Mikey98118

Dropping down from oxyacetylene to propane and air gave me a lot of hesitation too... twenty-two years ago. Burners have come a long way since them. You need to mentally let go of torch technology and embrace burner technology--or forget forge work. If you don't get your head in the game you'll make a big mistake, like trying to use an acetylene regulator to run propane.

I love small; all my favorite cars were and are small; the wife and house are too. Anyone who follows my writing knows that I get excited about small burners in small forges. But sometimes we just gotta look up from our obsessions and admit that the other guy's dog is pretty cool too. Ribbon burners aren't my thing, but they are still magic.

Okay, two bars are about 30 PSI gauge pressure, so .7 to 1 bar more means your burner blows out at about 45 PSI; that doesn't say much for their stability in this forge. On the other hand, fan-blown ribbon burners provide positive pressure; they are also a better design for larger forges. I suggest that this path solves both of your problems while providing the most frugal design for fuel use. Your forge is too large to use off-site anyway, so such fan-blown burners present no downside.

You would do well to leave a small steam and water drain hole (about 1/8") in the bottom of the forge to allow collected moisture to escape through before heating the seal coating. The second "T" photo shows an excellent flame. I think that both your efforts and photo records have been outstanding so far. I don't know why they haven't generated more comments. Would you look to go into your door design more?

Most American tanks have similar sizes; but not all. Foreign built tanks can be very different in sizes and shapes.

Since the smaller the burner size the shorter the gas jet needed, some of the smaller jets would probably work out okay. Furthermore, being a threaded brass part, they should work out well as a base for holding capillary tubing for longer gas jets onto...

I've looked at both flame photos, and they are acceptable.

Have you ever heard the advice never to look down the barrel of a gun? You are considering excepting a situation where all the possible things that can go wrong will leave you on very thin ice; why would you do that?

Well, it can be turned down low enough...but I think a winter break in El Paso sounds better. A word to the wise. Any well made miniature burner (3/8" and under) Tends to be very hot running. So you could get what you want from a typical linear burner for less fuss...just a thought.

MIG contact tips come in very limited sizes since they are only designed to run welding wire through. The next best plan is to drill into half-hard brass, creating your own gas jet. Most people aren't set up to accurately drill miniature holes, and so I suggest capillary tube to get around their limitations. Whichever way people go has its own problems. In MIG tip tables I recommend both .023" and 030" contact tips on my 3/4" burners since one is a little undersized and the other is a little oversized. But one will always turn out best on any given burner because none of them are exactly the same.

The best solution is to build or buy a 38" size propane burner, like the one pictured write now on Burners 101 thread. In meantime, their are much hotter propane torches to use: https://www.amazon.com/Mag-Torch-MT245C-Propane-Pencil-Burner/dp/B000646QRG/ref=sr_1_7?ie=UTF8&qid=1515298192&sr=8-7&keywords=Mapp%2Fpropane+torch

Yes, EDE, that is a perfect hard flame on what I'll assume is a 3/8" Mikey burner...BUT we need to discuss how you choose to build it. Did you decide to use the narrower air openings, which I felt would increase swirl, leading to increased flame sizes? Does it produce a stable flame over a longer pressure range? I am pleased to see you stuck with all stainless steel construction, which costs so little additional money in small burner sizes. Glad to see you back, and how the heck have you been?

Rigidized and seal coated as a minimum.

True; I missed that one. Glad you didn't

Cutting ceramic blanket right for tunnel forges The formula for finding the area of a circle is plastered all over the Web, including calculators, so what can so many people find jittery about it? I think it is the fear of cutting a relatively expensive product wrong the first time and having to patch it together. This nonproblem comes from ignorance of three facts: (1) You don't want to try for a perfect matchup in the first place. Ceramic fiber blanket is springy; you want to cut it oversize so that it must be compressed to fit in place. (2) If you have a brain in your head you will rigidize the blanket once it is in place, which will also glue together any patches you may have in the material. (3) The last thing you do is plaster a seal coat over the blanket, so any leftover seams will disappear anyway. So what is there to get uptight about?

A good burner flame is the hardest part for most guys to get passed because it is the part that causes the most anxiety.

You have a good burner flame, but The rest of your plans are in the ditch.

Sorry Wayne; you think right

In your shoes, I would use Plistex from Wade, and get on with business.

Forges 101 is a permanent thread with information touching on every question you asked here, and much more that you didn't. You started out stating that you want a forge to run on natural gas, and then went into how to make it portable; since NG is usually run with fan-blown burners it is a poor candidate for portability.Also, unlike pumped NG from a utility, the compressed fuel in a cylinder is very extensive in many places, because there is no demand for it.

My sainted mother used to call it "ignorance tax"

Never heard of them, Buzzkill; this isn't surprising. I expect new bricks coming on the market to continue increasing, in response to increasing demands for high tech brick, which can do more. Fuel costs more money all the time, and that drives customers to pressure manufacturers to improve their products in order o protect their markets.

The bricks I recommend are K26; that "K" in their name is important because this brick from this manufacturer( Morgan) can match the insulating value of ceramic wool at 2000 F and up, but is much tougher than the standard foamed clay bricks that can't withstand thermal cycling. By that I mean the fast thermal cycling found in forges; not the days long cycling found in kilns.

If it had been offered for sale with other jewelers tools at fifty bucks, it would have merely been typically overpriced, and would probably even succeed, but as it is it has definitely entered the twilight zone

Water glass melts at 1900 F. Fumed silica is use-rated for 2300 F; it begins to melt at 3000 F.