I am trying to build my own super-efficient refrigerator and i want to
braze 1/4" tubing between the compressor, water-cooled condenser,
evaporator, etc. I have had lots of soldering experience and limited
Is it possible to braze 1/4" copper connections using solely MAPP gas
and the right torch tip? I have some Silfos 15 brazing rod i can use.
What temp flame do i need to successfully do this?
Any suggestions? Thanks!
Yes Mapp gas will braze 1/4 no problem. If your going from copper to
steel Id sugest 45% silver instead of Silfos 15. Copper to copper and
SF 15 is fine. I doubt that your project is going to be super
efficient but have fun anyway.
> Yes Mapp gas will braze 1/4 no problem. If your going from copper to
I dunno about doing copper-steel transitions with MAPP.
Lately, I've used the MAPP-Oxy combi rigs you can now buy anywhere....
Pretty good results to far.
Beats the hell out of dragging our big oxy-acet sets around for a little
sensor job or something.... and I can never find a smaller tip around
the shop, anyhow. I'm not a plumber, and putting a 1/4 stub into a line
for sensor can get 'tricky' with a #6 tip...
I don't use saddles....
Its 1/4 inch Jake.. No problem. Been there done that.
Its just personal prefrence but I never have used an oxy/acy rig for my
regular job, I can but dont like them unless Im welding something.
Personal prefrence. I prefer a turbo torch for brazing and I use the
Mapp for soft solder on smaller water lines. Once I go over an inch
for soft solder (and thats pushing it) I use the turbo on a B tank.
BTW that Delphi thing... Fell through. Turns out they cant afford us.
I didnt care for that idea anyway. It seemed like treason to my UAW
> Its just personal prefrence but I never have used an oxy/acy rig for my
Isn't a B tank air/acet? Does that work OK on copper/steel transitions
in the 1 1/2" - 2" range (silver)? I've never used a Turbo torch or B
gas... but that might be a good choice for sensor work.
The deal with Delphi is nutty... they offered a bunch of folks early
retirement and one hell of a lot of them took it.
I was in the Delphi plant in Kokomo, Indiana yesterday... one of the few
rumoured to survive all this.. and the skilled trades situation is pure
chaos. I honestly don't know how they're going to run the plants, now.
In this case... a IC chip placement robot had 'belched' because a part
was the wrong size... it happens and in normal days a plant electrician
would have replaced a common fuse in a picker robot... recycled the PLC
and had it running in 10 minutes.
We were about 1.5 hours getting there and about the same ten minutes
getting it going. I tried to explain to the new $13.00 an hour plant
electrician what was going on... but frankly... his eyes looked like
they were glazing over.
I don't think this is going to work for them...
Yeah, Ive brazed 2" steel to copper on chiller barrels no problem.
For small stuff like sensor work and Im assuming under 1/2" Mapp gas
will do fine.
Yup my bud is getting 2.2K a month for life and BCBS for 10 years. Id
take it to.
Personally Im ready to retire. Im sick of driving a service van. One
local University is looking for a maint. man, 25 an hour plus bennies.
Shit I could retire from the UA collect that pension and work for ten
more years and get two. Plus not have to work as hard. In places like
that when something big happens they always call us and to them, big is
anything that involves tools larger than a pocket screwdriver. :)
No its not working for them at all. My friend is a fitter in the
Saginaw plant and theres not many left and no one to replace them.
Yet. They ran a huge ad in the paper wanting skilled tradesmen and the
list of qualifications was unreal. I should have posted it as Im sure
it would have been a hoot. You know of course that Penske is seriously
loking at buying out Delphi so Im sure by years end there will be some
Plant skilled trades dont really have the knowledge that the guys
outside do and I think thats due to the very limited scope of work each
segment does. Like with sparkies, one guy does switches, another guy
does receptecals, still another guy changes light bulbs.
I had to work on a small process chiller at AC a long time ago and I
swear to God that it took me all day to replace a contactor. First I
had to move the machine which required a pipefitter and two
electricians. All they had to do was uncouple the quick connect for
the fluid and un wire it from the disconnect. Shit by the time the
right fitter came over, (the quick connect guy) it was break time, an
hour goes by and the electrician shows up but has to come back after
lunch with a helper. Heyzus Kreist im glad there wasnt a belt involved
or Id have had to put up with the millwrights to. 10 min to change the
contactor and the process reversed itself. By the time the sparky came
over (a diffent one) I had to show him how to wire the machine back
into the disconnect. He had no clue. I hate plant work.
Never bothered me, but my old R12 stuff had better than 1-1/8"
suction lines, anyway, and I insisted on hard copper, low oxygen,
and always brazed with nitrogen flowing whenever possible.
Those medium (251 cu ft) tanks were heavy, but I got used to them.
There were two tanks - oxygen and nitrogen. The oxy-ace cart weighed
in at just under 100 lbs. You develop the right muscles to
effortlessly heft them after awhile. Small kits are nice, but
frequent trips to the gas dealer are NOT.
Oxy-propane is a viable alternative for most sized braze jobs, but
the tip size is larger. This does offer more control, in the smaller
jobs. There are tip equivalent charts all over (see Google) for
comparing Acetylene to Propane.
Also SilFos has a melting point chart. I only used Zero-Sil or 40%
silver solder. The Zero-SIl (no silver phosphor-bronze) melts at 1350
F, and the 40% at 1625 or so (if my memory serves me). The 15%
prolly somewhere in between there. I only used air+MAPP for soft
solder jobs, in plumbing, because MAPP is not economical for use at
brazing temps (silver solder melts at cherry-red temperatures).
If it's BTU's you want, go for oxy-propane. If it's higher temps for
quicker heating, go with oxy-ace. With the OxyAce, my favorite
welding nozzles for silver brazing are 0, 1, and 3, with 5 to 10 PSIG
of both oxy and fuel, while with OxyLPG, it's sizes 5, 7, and 9, at 2
PSIG oxy and about 1/2 PSIG fuel!
This was for building systems, though. And there was generally some
cutting involved, as well (fabrication).
For small field repairs, a MAPP torch would be fine. No unwieldy
hand trucks and hoses to mess with. Never on MAPP on a propane torch,
though. It does not work well. Regular MAPP "Turbo-Torches" aren't
that expensive, anyway. The real expense is feeding them!
In my early days, I have done brazing with air acetylene and 15%
silver braze. One other fellow I know does 15% with a mapp gas torch
from the hardware store, so it can be done. My original teeny tiny tip
for the air acetylene wasn't hot enough, so got a turbo tip which did
I was then introduced to Stay Brite 8, and have never once looked
Flame? As hot as possible. When the copper starts to glow orange,
that's about the right temp.
Christopher A. Young
You can\'t shout down a troll.
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