kcrucible
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Posts posted by kcrucible
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Kcrucible; Thanks for your input I found your site interesting, looks like you are going through similar growing pains with your projects, I just finished my new forge and will fire it up soon (letting ths tc100 dry out on the kaowool) I'll be posting photos of my shop and toys when I get the bugs worked out of my new used computer. My old E-machines dinosaur underwent a slow agonizng death by slothness.Some young buck hammer swinger saw my old 10"square box forge and made an offer I could'nt refuse. I hope my variation on the Zoeler 3/4" side arm burner works out well on this 10" round forge take care... Clifford
Glad you found it entertaining. I originally just started it as a way to document what I was doing to show friends and family, store links to suppliers if I needed to find them again, etc, then I realized that other people might find it useful too and have been trying to broaden the appeal... talk about the science of it, why I'm doing certain things a certain way, etc. It's a little funny to me to be an utter novice at this presenting things in a lecture format.
My wife has been keeping me busy the last two weeks on other projects, so haven't had a lot of time for the forge. Still waiting to get the welding done! But at least I now have an answer concerning extra insulation in an insulating castable, and forms made for my rather unique lid. I find half of my entertainment comes from trying to accomplish unusual things. I'll probably spend more time making the foundry/forge than actually using it. Haha!
So, you ultimately went with the "traditional" kaowool after all, eh? I understand it's hard to beat for quick forging work. If I didn't have my heart set on melting glass I'd probably be doing that too. In any event, if you want to give me a link when you get your new pictures uploaded I'd be happy to pass people along to look at your work. What did you do differently with the side-arm burner? -
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 -
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. -
The only difference is my blown burner is only 1 inch in diameter whereas theirs is 2 inches. However there is no way I would be able to size up to 2 inches without pouring a whole new shell.
That gets back to volume of air/fuel vs pipe diameter... ie velocity. Increasing the pipe diameter is one way to decrease velocity, but you could just put less air into the tube. You could use a Y (use the inline portion to inject) to split the air stream in half and only send half of the air into your burner, for example. If you add a valve to the output of the Y that feeds into your burner, then you can directly control how much air goes in. If you dial down the aperature then the rest of the air escapes through the other port. This gets around my earlier thinking that trying to reduce capacity would just increase velocity because there's a pressure release. It's easier for the excess to go out the other way than build to a higher pressure.
The only remaining idea that I have is to use a 1/4 inch tube to inject the propane hoping that will slow down the gas enough so that it doesn't try to pop off the end of the torch.
That sounds like a good idea to me. The longer the tube is the better I'd think... more time to slow down.On top of that the hair dryer I was using as a blower died for unknown reasons and now I don't even have something to move air.
My guess is that the hair dryer couldn't handle the back-pressure being generated by putting that much air through that small a pipe. Putting in the pressure relief port I mentioned above should help keep the pressure nearish-atmospheric. -
However, budget restraints dictate creativity as storebought stuff aint cheap, and I am, so I must endeavor to find an alternative solution if possible. If not I"ll have to bite the bullet and buy commercial refractory.
Again THANK YOU for your input.
CLIFFORD
Some suppliers aren't nearly as expensive as others.
http://elliscustomknifeworks.hightemptools.com/castablerefractory.html
They were relatively cheap, though a 55 lb bag wasn't cheap on the shipping. There was a bit of a shipping snafu, but they eventually got it worked out and I don't hold a grudge. I link to them on my blog as suppliers. You may want to look through the links for other sources too. -
i can probably get ahold a TON of brass casings so if those can be used for anything let me know please
I don't think that you can use it for building a forge, but it'd be a GREAT source of material to melt down for casting! :) -
Every suggestion helps.
The problem with sizing up is that the forge is cast already so that wont happen. Also empirically it should be possible to do a 1/2" blown burner as much as a 2" one if the fuel mixes properly with the air and the velocity is right. It is clear that the flame can burn, it just detaches. If it detached pure blue, I would say that the velocity is just too high but the mix is right. However, it is detaching when the flame is still yellow and I think that might mean that the mixing isnt working the way I want. That could be a function of the right angle entry of the propane rather than firing the propane right into the moving air stream as direct injection would do. So I will try the direct injection and get back to you.
Well, there are two issues... one is the richness, one is velocity. They're somewhat interrelated, and somewhat independant.
Your previous post where you said that you turned down the gas until flameout, it could be that the high velocity of air is what caused it to blow out, not neccessarily that it was down to no gas. A slower air velocity may allow the smaller quantity of gas to burn properly. If you did something like hold the hair dryer away from the input port so that different amounts of air escape instead of entering the pipe, you could try tuning that?
If I were trying to diagnose the problem I'd probably start with a very small amount of gas (the least you can manage) and almost no air, then start adding air a bit at a time till you got the ratio correct. Then you could scale up both gas and air at the same time until you had substantial heat and good flame, etc. (then you mark your dial, etc, so that you can just start there every time!
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It occurs to me that your flame detachment problem is probably a function of air velocity. The stabilizer is intended to slow down the air/fuel mixture, but it's not doing enough.
Assuming that the air/fuel mix is right, then it's just a matter of slowing things down. You could try increasing from a 1" tube up to a 1.5" or 2" tube at the exit. That should (I think) make the same volume of air exit at a slower speed (basically the inverse of putting your thumb over a garden hose.)
Adding a rheostat to the hair dryer might do the trick too (like a dimmer switch), though that will change the air/fuel ratio, as would diverting a portion away from the air intake.
Just trying to be helpful, even though I'm more novice than anyone here. ;) -
Well, I think I might have the wrong pour to go with blown burners. They flame out too fast when using a hair dryer as a blower. I suppose I need to get a gate valve to control the air flow.
All in all it is frustrating. I took up the hobby to hit metal, not spend 2 weeks trying to heat it. I now wonder if I shouldnt have stuck with charcoal. What good is a propane forge if one cant use it.
Singed ... Frustrated.
I notice on your burner picture that you're just using a 3/4" to 1" reducer for the flare.
http://www.iforgeiron.com/index.php?app=core&module=attach§ion=attach&attach_rel_module=post&attach_id=23848
Flares have been reported to be important for flame stability outside of the furnace, but apparently many run without inside. That reducer probably is still threaded, so you'd be getting a lot of turbulance at the ends. You could try running "bare" and see if things change. You could also get a proper flare from Zoeller. Ron Reil swears by them. Here's what he has to say about flares....
http://www.abana.org/ronreil/design2.shtml#premade
The following four factors are, in my opinion, what a flared nozzle does to contribute to burner performance, and why you should use one of your own making, or one of the stainless flares offered here.
1) The flared nozzle acts like the "impedance matching device" found on radio transmission antennas. It creates a "pressure transition" to balance the internal pressure of the burner tube to the lower pressure of the forge chamber atmosphere.
2) It slows the gas stream to a velocity below the burn velocity...its flame holding and stabilizing function.
3) It creates a low pressure in the nozzle step that, in effect, invites more gas down the burner tube, allowing a slightly greater output than would occur without it. This factor is not proven or provable with our crude testing equipment, but I can clearly see its contribution in my mind.
4) The last function is to initiate the burn earlier so as to prevent the injection of cold gasses and free oxygen into the chamber of the forge or furnace....the result is a hotter chamber and less, or no, scaling.
If you would like to buy premade burner flares that have a perfect 1:12 taper, and made of stainless steel no less, there is now a source. Most of the problems that I deal with when helping guys with burner problems relate to the rate of flare of the burner flares that they put on their burners. If the flare is not made correctly the burner will not function correctly. I was astounded when Larry Zoeller sent me one of his "press formed" stainless steel flares to try. I removed one of the old forged flares from the number one burner on my four burner forge and installed Larry's stainless flare. My old mild steel flare came off in fragments, as it had totally corroded through in only two years of use. The best I had been able to do for "idle" pressure with my old forged flare was 2 psi. Below that the flame would start to pulsate or huff. When I put Larry's flare on the burner it easily held the flame steady all the way down to a little below 1 psi! His flare just doubled the "idle" economy of my forge! I have ordered 7 more from Larry, they are that good. I can certainly make my own flares, but to obtain the precision that Larry has achieved I would have to set up a hydraulic press as he has done.
If you would like to obtain some of these superb flares, contact Larry at the address shown below, or at his e-mail address. I am sure you will be very satisfied with the results of your purchase. You may initially think that his price of $6.50, plus shipping, for a burner flare is steep, but remember that he not only makes them from stainless steel, but they are drilled and tapped, and come with two stainless set screws installed also. They are ready to just tighten into place on your burner. BTW, I get no payment of any kind for this "add." I just think that these flares meet a big need out there in the metalworking field and should be made available to the forge and foundry community. Please be aware that these flares can melt and deform if used on the Micromongo Burner when its run at high gas pressures. In the case cited in the linked document, Fred was running them at 25 psi. -
Jeweller's Saws would cut firebrick.
I've ordered a lot from Rio Grande over the years... here's one example from there. -
I'm putting together a how-to on this blog (assuming that it works... otherwise it will be a how-not-to!)
Even if it doesn't work, I have links to some other sites that have plans, such as Backyard Metalcasting and parts suppliers.
http://kcrucible.wordpress.com/ -
I saw Reil's design actually. It is based off a cross tube for the gas which is drilled to create a gas jet as a small pinhole in the tube. Furthermore it has a flat design where air flows straight through the tube rather than from the sides. I considered that but saw a couple of design problems.
First of all there is no way to adjust forward and backward jet placement in the tube. Once the holes are drilled then the jet is positioned and there is pretty much no going back. This prevents tuning the flame and certainly prevents the use of MIG tips as a jet because the jet would be too far in the bell reducer. My jet tip ends right about at the end of the nipple and it looks like I need to back it off a bit. Short of redrilling a new tube location, that cant be done with the Reil.
He has other designs that eliminate these problems and is functionally the same as yours, though without the expanded air intake chamber, just using slots in the tube wall (originally just a hole, but the text on the site describes the slot as an improvement, though there are no drawings indicating that.) Your design theoretically can draw in more air than his mongo series because of the larger intake area, but I suspect that your jet doesn't provide enough suction to require it in which case it'd be a little over-engineered. What pressure are you using? On the positive side, if you ever wanted more heat you could probably just swap out the 3/4" tube for a 1" tube (since you have the bushing anyway) and upgrade the tip for more fuel. Nice and flexible.
I built one based on the mongo principles but haven't had a chance to fire it up yet as I'm waiting for my regulator. My link also has embedded images to the original Reil burner and the Mini-Mongo. Kcrucible's Propane Burner
Anyone want to give me any feedback prior to firing this bad-boy up?
Yes, I know that forward/back adjustment will be difficult and consist of heating the solder to push the ejector in/out, but I believe that the placement should be ok as-is. Just blowing into the brass nipple (low PSI) with the choke fully open causes more air to exit than when I blow in when it's choked down, so I think the venturi is working properly. -
I thought it was exactly the opposite?
http://yarchive.net/metal/acetylene_regulators.html
">VERY IMPORTANT: Do not run a propane regulator on acetylene.
>Acetylene regulators contain special gaskets that are immune
>to the solvent fumes found in acetylene. Propane is purer,
>so propane regulators do not need these special gaskets.
>Acetylene can ruin a propane-only regulator, cause leaks,
>and otherwise cause danger to the user.
Bob, this is an important issue. It is true that one can use an
acetylene regulator on propane, but it is equally true that the acetone
in the acetylene regulator may eventually swell any butyl or other rubber
o-rings or gaskets in a propane regulator. If one can find a regulator
using teflon or other fluorocarbon gaskets and diaphram components, one
might be able to simply interchange the regulator from acetylene to propane.
"
Thinking of going to blown burners.
in Gas Forges
Posted
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.