Phoson 0 brazing rod

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jscarmozza
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Phoson 0 brazing rod

Post by jscarmozza » Mon Feb 04, 2019 4:01 pm

I have never used this type of brazing rod, but I understand that if used on clean copper, brazing is done without flux. My question is how is oxidation of the base metal prevented when applying heat? Is it through flame manipulation, oxidizing or reducing, or some other technique? Thanks, John

Harold_V
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Re: Phoson 0 brazing rod

Post by Harold_V » Mon Feb 04, 2019 4:52 pm

The title gives a clue. Such rod contains phosphorus, which has a serious affinity for oxygen. Strange as it may sound, it works quite well. My limited experience is with Sil-Fos.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

jscarmozza
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Re: Phoson 0 brazing rod

Post by jscarmozza » Mon Feb 04, 2019 5:05 pm

Thanks Harold, looking forward to giving this stuff a try. John

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NP317
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Re: Phoson 0 brazing rod

Post by NP317 » Mon Feb 04, 2019 9:04 pm

Just don't braze up a copper boiler with Sil-Fos rod, or similar.
I have read that Sulfur from burning fuels degrades the joints.
~RN

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10KPete
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Re: Phoson 0 brazing rod

Post by 10KPete » Mon Feb 04, 2019 11:15 pm

Absolutely correct, Russ! Makes changes causing brittleness.

I used to do a lot of fabricating with Sil-Fos, gas and tig, and it can't be beat for how handy it is compared to actually welding copper, which takes loads more heat!

Pete
Just tryin'

jscarmozza
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Re: Phoson 0 brazing rod

Post by jscarmozza » Tue Feb 05, 2019 9:19 am

Ok guys, you just opened an old wound...does the sulfur in coal really affect Sil-Fos and Phoson solder, I hear so many different opinions that I don't know what to believe. I've been running my LE Atlantic on charcoal (real wood charcoal that I make myself) because I suspected that the LE boiler was fabricated with Phoson-0 and would be adversely affected by burning coal in it, a lot of people think I'm nuts. A very experienced live steamer told me that he's never heard of a copper boiler failing for the aforementioned reason and that he'd be more concerned about the water that's in the boiler than the fuel that's heating it. Another told me that flaws in the soldering process and flux pockets are the culprit. Harris's web site says that they don't recommend Sil-Fos for high temp applications and I think they mention something about sulfur, but I'm not sure. Phoson joint's are said to be brittle at low temps but fine at higher temps, a good reason not to hydro a boiler with cold water. If I recall what was on the LE boiler fabrication drawings, they said to heliarc some of the components (castings) and use Phoson-0 for the rest of the joints. There has to be a lot of LE boilers out there, are there solder problems with those boilers? This coming season I was thinking about switching over to coal, the charcoal burns clean and hot but very fast...so I'd like to air this matter out beforehand. Thanks, John

jscarmozza
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Re: Phoson 0 brazing rod

Post by jscarmozza » Tue Feb 12, 2019 1:33 pm

I did some further research and found that Sil-Fos 15 is not recommended if exposed to sulfur or steam as would be the case in a copper boiler, and that phosphor/copper brazing alloys (Phoson) tend to make brittle joints. So far that's all I can find, but it's enough to resurrect my concern for how my LE boilers were fabricated.

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