[TheForge] Chip Bed Forge

Mon Feb 20 19:42:46 EST 2006

Reminds me of the time I visited Boxford's, who besides making educational
CNC equipment also make wheelchairs. They had jigs set up and were brazing
the frames together, so I asked why. They explained that it was thin-walled
cold drawn steel, and it would lose a lot of its desirable properties if it
were welded.

I suggested that mig welding was better for bodging stuff together, being
better at gap filling, so the brazer (who was really annoyingly young) took
two pieces of 3/4" pipe, and simply brazed them together in a 'T' with no
end prep, neatly filling a 3/8" gap with braze.

Damned if I can do that...

Rich.

> -----Original Message-----
> From: theforge-bounces at mailman.qth.net 
> [mailto:theforge-bounces at mailman.qth.net] On Behalf Of Mike Porter
> Sent: 21 February 2006 00:17
> To: Sponsored by ABANA
> Subject: Re: [TheForge] Chip Bed Forge
> 
> 
> Hope my assessment of European heating equipment was more 
> accurate. Feel 
> free to correct any mistakes with just as much ruthless 
> abandon. I try not 
> to be unfeeling about people, but equipment must stand on its 
> own. What's 
> that English expression..."let the weakest go to the wall"? 
> Of course, we 
> are only doing so well on this side of the pond because 
> someone decided to 
> push propane instead of butane.
> 
> You and I should get a chance to compare notes more closely 
> on brazing 
> hearths in the coming months, as joining is the thrust of 
> book two. But, you 
> would have guessed that already, if you've been following the 
> thread on 
> vision enhancement.
> 
> It is my contention that the steady retreat of brazing and 
> soldering before 
> the onslaught of welding technology (which started during 
> world war two) is 
> over. Joining is a process that is far better suited to 
> today's Hi-tech 
> world, and to the demanding sort hobbyist that world is 
> creating; very much 
> like revisiting the late nineteenth century.
> Mike P.
> 
> ----- Original Message ----- 
> From: "Rich Maynard" <rich at maynard.org.uk>
> To: "'Sponsored by ABANA'" <theforge at mailman.qth.net>
> Sent: Monday, February 20, 2006 1:49 PM
> Subject: RE: [TheForge] Chip Bed Forge
> 
> 
> > Hi Mike!
> >
> > It's 'Design and Visual Arts' by the way, not 'technical 
> department'!
> >
> > Rich.
> >
> >> -----Original Message-----
> >> From: theforge-bounces at mailman.qth.net 
> >> [mailto:theforge-bounces at mailman.qth.net] On Behalf Of Mike Porter
> >> Sent: 16 February 2006 17:02
> >> To: Sponsored by ABANA
> >> Subject: Re: [TheForge] Chip Bed Forge
> >>
> >>
> >> Michael,
> >>  Try Flame Engineering if you want to find "state of the 
> British art" 
> >> crafts heating equipment. Unfortunately, every bit of 
> their stuff is
> >> also quite out
> >> of date. England and the rest of Europe designed all their
> >> forging/brazing
> >> equipment to run off of butane--not propane. Butane had been
> >> thought to have
> >> several advantages over propane. One of them is that butane
> >> receives a big
> >> flame temperature boost (356 degrees more than propane) from
> >> a lot less
> >> added oxygen (a ratio of 1.8 to 1 instead of propane's 4.7 to
> >> 1). But, the
> >> main advantage was supposed to be safety. Propane cylinder
> >> pressure is 109
> >> PSI at room temperature, to butane's 17 PSI. Sounds almost to
> >> good to be
> >> true, right? Well, it is. Lower pressure turned out to be a
> >> mixed blessing
> >> at best. You see, all their heating equipment needs large expensive
> >> motor/compressors, and the attendant safety equipment that
> >> goes with such a
> >> system...and we find it all down hill from a design
> >> standpoint from there.
> >> Oh sure, 17 PSI is plenty of pressure to establish a flame
> >> with, but the
> >> fuel cylinder rapidly super-cools, with a resulting drop in
> >> pressure that is
> >> pretty close to zero. Europe is now starting to mix butane
> >> with propane,
> >> playing catch up, but not doing very well at it. Catching up
> >> always requires
> >> 'fessing up to your mistakes as a first step.
> >>
> >> The only real innovator I have found in English heating 
> equipment is 
> >> Bullfinch, who not only has come up with some pretty clever single 
> >> gas torch designs (I love their ignition system), but even 
> appears to
> >> have its own
> >> foundry. However, I tested Bullfinch's biggest brazing torch
> >> against a 3/8"
> >> tube burner last year, and the burner won (just). When tested
> >> against a 1/4"
> >> burner with a much narrower target pattern, the 3/8" burner
> >> was completely
> >> blown away, but by then I'd got rid of the torch, so they
> >> couldn't go head
> >> to head. For about fifty-seven bucks you can buy a High-heat
> >> Torch (Model
> >>  "D" blowpipe): Made by Grobet USA, which will keep up with
> >> the 1/4" burner.
> >> The Model "D" blowpipe uses compressed air, to collapse a
> >> brush flame into a
> >> super fast (and therefore super-hot) needle flame. All this to say:
> >> "European heating equipment isn't worth the shipping charges,
> >> let alone the
> >> prices they ask."
> >>
> >> Apparently, Europeans agree with this view, since you can 
> find used 
> >> brazing/forging equipment for sale on UK sites at about 
> 1/10th of its 
> >> original price. As near as I can tell, sales to the school 
> system is 
> >> all that keeps these guys in business. However, the head of a
> >> London school's
> >> technical department corresponded with me for a while last
> >> year, while he
> >> was building a tube burner and pipe forge for home use.
> >> Apparently 1/10th
> >> the price still didn't make local gas forge designs appealing
> >> to him. You
> >> can draw your own conclusions :-)
> >> Mike P.
> >>
> >> ----- Original Message -----
> >> From: "Michael Horgan" <lughaid at earthlink.net>
> >> To: <theforge at mailman.qth.net>
> >> Sent: Wednesday, February 15, 2006 9:35 PM
> >> Subject: [TheForge] Chip Bed Forge
> >>
> >>
> >> > Some years ago I made a gas forge for use at the Renaissance  
> >> > Faire, hiding the hot box under some black lava rock. It worked
> >> pretty well , at
> >> > least as a nail forge, but you could only heat one end of
> >> the bar, with no
> >> > pass through. Last year we used a Whisper Mama, tucked away in a 
> >> > faux-brick forge.  Still pretty obviously a gas hotbox.  I
> >> wanted a coal
> >> > or charcoal fire, but the Faire site, regulated by the Army
> >> Corps of
> >> > Engineers and the local county Fire Inspectors wouldn't
> >> allow the "Open
> >> > Fire"
> >> >
> >> > This year we are putting together a ceramic chip forge, 
> basically a 
> >> > gas burner feeding the bottom of a pile of heat resistant
> >> "rocks."  I've been
> >> > looking at the past postings on the forge, and talking off
> >> list with Paul
> >> > Boulay , Rex Price, Frosty and Mike Porter, about the 
> ins and outs, 
> >> > advantages and disadvantages of this type of forge. Whether
> >> it can be made
> >> > to work with a venturi burner or if a blower is needed,
> >> what type of media
> >> > to use  for best heat transfer to your steel, and so on.
> >> I've also been
> >> > looking at the "expensive" commercial versions available in
> >> England as
> >> > used in the school systems,as shown in the graphics page
> >> here,  and some
> >> > slightly different types available in Germany,
> >> >
> >> http://www.angele-shop.com/catalog/index.php?cName=gas-forges-
> >> gasforges .
> >> >
> >> > There have been some great ideas pop up, not to mention 
> the usual 
> >> > kludges I'm apt to come up with. <GRIN>
> >> >
> >> > Mikie in particular has a great idea for a recuperative 
> forge that 
> >> > looks great for a commercial forging station, if perhaps a bit
> >> more than I was
> >> > looking to do as a portable forge at the Faire
> >> >
> >> > Seems like there's some interest in this, so I'll be 
> summarizing in 
> >> > later messages some of the stuff we've been talking 
> about, as well 
> >> > as the results from some experimentation I'm doing.  
> I've got some
> >> refractory
> >> > media due in this weekend so I can try to produce some
> >> results to share.
> >> >
> >> >
> >> > Michael D. Horgan , lughaid at earthlink.net 
> >> > http://members.aol.com/lughaid/ posting from  A BRAZEN FORGERY
> >> > Blacksmithing and Metalwork
> >> > Claremont, Ca.
> >> >
> >> >
> >> > _______________________________________________
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