Silver soldering torches

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RThomp
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Silver soldering torches

Post by RThomp »

Looking for recommendations on silver soldering torches, for some 1.5 scale detail part work, plumbing, half round on tender etc.
I've seen recommendations on turbo torches, etc but didn't know if there was a specific model/size that's ideal. Also I've read some references to using propane which would be nice.
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NP317
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Re: Silver soldering torches

Post by NP317 »

For half round on tender top edges I've used soft solder paste and a small propane torch. Has worked fine on two tenders. Controllable.
For pieces using silver solder (45% and 56%), a MAP torch works for "smaller" parts, and oxy-acet for larger items that need more concentrated heat quickly. Also controllable.
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Greg_Lewis
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Re: Silver soldering torches

Post by Greg_Lewis »

Russ mentions O/A but it's important to understand that you don't set the flame the same as for welding. Doing so can easily end up with things getting too hot. Set the flame for a long feather — I set mine for about 12 inches. Then I heat the opposite side of the piece slowly and let the heat soak through. Don't rush it. I frequently set small stuff on a short piece of angle iron sticking out the side of the bench vise and play the O/A flame on the underside of the angle, letting the heat spread up and into the parts. And I highly recommend the black flux as it has a wider heat range than the white stuff.
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NP317
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Re: Silver soldering torches

Post by NP317 »

I agree with Greg's advice.
RussN
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milwiron
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Re: Silver soldering torches

Post by milwiron »

Bigger than a handheld hardware store type torch but smaller and cheaper to run than my rosebud. Shown running at a couple psi. It'll run up to 20+ psi. It was about $12.00 to build. Simply a smaller version of foundry burners shown online.
propane torch.jpg
propane torch.jpg (175.04 KiB) Viewed 2570 times
gas end 2.jpg
gas end 2.jpg (152.32 KiB) Viewed 2570 times
"Measure twice, curse once."
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Bill Shields
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Re: Silver soldering torches

Post by Bill Shields »

If you want to purchase something and you gotta silver solder, there is Sievert, Sievert and Sievert.
torch on mud ring.jpg
torch on mud ring.jpg (274.08 KiB) Viewed 2541 times
after that, there is Sievert

in the above, i am using 2 Sievert torches to raise the temp to the point where I can just 'touch' it with the O/A torch to cause the silver to melt.

I know it looks clunky, but the firebrick are sitting on a board that is sitting on a lazy susan bearing, so that I can 'roll things around' as needed.

for smaller, on the bench parts, Sievert makes turbo tips.

torches are held by old milling vises that are accurate enough to hold torches :mrgreen:

for really big parts...O/A is great but you can (as mentioned), have puddles quickly, and it really takes 3-4 hands to use a rosebud for general heating and a small tip for local heating.

milwron: that is a neat torch.

looks like a variation on an Oxygen Lance used to punch holes in THICK steel plate
Too many things going on to bother listing them.
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Harold_V
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Re: Silver soldering torches

Post by Harold_V »

NP317 wrote: Thu Feb 02, 2023 1:02 pm I agree with Greg's advice.
RussN
Yep! It's spot on and will keep you out of trouble. It's all too easy to overheat when silver soldering.

Fact is, if one is soldering small items, it's hard to beat a furnace solder job, which heats uniformly and prevents overheating. That, of course, would not be possible with many items.

H
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FKreider
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Re: Silver soldering torches

Post by FKreider »

milwiron wrote: Thu Feb 02, 2023 3:41 pm Bigger than a handheld hardware store type torch but smaller and cheaper to run than my rosebud. Shown running at a couple psi. It'll run up to 20+ psi. It was about $12.00 to build. Simply a smaller version of foundry burners shown online.
Curious how you utilize this torch, in general I love the idea as the commercial torches can be quite expensive.

Do you set this up pointing at the work for general heat and then apply spot heat with another smaller torch?
-Frank K.
RThomp
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Re: Silver soldering torches

Post by RThomp »

Doing some googling led me to these


https://www.amazon.com/STK-9-TurboTorch ... B0006519QI
https://www.amazon.com/Sievert-Industri ... B01G5EWUA2

https://www.amazon.com/Sievert-Industri ... B00OTJ1IAE - looks nice because you can use a 20lb propane tank.

All look similar in size, the "turbo torch" is actually a little more expensive than the sievert

Any one in particular you'd recommend?
Last edited by RThomp on Thu Feb 02, 2023 9:59 pm, edited 1 time in total.
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milwiron
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Re: Silver soldering torches

Post by milwiron »

FKreider wrote: Thu Feb 02, 2023 8:45 pm
Curious how you utilize this torch, in general I love the idea as the commercial torches can be quite expensive.

Do you set this up pointing at the work for general heat and then apply spot heat with another smaller torch?
Much of the time I use the ball valve as a handle and use the legs just to set it down. I made it for silver soldering but most of the use has been for case hardening small parts that smaller propane torches struggle with.
"Measure twice, curse once."
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Bill Shields
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Re: Silver soldering torches

Post by Bill Shields »

That turbo torch looks like it mounts on a small bottle, which can be annoying to work with.

The sieverts that I use are interchangeable tips that mount on handles on the end of hoses connected to Bbq bottles with a regulator attached.

So I have 2 handles, 2 hoses, 2 regulators and maybe 10 tips..which also include long reach pipes because you do not want to hold one of the big tips on a 6" pipe, as you can see from the photo. The longest pipes that I have are 24" long and well worth having when warming a boiler from 2 sides at once.

Sieverts turbo torch has an interesting trick in that it seems to wrap the flame around a piece of pipe to warm more than just the nearest point...up to maybe 1" pipe. After that the flame just splashes around

Just an FYI

The last time I used my o/a rosebud to silver solder a copper boiler for a 1" scale loco, I chewed through a full size bottle of acetylene before it was over and my arm was very tired from waving it.

Building a brick semi enclosure and hitting it with sieverts is a lot easier...kinda like what Harold recommended...a furnace is a nice way to go.

Wish I could figure out a way to do an entire boiler in an enclosed furnace...
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Greg_Lewis
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Re: Silver soldering torches

Post by Greg_Lewis »

I did some relatively large assemblies, about the size of a lemon, using the brick enclosure that Bill mentions, and a weed burner from Horrible Fright. The only issue was the heat bouncing back at me, but I only did four of these, if there were more I'd have figured out a solution for that.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
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