jet size

Hi Gentleman

I'm trying to solder a 4" copper boiler. the boiler is 13 gauge and the end plater is 3 mm. the problem is the solder will not run, yes i know what you are going to say, NOT ENOUGH HEAT. and that silver soldering is easy. I agree it is easy if you can do it. But my question is.... am i better using a big burner on the gun, or would i be better with a smaller size burner ? I'm using Tenacity No5 flux and Brazetec 5507 solder ( 55% ) copper, zinc, tin.. the flux goes clear but the solder just will not run. Yes everything is clean, pickled, washed and wire wool used to shine it up.. Any suggestions please

regards

Dave.

A bigger burner is usually best to bring the whole thing upto heat rater than doing just a smallarea and trying to chase the solder around the joint. I would be looking at a 30-35mm burner on a propane bottle with plenty of suitable bricks to reflect heat back onto the work.

J

I find T5 flux doesnt flow half as easily as easyflo, but then if your not well versed in SS I gues it is a lot more forgiving. What thickness SS rod are you using, all supposed to melt at same point but the thinner it is the quicker it will melt (from experience)?

Hi Fizzy

the rosa are 1.0 mm also have some 1.5 mm but they take about 3 wks to melt lol

regards

dave

The rods are 1 mm

I managed to solder a 3 1/2" boiler with a 17mm propabne burner and a blowtorch for backup. I am confident that anything bigger would need a much bigger burner.

Neil

I'm not too sure on the specs of your "solder", I'm not a steam man, but shoul it not be a silver based alloy, too late now if you'v used one with tin I think. The experts will be along soon. Ian S C

Its a 55% silver one so OK.

Same make up as Silver-flow 55 which also has 2% tin (AG155)

J

Edited By JasonB on 26/07/2013 08:00:31

And Brazetec 5507 even has a little Cadmium in it !! I think I would go with more bricks, and more heat. Copper EATS heat, and is very different than silver soldering steel components.

Hi Gentlemen .

thanks for all the advise, I've now cleaned everything up again, but this time I'm going wrap the boiler up in a fire blanket ( meant to have done that the last time but forgot, memory's not what it was lol)

I'm pretty sure there was enough heat but the blanket can't do any harm.

regards

dave

Dave, you don't say how big your torch is?

Neil

Hi Neil.

all I can tell you is its from Machine mart. Came with 3 burners 12, 14, and 17 mm running on propane at max pressure with largest burner. I don't think it's heat, as when I did the other end of the boiler we even put an Oxy torch on it, Again everything was cleaned with wire wool. And took over an hour to do 4" boiler dia. same thing, It just didn't want to run. That's why I changed the flux to Tenacity No 5 in case I was burning the flux out. Even the tenacity made no difference. The next time I have a go, I'm going to wrap the boiler in a fire blanket. Just to make sure it's not. A heat problem.

Regards

Dave

Did the regulator come with the torch? or are you using a low pressure reg rather than a high pressure one, you want 3 to 4 bar.

And the 17 is still a bit small, based on Silvert burners a 17mm gives 1.2Kw, 28mm 7.7Kw and a 32mm 26Kw.

Edited By JasonB on 27/07/2013 07:11:12

Hi Jason

the regulator came with the torch.

regards

Dave

Hi Dave,

The same otorch as mine. The 17mm burner is not enough. Go for the next set up they do and be prepared to use a lotr of gas! Whole set is cheaper than one seivert tip!

Neil

Please don't bite my head off, but are you sure you do have silver solder ? Can be easy to mix up. just that I have done it myself.

Hi Gorden

lol, yes, I'm sure. The only solder I have in rod form is S/solder.

regards

Dave

Folks, Dave and I have the FC109 torch kit HERE as Ian suggests I would like to get the FC108 kit sonmetime as although it doesn't seem much bigger the 35mm burner should be about 15 times more powerful and the 50mm must be well scary....

For anyone reading this thread and thinking of getting a torch kit for brazing, THIS would probably be a good a starter kit as any, but oddly it leaves out the 17mm burner, which I suspect is the best for general purpose use, I'd guess at it being about 4-5 times the power of a standard blowtorch.

Neil

Edited By Stub Mandrel on 27/07/2013 13:31:55

Neil

50mm ? wonder what the fire brigade charge to be on standby ? Lol

Also worth making sure you have a decent size propane bottle when using the bigger burners as the bottle will chill quite quickly and pressure will drop. The 3.9kg bottles are a bit on teh small side.