Controlling Silver Braze Flow

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tornitore45
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Controlling Silver Braze Flow

Post by tornitore45 »

I am brazing a small flange to a 5/16 SS pipe
The fixture to hold the pipe square and pipe bend oriented holds the flange with 2 #2 screws
I am afraid the screw head will solder to the flange, there is less than 0.15".

What is the method to keep the screw free from solder? Only have propane torch, no oxy to apply soot.
Mauro Gaetano
in Austin TX
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Harold_V
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Re: Controlling Silver Braze Flow

Post by Harold_V »

Mauro,
While I don't know that I'm on the right track, I wonder if, maybe, you can use a soft pencil (#2) to create a barrier, so the solder won't flow there. I am not aware of anything that will prevent the solder from sticking, or the flux traveling to the screws, and that's key to success. No flux, no solder. Unfortunately, once molten, the flux tends to spread. Maybe the deposited lead (graphite & clay mix) will prevent that from happening. Dunno!

If you happen to determine a fail safe method, please post accordingly. I'd really like to know what works.

H
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BAdams
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Re: Controlling Silver Braze Flow

Post by BAdams »

"Masking Mud" is used in some jewelry applications to limit solder flow.
https://www.rondacoryelldesigns.com/onl ... -p76161121
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tornitore45
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Re: Controlling Silver Braze Flow

Post by tornitore45 »

I have 15 flanges to braze. I tried a couple by using black oxide alloy screw hoping the the oxide would keep the solder from wetting.
It worked but the black flux I am using is so darn good at its job that the screw head are 90% cleaned out of the oxide and would stick if reused. I am running out of new screws.
Next I'll try the pencil = graphite = soot which is what I heard before.
Mauro Gaetano
in Austin TX
Rolland
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Re: Controlling Silver Braze Flow

Post by Rolland »

I have used soap stone marker to control solder flow. The kind used to mark metal or in welding
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tornitore45
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Re: Controlling Silver Braze Flow

Post by tornitore45 »

Thank you all for the suggestions, they will be stored for the next occasion.
Sometime is better to eliminate the problem instead of solving it.
In this instance I could put a fine short thread on the pipe end and on the flange. enough to keep the flange square and oriented.
Eliminating the fixture had the advantage that the assembly heats up faster than the smoke detector in the garage reacting.
Keeping the dog and wife inside the house from freaking out.
Mauro Gaetano
in Austin TX
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tornitore45
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Re: Controlling Silver Braze Flow

Post by tornitore45 »

I happened to look up https://www.armadilloclay.com/kiln-acce ... parts.html
they list a "Kiln Wash" 2lbs for $5.40 and they are local

I wonder if this is going to be equal or work the same as Making Mud Basically we want something that dry out and does not burn.
Mauro Gaetano
in Austin TX
Patio
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Re: Controlling Silver Braze Flow

Post by Patio »

I wonder if White Out would work. I see it used on the TV show, Forged in Iron, when they are making Canister Damascus steel. It is used to line the container so the steel put inside won't stick, allowing them to remove the canister from around the forge steel. Just a thought, I have no real knowledge.
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tornitore45
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Re: Controlling Silver Braze Flow

Post by tornitore45 »

White Out
You mean the little bottle used to correct typos? That can be expensive for anything but jewelry sized work.
I suppose anything with a mineral content in a pasty solution has potential to work.
Another thing to file away
Mauro Gaetano
in Austin TX
John Hasler
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Re: Controlling Silver Braze Flow

Post by John Hasler »

Googling for antiflux gets quite a few hits including some with diy recipes but I have no experience with any of those products.
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tornitore45
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Re: Controlling Silver Braze Flow

Post by tornitore45 »

ANTIFLUX The secret of finding stuff is to know the trigger word. I newer thought to use Antiflux.
Mauro Gaetano
in Austin TX
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