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Need info on a good oxy/acteylene set up for brazing
- Thread starter helmbelly
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yes
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- Dec 18, 2022
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I payed 28 bucks 4 months ago to swap my bottle and it is a large bottle....
so even steven right? I mean same price - somewhat
Last edited:
- Joined
- Jan 2, 2019
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- 7,177
If it really just blew out uncontrolled you need to have your gauges checked, but it shouldn't come out any quicker than the tip you're using will flow. Something isn't right if the bottle got emptied with just a few attempts at lighting the torch.
You may want to call your LWS and ask if you can bring your whole rig down there to check it out.
John
- Joined
- Jan 2, 2019
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- 7,177
It's a little rig, take it all down if they'll let you. Bet it's something simple....
John
Got it! Had a bad oxy regulator. LWS has a repair service but I can feel it coming out right at the brass fitting that attaches to tank nozzle - gotta be an old o-ring in there. Good news is that in my Craig's List deal the guy gave me an extra set of hoses that had a good Victor oxy reg so I just switched them out. Got a nice gas flame going late today and made a couple of the worst brazes ever botched. It seems like the 'heating moment' where everything is hunky dory is quite a sweet spot. I am getting things over red, too hot and the silver is not running it's getting red and not running or pooling. So I just will spend time tomorrow playing with pieces and trying to figure out workholding. I made a little firebrick corner is it good practice to just lay your steel directly on firebrick or should it have a heat sink touching the workpiece - like laying the work steel on top of n old piece of steel or some big washers? The guy at the LWS gave me several brass, bronze and bronze with flux coating as "samples" for $2 - nice guy. So with any luck maybe photos tomorrow - I aint showing what I made today!
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Note, the right temp for typical silver brazing alloys is barely glowing at all, you can't even see it in bright light. If your steel is noticeably glowing then you're probably too hot. The flux becoming molten and clear is your best temperature indicator.
Bring it all up to temperature as evenly as you can so that when you touch the silver to it, it wicks around everywhere by capillary action. Sometimes for a thick piece, you need to hold it at that temp for a while, to let the heat "soak in" to the thicker sections.
But don't dawdle either, the clock is ticking — you're usng up your flux — so do try to git 'er done as rapidly as you can, consistent with full penetration. This takes practice, so don't feel bad about roasting your first few trial pieces.
Stainless is extra tricky, not just because of the oxide layer, but also in the heating phase due to relatively low conductivity of SS, makes it easier to burn it locally while trying to get it evenly hot. Keep the torch moving, don't point it at any one spot. Catch the localized over-heating early and push some molten flux over the place that got too hot — hopefully some fresh flux will lift whatever oxidation you got where you overcooked the original flux. If there's ever burnt flux where you need the silver to flow, the silver will not flow there, and if some fresh flux can't clean it, then you will have to cool that part, soak the flux off, and completely clean the burnt area down to shiny steel and start again. Some burnt parts cannot be saved and will have to be tossed and re-made.
