[NewtonJones]

Interesting point techmanterry ... my HVAC instructor (I'm a student) says the same thing .. but I'm stubborn as hell and have experience brazing copper to copper for craft type stuff .. you don't flux it, it won't join there. And, those flux less joins are just so UGLY I've seen info that said to put just a tiny bit of flux on the outside of the join, seen other information that says flux will get in the line set and stop stuff up ... like the TXV. Opinions?

 

[NewtonJones]

So, how do you braze copper to steel anyway? Keep the heat on the steel, keep the heat on the copper? Thermal conductivity coefficient for steel is a heck of a lot lower than copper. Seems like ..you gonna need a lot of heat going to get that done. Do most folks (remember, I'm a student) use air/acetylene .. with a big ass tip?? Nothing worse than finding out mid job ... that your torch ain't got the umph to do what you are trying to do. Been there, done that ... not pretty.

And .. on a side note. I got this stash of brazing rod I bought on ebay. Harris part 66000 ... sa

Steel-Copper=45% Silver Solder&Flux.
no 'Soft solder or 'Phoss of ANY kind will work.
Any other Co's around you could beg,borrow or buy from?

 

[NewtonJones]

lol mrkelly ... my idea of flux is to scrap a bit off a borax cone and mix with distilled water. Then .. I'm decidedly old school

Problem corny is,
They will not sell you a 'piece' of 'wire'.you buy the Roll or walk.
Back when Silver was so high,you would go broke buying a roll and the Supply house's were selling the sticks separately.
I came from Old Skool with such but Today,the Stick is the Ship Man. No more dried paste,dirty 'wire and,
Brings a Big Smile to my face every time I use them.
You do as you feel necessary. And yes, I have used that 'flux,as 'flux is just about 'flux regardless. I've used Borax Powder back in the Day.:grin2:

In Your defense,I'll admit that the Bronze,coated,are less than functional and prefer the Paste & Dip for Them.
However,if You Try those coated,Silver Solder 1's,it will make a grump,Smile. Did me anyway.

 

[NewtonJones]

I'm still struggling with this brazing thing anyway .. remember, student. I have a LOT of experience with torches, brazing, etc ... I'm struggling with HVAC brazing. My instructor says no flux .. and he dabbles the brazing rod on. I am used to .. situations involving flux ... and seeing capillary action suck the metal around the join. He says ... (no flux) you stay too long on the join you suck it into the join. That man did not fall off the turnip truck yesterday ...which should probably mean I need to shut the hell up and listen. Only .. it looks like such a crappy join when we are done .. globs of brazing stuff everywhere. I'm used to .. clean joins, just enough brazing rod to run around the join .. and it looks nice. I go out side an look at my heat pump .. it looks like crap. Am .. I being way too anal about this?

 

[NewtonJones]

Thanks Poodle Head .... I got a couple pounds of Dynaflow rods .. and plenty of gas in my torch I already dream this stuff in my sleep ... makes it hard to sleep. So, I'll do it over and over and over ....

Student Man,

I want you to do several things -

Call Harris, tell them that someone you know (Me) told you to never use anything but Harris products.

Then ask them if they can furnish you with the printed instructional literature for their products.

Then I want you to read all of it - even what you think you will never need to know - like a novel. Read it over and over until you can dream it in your sleep.

Then I want you to practice what it says. On your own time and on your own dime.

Relax and let it happen.

Soldering / brazing / welding is an Art and a Science. Master it by practice. Relax, let it happen, and you will become great at it. A skill once learned is never lost and always available to you. Make whatever you do a Masterwork - your Master Piece - you will never regret it.

PHM
--------

 

[NewtonJones]

Looks good to me Sorry for hijacking your thread Loopy. Please accept my apology.

Thanks for all of the input. I picked an ounce of Safety Silv 45 this morning, cleaned everything, mixed flux with some water and had another go at it. The solder flowed right in and is holding pressure. Not my prettiest work, but it's holding and that's most important.

 

[NewtonJones]

Sometimes air/acetylene .... sometimes oyx/propane with a rosebud. Don't have a turbo for the air/acetylene. Don't think the oxy/propane is quite as hot as the acetylene ... but it puts down more more heat faster. Its a bigger rig with regulators ... not the hardware store bottles.

 

[NewtonJones]

Thanks bbeerme ... I'm just doing copper to copper with the dynaflow. Good to know .... good thread. I read that the mini-split manufacturers started putting flare fittings on their units because folks were creating such messes with brazing .. toasting valves. and such. I also so read that ... mini-splits have a bad rep because you get so many DIY installs.

Those Dynaflow rods, or 15% silphos, is not rated for copper to steel. It'll never happen. You can do copper to brass if you use that white flux paste, but I never do, I always use the much higher silver content solders for anything other than copper to copper.

 

[NewtonJones]

Better question is .. what should I be using? It seems the presto-o-lite torches are popular ... with a turbo tip. Oxy/acetylene gets really hot .... and I'd be afraid of burning a hole in something. The oxy/propane rig I have is no where near as "hot" as oxy/acetylene, but it does put down a lot of heat fast and the rosebud distributes the heat. I tend to overthink stuff I guess. Should I just get the turbo tip for the B tank?

Sometimes air/acetylene .... sometimes oyx/propane with a rosebud. Don't have a turbo for the air/acetylene. Don't think the oxy/propane is quite as hot as the acetylene ... but it puts down more more heat faster. Its a bigger rig with regulators ... not the hardware store bottles.

 

[NewtonJones]

Ignorant question

Ignorant question, but what would you use soft solder for? Low pressure applications like a gas line?? Solder is big no, no for refrigerant lines .. right?

I use MAPP gas for soft solder and oxy/acetylene for everything else.