Metric T-Burner

[Vandle]

Just trying to build a Frosty T-burner in the UK.  I have a 3/4 inch T and a 6" * 3/4" pipe.  Gas pipes are 1/8" BSP Tapered pipe and I have bought a 1/8" male to male nipple to fit in the T.

Problem is our MIG tips have an M6 metric fitting, which is a sloppy fit inside a 1/8" BSP pipe nipple.

I've looked everywhere online to find an alternative way of fitting the MIG tip but no luck so far, so maybe someone on the forum has had a similar problem and come up with a solution?? I should live in the States maybe?

 

[timgunn1962]

Many of the mini-migs take an M5-threaded tip (14K) and these are widely available. M5 is also a standard thread for pneumatic fittings. 

I used a 1/8" BSP to M5 hex reducing bush to fit these mig tips into Amal atmospheric injectors when I was experimenting with jet sizing a few years ago. I never came across a fitting that would make it easy to build a T-burner though. I wasn't specifically looking, but I'm pretty sure I'd have bought a handful if I'd seen anything.

The MB360 MIG torches use an M8-threaded tip, available in 0.6mm (which surprised me), 0.8mm and 1.0mm  There are also bigger sizes (1.2mm and 1.6mm, maybe others), but they are bigger than "we" are likely to use. There won't be enough meat in the 1/8" nipple to tap out to M8  (tapping drill size for 1/8" BSP is only 8.8mm), but you'd probably be able to find a 1/4" BSP fitting with enough wall thickness to tap M8.

 

[swedefiddle]

Good Morning, Vandle

Screw a plug into the end of your tube, tight. Drill the center of the plug with the appropriate size drill for your Mig Tip, Tap the thread. Job Done, Finished. No store required. If you have access to a metal lathe, drill the hole that way.

Neil

[Jasent]

You can use and equivelant of a 1/8"mpt X 1/8" fpt elbow.   I've run in to the same issue here in the USA.  Some of the parts I found where to big of an inside bore. I was going to use the elbow till I found the right ones that had a smaller inside bore. 

[Jasent]

One more thing. You mentioned you had gotten a 3/4" T.  Hope you ment a 1"T with 3/4" chase?

[MonkeyForge]

Hi Vandle, it will be useful if you update your profile to update your profile with your location. We know you are in the UK when we read this thread but will likely forget that when you start another thread. I could also not easily find parts that would easily convert to M6, I did find them in the end. I do not know if they are available or easily available for you but I used a 1/4  female to 1/8 male adapter from Georg Fischer. These reducers can be drilled 5mm and tapped M6 afterward. In most cases it will mean you need to use an extra adapter to get your hose connected. see pictures of the part and part number:

[jcornell]

In the USA there are difference categories of pipe - by way of example, Schedule 40 and Schedule 80.  A schedule 80 pipe has a thicker wall.  If you're trying to mount a mig tip, you MUST use a thicker walled pipe - the 1/8" Schedule 40 doesn't have sufficient Inner Diameter (ID) to tap the threads properly, while a 1/8" Schedule 80 does have the proper ID.  Now, I know next to nothing about British pipes, but I'm willing to bet a cookie that if you go to a British plumbing supply house and ask if they stock thick walled 1/8" pipe nipples, you'll be able to tap for your metric mig tip without much problem.

[Mikey98118]

I think you have the right of things, and I am surprised that someone on the English side of the pond hasn't already posted all the essential pipe facts for forge builders in the UK.

[Vandle]

Thanks to all of your great replies. I received a 1/8" BSP steel hydraulic fitting today as suggested by TimGunn (cheers Tim), drilled and tapped to M6 successfully and built the T-burner.

Unfortunately, no Jasent, I have not used a 1" T.  It's 3/4" pipe fittings all the way round. The burner either wont light unless I turn the gas almost off, or it lights at the mig tip and burns down the length of the tube. Too much air, too little air?  I'm running at about 7 - 14 psi (0.5 to 1 bar). Any ideas anyone. 

Not fitted a flare as yet since I had hoped I would get something out of the burner to heat the pipe I'm planning to flare out. I've adjusted the position of the MIG tip from way back in the T to almost inside the burner pipe with no effect. I've even cut down a MIG tip to ensure it's not too extended. My only variation from the plan is that I have used this http://pipeworksuppliers.co.uk/index.php?route=product/product&path=80&product_id=208  Should have read the instructions a little more, but I've since seen posts where people have had to reduce the air intake of Frosty's burner.

I'll wait a while before ordering a 1" by 3/4" T just in case anyone has another idea. This is the second burner I have built, the original last week a Ron Reil burner did exactly the same as this which I put down to poor build on my behalf.  I then came across this T burner and thought it would be easier. Pressure related? Seems odd that both have a similar problem.

[Jasent]

Are you lighting it out side the forge?  If so try putting it in the forge then light it. I didn't use a flare and it would not work well out side the forge but inside it works very well

[Vandle]

Not assembled the forge yet Jasent. Thanks for that, will start on it tomorrow. I'm trying something a bit different for the forge — it will either work brilliantly or melt!!! Will let you know. 

[Jasent]

What are you trying?

[Vandle]

I have a double walled chimney liner with internal insulation. I'll add two layers of insulation wool and an insulated brick floor inside it. The steel wall of the liner is very thin, hence it may not be sufficient to withstand the heat. Depends on the insulation. It's free, so I thought I'd try it as an experiment. You never learn without busting a few things! 

[Mikey98118]

It should work okay.

[Jasent]

Please update us on the build

[Vandle]

Just chilling to Rag n Bone man over a bottle of French red, so back to forging in the morning. Will let you know. 

[Vandle]

Many thanks for all the advice guys.  I got the forge working in the end - in the forge the burner lit fine even outside it would not light.  I increased the size of the flare so that now it is all working fine as a burner on its own and within the forge. Just hardened my first knife blade so very happy!..

The forge body itself is so far running ok, but when I first lit it I ended up with a face full of particles from the lining blanket, so lined the inside with fire cement. This is slowly coming apart and the fire blanket seems to be degrading. I used a couple of fire bricks out of the lining of a log burner as a floor and they too are rapidly dissolving.  Overall I'd say the chimney liner idea is ok as a first attempt with parts that cost me next to nothing, but wouldn't recommend it as a long term forge.  I'll get some bricks from Vitcas next and build a small brick forge.

Thanks again.