I’m too lazy to look it up but there’s an arbitrary point, about 500C I think, that delineates soldering & brazing. ? Otherwise as said it’s just melting a filler material into the joint.? Where the heat comes from doesn’t matter, I’ve used a torch on electronics (some things really need a lot of heat that most soldering irons just can’t deliver). ? Tony ?
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From: [email protected] <[email protected]> On Behalf Of Bruce J via groups.io
Sent: Saturday, 21 September 2024 5:43 AM
To: [email protected]
Subject: Re: [7x12MiniLathe] Large work holding? And honestly the only difference between ‘brazing’ and ’soldering’…is the temperature.? Both are the same process: joining metal by melting a metal of a lower melting point to ‘wet’ the metal to be joined with the aid of a flux. Cleanliness, flux, heat.? ? On Sep 20, 2024, at 10:01?AM, Miket_NYC via groups.io <mctaglieri@...> wrote: ? Actually, that old plumber's "3 basic rules" apply just as well to brazing as to soft soldering. You're just using different flux and (a lot) more heat. ? On Fri, Sep 20, 2024, 12:46 PM Ralph Hulslander via <rhulslander=[email protected]> wrote: You do not want to "solder" a steam boiler! You need to braze it. I do have to admit I have soldered a steam coil which was not directly fired. ? The old plumber who taught me to solder had 3 basic rules: ?1. Cleanliness is the key to success - surfaces to be soldered MUST be cleaned to bright, shiny metal. ?2. Flux is your friend - apply it to all surfaces before heating. ?3. Solder flows towards the heat source - that was before hot melt glue guns were common.? The basic idea was to apply heat to the area you want the solder to flow towards, not the outer surface.
? --?
Bruce Johnson
The less a man knows about how sausages and laws are made, the easier it is to steal his vote and give him botulism. ?
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Just to add to point #3, the part needs to be hot enough to melt the solder. ? The iron or torch is used only to heat up the part, not melt the solder / braze / whatever.? Please take note, YouTube videos full of cold joints. ? Tony ? ?
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From: [email protected] <[email protected]> On Behalf Of Roy via groups.io
Sent: Friday, 20 September 2024 11:08 AM
To: [email protected]
Subject: Re: [7x12MiniLathe] Large work holding? The old plumber who taught me to solder had 3 basic rules: ?1. Cleanliness is the key to success - surfaces to be soldered MUST be cleaned to bright, shiny metal. ?2. Flux is your friend - apply it to all surfaces before heating. ?3. Solder flows towards the heat source - that was before hot melt glue guns were common.? The basic idea was to apply heat to the area you want the solder to flow towards, not the outer surface.
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Re: detection of alluminium
"Try melting a piece of it? Steel and Al have very different melting temps."
Steel would be easy. He's trying to tell aluminum from magnesium.
Mike Taglieri?
Try melting a piece of it?? Steel and Al have very different melting temps.
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Re: detection of alluminium
Try melting a piece of it?? Steel and Al have very different melting temps.
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Re: detection of alluminium
There acid to test types metal?
I never worry about it unless I am? welding or foundry work.?
Stainless is a different story because you know if 400 type and if a magnet sticks then 400 most machines it a bad day
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Dave?
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On Tue, Sep 24, 2024 at 06:05 AM, Jacques Savard wrote:
?
I have? some? metal? from? picnic table? whit glass?
2 interrogation
A? howto? verify? it is alluminium? ?maybe? magnnetic? ok? but? do you have? any other? method? like? acid? vinegar? or so
B? ?is it possible to? make a check? playing? dising? whit? sand blasst? on? these? kind? of? tenpered glass table? or? no? everything? exploded
?
jack 47 71
?
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Re: detection of alluminium
I don't have one of these tabletops, but I had a thought. A cell phone has a polarizing filter. Would that also show the effect?
On Wed, Sep 25, 2024 at 9:52?AM Mark Kimball via <markkimball51= [email protected]> wrote: It isn't absolutely necessary to use two polarizers, if you have a pair of polarizing sunglasses.? Indirect light from the sky on a clear day is partially polarized, so just put them on and look at the sky through the glass.? Sky light isn't 100% polarized so the contrast between the light/dark regions won't be as dark as with a pair of polarizing filters.? But just about everyone has some polarizing sunglasses lying around.
?
I see this effect most often when driving since the car's windows are made with tempered glass.
--
Buffalo John
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Re: detection of alluminium
It isn't absolutely necessary to use two polarizers, if you have a pair of polarizing sunglasses.? Indirect light from the sky on a clear day is partially polarized, so just put them on and look at the sky through the glass.? Sky light isn't 100% polarized so the contrast between the light/dark regions won't be as dark as with a pair of polarizing filters.? But just about everyone has some polarizing sunglasses lying around.
?
I see this effect most often when driving since the car's windows are made with tempered glass.
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Re: detection of alluminium
Dear Roy, Many thanks for the Maltese pattern detection method for tempered glass. Regards, David (nr. Oxford, UK)
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On 25 Sep 2024, at 00:56, Roy via groups.io <roylowenthal@...> wrote:
? Aluminum will react with a strong base, ferrous metals won't. Probably the easiest to obtain is a drain cleaner; the kind you want will contain either sodium or potassium hydroxide. You'll probably need to scratch the surface (to break the oxide layer) under a pool of liquid. Magnesium is much less common due to cost & manufacturing difficulties.
?
Tempered glass MUST be annealed before attempting to cut it, otherwise the whole piece shatters into little cubes as soon as any part of the surface is breached. An easy way to identify it is with 2 polarizing filters - put the glass between the 2 of them & rotate one of them; tempered glass will show a, "Maltese" cross pattern, plain glass won't.
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Roy
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Re: detection of alluminium
Aluminum will react with a strong base, ferrous metals won't. Probably the easiest to obtain is a drain cleaner; the kind you want will contain either sodium or potassium hydroxide. You'll probably need to scratch the surface (to break the oxide layer) under a pool of liquid. Magnesium is much less common due to cost & manufacturing difficulties.
?
Tempered glass MUST be annealed before attempting to cut it, otherwise the whole piece shatters into little cubes as soon as any part of the surface is breached. An easy way to identify it is with 2 polarizing filters - put the glass between the 2 of them & rotate one of them; tempered glass will show a, "Maltese" cross pattern, plain glass won't.
?
Roy
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Re: detection of alluminium
If you have concentrated nitric acid, that won't harm aluminum but will attack most other metals, including magnesium. Also, shaving of magnesium will burn brilliantly. (That's how they made flashbulbs).
On Tue, Sep 24, 2024, 9:05 AM Jacques Savard via <jacquessavard= [email protected]> wrote: ?
I have? some? metal? from? picnic table? whit glass?
2 interrogation
A? howto? verify? it is alluminium? ?maybe? magnnetic? ok? but? do you have? any other? method? like? acid? vinegar? or so
B? ?is it possible to? make a check? playing? dising? whit? sand blasst? on? these? kind? of? tenpered glass table? or? no? everything? exploded
?
jack 47 71
?
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Re: detection of alluminium
Perhaps Archimedes could assist.
On Tuesday, September 24, 2024 at 07:52:13 AM PDT, paul mcclintic via groups.io <cannontandem@...> wrote:
Not sure if it is a shape you could figure out its volume. If it is you could weigh it and see if that is the correct for that volume of material. Paul M
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Re: detection of alluminium
There are some chemical ways to test aluminum but require strong chemicals.? Calculating the density is a much safer way to go.
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Re: detection of alluminium
I assume by from a picnic table you mean it is a frame or part of a frame. If it looks like a cast part, then if it is magnetic, it is not aluminum. If it isn't magnetic, it could be aluminum or magnesium. Aluminum is 2.7gm/cm^3 and magnesium is 1.74 gm/cm^3, so if you can weight it and measure the volume (Archimedes), you can figure out which one it is.
you can also check out searching for "test aluminum versus magnesium"
Here is one example
On Tue, Sep 24, 2024 at 6:05?AM Jacques Savard via <jacquessavard= [email protected]> wrote: ?
I have? some? metal? from? picnic table? whit glass?
2 interrogation
A? howto? verify? it is alluminium? ?maybe? magnnetic? ok? but? do you have? any other? method? like? acid? vinegar? or so
B? ?is it possible to? make a check? playing? dising? whit? sand blasst? on? these? kind? of? tenpered glass table? or? no? everything? exploded
?
jack 47 71
?
--
Buffalo John
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Re: detection of alluminium
Not sure if it is a shape you could figure out its volume. If it is you could weigh it and see if that is the correct for that volume of material. Paul M
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?
I have? some? metal? from? picnic table? whit glass?
2 interrogation
A? howto? verify? it is alluminium? ?maybe? magnnetic? ok? but? do you have? any other? method? like? acid? vinegar? or so
B? ?is it possible to? make a check? playing? dising? whit? sand blasst? on? these? kind? of? tenpered glass table? or? no? everything? exploded
?
jack 47 71
?
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Re: Brazing (was: Re: Large work holding)
I? verify? on? the? box
it is? mark? 50? amp
it? look to me? a bit? to hight? but? that? is? 500w? around?
the ok
jack 47 71
nb? the first? messge? said? server? was? bad? configured ??
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It's not just the lower melting temperature; the cadmium makes the liquid flow better.
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Roy
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Re: Turning Brass on 7x16?
Good find! The picture is better than my text ;-)
?
Roy
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??? interesting , whats the power source ?
??? thanks
animal
On 9/22/24 8:01 AM, Jacques Savard
wrote:
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here? the photo? of? my? special? carbone welder
the black part? are? insulated? ?and? the 2 part? can be?
move? to? touch or? a bit? distenced for? plasma? building
jack 47 71
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Re: Brazing (was: Re: Large work holding)
I used sil-phos in refrigeration. Doesn't need flux, prepping is minimal, stands up to relatively high pressures; Needs higher temps though.
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davesmith1800
BuffaloJohn