silfos brazing advice

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 welding experience.
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!
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dingus wrote:

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.
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> 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....
Jake
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Jake wrote:
..

you ride your ponies bareback?
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Jake wrote:

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. LOL
I didnt care for that idea anyway. It seemed like treason to my UAW pipefitter brothers.
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> 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...
Jake
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Jake wrote:

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 major changes.
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.
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wrote:

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!
--
-john
wide-open at throttle dot info
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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 the job.
I was then introduced to Stay Brite 8, and have never once looked back.
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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On Wed, 18 Oct 2006 01:13:40 GMT, "Stormin Mormon"

Stormy in a home with a flame..................................... Damn downright scary!! Bubba
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On Wed, 18 Oct 2006 01:13:40 GMT, "Stormin Mormon"

What kind of rod do you use to fill the holes? ;->
--
-john
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~^Johnny^~ wrote:

Machine screws and epoxy. :)
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dingus wrote:

Hi, I hope that you have recd proper advice for brazing. I am interested in your super-efficient fridge. Let me know when U have completed and achieved results. Thanks, psdayama
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