Solder for copper primer lines

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Vertical
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Solder for copper primer lines

Post by Vertical »

I'm having trouble finding info on the proper type of solder to use for this. Specific location is the the soldered brass bulb/sleeve fitting where it attaches to the intake manifold jet.

I have various electrical and plumbing solders around, but leaning towards some that's 6% silver and acid core. Specs say application temp 400-700F.

Any recommendations?

Thanks!
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Bruce Fenstermacher
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Re: Solder for copper primer lines

Post by Bruce Fenstermacher »

I've used what ever I picked up of my bench which would have been some type of solder I would also use for electrical. I've never had an issue and really never thought much about it. Wonder what really fancy solder they used in the '30s and '40s to make the same connection on my A-65? Bet the same stuff in the '50s. And I'd be surprised to find it wasn't anything but the cheap stuff from the local hardware store.
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GAHorn
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Re: Solder for copper primer lines

Post by GAHorn »

Ordinary solder will do the job at around 600-degrees, but Brazing silver-solder is the strongest and withstands higher heating: https://www.amazon.com/Harris-Safety-Si ... 05&sr=8-17
'53 B-model N146YS SN:25713
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redacted
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Re: Solder for copper primer lines

Post by redacted »

Silver all the way, 56% or whatever. Otherwise it won’t stick.
Nathaniel Perlman
1952 170B
N2282D S/N 20434
Vertical
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Re: Solder for copper primer lines

Post by Vertical »

Hmm. That's quite a variety of suggestions. I've never silver brazed before, but I'll do some research.

Thinking out loud...I suppose the absolute worst case scenario would be priming a hot engine and having a failed joint spray fuel on the exhaust..
hilltop170
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Re: Solder for copper primer lines

Post by hilltop170 »

Silver soldering is NOT the same as brazing and requires special solder. It is good for joining copper and brass but requires higher heat than lead solder plus special flux and the joint surfaces must be absolutely clean and completely fluxed for the joint to hold. It is much stronger than lead solder if done properly but is easy to overheat the work. Practice on a similar joint and get competent before trying to solder the actual parts.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
2023 Best Original 170A at Sault Ste. Marie
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
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cessna170bdriver
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Re: Solder for copper primer lines

Post by cessna170bdriver »

Vertical wrote:Hmm. That's quite a variety of suggestions. I've never silver brazed before, but I'll do some research.

Thinking out loud...I suppose the absolute worst case scenario would be priming a hot engine and having a failed joint spray fuel on the exhaust..
There’s no need to prime a hot engine.
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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redacted
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Re: Solder for copper primer lines

Post by redacted »

I just fixed a primer line last week during annual. cleaned the line with sandpaper, flux, slid the piece into place, hit with mapp gas torch, silver solder. done. not rocket surgery here, just silver. metallurgy is neat!
Nathaniel Perlman
1952 170B
N2282D S/N 20434
Vertical
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Re: Solder for copper primer lines

Post by Vertical »

cessna170bdriver wrote:
Vertical wrote:Hmm. That's quite a variety of suggestions. I've never silver brazed before, but I'll do some research.

Thinking out loud...I suppose the absolute worst case scenario would be priming a hot engine and having a failed joint spray fuel on the exhaust..
There’s no need to prime a hot engine.
Uh oh..I guess I've been doing it wrong.
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Bruce Fenstermacher
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Re: Solder for copper primer lines

Post by Bruce Fenstermacher »

The key to soldering using lead or silver is a clean joint. Have yet to have any luck with silver but I don't practice/experiment either. Go with what you know.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
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Vertical
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Re: Solder for copper primer lines

Post by Vertical »

Ordered some Harris Stay-Silv 45 and matching flux. Watched a few youtube videos. Doesn’t look any different than soldering plumbing fittings.-Just higher heat.
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