Brazing Q's.

[killermiller]

I read the stickies and they don't tell me what I need to know...

I am trying to practice brazing by swaging and cutting about 3 inch pieces of copper tubing and trying to braze them together. I am using copper/phosphorus brazing rods(unsure about %'s) and petrolium based pluming flux. The torch I am using is a an Oxy/Mapp

The problems I have is that the brazing rod melts but doesn't stick or is very clumpy so I guess my questions are:
Do I not have the torch hot enough?
Am I using the wrong flux?
I read somewhere that I should use water based flux, should I be using that?

Thanks.

[n00b 0f l337]

With copper phos you dont use flux, you want to always avoid using flux as its a contaminent which I'm sure Xeon will agree with. We only really should use it in copper to steel, and then with 45% silver or so.
Try without flux ;)

[killermiller]

What about the brazing rods melting clumpy?

[n00b 0f l337]

No idea, possibly caused by the flux, I've got harris and silfos 15% silver phosphorous rods and its just about getting the heat.

[killermiller]

Should the tubing be hot enough to melt the rod?

[runmc]

Copper needs to get red hot - no flux - sand realy good first inside and out.

After the solder melts and flow let off on the torch. You can get it to hot and the solder will flow out of the joint. Actually the tubing should be doing the melting,

[Xeon th MG Pony]

When copper pipe is made, all the dies and such are coated in oil, as such so will be the pipe, my methode befor sanding is I wash the pipe with acetone or alcohol, sand then wipe down again, with a 5%/15% rod will give you a clean solid joint every time.

The coper pipe should be a brightish red tap the rod on the pipe, the second it touches the pipe it should melt and flow, if it doesn't keep heating.

[n00b 0f l337]

Also if your using the homedepot copper/phos, good luck, get some proper rods.

[killermiller]

The working temp for the rods I am using is 1310-1475. Is that ok?

Also if your using the homedepot copper/phos, good luck, get some proper rods.

Well they are Bernz-o-matic, but yeah, from Home Depot.

Can you suggest a brand of rods?

Thanks everyone for the advice.

[Xeon th MG Pony]

The working temp for the rods I am using is 1310-1475. Is that ok?



Well they are Bernz-o-matic, but yeah, from Home Depot.

Thanks everyone for the advice.

There is your problem there, go to ebay and get some real rods, or rons shop.

[PhilippF]

When you reported that the rod melts but does not stick to the copper, I think you put the rod in the flame where it wa melted. As said above, heat pipe and fitting until it gets red glowing, remove the torch a little bit and touch with the solder. It should be drawn into the space between by capillary force. If you cant get fully around because the pipe and fitting gets colder, heat it again, put the flame away again and continue soldering, etc..

There are basically 3 types of soldering joints here:

1. Fitting under pipe: Easiest to make because you have gravity on your side. Just heat and solder around.

2. Fitting over pipe (pipe facing downwards): This is more tricky because you have to make the solder flow against gravity. The trick is to heat the pipe first, then only heat the fitting, so the solder flows inside the hotter fitting and not down on the pipe.

3. Horizontal pipe and fitting: Heat both, then solder, but apply solder mostly on the top of the joint. Gravity makes it flow downwards. If necessary tip with solder at the bottom also, but be careful not to get a big drop on the bottom.

If anything remains unclear, please ask again.

And for the solder: As said above, the right solder is half the job. Dont use any additional flux.

And if you want the inside of the pipe to be nice and clean, braze with an inert gas like Nitrogen, Argon or CO2 flowing through the pipe, so you avoid oxidation of the inside. If you dont have such a gas, some people also use a little bit of alcohol dripped inside the pipe before soldering, the vapor also keeps the inside from oxidating, but be very careful as this can very easy cause a little fire or explosion... better stick with the inert gas.

Regards,

Philipp

[killermiller]

Should I keep the torch in one spot to heat the pipe or move it around?

[PhilippF]

Move it around to heat the pipe equally.

[Gray Mole]

If you can contact a supplier that offers a choice of rods, anything made by Harris is a good choice.

If you can get them for a decent price, I highly recommend rods that are copper/phosphorous/silver with 2-5% silver. Can get pricey but they flow nice.

I picked up some 5% silver rods like that and they're the easiest ones I've found to use. I tend to use them for a wide variety, and only the 55% silver with flux for SS to copper/SS.

As Ron pointed out, it's a really good idea to clean the pipework prior to brazing. Even a little oxidation on the pipe can give you grief, and it takes less heat to get the braze started if the pipes are shiny clean.

If you use a rod with even a small amount of silver you 'can' use a flux with it, but there's really no need unless your rods doesn't have a phosphorous component. The phosphorous is actually what 'bites' into the copper, with the copper component the filler.

Cheers

Gray

[tim-]

well .. even cheapest copper phosphor rods do the job very well as long as you have enough heat. silverrods have lower melting tempture and easier to braze with torch.

[killermiller]

If you can contact a supplier that offers a choice of rods, anything made by Harris is a good choice.

If you can get them for a decent price, I highly recommend rods that are copper/phosphorous/silver with 2-5% silver. Can get pricey but they flow nice.

I picked up some 5% silver rods like that and they're the easiest ones I've found to use. I tend to use them for a wide variety, and only the 55% silver with flux for SS to copper/SS.

What are rods @ under-the-ice.com?


As Ron pointed out, it's a really good idea to clean the pipework prior to brazing. Even a little oxidation on the pipe can give you grief, and it takes less heat to get the braze started if the pipes are shiny clean.
Should I be sanding them or using a chemical?

Gray, it is nice to see you are doing better. Thanks everyone for the info.

[killermiller]

Well I tried brazing with no flux and I first I was still having problems. I kept trying and I guess my flame got hotter and all was well. I read in the manual that the flow of oxygen would start to increase. Before I would always turn it down when that happened. I am pretty excited. Thanks everyone for the advice.

[gosmeyer]

Glad you got to see some positive results:up:
Now just practice so you can build your confidence up :D After some time you will see how easy it really is.

[Freddie123]

Great to hear! You nearly always find its something simple like not enough heat etc.

[PhilippF]

Happy to hear you are doing well with the copper :)

If you do a lot of brazing in the future, you could consider changing to a torch with a "C" tip, this consists of about 5 flames heating the pipe equally around. After some usage you can make really quick brazes without heating the surrondings too much. I use a Smith Quickbraze and am very satisfied with ist.

Regards,

Philipp

[Xeon th MG Pony]

Happy to hear you are doing well with the copper :)

If you do a lot of brazing in the future, you could consider changing to a torch with a "C" tip, this consists of about 5 flames heating the pipe equally around. After some usage you can make really quick brazes without heating the surrondings too much. I use a Smith Quickbraze and am very satisfied with ist.

Regards,

Philipp

Have you tried doing 1" pipe with it? I got a 5 Ton scroll that I need to debraze and I'm thinking of geting that kit, but I want to KNOW if it will work, I'm geting tired of the "ifs"

[PhilippF]

I recently bought a larger C-tip for the Quickbraze to braze Evaps. I havent tried it yet, but considering the already awful power (with ace+oxy) of the small standard C-tip I would say yes, it will definitely be possible to solder one inch pipes.

[[XC] 2long4u]

That is a super nice setup. $450 tho. Can you just buy the tip?

[Xeon th MG Pony]

150 on ebay.

How about debrazing with oxy mapp? 5 ton scroll is a tuff one to be sure.

[PhilippF]

450$ ??? I paid 214 for the kit and then another 80 for the extra C-tip, but regulators and bottles were already here....

http://www.jandrweldingsupply.com/

[Xeon th MG Pony]

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&rd=1&item=230163692669&ssPageName=STRK:MEWA:IT&ih=013

152 dollars Cad

[PhilippF]

Depends on the wall strength of the one inch pipe. But I THINK (<- havent tried it myself!) it should be no problem with MAPP and Oxy with 1 or 2 mm wall strength.

[Xeon th MG Pony]

Lets hope! I just ordered it, your the only one who has used one willing to comment! every one ells did not! Either way I planed on geting it as twin flame will be far superior quality braz then standerd torch.

[PhilippF]

If you want to see some pictures in use:

http://www.extremecooling.net/index/e107_plugins/forum/forum_viewtopic.php?31199.20

Ice-man also uses this torch (cant be so wrong then :) )

[Xeon th MG Pony]

Ooooooo ja! ja! This will be a very nice torch to have even if it fails to bebraze the scroll it will greatly improve life in other aspects of evap moding & repair!!

[PhilippF]

And what is also cool with this torch are the thin very flexible hoses that come with it, almost no weight in your hand.

[Xeon th MG Pony]

Yes I noticed how nice the hoses looked.

[Freddie123]

http://cgi.ebay.co.uk/SMITH-T7-TWIN-FLEIXBLE-FLAME-TIP-VERSA-TORCH-QUICKBRAZE_W0QQitemZ230160713562QQihZ013QQcategory Z11774QQrdZ1QQssPageNameZWD1VQQcmdZViewItem that looks like one of the things you're getting and it can do up to 1 3/8"

[Xeon th MG Pony]

Dam that guy is fast, all ready have a tracking number and it'll be on its way by thursday! I nominate that ebay shop for the stores link for brazing suplies!

180 Cad total so any fellow Canadians need a torch! there ya go!

[killermiller]

Great to hear! You nearly always find its something simple like not enough heat etc.

Glad you got to see some positive results:up:
Now just practice so you can build your confidence up :D After some time you will see how easy it really is.

Happy to hear you are doing well with the copper :)

If you do a lot of brazing in the future, you could consider changing to a torch with a "C" tip, this consists of about 5 flames heating the pipe equally around. After some usage you can make really quick brazes without heating the surrondings too much. I use a Smith Quickbraze and am very satisfied with ist.

Regards,

Philipp

Thanks everyone. Yeah, it was pretty easy once I got the hang of it. The "C" tip sounds like a pretty useful tool. If I ever get to that point, I will have to keep that in mind.