Thinking of going to blown burners.

[edge9001]

I didn't join this board or hobby to design a perfect propane jet. My goal was to actually hit metal but I dont have anything that will heat my forge.

while propane is a cleaner way to heat metal, you can't go wrong with solid fuel forges they can be a lot simpler or more complicated depending on the exact design.

I have both a propane forge and a charcoal forge. The gasser works but I'm still working some of the kinks out of it. The charcoal forge hasn't given me a bit of trouble since day one.

I'm not saying you should drop the propane forge,but it seems you are getting s little frustrated with it.A simple brake drum forge will get you hitting on the hot stuff in the mean time. you can build one of them for less than $50 depending on where you get your materials. with both forges you can work on the propane forge and still work on some projects at the same time.

Good luck with it

[Robert Simmons]

the problem is my neighbors. Charcoal was bad enough but with coal and coke I would not only be damaging my health but probably get all my neighbors hating me.

I am about to throw in the towel completely. I cant get any burner to work and I cant go solid fuel. It looks like I might have wasted a lot of money for xxxx that will sit around unused. I wonder if I could sell off the forge or something. Get some of my money back and take up knitting or something.

[Robert Simmons]

Update. I got one burner to be stable enough to run in the forge by changing the size of the nozzle to a 1/16th inch hole. The burner caused a significant tornado of blue flame in the forge. Interestingly I didnt see much flame comming directly out of the burner but only the constant tornado of blue burning gas. I also managed to flash burn my face lighting the xxxx thing. It put in too much propane too fast in a confined space and when I lit it, it flashed right into my face. At least I had eye protection and my welding jacket on but I feel appropriately singed and chastized.

At any rate I let it run for a good half an hour and it got hot in there like an oven but nothing impressive, certainly nothing strong enough to actually heat something red hot. So I guess for whatever reason that isnt going to work. Although the burner was stable, the result was less than impressive.

I was hoping I could use this forge as a furnace as well but its pretty clear that it wont get that hot with the current blown burners. In addition the forge puts out so much flame out the front and with periodic pulses of flashing yellow that it just isnt really usable like that. Perhaps I made a mistake in trying to induce a tornado effect in the poured forge. A any rate it seems that the forge just wont get hot with the given burner setup.

A very frustrating project -- and not the one I wanted to be working on. I wanted to be working on a railing for my front patio and stairs. Instead I am still working on heating.

[kcrucible]

A very frustrating project -- and not the one I wanted to be working on. I wanted to be working on a railing for my front patio and stairs. Instead I am still working on heating.

Well, I know that this isn't exactly a welcome suggestion, but you could just buy a pre-made burner. Let someone else have done the work, unfortunately that means a bit more money.

Here's a list of pre-made burners that I've found, both atmospheric and blown (at ellis)

Ellis Knifeworks
Zoeller z-burner
Hybrid Burner's T-Rex burner

If those burners don't work for you, then it's the forge body itself that's the problem.

[pkrankow]

You have a very large forge cavity using a denser refractory. It is going to take time to heat up. It may be that my 30 minute suggestion was not nearly long enough. Your blue flame indicates that the flame is at 3000F, even if the forge body did not heat up to that point.

I am a proponent of tiny forges for beginners because making a new larger forge isn't a challenge after the first forge. The forge I use is only 150 cubic inches, has 2 inches of kaowool in a body made from 1 (one) 2ft piece of stovepipe, and the cavity is sized to a stove firebrick, about 9x4. It is mailbox shape, the back is mostly closed with a low pass-thru slot, and the single burner injects straight down with no attempt at swirl even being made. I use a scrap of kaowool to close the front when I need to as the hinged door I originally designed didn't work. This forge requires less than 2 linear feet of 1 inch kaowool to build (that's 4 square feet). It is assembled with self drilling sheet metal screws, and the burner holder is a piece of pipe with rigid conduit nuts on the inside and out of the shell.

This is the second forge I built as the first was too hungry for me to feed. It was about 600 cubic inches, 2 burners. I recovered the kaowool, burners, plumbing and fastenings to build my current forge. The first forge cost about $300, mostly in fittings, the second cost the pipe and a box of screws since I recovered more than I needed. Kaowool that has been fired is much more nasty than new kaowool.

The picture shows heating 2 pieces of 1 1/2 inch 4140. I have melted coil spring.

If you choose to go this route don't hurt your big forge body, if you stay with smithing you will want to have that monster at times, and you will also find that my design is too small to do many things with, even though it is big enough to do a whole lot of things. Heating pieces longer than 9 inches is easy, you just heat and move then heat and move...

I have rarely needed to heat sections longer than 9 inches, and every time was for the last operation of bending or wrapping with the part too big to go back in after being bent.

I am typically limited to forge sessions of about 1 hour or so. Having my forge get hot in short order is important, as is having the forge cool enough to move when I am done. Since my daughter (2 year old) doesn't nap anymore forge time has been non-existent the last few months.

Phil

[Robert Simmons]

I have the forge designed so I can put insulating fire brick into it. I have thought of putting some in the back and pushing forward to get a much smaller volume.

The long and short of the thread is that I am going back to atmospheric. Less factors to juggle, less danger (propane cant pool easily because it draws its own air). I will just have to get the right burner designs and move on. All the failures, expenses and dangers have finally overcome me. At least I got my atmospheric burners to work.

I wonder if I can layer the floor with insulating brick and reduce volume even more. It is insulating fire brick though so I don't know how well that will work. Anyone know whether there would be problems using paver bricks for hard bricks? I have a bunch of pavers left over from doing my driveway and thought they might work nice if they can take the heat.

[edge9001]

I don't know about regular brick, I would like to know. When I bought my forge, the maker had a red 3-hole brick in the forge I guess hisplan was to use it as a floor. I took it out just in case. I would love to know if it would work.

[Robert Simmons]

Well I just fired it for over an hour with a 1" Venturi burner. It made my garage over 120 degrees but didn't raise the temp of the forge beyond baking a couple cookies temp. It seems I poured it way too large. Perhaps I can use it to anneal or something. As it is, the prospect of going to solid fuel is looking better and better. If I cant get that working then I guess I am xxxxxx. But I do hate being out the cash for the propane forge. Live and learn I guess. perhaps it is time to go old school again (and I mean old before Coal and Coke were popularized) to charcoal.

[kcrucible]

I wonder if I can layer the floor with insulating brick and reduce volume even more. It is insulating fire brick though so I don't know how well that will work. Anyone know whether there would be problems using paver bricks for hard bricks? I have a bunch of pavers left over from doing my driveway and thought they might work nice if they can take the heat.

One potential problem with normal pavers is that they have cement, and cement has water as a material component. When you heat it up high enough, the concrete breaks down. That's the reason that everone says not to use portland cement as an element in refractory mixes.

That's not to say that you couldn't toss em in there, but probably won't have a lengthy life.

Well I just fired it for over an hour with a 1" Venturi burner. It made my garage over 120 degrees but didn't raise the temp of the forge beyond baking a couple cookies temp. It seems I poured it way too large.

I think your main problem is that the castable is a heat sink, so instead of reflecting your heat back inside it's leaching outward. It takes time to bring all of that material up to temp (though once it's AT temp it should hold it a long time.)

What castable did you use? It is an insulating castable, right? Did you use ITC-100 on the face?

Here's a discussion of the benefits of castable vs wool.





Depending on the temps you're planning on hitting, you could always line the INSIDE of your poured furnace with Kaowool, etc to reduce the volume and dramatically increase insulation value. Any heat that makes it through the wool would them be slowed down by the castable, making it better than most forges which just have the shell at that point. It'd definitely get up to heat faster than what you have right now though.

http://elliscustomknifeworks.hightemptools.com/inswool.html
http://elliscustomknifeworks.hightemptools.com/itcproducts.html

http://shop.clay-planet.com/inswool-ceramic-fiber-blanket---by-the-square-foot.aspx

[pkrankow]

Stove firebrick can take the heat for quite a while.

Here's the burner I am using. It is ...somewhat... resistant to wind, sorta, maybe...

Yes, it is significantly more resistant than a Reil burner. I built one of those too and found it disappointing.



You tune it by cutting the contact tip shorter, and tweeking it with a small wrench through the intake to bend the contact tip till is burns straight, depending on the quality of your machining job.

This is one of the less expensive designs to build and test, it's really only 4 parts, a contact tip, a compression to npt fitting, a particular Tee, and a pipe.

If you have access to a lathe then you don't need extra fittings to jig with.

Phil

[Robert Simmons]

Success.

Just when I was about to give up, I trued a couple more things. As you recall my forge is casted for three burners and yet I have built only one to date. None of the blown burners worked properly but I was able to get a venturi to stay lit. That torch was a modified version of my first black iron pipe burner with a bigger nozzle and a flame stabilizer instead of flare. So I put that in the forge and then lined the forge with ITC100 and then fired it. I went slow at first to cure the ITC100. Then I buttoned up the back doors and the venturi went yellow in its burn. Then I had a moment of inspiration. I took the hair dryer and pointed it at one of the unoccupied burner holes and the forge started to ROAST hot. Producing very little CO and not too much dragons breath. The venturi was in the middle slot and we had the hair dryer in the back one. We also tried the dryer in the front one with similiar heat but slightly different convection in the torndo (heating the back more than front. So if you put the hair dryer in, it heats more the opposite hole you put it in. So I was able to get the metal up to yellow hot. In the process the ceiling exhaust fan was perfectly able to vent any collected CO and it remained pegged at 0.

So here is the system we are rigging up. We have the venturi in the middle and on the two sides will be pipes carrying air being injected directly into the burner. We will have two pipes through individual gate valves up to a T junction. In the T junction I will put in a 2" bell reducer and nipple so I can just set the hair dryer in there til I get a real blower and then I will attach the blower there. I will be able to adjust air flow balance through the two gate valves and the heat will come through the venturi.

It is something of a blown forge where air is forced right into the burn chamber rather than into the burner. I will post a video when I have it done and polished. I need to weld on some holders with set screws to hold the burners and air tubes in place and put on some finishing touches, not to mention a new table for it since I want my welding table back.

[youngdylan]

I can't offer too much constructive but I can say that home brewed atmospherics DO work, there athousands of them in use all over the planet. When you do finally crack it (and you WILL) you'll love the concept. I've build about a dozen burners now, constantly modifying them as I go. All they are is a small tube squirting gas down a large tube and a bit of tuning, and can be knocked up in 1/2 hour.

The whole concept of propane heating is so verastile, a pile of movable firbricks and as many heaters as needed and you can heat just about anything.

I've got and induction hjeater coming and that combined with a large oxy-propane torch with hard firebricks and a few gas forges means I'm seriously thinking of getting rid of my coal forge to free up valuable real estate. Here's some more details

http://blacksmith.org/forums/threads/404-Is-my-coal-forge-toast-....you-know-ancient-history

Robert, keep perservring with the propane option. I've been in a tunnel like that many time when you think you're getting nowhere .... you're learning a LOT as you go go and that learning is always good, 9 time out of 10 you're sooner or later glad you've got that learning under you're belt

Saftey is everything with propane forges, ventalation and flame failure devices are musts .... I only started using the later after I had a VERY LUCKY escape. I didn't switch the shut off valve off fully, just a tiny bit ajar without knowing it, left the workshop clapped out and out of focus after a long sweaty day ...... it's good job they add that smellt chemical to propane ......do I need to say more!

[youngdylan]

Yes, many years ago when the plans came out, I built three Sandia style forges for myself and a couple of friends. They worked OK but always needed tuning so I built a manifold and added a blower. I'll have to take some pics and post since I don't already have one on the PC.

H. is that because opening and closing the door(s) alters the heat input ? Do you still use it, are they worth the time to build? I just can't bear the heat from mine at times.

[youngdylan]

This is a picture of the forge that Rob Gunter and sons used at the 2009 SaltFork Conference last october. http://picasaweb.goo...250849539729714

Check the Saltfork web site for our 2010 conference! http://www.saltforkcraftsmen.org/). Click next to see more photos of the forge, or "view all" to view more coverage of the conference.

Roy Tate

Roy

Thanks for the images/links. Am I doing something dumb but I couldn't find a way to see more pictures on the Saltfork site.

What is the heat exchange method you use, how does opening the doors affect thing, especially a door at the back for long bars.

I don't have much (any) experience of them but I'm fascinated by the concept. To me it just seems plain WRONG pumping all that heat in the exhaust gas into the room ... wrong on so many levels.

[ThomasPowers]

I'm at 4700' and I have several smithing friends---including a professional smith who have no problems at 7000' using propane systems.

If you are burning off the end of the burner you have too great a gas speed, it's faster than the combustion speed, why a flair helps as the gas speed drops as the pipe flairs out and you hopefully hit the point where gas speed = combustion speed and the flame is stable. Going from a 2" pipe to a 1" pipe certainly cjanges the gas speed on a design! Also if you are not using the same blower it changes the speed vs a specific design.

Note that you have to be able to tweak the amount of air and it helps to be able to do the same with gas.

Now what did the local smiths say about your set up when you showed it to them? I know that there is an ABANA affiliate for your region and having one knowledgeable person look over things and make suggestions is worth a hundred on the net! When I had my first propane forge I had a burner problem, took it to the next meeting and it was tweaked perfectly in about a minute and I haven't fiddled with it in the 10 years since! (blown burner, the aspirated burners I tweak regularly)

[kcrucible]

Success.

Congratulations! I wonder whether the big difference is the ITC-100 or using the second port to supply additional air?


It's always nice to hear people getting things to work.

[Robert Simmons]

Perhaps both. It definitely heats better with the ITC without the extra air but the air punches it up a notch.

I only used a thin coating, maybe 1/16th of an inch, of ITC. I am debating acquiring more.