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The big green turd (New HT setup!)


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Hey everybody! Remember this thread a while back? www.bladesmithsforum.com/index.php?/topic/32608-in-search-of-an-improved-ht-apparatus

I finally got around to putting all of that information to use! Huge thank you to Tim Gunn, Jesus Hernandez, Wes Detrick, Sam Salvati, and all the wonderful and helpful people that were willing to cure a little bit of my vast expanse of ignorance.:D

I'm not really sure what to say about this thing, so if there's something you want to know about it, just ask! I haven't fired it up yet, but as soon as I get some propane I'll have to figure it out.
 
theturd.jpg

I took the back end off to show you guys. If there is an explosion, it should just pop in half.
the turd2.jpg

The front of the furnace. Should I make something to cover the front up? I have an extra firebrick.
theturd3.jpg

My type K probe and sheath. There is a hole in each end of the furnace so I can make sure the heat is even.
theturd4.jpg

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1 hour ago, Collin Miller said:

the turd2.jpg

The front of the furnace. Should I make something to cover the front up? I have an extra firebrick.

The smaller the opening you have the better you are able to hold heat. Two 1' layers offers better insulation for holding heat especially the size this forge is going to be!!

This thing is a huge!!!!!!!!! What kind of burners are you going to run on this monster!!

The next thing that jumps out at me with this pic,  is there is not coating over your insulation.Regardless of what brand this refractory material, exposure to heat and flame tends to put the fibers into the atmosphere. You beath them into your lungs and that is very bad. Once in the lung they never leave.  I am going to include couple of links. Google what airborn refractory dust can do to your lungs.  

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1128261/

http://secure.anvilfire.com/itc-ceramic-coatings.html

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2 hours ago, C Craft said:

The smaller the opening you have the better you are able to hold heat. Two 1' layers offers better insulation for holding heat especially the size this forge is going to be!!

This thing is a huge!!!!!!!!! What kind of burners are you going to run on this monster!!

The next thing that jumps out at me with this pic,  is there is not coating over your insulation.Regardless of what brand this refractory material, exposure to heat and flame tends to put the fibers into the atmosphere. You beath them into your lungs and that is very bad. Once in the lung they never leave.  I am going to include couple of links. Google what airborn refractory dust can do to your lungs.  

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1128261/

http://secure.anvilfire.com/itc-ceramic-coatings.html

Thank you! I will be using one weed burner (no, not that kind) torch. I guess we will see if it reaches temp or not! haha

unnamed (3).jpg
turd.jpg

And thanks for the info on the insulation blanket. I was wearing a respirator and gloves the whole time I was working with it. I used one layer of 1" 8lb ceramic blanket because that's what was recommended by @timgunn and he seems like he knows his stuff...
I haven't coated it, but like I said I haven't fired it up yet and I wore a respirator, so no damage done to my lungs so far. I have a friend with some refractory, but I got the impression that I should leave the blanket without coating... maybe Tim or @Sam Salvati or @Jesus Hernandez or somebody who's built something like this before could weigh in on this?

A reply from Tim Gunn in the thread linked in the OP:

"A Don Fogg style 55 gallon drum HT forge is cheap, about as simple as it gets and sounds very much like Jesus' suggestion.

 

Basically, it is a 55-gallon drum, mounted horizontally and lined with a single layer of 1" Kaowool blanket, with a small burner mounted into the original 2" bung hole low down at one end. High up at the other end, a fairly small (maybe 2" wide and 3-4" high) opening is cut for workpiece access and exhaust gas egress. In the two I've seen, the workpiece is hung in wire loops which are just extra to the wire holding the blanket in place.

 

The burner is not a tight fit in the bung hole: the temperature adjustment is basically done by putting a thermocouple in and adjusting the gas until the temperature is where you want it to be. It's the balance between the amount of burner flame and the amount of extra air coming in around the burner that gives the temperature control, so it does not need a fancy forge burner, a cheap torch will do the job.

 

I'm pretty certain the large volume is a big factor in getting even heating (radiative heat transfer follows an inverse-square law). Temperature can be held within surprisingly tight limits once correctly adjusted.

 

The design is very elegant: just about any attempt to improve it seems very likely to make it perform worse: more insulation, ITC100 and multiple burners are just three that I've heard suggested by folk with an "if it ain't broke, keep fixing it until it is" outlook.

 

If a 55 gallon drum is too short, I'm pretty sure any other suitably-sized cylinder should work, even a couple of 55-gallon drums joined together. I think the diameter drives the airflow by providing the effective chimney height for the draft, so a long, skinny cylinder might not work as well. I think standing the drum on end would probably not improve things at all either, but I could be wrong."

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My contribution to that thread was minimal, but I am glad that I could lend something to it.  I am excited to see if fired up Collin.  Good on your for making it and figuring out the headaches for me :D  I am excited to see what you make with it.

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Looks good Collin. 

I'm not entirely sure about the firebrick splits for a work support: they look like a lot of thermal mass.

Whilst the general idea of extra thermal mass to help even out fluctuations is good, the downside is that it slows the response to any adjustments you make to get the temperature right in the first place. You may find it greatly increases the time it takes to get the temperature set.

You may not: I don't know and the only way to find out is to try it.

I thought I'd mention it as a possibility now just in case it proves to be a problem: removing the bricks looks like a quick and easy thing to do. It's the head-scratching, posting and waiting for folk in different time zones to respond that usually takes the time if a problem arises.

I'd certainly keep them in, try it for the first run and then decide whether to keep them permanently.

 

 

 

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This bricks are not only useless but also heat sinks so they do harm. All really is needed is some 1/4" round v shapes to support the blade if anything.

 

despite what some who haven't built one might say, 1" of wool is more then sufficient, with safety really the only reason to coat it. Again keep in mind the use of wool and not hard firebrick, wool being reflective and hard brick being absorbative, use a coating that will not take forever to heat up. 

Also again, despite what some who it seems haven't built one would say, I found larger openings makes the whole setup more tune-able' it is a positive pressure system using an atmospheric burner like your weed burner. I choke off the top or open the top hole to adjust for the pressure and get much better control over how the heat "fills" the barrel.

Edited by Sam Salvati
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 Collin, I have to say neither have I ever built one of these nor, had I read the original post, (the link did not work and I was in a hurry that day) so I really did not what you were trying to accomplish with this build! I did however copy the address and paste it too my browser so I could read the original post tonight.  There is a big difference between a straight forge used for heating to temps needed to move iron and one designed to HT.

So my advice about closing the end was more geared to that!

Also any time I see refractory uncovered in a forge being used, it makes me cringe. When you have a family member who has COPD you realize how precious being able to breath! So when I said it needed a coating that was more geared in the direction of being able to keep airborne fibers becoming a problem, it was advice given as a warning. Not knowing you I do not know if you are aware of this or not! I was merely trying to pass on knowledge that might save your health from being affected! Ask Ed Caffrey about what airborne particles can do to your lungs. 

Advice given by me may not have the knowledge that others in this field have but, you can be guaranteed, my advice is never given frivolously! Especially when it comes to safety!!!

Edited by C Craft
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22 hours ago, Wes Detrick said:

My contribution to that thread was minimal, but I am glad that I could lend something to it.  I am excited to see if fired up Collin.  Good on your for making it and figuring out the headaches for me :D  I am excited to see what you make with it.

Thanks Wes! You were a great help with finding a thermocouple, I had absolutely no clue what I was looking for :lol:

20 hours ago, timgunn said:

Looks good Collin. 

I'm not entirely sure about the firebrick splits for a work support: they look like a lot of thermal mass.

Whilst the general idea of extra thermal mass to help even out fluctuations is good, the downside is that it slows the response to any adjustments you make to get the temperature right in the first place. You may find it greatly increases the time it takes to get the temperature set.

You may not: I don't know and the only way to find out is to try it.

I thought I'd mention it as a possibility now just in case it proves to be a problem: removing the bricks looks like a quick and easy thing to do. It's the head-scratching, posting and waiting for folk in different time zones to respond that usually takes the time if a problem arises.

I'd certainly keep them in, try it for the first run and then decide whether to keep them permanently.

Thanks a lot for the reply, Tim! The bricks are super easy to remove, I can just pull the lid off and take them out. 

14 hours ago, Sam Salvati said:

This bricks are not only useless but also heat sinks so they do harm. All really is needed is some 1/4" round v shapes to support the blade if anything.

 

despite what some who haven't built one might say, 1" of wool is more then sufficient, with safety really the only reason to coat it. Again keep in mind the use of wool and not hard firebrick, wool being reflective and hard brick being absorbative, use a coating that will not take forever to heat up. 

Also again, despite what some who it seems haven't built one would say, I found larger openings makes the whole setup more tune-able' it is a positive pressure system using an atmospheric burner like your weed burner. I choke off the top or open the top hole to adjust for the pressure and get much better control over how the heat "fills" the barrel.

Thanks for the information, Sam! I might experiment with some different blade rests. I might just lay blades flat on the angle iron. The firebricks are a huge heat sponge now that I think about it.

30 minutes ago, C Craft said:

 Collin, I have to say neither have I ever built one of these nor, had I read the original post and really did not what you were trying to accomplish with this build! There is a big difference between a straight forge used for heating to temps needed to move iron and one designed to HT.

So my advice about closing the end was more geared to that!

Also any time I see refractory uncovered in a forge being used, it makes me cringe. When you have a family member who has COPD you realize how precious being able to breath! So when I said it needed a coating that was more geared in the direction of being able to keep airborne fibers becoming a problem, it was advice given as a warning. Not knowing you I do not know if you are aware of this or not! I was merely trying to pass on knowledge that might save your health from being affected! Ask Ed Caffrey about what airborne particles can do to your lungs. 

Advice given by me may not have the knowledge that others in this field have but, you can be guaranteed, my advice is never given frivolously! Especially when it comes to safety!!!

No worries! I appreciate that you're looking out for me. My Grandma has COPD, so I've seen the effects of it first hand. I'm a it of a fitness/athletics enthusiast anyway, so breathing is something I like to be careful about. 




Onto the update!
So I went into town and got a bottle of propane at the hardware store. Went home and got the thermocouple set up, plugged in the propane, put my respirator on, and lit the burner up. I started off with the burner shoved way too far in the bung hole, not giving it enough oxygen and filling my shop with unburnt propane. However, it did get up to about 600F, which was hot enough to make the residue on the inside of the barrels smoke like crazy! Smoke began to build up on my low ceiling, so I held my breath to open up all the windows and went outside for a bit.
I spent my time outside reviewing mental notes, and remembered that the burner should actually be just outside the bung hole. Eventually, the smoke all cleared and I went back in, checked the thermocouple that was up to about 800F, adjusted the burner, and waited for the heat to build. The smell of unburnt propane went away and the heat began rising relatively fast. 
The heat stopped rising at roughly 1150F, at which point the inside of the furnace was glowing a dull red. I fiddled with the burner again, moving it farther away for more oxygen, and got up to 1310F, where the heat stagnated again. My burner began to act up a bit, and then fizzled out. I thought I was out of propane, but after checking the tank by shaking it, it felt like there was some left, but it was just cold.
I heard propane coming out of the burner again, and then a bit of an explosion as cold propane was jetted into the furnace, still about 1000F.

I got the furnace up to 1335, where a lot of dragon's breath started coming out of the mouth. The angle iron supports looked pretty hot, so I decided to put a piece of 80crv2 in there to make sure my thermocouple isn't lying to me. Soon enough, the bar disappeared in the reddish orange glow, holding at 1350 by shaking the propane take periodically to keep it from going out again.
I quenched the dull red steel in water, thinking, "If this is up to temp it will definitely harden" but after quenching the steel was dead soft and wouldn't snap under hammer blows. So I know my thermocouple is on, but I think I need more oxygen judging by the amount of flame coming from the mouth of the furnace. I could be wrong though, and I don't know what the best way to get more oxygen in there, as the burner was a good inch from the outside of the bung hole, where I found I was getting the most heat. 

As the ice crept up and covered my entire bottle, and the temperature wasn't rising anymore, I shut it down. I felt a bit defeated, but confident I could make it work somehow, being a measly 200 degrees from my target temperature. I was happy that the bar a pulled out was a very uniform red heat, and the thermocouple only read about a 40 degree difference from end to end. This could also be skewed by pulling the probe out and moving it to the other end.

TLDR: I ran the burner for at least an hour, but couldn't get it over about 1350F. I think it needs more oxygen, and I was having trouble with the propane tank freezing. I might remove the fire bricks next time I run it so it will heat up quicker. Also, would a thin, painted on coat of refractory be sufficient to hold down the fibers without affecting the performance negatively? 

I wasn't sure how to, or if I should upload the video to this site, so I just uploaded it to my Instagram and am linking it here www.instagram.com/p/BUEAnyjDiDD/?taken-by=collin_miller_bladesmith

It's a super crappy video, but I was hoping it would be useful to show you guys what's going on so it would be easier to troubleshoot. I have never even made a gas forge, so all of this is SUPER new territory for me and I have basically no idea what I'm doing.

Thank you all so much for the help! I would never be able to figure this out on my own.

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That's been my experience with the weedburner torches as well, they seem to crap out right before they get hot enough.  I was hoping you'd figured out a way around that.  Maybe larger inlet and exhaust ports?  Those torches don't seem to pull in enough air if there is any backpressure at all.

Sam, you run yours vertically with a T-rex burner, is that right?  

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8 hours ago, Alan Longmire said:

 

Sam, you run yours vertically with a T-rex burner, is that right?  

Yes I do. I've run the one at New England School of Metalwork which was a horizontal, and had QUITE large ports. 

 

Honestly its it's worth it to spend the 200$ on the t-Rex burner. I tried the weed burner and another eBay burner which worked ok but just barely made temp. The t-Rex will make a honest forging temp down to sub 1000 temps. All with  a very controllable heat and atmosphere. I've never seen it's equal in an atmospheric burner. And for every shaved ape that jumps in and says "don't spend that money just build one!" You couldn't build one as nice for as cheap and have help be an easy phone call away. 

Edited by Sam Salvati
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3 minutes ago, Sam Salvati said:

Yes I do. I've run the one at New England School of Metalwork which was a horizontal, and had QUITE large ports. 

 

Honestly its it's worth it to spend the 200$ on the t-Rex burner. I tried the weed burner and another eBay burner which worked ok but just barely made temp. The t-Rex will make a honest forging temp down to sub 1000 temps. All with  a very controllable heat and atmosphere. I've never seen it's equal in an atmospheric burner. And for every shaved ape that jumps in and says "don't spend that money just build one!" You couldn't build one as nice for as cheap and have help be an easy phone call away. 

"Shaved Ape"

LOL.

That's classic Sam. Love it.

Guys, please don't let Sam's "enthusiastic" rhetoric make you think he's being deliberately provocative.  He really does know what he's talking about. He's just very, shall we say, emphatic about it.  I think it has to do with being on TV all the time.  Celebrity ego . . . you know.

Grins,

Dave

 

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Collin, I've had the same problem with mine using a Zoeller style sidearm burner (I refer to it as my dinky little burner), the temperature tops out at about 1300°... The only real difference between yours and mine is mine is vertical, and you found two barrels of the same color instead of blue and faded yellow... I also have a 2 x 4" port for the burner, which allows for a lot of room for tuning the angle and direction of the flame.   

I see two options, either add another burner or take Sam's advise and get a bigger burner.  Since I already have a spare I'll be trying two burners first, perhaps with an extra burner I can get rid of the temperature gradient from top to bottom.  Honestly though I should probably just take Sam's advise and buy a trex...

Edited to add, I have an abundance of satanite I plan to use to stabilize the wool with, but I want to be sure everything works as it should first.

Edited by GEzell
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11 hours ago, Sam Salvati said:

Yes I do. I've run the one at New England School of Metalwork which was a horizontal, and had QUITE large ports. 

 

Honestly its it's worth it to spend the 200$ on the t-Rex burner. I tried the weed burner and another eBay burner which worked ok but just barely made temp. The t-Rex will make a honest forging temp down to sub 1000 temps. All with  a very controllable heat and atmosphere. I've never seen it's equal in an atmospheric burner. And for every shaved ape that jumps in and says "don't spend that money just build one!" You couldn't build one as nice for as cheap and have help be an easy phone call away. 

Well, I guess that settles it. At least It's a one time buy, and will probably end up saving me some money via time and propane.

10 hours ago, GEzell said:

Collin, I've had the same problem with mine using a Zoeller style sidearm burner (I refer to it as my dinky little burner), the temperature tops out at about 1300°... The only real difference between yours and mine is mine is vertical, and you found two barrels of the same color instead of blue and faded yellow... I also have a 2 x 4" port for the burner, which allows for a lot of room for tuning the angle and direction of the flame.   

I see two options, either add another burner or take Sam's advise and get a bigger burner.  Since I already have a spare I'll be trying two burners first, perhaps with an extra burner I can get rid of the temperature gradient from top to bottom.  Honestly though I should probably just take Sam's advise and buy a trex...

Edited to add, I have an abundance of satanite I plan to use to stabilize the wool with, but I want to be sure everything works as it should first.

Best of luck with your furnace! I've been following that migration multi bar sword you're making and it looks really exciting. You'll have to post yours so we can compare designs. I would prefer a vertical rig, but my current shop has low ceilings. I already need to dig  down a few inches for the new quench tank, because my tongs would hit the ceiling when I try to quench sword length blades.

Can anybody tell me what kind of hardware (like the propane hose, pressure regulator, valve, and anything else) I will need for the T-Rex burner, and where I should get it? The weedburner came with its own hose, needle valve, and what looks like a fixed 18psi pressure regulator. I thought of pulling it off of there and using it, but from what I read the T-Rex burners need lower and adjustable pressure. I know this probably sounds like a dumb question, but like I said I'm a total noob to all things propane.

Thanks again!

Edited by Collin Miller
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Hightemptools.com will have everything, but be ready for a trip to a good hardware store for the odd fitting. 

Buy once cry cry once is a mentality most should adopt if you want to take any part of blade making seriously. I've never heard someone say "man I could have gotten the crappier one" ever. The T-Rex burner will be around as long as an anvil, and equally as useful and indespensible, so consider it a worthwhile investment. And taking things seriously is something that needs a bit of doing if you want to make swords and not dumb heavy crowbars.

i find this is the first time in a long time I actually feel like saying this, but good job. Your willingness to take suggestion instead of ignorantly putting your head down and trying (and failing) to reinvent the wheel, and your lack of entitled attitude is very nice change to what I have seen as an all too common theme among forums. If you keep listening and doing, the pros will keep talking. Nice furnace and good choice as its really an incredible tool on the road to becoming a sword maker. 

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I just built one of these at my shop. With some help from JJ i got my temp spread to  a 9 degree variation. Im using a WARD T style burner that i built myself. Still trying to figure out what the best way to hold hot metal in the vertical Kiln would be.

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I did that, but makes it hard to do batches of knives at a time. would you suggest using Turnco or any descale compound since it takes a while for the steel to get up to temp??

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1 hour ago, Sam Salvati said:

Drill a small hole in each tang and hang with wire

This is a really good suggestion. I do this with almost every blade. I use either rebar tie wire or a hook I made from 1/8" round rod. Using this method also allows you to hang the blade dead vertical as you quench.

Gabriel, you might be able to make a cross bar with a line of holes to hang several blades at the same time. If they are small enough you could pull the whole bar and quench simultaneously?

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On 5/15/2017 at 8:38 AM, Sam Salvati said:

Hightemptools.com will have everything, but be ready for a trip to a good hardware store for the odd fitting. 

Buy once cry cry once is a mentality most should adopt if you want to take any part of blade making seriously. I've never heard someone say "man I could have gotten the crappier one" ever. The T-Rex burner will be around as long as an anvil, and equally as useful and indespensible, so consider it a worthwhile investment. And taking things seriously is something that needs a bit of doing if you want to make swords and not dumb heavy crowbars.

i find this is the first time in a long time I actually feel like saying this, but good job. Your willingness to take suggestion instead of ignorantly putting your head down and trying (and failing) to reinvent the wheel, and your lack of entitled attitude is very nice change to what I have seen as an all too common theme among forums. If you keep listening and doing, the pros will keep talking. Nice furnace and good choice as its really an incredible tool on the road to becoming a sword maker. 

Thanks a lot, Sam, means a lot coming from you! I've been around for a little while at this point, long enough that people have started asking me for advice and such. As soon as I explain the proper way to do something, most people will give me the "Couldn't I just...?" line. My philosophy is that if you don't want an answer, just don't waste a man's time with your questions. And I try to follow that.

The other part is that if I'm going to consider myself a professional, I need to produce professional quality. Inside and out. This has given me a bit of guilt with my primitive heat treat regime, so I'm fixing that right now. Giving my money to independent makers who produce high quality products is also a perk. 
 

On 5/15/2017 at 9:00 AM, Gabriel James said:

I just built one of these at my shop. With some help from JJ i got my temp spread to  a 9 degree variation. Im using a WARD T style burner that i built myself. Still trying to figure out what the best way to hold hot metal in the vertical Kiln would be.

If you have a welder, it is super easy to weld a little ring on the back and hang them from hooks or wires. That way you could hang as many blades as will fit through the mouth of your furnace. 

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