first burner it was quite complicated in nature and it worked like a dream out of the forge. When I put it in the forge it sends lazy yellow flames leaping out the end as well as any other direction the gas can get out. If I used only that burner in the forge, I would be lucky to get metal much past cherry red. I have tried using reil burners and just recently I thought about building one of frosty's burners to give that one a try. I am having essentially the same problems with every burner I try. The burners are hooking up to standard barbecue bottles for propane and a regulator that goes up to 60 PSI but I haven't tried to put it above 20.

When it comes to the forge itself, I first trid to do a cast forge with castolyte 3000 deg rated castable refractory. I cast what amounts to a mailbox in a 30 gallon drum. The floor 9" wide by 18" long. I had planned ot use firebricks in the forge to reduce the volume of the forge and thus its heating requirements. My burner when I put it in there had the same lazy flames issue. I was able to add air through using a hair dryer and then I got complete combustion with no fire leaping out of the sides. Using the blower i was able to get that forge to get the metal say a orangeish yellow but no hotter, certainly no pure yellow. This is despite putting bricks in to further reduce the forge's volume.

So recently i have been wondering if I am going about it the wrong way with all this complexity and if I should just use a pile of bricks as a forge with a hole drilled in a brick to allow entry of the burner. The idea could be called the brick pile table forge. Basically you use 8 insulating brick and make an 18"x18" table top with the bricks. Then on top of that you can pile bricks as you want to set the volume of the forge. If you wanted to create a forge that was bigger you wpuld need to drill some more burner holes of course. The advantage is that I could have the forge basically only the size of two bricks stacked on each other most of the time but I would have the advantage of being able to reconfigure the forge to suit the task and easily replace any bricks that become damaged. So I set up a tiny forge the size of 2 stacked bricks in internal volume and with only the 1" original black iron burner to heat and fired it up. I used a hard brick for the floor of the reconfigured floor to be more durable. The idea was sort of like frosty's variable volume forge with a bit less complexity.

Again the flames leaped out front and back for a good two feet. The forge got bright red to orange hot but not much hotter than that. This is despite varying the propane from 5 psi to 15psi.

I am beginning to despair of getting a propane forge good enough to reach welding temps but also of even reachign temps appropriate to do really good forging. Hitting metal when it isnt hot enough makes the whole thing much harder to get into. I still love to do smithing but I just cant figure this out. Is it the burners? The forge? The propane bottles? I have no idea at this point. I haven't been trying to invent anything new really, just filching other people's ideas and ad adapting them to my financial situation. Anyway. Any advice of a constructive nature would be appreciated.

I am at my wit's end here.

-- Robert

Many people have no problem with "standard" burners at high elevations. I think you're drawing conclusions with precious little data. If I remember, you were unable to get regular burners to work at all. "Grain of salt" time, I'd say.

For high altitude I found that it works to introduce supplementary oxygen directly into the chamber via a blower rather than building a burner that is a blown burner itself. This completes combustion and almost all gasses are consumed inside the forge. You might try it. I am thinking of building a variable volume forge something like the one frosty has but I will be supplementing the burner with extra air flow to increase temperature and complete the burn.

Frosty,

Thanks for taking the time to reply. I have a forge but it is just too big for the small work I am doing as a beginner and thus I am thinking of your plan. I will have to check out your burners and see if I can build one in my shop. I tried a number of atmospheric burners and had trouble keeping them lit in the forge and then when lit they weren't producing complete combustion, instead producing long lazy yellow flames. I also tried a couple of directly blown burners but have had problems with those as well because my flame kept leaping off the burner and flaming out. So I went to a composite after one day accidentally directing my improvised blower (an old hair dryer) into the forge and saw the forge suddenly roar to life.

I dont know how the vertical up burners would work. I would worry about dripping molten flux into the burners but perhaps it could work. I dont suppose you have an opinion on 90 degree directional burners like the two in THIS pdf. The other problem I woud wonder about is back pressure with the burners shooting right at the floor only 3 or 4 inches away. Clearly you resolved that with your tuned burner. I would love to know how.

Anyway, I also was wondering how you cut the holes for your burners. I heard that you ditched the soft brick on top in favor of pleated kaowool packed tight. How tight did you have it packed? How thick is the resulting pleated kaowool and how did you punch holes for the burners through that? Also I noticed you use only a single layer of soft brick for the bottom insulation? Is that enough to make the forge not heat up massively? Also what thickness metal did you use for the frame?

I am thinking of a design like yours, especially the scissor jack adjuster is just brilliant. I thought the bottom frame could be a set of soft brick with a set of hard brick on top which will hold heat and help out with durability. Also I was thinking I could put a ring of soft brick on side around the hard brick for more insulation. Then I had thought of doing the roof as you did of course. I was trying to decide between making the right wall 3" of kaowool with burners sticking through it or putting them vertical as you did. Vertical has its benefits of course as the heat is right on the material but I was wondering about the danger of overheating the burner. A quasi melted brass tub breaking would be depressing to say the least. Currently my atmospheric burner doesnt get that hot at all. It may still be worth it to add a blower tube to introduce more air for special circumstances, what do you think? Finally I thought of coating all the kaowool with ITC-100 to complete the structure.

Anyway, I was wondering what you think of the idea.

I tried to send frosty a PM but his box is full so I thought I would ask here.

On some gas forges such as Frosty's variable volume forge, that I have seen, the burners are mounted vertically with the burners facing directly at the floor of the forge. This would seem to me to have two problems first I would be worried that the Venturi burners would suffer from so much back pressure that they would have trouble operating properly and second, I would think that the heat of the forge would back up into the burner and damage the burner tube. So I am wondering how they make this work and how do they avoid those problems.

I like the concept of the variable volume forge because my static volume forge takes a hell of a lot of fuel to heat because of its thickness cast and its inability to vary its volume. Frosty's design seems easy enough to implement and would allow one to close down the forge tighter and use less fuel when working with smaller work. However, I have found that Venturi burners seem to perform much better when extra air is introduced into the chamber to assist combustion, a sort of a composite blown and Venturi burner in one.

Are there other designs of variable volume forge I should be looking at?

-- Robert

Robert, understanding the dies or surfaces that you use with your hammer or anvil will help you more than anything. Hofi has taught the nail making techniques to countless smiths and they have passed them on to countless other smiths. Tom Clark was one of them that I saw demonstrate this for the first time. I'm sure there are videos some where out there of either Uri Hofi or Tom Clark making nails. They are doing a two-sided taper turning 1/4 turns back and forth with the hammer tilted appropriately useing the near radiused side of the flat die of a square faced hammer on the flat face of the anvil starting about an inch back from the end of the material and moving up as the taper develops which causes the material on the far side of the forging to lift up off the anvil so the heat does not get sucked away. They continue the taper saving the point for the end. This lights up the material and allows you to forge for alot longer than using flat dies with full contact.

And as mentioned nail "rods" were actually square and were slit from sheet/plate. If you want hammer control practice you could make all your round stock into nice even sq stock...

Also I was wondering if there is anything I can do to get more forging time on the nail. It seems to cool very quickly even when attached to a 2 foot section of rod. Is that something you all observe as well? I was looking at a couple of videos of people forging nails and it seems they have a bit more time than I do to forge before it cools.

I am doing the nails to gain experience as a newbie to smithing. I hope they will help me learn the control I want. Thanks for all the advice.

Greetings,

I am a newbie to blacksmithing and so I thought that I would start by making a bunch of nails to learn hammer control. I took a 1/4" inch rod and I have a 3/16th nail header that I fashioned by drilling a hole in 1/2" plate, expanding it with a cone shapped piece of steel and welding on a handle. I started working on the taper and I am getting better at that with some frustrations. First of all I am using a propane forge for my work so that might be of interest.

Questions:

1) When trying to taper the round rod, It keeps spinning in my holding hand. I have a hard time holding it, especially when it is curved slightly from working the rod. One thing I have noticed is that I shouldnt hold it so tight against the anvil but are there any other tips? I suppose I need to really square the rod before trying to taper but that still wont change the spin as it was happening with the 3/8ths square that I had as well.

2) While tapering, occasionally the metal will splinter when I get down thin. Why is that and how can I avoid it?

3) I am heating to yellow and when I pull the rod out it seems like I only have about 10 to 20 seconds max of time to hit. If I try to brush there is no way I could do more. Is this normal because the rod and nails are so thin that they cool so fast?

4) Finally, I taper the rod to a spike end and then I put it in my improvised nail header. Then I measure where I want to cut it. Since I dont have a hot cut hardy (thats next) I use a cold chisel I have that is actually for wood but works or I use the corner of the anvil and bend the nail to the side and then straighten only the nail part. After I straighten, I put it back in the forge with the nail 90 deg to the bar. When I pull it out, I put the nail header on, bend back and forth a couple times and it breaks. Then I drop the whole thing over my pritchel hole and try to pund down the head with straight down strikes. The problem is that it isnt working. One of two things is happening. Either I am punching the nail all the way through the set or I have too much metal above the head and it is just bending over. How can I stop this from happening in the nail set?

Thanks in advance.

A longer flame is indicative of more burning fuel as the flame must originate outside the tube and then be burned. If the flame gets longer than it is simply taking longer for the gas to slow down, mix and ignite. Inside the forge, the back pressure will interfere with the velocity and 02 content and therefore the burner will burn yellow rich. Adding air in as I do, while not the only solution, helps add more O2 to the flame and finish the burn while not increasing the gas velocity. I think blown burners have to be really large to slow things down. My burner is externally blown. Another problem you will see is when you put it in the forge and put fire bricks on the door, the flame characteristics will change dramatically. Such is the pain of atmospheric forges.

put it in a forge and see what it does there. It will be COMPLETELY different from running it in open air.

As for flame holders, If I had it to do over again I would use a cone mandrel and expand a 1/2" inside diameter pipe to 3/4" inside diameter and weld that one so the cone sit higher than the rest of the tube exit. It should cause the flame to glue to the end.

And you have flame shape you do because of wake turbulence. That is why my flame holder is a long cylinder 2 inches long.

But anyway, put it in the forge first with the forge buttoned up for work -- because you will be shocked at the diff.

After my experiment with the flame holder, I suspect that this is Robert's problem too. It seems like the flameholder is choking back gas velocity, limiting the venturi action. The result is that a lot of unburned gas enters the chamber, so needs a lot of additional air pushed in to finish combustion.


I think this choke-back effect is why Ron Reil said he'd never use a flame holder.

http://www.craftkb.com/Uwe/Forum.aspx/blacksmithing/1/propane-burner-question

Where did you see that? What safety issues? Maxon blowers I've had from the twenties had a connection for the gas to be fed directly into the blower. Same way I've done on many forges.

Yeah I have read that thread completely. However, I didn't feel that it answered these questions.

Robert, check out page 385 of this book...

http://books.google.com/books?id=cCJ_YyAEqnQC&pg=PA362&lpg=PA362&dq=flame+stabilizer&source=bl&ots=Zmbx0gF-x_&sig=GK-l-lgCQpMoadoNGzoe2QhrKRU&hl=en&ei=WxhoTJbmC4OglAfunpGfBQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBsQ6AEwATgU#v=onepage&q=flame%20stabilizer&f=false


Seems to be basically what you ended up with.

I dont think Hofi is trying to say everyone but him is doing it wrong. I think he is more like saying "here is an alternative way." It is up to everyone to choose the way that is best for themselves. I think people get too upset when people disagree with their way and then take it as a personal insult. That is just my opinion of course but I think there is room for all techniques.

I am personally interested in the style and trying to find out if it is actuall worthe the effort. Being a programmer, I am acutely aware of repeditive motion injuries and what they can cause. Several tendons in my left wrist flame up to a nasty level of pain on occasion after years of typing. I will never be able to reprogram my head to type differently or my golf swing to be different since it is so ingrained in my head and muscle memory. That is why I am interested in learning Hofi's technique right out the door before I have burned any hammering motions too far into my brain.

To those that have a technique that suits them and leaves them happy, I doubt anyone is realy tying to say your tecnique is incorrect, just that there are alternatives. Chocolate and vanilla are both yummy flavors, we dont need to get upset over debating which is better.

In freedom there is variety and that variety is what makes the world interesting.