[TheForge] Problems with propane burner

[Marc Godbout]

Well, opening the doors did the trick. I set the m in their normal
configuration and all is well with the world. I'll throw some replies
below anyway for the terminally curious.


On Sat, 2003-09-06 at 23:04, Jerry Frost wrote:

> How long is the tube straight before it begins the sweep? You might try
> giving it 8" of straight tube before it hits the 90*. This should allow good
> induction and give the mix a head of steam before it makes the bend.
> 
FWIW, there's maybe 4/5" of perfectly straight tube, then about another
2" - 3" before the tube changes direction enough to be in the way.

> Ah indeed! Good, I wasn't able to get a cross for mine and had to drill the
> "T" for the supply. Using a pipe nipple though leads me to another thought
> and that's the distance between the jet and the tube's throat. I use 1/8"
> lamp rod so it's adjustable. Lamp rod and 1/8" pipe are the same thread but
> the pipe is tapered where the lamp rod isn't. When you tap a fitting for
> lamp rod you have to creep through with the pipe tap or the lamp rod will
> wobble, making alignment almost impossible. When I tap the hole I only go
> till the lamp rod will just pass, this means making 1/4 turns with the tap
> wrench, backing it out and trying the lamp rod till it goes. I also use a
> locknut to help hold it straight and lock it in position.

I got the cross fitting from McMaster-Carr. Unfortunately my local
plumbing suppliers don't carry these. They're about $10, I believe, so
that's a little more than I like to spend for such a thing. The nice
thing is that there's plenty of room for in-and-out adjustment of the
jet. 

My attachment method was to an untapped hole through the plug for the
nipple, which is secured by a set-screw. I use a lamp union (if that's
what they call lamp parts) at the end of the nipple and a lamp bushing
in the other end of the union. The bushing just happens to have the same
thread as the mig tip, 1/4 X 24. And there's enough thread in the nipple
to make a nice, tight, fit on the lamp union. I silver soldered the
whole thing anyway to make sure it was gas-tight.
> 
> If you can block one intake port without effecting performance you're
> feeding it way too little, try either chasing the 0.035" to 0.040" or try a
> 0.045" mig tip.

The .035 mig tip is already .042, IIRC. I think that's a #57??? Anyway,
covering the intakes does affect the flame at the high end. I'll need to
add a choke to keep scale down.

> Something that'll help is assembling as much as possible before you drill. I
> have a lathe but but before I drill I assemble the "T", bushing, tube and
> make match marks so I can reassemble it later and have it as aligned as
> possible. Still, the first one I made before I had the lathe set up and had
> good luck assembling it all first.

Another thing I've heard of people doing is soldering the tip directly
to copper tube. That give lots of flexibility to adjust. I haven't tried
this myself, but a person I know says it works well. Securing it in
place with setscrews pinches the tube, so I suggested using a
compression fitting in the plug and running the tube straight through
that. That seems to work fine.


> Also, Ralph's tube is straight for a goodly distance before it hits the
> bends.
> 
That's true, too. Maybe that's a key. Plain old threaded, though, is
definitely not the way to go.

> Lastly I could certainly be wrong about wider turns being better than
> tighter ones. Smooth could well be much more important than radius.
> 
Maybe. But since the conduit is both smooth and wide (there's a sexist
joke in there somewhere, I'm sure) I have both bases covered (I hope).
> >
>  >
> > I think the first thing to try would be to put the doors in their normal
> > resting place. That will leave a 4" X 8" opening in each end. Another
> > cheap thing would be to try a straight 10" length of 1" nipple instead
> > of my conduit bend.
> >
> 
> I agree, try opening the doors, then a straight nipple. 8-9" unless you have
> the 10" laying around, longer isn't necessarily better.

And thanks again for the advice. As mentioned above, that was pretty
much the problem. 
> 
> Most importantly, only change one thing at a time, if you change several
> it's easy to lose track of or not even know about a change in performance.
> Keeping notes can be handy too.

Ayup. And I'm still a New Englander, so I'm legally allowed to use that
word. I'm a firm believer in changing one thing at a time. Time spent
here saves lots more just from the knowledge alone.
> 

Well, now I'm on to ITC-100 coating and putting the finishing touches.
If I don't get distracted with the 1/2 dozen other projects running
around my brain, I should have this beast up and running full-time by
the end of the week.

Thanks.

-Marc


-- 
Marc Godbout
http://www.ironringforge.com

New England Blacksmiths Membership Director
http://www.newenglandblacksmiths.org