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I Forge Iron

First Forge! Then a problem


AKM

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Long time lurker, first time poster.

Working on my first forge! decided to go for a propane thank shell with a single burner, 2" of Kaowool plus rigidizer. Pics are included:

IMG_20181207_184620.thumb.jpg.3aa2098a9a615ae2eab6200dd5bab4fe.jpgIMG_20181207_184625.thumb.jpg.83a7316e68329abb230d49070451357e.jpg

 

All things were moving along smoothly! Went and built a small stand to hold the tank, lined with Kaowool and got all the cutouts nice and even. Then Disaster:

IMG_20181213_171747.thumb.jpg.82ca05d82260f8b7efb2f858c7b3bca5.jpg

Im not sure what I was thinking, maybe seeing the name "Meeko's Red Devil" so many times on this forum I somehow equated that as "use this stuff" rather than "avoid this stuff"

I put about a 3/8" ish layer of the cement on the bottom and sides of the forge, then in my usual perusing of Iforge I realized that was not the right choice.

 

What I think my options are:

1) Cry

2) See if I can scrape off the layer of cement, and patch any kaowool spots with left over pieces I have. Then replace with Kast-o-lite 30.

3) Same as above, but go with Metrikote/Plistix instead of Kast-o-lite.

4) Replace all the kaowool, and then choose the ITC or the Kaowool

5) Just cover up the cement with one of the above mentioned.

 

Looking for suggestions, comments, encouragement & curse words

 

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I don't know the right answer but I do know if you are looking for curse words, even if you get them, the moderators will take them back away.  If it were mine, I would assume leaving it in and covering over it would be a bad idea.  Bad foundation and all.  As far as the kast o lite vs metrikote/plistix, a current method which seems to work well is 2 inches of rigidized ceramic blanket, 1/2 layer of kast o lite and a final thin layer of metrikote/plistix.  I believe the wise ones are steering people away from ITC towards the metrikote or plistix.  I went with the metrikote and I am happy with it but it sounds like people are happy with either choice.

I personally would attempt to remove the cement however possible with the least damage to the kaowool.  Then patch the spots with more pieces of kaowool and rigidize.  Then coat with what you choose.  

The forge itself looks good.  It sucks you had a snafu in there.  At least you noticed it instead of just having an inferior forge, now you can over come it.  Based on how it looks now, I doubt you will have any problems making it work in a way that you like.  

What is the internal volume planned to be?  What burner are you planning on using?

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AKM

Sure like the look of that forge.  is your volume 350 cu in or less?  I think AnotherCurtis and IDF&C are right on getting that stuff out of there.   I like the angle and position of the burner mount.  though I'd probably put the mounting bolts a bit farther apart from top row to bottom.  burner should impinge on the floor and should swirl.  Keep us posted. 

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If it has not been fired, the cement may not be as hard to take out as you suppose; the fiber blanket will easily delaminate, until it is fired. Next, patching ceramic fiber isn't hard if you use fumed silica in water to "glue" on your patches. Finally, some ragged spots in the fiber insulation is no big deal, if you are going to use Kast-O-lite over it.

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Thanks for the suggestions everyone!

I think I'll try to remove the cement, then go with filling the patches.

Found a place that will sell a 5lb bag of Kast 30 pretty cheap so I think thats the way to go since I really don't need the 55lb bag I usually see.

I'll be back in the shop next week so I'll post pictures of the burner and results of my cement removal for those interested in either.

As far as volume I'm not really sure, I never considered it. Might have been a rookie move, but about 90% of the fabrication of this was a combination of what I thought looked right and the tips I picked up browsing Iforge. I had the propane tank already, the rest I just went on gut and things I thought made sense for a decent forge.

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Forge volume should be calculated to determine what burner setup you need.  Suggestions have been made and can be made based on volume and whether or not you intend to forge weld.

Too little and you have a cold forge.  Too much and you make puddles of your work.  A bunch of examples of the former on this forum.

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Update from the shop!

Went ahead and cleaned up that cement, was a really good choice because it also had not even set correctly, it was basically sand about 1/4" deep.

I just cleared out what I could, and inserted a fresh strip on the bottom of the forge, now  ridgidize and wait.

IMG_20181217_113201.thumb.jpg.895149f13db34f02c3a38fbae726680e.jpg

IMG_20181217_113902.thumb.jpg.ab2b0eeddfa0628873a6b922342dee4e.jpg

As for the burner, its a home made one:

IMG_20181217_104929.thumb.jpg.91dd1d28c310fbbacd419746e2097b4d.jpgIMG_20181217_104938.thumb.jpg.d02806d1cd89419b11591f547a6a1c8c.jpg

i used a bit of pipe insulation to give me a cover to adjust the Oxygen intake a bit.

 

And based on my measurements. I'm looking at about a 332 cu forge

Ordered the Kast 30.l, That'll be the next step.

Any thoughts on the size/burner I have going?

Thanks!

 

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We would need more information on that burner.  What is the main tube ID and length?  What size is the orifice/jet/accelerator?  Have you lit this burner yet?  Could you get an image of the flame it produces?

This is in the tube burner category so Mikey is the guy when it comes to them.  Burners 101 is a long thread but has lots of good information, a lot of which pertains to tube burners from Mikey.  One big one to point out, using the holes as air inlets produces a lot of turbulence which slows air induction.  Burners like yours generally can't provide enough air and run rich which is then a carbon monoxide producer as well as not being as hot.  If you go to Ron Reil's website and look into what he called the minimongo, it is similar and contains his thoughts on how it performs.  If you like the style, look into the Mikey burner to see how he accomplishes air induction.  

This is not meant to be discouraging, the burner itself looks good and may be able to produce a good flame or at least a good enough flame that you are happy with it.  If you post a image of the flame you are producing, it can be looked at and recommendations can be made to get your burner running the best it can.  One of my forges has a burner which is too big and runs quite rich and it works just fine as long as I am willing to accept that it uses more fuel to do the work.  I just wanted to warn about the possible lack of air and production of carbon monoxide if so.  Be sure to be well ventilated as we all should be anyway. 

If in the end you can not get this burner to run to your satisfaction, it appears you have the shop skills to produce another burner which will.  At that point I would look into the Frosty T if you want simple or the Mikey if you want configurability and then build one to it's specs.  Unless you want to design your own in which case, you can read burners 101 to understand the science of the burners, to avoid some of the common mistakes and learn to read your flame so you know what you are looking at.  

The general thought on a properly functioning 3/4 inch burner is 350 cu. in. of properly insulated forge space in order to get to welding temperatures.  This recommendation is a general thought and it all depends on the design and build of both the burner and the forge.  

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Solid info AnotherCurtis, not discouraged at all, only more eager.

This burner was gifted to me when a friend realized I was starting to build a forge and I just worked it into my plans. I have not fired it up yet, so I think I'll address that as I wait for my Rigidizer to dry/ Kast 30 to arrive. I'll also have to re-read through burners 101, see what there is to be seen.

I'll post flame shots/dimensions of the burner tomorrow, and work from there.

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Nicely put, Curtis. I would add that drilling a little hole (1/8" to 3/16") in the bottom of the forge for some of the steam (that turns back into water) to run out of is a big help, both when cure firing the insulation, and during the years to follow. Otherwise moisture from the air, which can accumulate in the insulation layers, will turn to steam when the forge is run, and has no safe path to leave without damaging seal coatings.

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All good info guys, I'll drill that hole and look at drying the rigidizer.

The burner has been lit! The results were...  Mixed:

IMG_20181218_132259.thumb.jpg.d4476ce81a446b9a847f8a4411d0ba93.jpg

 That was running at around 12-15 psi. I've included a rough drawing of the measurements I feel are important to the formula:

IMG_20181218_134120.thumb.jpg.74db1ee667d05f8a4c23b0a673cbdc58.jpg

As far as I know, the Oxygen intake is way off and my pipe length is off from the respected ratio. The pipe was also getting quite hot most of the way down towards the mig tip.

My gut would be to replace the fitting up top near the mig, possibly with a T-Burner design via Frosty, and get the right length pipe, see what that does. I like the mig tip connection of this burner. And wanna incorporate that into the new tube design.

 

Thanks for all the suggestions so far guys!

 

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Burner appears to be a version of a Dave Hammer style burner.  Possibly not the most efficient burner out there these days, but not worthless either.  In my experience these burners are very sensitive to gas orifice location and flare geometry.  Before I made any major modifications to the burner I would try the following:

  1. Confirm you have a true propane rated adjustable regulator, not a fixed pressure regulator
  2. Adjust the location of the Mig orifice forward and aft in the tube to see if you can induce more air.  To my untrained eye the flame doesn't look that bad (provided the orange color burn off is just coming from your stainless flare).
  3. Adjust amount of coverage the flare has on the mixing tube (move it fore and aft).  This has a surprisingly large effect.  In the forge you may end up not wanting a flare at all.
  4. If none of this gets you where you want to be, try switching the mig tip to one size larger. 
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Decent idea Latticino, here we're the results:

IMG_20181218_161417.thumb.jpg.07522630e99ba11cd6db48d3f6c65094.jpg

This was adjusted so the Mig tip was as far back as I could get it, almost 1" farther that it's start point. Then I adjusted the end flange to be as far down as it could be. But I started getting blowback on the gap between pipe and flange. So I tested again:

IMG_20181218_162220.thumb.jpg.a4716f11af7bca2e4e3be753dab81e1e.jpg

This was test 2, I moved the mig tip about 1/2" forward, and the flange a little farther down the pipe. This worked, but I couldn't ignite the burner without closing off the Oxygen first.

IMG_20181218_163048.thumb.jpg.0c400db216e382d9dd3e7ef453d1ada5.jpg

This was my final test. With mig tip the same and flange further up the pipe. I adjusted the pressure to be about 20 psi. But it now would go out after about 2 min of burn.

I have a regular that goes up to 20 psi. Hopefully some tests help add info to this. 

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That is a good looking flame.  It weel heat!  Good job.  

The yellowing on the nozzle(flange) leads me to wonder if this is a galvanized part.  People are often choosing stainless for their nozzle as it holds up longer to the oxidation due to heating the metal.  In your very first picture of the flame you can see that the part has a cherry to it.  

You also have an 0.025 mig tip which I believe is on the smaller side for 3/4 inch.  I believe Mikey burners usually use an 0.030 (his book states 0.023 or 0.030) and Frosty T's use an 0.035.  Due to the holes for air inlets, I don't know that you can go larger and induce enough air.  

You made a comment about test 2 requiring you close down the air inlets to start the burner.  My Mikey burner does the same.  Close the air most of the way, light at lower pressure(5PSI), wait a minute for the nozzle to heat, open the choke some more and wait a few minutes until opening it completely and ramping up the pressure.  IIRC Mikey states this as the startup procedure in his book under the tuning section of the half inch burner chapter.

You state that in the final test it goes out after about 2 minutes of running.  What do you mean?  Does the flame lift off the end or backfire or ?

All this said, if you get the flame stable and point it into a forge, the forge is going to get hot.  

I imagine Mikey will be along soon to give his read of the flames and correct anything I have wrong here.  I look forward to seeing this burner in your forge, please keep us updated.

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On 12/17/2018 at 9:28 AM, AKM said:

Any thoughts on the size/burner I have going?

I think your MIG tip is just fine in this particular burner; yes they do vary.Two different Mikey burner can, that is made by old Mikey his very own self can vary. Even if this was rocket science, they ain't rocket parts :)

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  • 3 weeks later...

Hey all,

Sorry for the delay, I spent some holiday time in NY and the work piled up in my absence... Anyway... Back to the build.

The Kast 30 arrived while I was away, so the first thing to do was cast the bottom and sides of the forge. I did this over 3 days. Giving the bottom and either side a full 24 hours each for cure time.

After a cure and heat cycle, it was finally time to start the forge!!!!

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After running it for a bit letting it get up to temp, I put a piece of 3/8 round in to see what kind of heat I was getting, and there came a surprise.

IMG_20190107_153854.thumb.jpg.ac5885a477fdb109cac82040431ef397.jpg

I was only able to get a decent orange coloring. I left it alone for a bit of time and it seemed to pleateau around there and would not get any hotter.

There are a few spots that need a bit of tweaking, like the brick fit and the burner tube needs some insulation around it. But I expected it to be much hotter. My current theory is that my regulator isnt what I thought it was. I think it isn't giving me much pressure. But open to any suggestions/questions! It getting real close!

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Right at this point you need to go for a re-emissive coating; that will do you the most good. Then we can discuss a better baffle wall. You will want to use the same coating on its hot-face. You have plenty of input heat. Now, it's time to quite thinking "gas furnace" and start thinking "radiant oven."

My first forge, was a great design and had a very hot burner, only got up to bright orange; just like yours does now. Then I put on a heat reflecting (re-emissive) coating, and it went to lemon yellow heat. BTW, you are also losing a lot of heat from too much secondary air induction between the burner's mixing tube and the burner portal's pipe. Do you have any wool scraps left over to stuff between them, while you make a washer?

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Or, you could drill a large enough hole in a pipe cap for your burner, and drill small holes in it--ONE AT A TIME, while watching the exit flame coming out of the forge's exhaust opening; once the forge is burning clean (no blue exhaust flame), stops drilling more holes in the cap.

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According to my measurements, I have about a 320 ish cu/in forge, the front opening is 5x7.  and that was before putting in Kast 30, so I think it's not a size issure,

I'll give your suggestions a try Mikey, stuff the portal  pipe and get my bricks sitting better, see if that changes anything.

I'm not 100% sure on my regulator, but according to my gauge I am getting around 20 psi out of it, that seems like plenty, yea?

I'll also tweak my burner placement, see if I can just get the max outta it.

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On 12/18/2018 at 12:49 PM, Latticino said:

Burner appears to be a version of a Dave Hammer style burner.  Possibly not the most efficient burner out there these days, but not worthless either.  In my experience these burners are very sensitive to gas orifice location and flare geometry.  Before I made any major modifications to the burner I would try the following:

  1. Confirm you have a true propane rated adjustable regulator, not a fixed pressure regulator
  2. Adjust the location of the Mig orifice forward and aft in the tube to see if you can induce more air.  To my untrained eye the flame doesn't look that bad (provided the orange color burn off is just coming from your stainless flare).
  3. Adjust amount of coverage the flare has on the mixing tube (move it fore and aft).  This has a surprisingly large effect.  In the forge you may end up not wanting a flare at all.
  4. If none of this gets you where you want to be, try switching the mig tip to one size larger. 

BTW Latticino, I think your burner advice did him a world of good. Thank you :)

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