Glad the drawing works better. I feared the doorways would warp, now I wonder how Chile forge gets away with theirs? Don't quite get what you mean by extra piece of kaowool, trying to wrap my head around that still. Do you mean 3 inches of the stuff total on the floor? The kastolite will accumulate in the corners of the floor rounding them off significantly which is crudely sketched on the left side of the drawing in a light color.

If the Kaowool is that much harder to keep rigid as a D compared to it being crunched into a tube shape then maybe some pieces of twine tied around it and the body would work until rigidized. Or maybe a solid form resembling the finished chamber shoved into it is better, probably a bunch of ways to do it with decent results.

The stand I'll do different when the forge body is constructed alongside adding a shelf for firebrick. I have a couple of ideas in my head on how that could work. Still in no rush to create this as some of important bits are delayed in shipping.

21 minutes ago, Mikey98118 said:

What you want to do is keep the steel shell at least one-inch away from the opening's refractory

Going to write this down in the shop so I remember. Makes me even more curious with how the Chile Forge is designed

Draw 3 concentric circles on a piece of paper, the outer circle represents the forge shell. Estimate the next one in at about 1" and the 3rd" another inch in. The two inner circles represent the ceramic blanket. Now estimate how wide you'd like the floor and draw a line that long horizontally across the bottom inside the inner circle. Make sure the gap between this line is the same or less than the space between the inner two circle. 

The "floor" section is an additional inch of insulation between burner and whatever the forge is sitting on. Feather the edges running lengthways in the forge chamber. Feathering is stripping the thickness of the blanket so it lays with an even flat surface. 

Rigidized and coated with a flame face refractory you have a D shaped forge in a round shell. There is no downside and it's way easier to make than starting with the shell.

Not crumpling up the blanket is why you use 1" thick instead of 2", 2" thick rolled into a tube wrinkles like crazy and makes a generally poor surface for directing the flame in a smooth circular motion.

You haven't been a member here long enough to remember all the posts by guys wondering why their brand new Expensive Chili forges were warping, some were even popping seams they warped so badly. The steel lining of their doorways is typically only about 1" and IIRC maybe 16ga. Yours on the other hand looks like it's at least 4" and what, 1/4" thick? A closed rectangle like that is structurally very strong. Many times as strong as strong as the wide flat end of the forge and the shell itself. Your thoughts will PROBABLY warp your forge so badly it won't stay together at all.

Just out of curiosity how EXACTLY will twine hold Kaowool against the inside of the shell? If the thought is to use it to form the blanket to the outside of a form, it won't work well if you can pull it off. I tried and abandoned this a couple decades ago. 2 major issues, #1 the twine will compress the blanket and lower it's ability to insulate making the forge run cooler than it should. #2 is getting the rigidized blanket Ds, tubes, whatever to slip smoothly into the shell and then the inner one into the outer layer. Being rigidized they can's expand and hold themselves in place where they should.

Emplacing the blanket in a simple cylinder is a piece of cake. Wearing breathing protection ALWAYS when handling ceramic blanket!! Simply cut a piece as long as the chamber and about 1" wider than necessary to make the circle around the inside of the shell. Gently compress it enough the ends fit together and let it relax, it will expand and hold itself in place without help of any kind. 

Rigidize and cure. Then repeat the above process for the second layer but stagger the seams so they do NOT overlap. Rigidize, cure and cut your burner port. Do I have to tell you NOT to put either blanket seam over the burner port?

Lastly just feather and lay the section of blanket for the floor and rigidize in place. If the floor section is a LITTLE bit too wide and the ends feathered thin it will flow up the curved sides of the  cylinder shaped and rigidized blanket already laid. This means you do not need to try chamfering the hard refractory as in your drawing above.

Once cured, butter it and apply whatever water setting HARD refractory in THIN layers. The thinner the layers the stronger and less likely it will be to spall and break with the FAST thermal cycling of a propane forge. If you use Kastolite 30 1/4" all round is more than enough and a good kiln wash makes it pretty flux proof.

When you do this to the ends simply wrap the blanket around the edges of the opening and finish it with yard refractory and kiln wash.

This last brings up a question. Will you be putting doorways in each end? The back one is called a pass through and is necessary if you wish to work steel much longer than about 2/3" the inside length.

Frosty The Lucky.

As to a pass-through in the rear forge end; an under sized opening calls for work to enlarge, but an over sized opening will prove much harder to correct.

Correct or adjust to the needed size / position? Maybe using something, fire brick or kaowool, door, etc. to block pass throughs is from too long ago?

Frosty The Lucky.

Thanks for the in depth explanation Frosty, going to read through it once again when assembling. The forge shell can be any thickness I have a ton of sheet metal and plate though my idea was to make the main shell or the "cylinder/D shape" 14 gauge and the front/back parts where the doors are 1/8" plate. The doorways were intended to be 3/16" plate, you were very close. Fire brick will work perfect for closing the back end since they're going to be similarly sized openings, this can be changed however.

I thought over the twine idea in my head and you're right, it won't work well so not going to bother attempting it.

Taps finally arrived, even with a Mill (which I don't ever use) my ability to tap is god awful, good thing I bought a couple of extra pieces of the 1/4" adapter and tees to take my time with and get them aligned just right. Unfortunately one of the wrenches I bought is not very good quality wise. It holds the tap but wobbles loosening it up with the slightest of pressure. The small one is actually pretty ok which is nice, I included a pic of the setup. 

The heavy vise was pretty good in not crushing the threads, they appear ok but I may swap over to the flange idea since the Bridgeport has hit max depth on the table with the larger wrench. If I used a real tap guide in the Bridgeport it would be even better but couldn't find one anywhere so a half disassembled center punch will do the job.

Wanted to use some refrigerator copper tube per the Frosty suggestion but couldn't get my hands on a small enough amount that wouldn't break the bank. Since this is a test burner I think it'll be ok to use what I have at the moment, though if I get time this week I'm going to head over to a plumbing store and check a couple different fittings since I'm not very impressed with the swivel connector.

 

How is that tap wrench set up, what's that thing sticking out of the top of it?

Don't you have access to a drill press? If so you can forget wrenches and being bad at tapping holes. Put the mill in neutral and hand turn the chuck. The fittings are brass and you are only chasing them IF necessary and a tap doesn't require Conan muscles, just use the chuck key for leverage and grip. Disengage the mill head feed and let the weight of the spindle and chuck advance the tap. It's almost exactly the same as I described for drilling and tapping with a drill press. Unplug the thing for safety's sake, I do.

I was trying to compose a response for the mess of fittings in your pic before I realized the little piece of copper tubing will be replaced by the long supply line to the regulator. No?

Get rid of all that stuff except the mig tip. Replace the elbow with one that adapts from the propane fitting directly to 1/8" MPT and connect the propane hose directly to the elbow. EZ. PZ. You will of course need to tap the MPT leg of the T to accept the mig tip but you're getting that down. 

You're doing fine, just relax we'll talk you through this. After the first one you'll be wondering why it seemed so hard. Honest, you're not the first person I've talked through one of these and it really is a simple procedure once you learn how.

One pro tip for today. If a tool isn't doing what you want, do NOT put another one on it. There are lots of how to videos on the web or take a break and ask me. 

Frosty The Lucky.

 

The thing attached to the top is a center punch that has a spring in it, uploaded another photo of that. I bring the table up until the tap wrench is tight and the spring is compressed keeping pressure on the wrench whilst letting me spin it by hand. It would work FAR better with a real "Tap Guide" since this one has a lot of slop and unnecessary length being a hand held center punch and all. I'll try using the weight of the spindle instead tomorrow it should work pretty good for the 1/8"-27 pipe tap.

That piece of copper tubing you see is from a 1/4" Brass Female Flare Swivel. So what you're saying is I should get a 3/8" Flare (Hose connection) to 1/8" MPT which will be tapped to accept the mig tip making it the only brass fitting piece? I'm looking at the SKU F40-067 from supplyhouse. It's a lot of weight from the hose on the tee but I could weld supports to it, really no different than what I'm currently doing except it's a ton less parts.

Thank you

 

 

 

 

 

 

No wonder you can't tap a hole! Get that spring punch out of there! Take the wrench off the tap.

Put the chuck key in the drill chuck. This is only so you have a good grip and a little leverage to turn the chuck by hand.

Put the tap in the drill chuck and raise the bed till the tap makes contact with the brass fitting Do NOT put pressure on the tap. Using 1 hand on the manual spindle feed lever, gently turn the drill chuck so the tap turns the same direction as if you were screwing a bolt in. Yes?

If you don't know how to disengage the spindle feed from the feed mechanism, three are instructions ON THE MILL. If you can't find them take pics and send them to me. Find the mill's maker's name and model # and send them to me. If you can't find operating directions on line I can and I'll help you figure out how to use the thing without powering it.

Raising and lowering the bed is for gross positioning. Big movements like 2" or 2'. All operational height adjustments are through the spindle feed. The table IS for making horizontal movements, in out back forth, up down is spindle. 

Sorry, I'm shocked by how little you know about operating a precision instrument and the things you're (thinking up) are not only failure mode but could do serious damage to the machine or worse YOU.

For one last example did you gage the ID of the brass fitting to see if you are using the correct tap? OR did you just stick a 1/8" x 28 tap in the hole and start reefing on it?

Rolls of copper tubing is commonly available at real hardware stores for not much.

I'll have to do a serious search and see if I can't find the directions I drew / wrote up. At least you'll have pictures, even if they aren't current. Just describing operations isn't working, you don't know enough about basic shop tools and or how to use them.

We'll get you up to making HOT fire.

Frosty The Lucky.

Edited October 30, 2025Oct 30 by Mod34
Edited for inappropriate language

That spring punch method is actually what my machinist friend told me to do and it got the threads perfectly straight first try. He wanted me to avoid doing power tapping without experience. It was the prior attempts by hand without moving the chuck that got me bad results, I should have worded that better in the earlier posts. 

The real problem was how cheap the 1/2" capacity wrench is and I'm already sourcing a vintage to replace it. I'm surprised they're allowed to sell them on amazon with how bad it ended up being, can't even properly hold the tap in the jaw.

To recap a bit on the tapping, I misused the 1/8-27 pipe tap and went a bit too deep so the flare adapter doesn't fit in the tee quite right, I just need to tap a new tee and be careful not to go overboard with the depth since the 1/8-27 tapers. 1/4-28 worked great for the mig tip, tweco brand threads.

16 hours ago, Frosty said:

Get rid of all that stuff except the mig tip. Replace the elbow with one that adapts from the propane fitting directly to 1/8" MPT and connect the propane hose directly to the elbow. EZ. PZ. You will of course need to tap the MPT leg of the T to accept the mig tip but you're getting that down. 

Replace the elbow then connect propane hose directly to the elbow? I sent an image of the only fitting that makes sense from this quote. 

 

 

 

 

 

 

 

 

I suppose the new way is to find a tool to do a thing instead of just developing a little skill. 

Did your machinist buddy who says you need a mill and a rube goldberg stack of stuff to tap a straight hole tell you what tap wrench to buy too? How about you get him to show you how to tap a "perfect" hole with one of those?

I'm getting pretty tired of arguing with you about pictures and ideas you find on the internet. And worse your habit of mixing and matching those things without a clue. 

Last tip. There is an old adage, "A tool designed to do two things does neither well." The below pic is a cheap tap wrench that works far better, especially if you need straight. About $20 on Amazon.

Frosty The Lucky.

2 hours ago, Frosty said:

I'm getting pretty tired of arguing with you about pictures and ideas you find on the internet. And worse your habit of mixing and matching those things without a clue. 

If you're referring to the most recent image of the 3/8" Flare  x 1/8" MIP, that is because I am still hoping for clarification on the quote I put in the last post from your reply a few messages back. If not and the elaborate mill setup is what you mean, T style tap wrenches have a hole at the top for a reason and they can be used in both Lathes and Mills with a tap guide. I searched a bit and found a video that shows the method I used. It works for sizable taps but if you go real small it loses SOME precision. 

https://www.youtube.com/watch?v=25MvOH4GdBI&t=130s

At the end of the day a threaded hole is a threaded hole, if it's aligned with the burner tube for proper mixing then I don't think we need to tire ourselves out over which method for tapping to use/is best?

 

 

 

 

I have to apologize, I just don't have the patience for this sort of thing anymore. This wasn't supposed to be about different tools and methods and it's devolved into something I'm not doing.

Below is the link to the T burner directions published here. 

Be Well, Frosty.

https://www.iforgeiron.com/topic/43976-t-burner-illustrated-directions/#comments

We use tap guides all the time when tapping by hand at the shop i work in. It makes sure that the threads are straight. It is also the reason that taps are either conical or have a hole on the end. They can be used either in a mill, as pictured, or in a lathe. They are pretty common tools found in a machine shop. 

You can buy them on that site named after the giant river in S. America for less than $15. 

Also if you are going to do a lot of tapping i would highly suggest a ratcheting tap wrench. 

Just a reminder that the forum rule banning live links to commercial websites does not limit mention of the names of such sites, such as Amazon or eBay.

3 hours ago, BillyBones said:

Also if you are going to do a lot of tapping i would highly suggest a ratcheting tap wrench. 

If I do more tapping I'll definitely pick one up alongside an actual guide, thanks for letting me know! 

 

 

 

There is no need for an elaborate setup to tap a single hole in your part. Simply insert the tap directly into the the chuck, and move it down to the part by hand. Then, turn the chuck by hand to get the tap started into the hole correctly. Then release the tap from the chuck. Mount the tap holder on the tap, which is now started in axial alignment with the part's hole, to finish threading correctly with it.

BTW, I only use this method to tap critical parts. To thread a hole in a part like that? I trap the part in a wrench one hand and a tap in a holder in the other hand. After aiming as close as I can by eye, I just start threading, and allow the tap to center itself (gasp!) How is this possible? Brass is more forgiving than steel, and the tap used is a taper tap--not a plug tap.

If Mikey the picky-but will tap free hand, then how hard can tapping with the help of a drill press be? Common; this ain't brain surgery. Airplanes won't be falling out of the sky if you mess up a little.