Hello and a question

[Ben Iles-Smith]

Hi all, I’ve been lurking on the site for a while but thought it was about time I said hello! I’m a pretty recent convert to bladesmithing. Been at it about a year now. So hello from a UK Bladesmith 

 

Ive also got one or two questions about burners. I’m planning to build some blower burners based on the designs posted on the site. I particularly like the t-junction ones.

 

I couldn’t really figure out whether these needed to be sealed or just screwed together (I remember a post saying not to put Teflon on them though). So do they need sealing up? And would this be with plumbers tape (like that used on radiator fittings) or welded together?

 

Also am I correct in thinking the burner doesn’t need a flared end as we aren’t going for a Venturi effect?
 

Any help would be real nice

 

[Alan Longmire]

Welcome!

 

Blown burners are as simple as they come.  No tape needed, no sealing required, no flares, no tiny gas jets.  Just dump in gas while the blower's on and you're good to go!

[Ben Iles-Smith]

Thanks Alan that’s really helpful! I’m guessing just threaded black iron pipe works for this? 

[Alex Middleton]

Yup.  Black pipe is all you need.  I've used both 1" and 1.25" for my burner tube, I would recommend not using the 1" if you're planning on doing any forge welding.  I can get it up to temp in my forge, but I really have to pour the air to it to get enough through the pipe.  @Geoff Keyes has a pinned topic in the Tools and Toolmaking subforum called something like "Blown burners, a care and feeding".  Give a read through that before you get started.  Like Alan said, they are about as simple as you can get.

[Ben Iles-Smith]

Thanks @Alex Middleton. Really helpful post by Geoff, thanks for the tip.

 

Are you able to get the 1.25” to welding temp with ease? I do a bit of everything in the Forge so be nice to have the option.

 

Im guessing yours tapers down from 1.5” where the T junction is to the 1.25” at the Forge end like the ones shown in Geoff’s?

[Alan Longmire]

The great thing about blown burners is they don't care.  You can go with a restricted end in the forge like that for a more concentrated flame, you can flare it out to a 6" x 10" gaping hole for a diffused flame front (as long as you have enough air to prevent burn-back!), you can run it through a block of holes and call it a ribbon burner,  or just about anything else you want to do.  I've even seen one that was just a 1/8" copper line plumbed directly to a 100lb tank via a single needle valve, no regulator, dumping directly into a 4" iron pipe hooked to a vacuum cleaner on a dimmer switch.  Not the safest thing in the world, but it gives you an idea of how simple they can be versus those delicate flowers that are venturi burners. 

[Guy Thomas]

3 minutes ago, Alan Longmire said:

The great thing about blown burners is they don't care.  You can go with a restricted end in the forge like that for a more concentrated flame, you can flare it out to a 6" x 10" gaping hole for a diffused flame front (as long as you have enough air to prevent burn-back!), you can run it through a block of holes and call it a ribbon burner,  or just about anything else you want to do.  I've even seen one that was just a 1/8" copper line plumbed directly to a 100lb tank via a single needle valve, no regulator, dumping directly into a 4" iron pipe hooked to a vacuum cleaner on a dimmer switch.  Not the safest thing in the world, but it gives you an idea of how simple they can be versus those delicate flowers that are venturi burners. 

 

My "Ron Reil" style venturi burner represents that remark, nyuk nyuk nyuk. The small blown burner I built for my 55 gal. drum heat treating forge does work very very reliably.

[Alex Middleton]

Yup, 1.5" for most of the plumbing.   I use a 1.5" gate valve for controlling my air flow, but only because it was mismarked at the hardware store for $3.00.  Depending on what type of blower you use, Geoffs method of restricting the intake is simple and effective as well.

 

  I didn't have any issues getting the 1.25" burner up to welding temps.  I sparked more than my fair share of pieces before I learned that you dont have to run the forge wide open all the time!