Over annealing copper fire tubes?
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Over annealing copper fire tubes?
Not sure if I messed up here or not. I used a oven to heat to apx 900-1000 degrees (clean cycle) and left the tubes in the entire time. When they came out they had a powder of gray all over them. Unsure if it was from soot or if it is an oxide layer but it mostly comes off easily and very little discoloration relains after a light sanding.
Is there a worry about over annealing? A little bit of this discoloration remains where the tubes are being rolled in could this cause any future issues? Ideally I would acid bath them but don’t have the ability to do it so am just lightly sanding instead.
Is there a worry about over annealing? A little bit of this discoloration remains where the tubes are being rolled in could this cause any future issues? Ideally I would acid bath them but don’t have the ability to do it so am just lightly sanding instead.
-Chris Srch---- Home track Tradewinds and Atlantic Railroad
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Re: Over annealing copper fire tubes?
This is how they look
-Chris Srch---- Home track Tradewinds and Atlantic Railroad
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Re: Over annealing copper fire tubes?
Is normal...just clean and go.
When you over anneal cooper ...it melts into a puddle.
When you over anneal cooper ...it melts into a puddle.
Too many things going on to bother listing them.
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Re: Over annealing copper fire tubes?
Guess I normally start working it before that powder has a chance to form (small scale stuff). Will a little missed grey that ends up in the joint cause any long term issues ? Did the best I could but short of an acid bath won’t get 100 percent ( see first photo first inch of pipe)
-Chris Srch---- Home track Tradewinds and Atlantic Railroad
Re: Over annealing copper fire tubes?
...or turns into the metallic equivalent of a licorice stick. Gotta watch out when using an oxyacetylene torch to solder copper pipe.
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Music isn’t at all difficult. All you gotta do is play the right notes at the right time!
Music isn’t at all difficult. All you gotta do is play the right notes at the right time!
Re: Over annealing copper fire tubes?
The gray you mention is oxidized copper. If you've fluxed properly, it shouldn't be an issue, but, if not, it could compromise a solder joint. Best scenario is to remove all oxides, inside and out, even for rolled tubes.ChooChooChris wrote: ↑Sun Oct 02, 2022 3:43 pm Will a little missed grey that ends up in the joint cause any long term issues ?
Copper will NOT dissolve in dilute sulfuric acid, but copper oxide readily does. It wouldn't be all that difficult to clean the tubes inside and out by placing them in a capped piece of PVC or ABS pipe filled with battery acid, readily available at many auto parts stores. They need not all be done at the same time, so a relatively small piece of pipe would suffice. Rinse them well with running water after they are removed from the acid. Wear gloves and eye protection.Did the best I could but short of an acid bath won’t get 100 percent ( see first photo first inch of pipe)
H
Wise people talk because they have something to say. Fools talk because they have to say something.
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Re: Over annealing copper fire tubes?
Harold_V wrote: ↑Sun Oct 02, 2022 4:12 pmThe gray you mention is oxidized copper. If you've fluxed properly, it shouldn't be an issue, but, if not, it could compromise a solder joint. Best scenario is to remove all oxides, inside and out, even for rolled tubes.ChooChooChris wrote: ↑Sun Oct 02, 2022 3:43 pm Will a little missed grey that ends up in the joint cause any long term issues ?
Copper will NOT dissolve in dilute sulfuric acid, but copper oxide readily does. It wouldn't be all that difficult to clean the tubes inside and out by placing them in a capped piece of PVC or ABS pipe filled with battery acid, readily available at many auto parts stores. They need not all be done at the same time, so a relatively small piece of pipe would suffice. Rinse them well with running water after they are removed from the acid. Wear gloves and eye protection.Did the best I could but short of an acid bath won’t get 100 percent ( see first photo first inch of pipe)
H
It is a rolled joint. No solder involved just a tight squeeze. .75 od .62 id hole is .757 expanding Id of copper to .64 which if my math is correct is a 10 percent thinning of the material which every book says is “correct” for copper
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Re: Over annealing copper fire tubes?
As said earlier...do not worry about it.
You are good...
You are good...
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Re: Over annealing copper fire tubes?
Why did you anneal them? You don't need to anneal if you are installing tubes with a roller.
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Re: Over annealing copper fire tubes?
The first tube I did was not annealed and reaulted in surface cracking and lots of copper flakes that kept jamming up the roller . Hope I didn’t make a mistake doing that.Marty_Knox wrote: ↑Sun Oct 02, 2022 5:46 pm Why did you anneal them? You don't need to anneal if you are installing tubes with a roller.
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Re: Over annealing copper fire tubes?
You are ok.
I prefer to roll annealed tubes, but both ways will work if you have experience.
I prefer to roll annealed tubes, but both ways will work if you have experience.
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Re: Over annealing copper fire tubes?
What were you using as a lubricant? You shouldn't roll tubes dry. Just about any oil or grease will work, even Crisco.ChooChooChris wrote: ↑Sun Oct 02, 2022 5:56 pmThe first tube I did was not annealed and reaulted in surface cracking and lots of copper flakes that kept jamming up the roller . Hope I didn’t make a mistake doing that.Marty_Knox wrote: ↑Sun Oct 02, 2022 5:46 pm Why did you anneal them? You don't need to anneal if you are installing tubes with a roller.