# need massive info dump on solder/brazing



## drysdam (Jun 28, 2012)

I want to attach metal together. Generally small pieces of brass, aluminum and steel. I don't want to use glue. At least some of these connections may be heated to some degree.

I keep reading about brazing, soldering, silver soldering and other terms but everyone seems to using these words very loosely with no particular indication of what materials or torch types they are using ("propane isn't hot enough" doesn't educate me very far and "an ordinary blowlamp" is hard to shop for where the rubber meets the road). It doesn't help that even when speaking more strictly the terms seem to differ on opposite sides of the pond and from different historical periods.

What I need is a comprehensive source of information that will tell me more than I need to know, starting at the beginning, in modern US terminology. With a firm foundation, I will then be able to ask intelligent questions and be able to tell when the answerer doesn't know anything either. Does anything like this exist?

(I don't think I'm interested in welding, but it may be that the information I'm looking for would be part of a curriculum that included welding. That's fine.)


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## Troutsqueezer (Jun 28, 2012)

Getting information that is tailored specifically to one's education, experience and level of intelligence is something we all would like access to. Unfortunately, the world doesn't work that way. You're off to a good start by accessing this forum. Use the search tool here and use Google in general and cull the information as it applies to what you are seeking.

 Folks here are always happy to answer specific questions.


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## mklotz (Jun 28, 2012)

And to add to what Trout said...

Describe your particular application here and you'll get expert advice from the membership. Do that several times and you'll have lots of material from which to generalize.

Also, don't dismiss other methods of joining two pieces. Loctite adhesives are a boon and interference fits are often the way to go.


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## drysdam (Jun 28, 2012)

I'm a little skeptical that this information only exists as folklore. Also, I'm still too ignorant to even ask a question (e.g. to know what is even relevant). Is there at least a starter kit of info somewhere? I've tried the "Soldering and Brazing" book by Tubal Cain but it is either too old or too "foreign" (or both) to impart any information to me.

Basically, I'm looking for a "for Dummies" level intro to get me up the level where I can bootstrap myself farther.


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## rhitee93 (Jun 28, 2012)

Very generally:

Soldering or soft solder uses a filler material that melts in the 400-500 degree F range. This can be done with an electric iron, small torch, or a variety of other heat sources.

Silver Solder uses a filler material that melts at a much higher temp. 1000 deg F or more. As such it requires a bigger torch. It is a stronger filler material, and produces a stronger joint that is also more temperature resistant.

This link might help you a bit:
http://en.wikipedia.org/wiki/Soldering

Brazing is more like silver soldering, but I usually think of it as an even higher temperature operation. I don't braze often, so I won't speculate any more than what I have already. However, going to the same source as above may be helpful:
http://en.wikipedia.org/wiki/Brazing

One thing is that aluminum generally doesn't solder or braze at all. There are probably some exceptions for certain alloys and filler materials, but in general it isn't an option.


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## drysdam (Jun 28, 2012)

Is glue or fasteners the only option for (most) Al then?


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## Blogwitch (Jun 28, 2012)

There is no such book as soldering for dummies, purely because as already mentioned, every job is different, and I for one wouldn't like to teach a dummy to silver solder.

Just knowing where you come from helps, as US English and terminology is , when it comes to soldering, totally different to UK English.

In the US they say silver soldering, and it is a very soft solder like plumbers use, whereas we in the UK we would call it soft soldering, and it is also common in the US to call our silver soldering, silver brazing, a hard soldering process that usually uses butane torches to reach the temperatures required.

To write a complete topic on the differences of solders and techniques is not a thing I would relish, I could be there for weeks.

As already mentioned, do a search for "silver solder", in quotes, as I have put it, and you should come up with a lot of articles on this site describing the technique. I know for a fact that I have described techniques many times.


John


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## Rayanth (Jun 28, 2012)

MIG welding is another option if you really feel you need a metal bond (Aluminum-Aluminum)... but it's not really a do-it-yourself hobbyist option as far as I'm aware.

- Ryan


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## drysdam (Jun 28, 2012)

I'm looking at brass/aluminum for my current project. Parts around the diameter of a pencil and mostly smaller.

<i>In the US they say silver soldering, and it is a very soft solder like plumbers use, whereas we in the UK we would call it soft soldering, and it is also common in the US to call our silver soldering, silver brazing, a hard soldering process that usually uses butane torches to reach the temperatures required.
...
As already mentioned, do a search for "silver solder", in quotes, as I have put it, and you should come up with a lot of articles on this site describing the technique</i>

It sounds like I'd find articles describing at least two techniques. On a hard process in the UK and one a soft one in the US. Which one are you intending me to find and how do I distinguish them? Text doesn't always have an accent...


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## sunworksco (Jun 28, 2012)

Here is my friend Ken, "The Tin Man".
Watch his video hard soldering aluminum.


[ame]http://www.youtube.com/watch?v=RRWmpSE-hXk&feature=youtube_gdata_player[/ame]


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## rhitee93 (Jun 28, 2012)

drysdam  said:
			
		

> Is glue or fasteners the only option for (most) Al then?



There are many mechanical methods. Fasteners of all kinds, or interference fits as Marv mentioned. Regarding adhesives, some of the epoxies out there are amazing!



			
				drysdam  said:
			
		

> I'm looking at brass/aluminum for my current project. Parts around the diameter of a pencil and mostly smaller.



There is no metallurgical way to bond brass and aluminum that I know of. If this is what you are needing to do then I thik you are stuck with mechanical connections or adhesives.


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## steamer (Jun 28, 2012)

Under 300F I wouldn't worry too much about model parts held together with Loctite.

On the other hand.....I wouldn't loctite a boiler together!.....

There is no substitute for good engineering judgement!

What is the application?


Dave


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## pkastagehand (Jun 28, 2012)

My experience with US terms is that silver soldering (or silver brazing) are not related to soft soldering (lead and modern lead-free substitutes) used for electronics and plumbing.

Silver soldering is technically a "brazing" process because it happens at a higher temperature than soft soldering. I don't know those temps offhand but brass/bronze and silver brazing materials melt in the range of 1600 degrees F to 2200 deg. F. So unless the part is small you need something that has first off a high enough temperature and second puts out enough BTUs so that the parts heat faster than they conduct the heat away. 

That is why a small plumbers propane torch often doesn't work. It will get hot enough to melt silver solder, but if the parts are very big they conduct the heat away too rapidly to get the base metal up to temperature.

I mostly use the oxygen-acetylene torch for silver brazing because that is what I have.

Some folks have bought Turbo(TM) torches or similar that use propane as fuel but design allows them to put out more BTUs than the little hand helds. They generally hook to a larger tank and use a hose.

Aluminum can be brazed, but like welding it, it can be a trickier project for two reasons. Aluminum oxidizes almost instantly. So you clean it but before you get the torch lit it has a skin of oxidation on it already. So fluxes, etc. are very important (as they are in all metals but maybe more so). Also, aluminum doesn't change color just before it melts like many other materials do.

Welder's Handbook by Richard Finch is a nice source of info for basic welding information and includes soldering brazing info.

Welding by Robert O'Con is another book. 

Paul

PS I should also have mentioned that Kozo Hiroaka in his A3 book and possibly the others as well has a section devoted to explaining the mysteries of silver brazing.


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## rhitee93 (Jun 28, 2012)

giovanni  said:
			
		

> Here is my friend Ken, "The Tin Man".
> Watch his video hard soldering aluminum.



That was impressive! I've tried the "Flea market special" stuff he mentions and it is utter crap.
Your friend makes it look easy :bow:


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## steamer (Jun 28, 2012)

pkastagehand  said:
			
		

> My experience with US terms is that silver soldering (or silver brazing) are not related to soft soldering (lead and modern lead-free substitutes) used for electronics and plumbing.
> 
> Silver soldering is technically a "brazing" process because it happens at a higher temperature than soft soldering. I don't know those temps offhand but brass/bronze and silver brazing materials melt in the range of 1600 degrees F to 2200 deg. F. So unless the part is small you need something that has first off a high enough temperature and second puts out enough BTUs so that the parts heat faster than they conduct the heat away.
> 
> ...





Above 800F is technically the dividing line between "soldering" and "brazing"......In the US Silver Soldering is called that regardless....and I've seen heated arguments about the name....but lets not..... :

Dave


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## drysdam (Jun 28, 2012)

I'm not <i>worried</i> about parts glued together. I just don't want to use it. I'm sure it's easier but if I were looking to ease my workload I wouldn't be in the hobby in the first place. Doing the hard way when it seems more "right" to me is fine. 

But you guys can already see what I'm talking about in this thread and we're not even 20 posts in. "You can't braze Al" vs "Here's how you braze Al" vs "the term for this is X" vs "the term is actually Y under circumstance Z".

I'd really rather avoid wading through hundreds of (apparently?) contradictory posts without any way to tell who actually knows what they are talking about. I need modern, US-oriented, definitive source.


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## steamer (Jun 28, 2012)

Here ya go!

http://www.aws.org/w/a/

Dave


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## clivel (Jun 28, 2012)

The latest flyer I received from Camden Miniature steam advertises a book called "Welding Know-How" by Frank Marlow.

Quoting from the sales blurb "here is one book which covers every aspect of soldering, brazing, welding and cutting by electrical, gas and combined means" it would seem to answer most of your questions.

More info from Camden http://www.camdenmin.co.uk/new-items-after-booklist-65/welding-know-how-p-3556.html
Or if you are in the US directly from the publishers http://www.metalartspress.com/wkh.html


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## drysdam (Jun 28, 2012)

Thanks, I'm getting a book similar to that from the library. It looks like only a chapter is devoted to things that aren't strictly welding, but maybe that will be enough.

The AWS website was a good idea, but I don't see anything there that isn't about welding.


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## Bustedbricks (Jun 28, 2012)

It's much easier to state a specific application and work from there. What method you use to join metals depends a lot on what it is you want to achieve. 

Alu can be MIG, TIG and MMA welded with the right equipment. You can also solder alu with specialised flux and solder. However you cannot join it with other metals using these metals as has already been mentioned.

Brass, copper and steel can be soft soldered, silver soldered, bronze brazed etc. The method selected depends on desired strength, temp resistance, assembly sequence etc. There are so many variables.


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## panofish (Jun 28, 2012)

Brazing is fun and not too difficult for basic steel to steel and aluminum to aluminum.
You just need a torch with good high heat, like oxygen and gas for steel and propane can be sufficient for aluminum.
Silver solder is easier than bronze rods for steel but bronze rods are cheaper.
The aluminum brazing rods are cheap and are very easy because they don't need as much heat.

Here is a video I shot of my learning experience with brazing...

[ame]http://www.youtube.com/watch?v=WeRPdVDCLyk[/ame]


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## steamer (Jun 28, 2012)

drysdam  said:
			
		

> Thanks, I'm getting a book similar to that from the library. It looks like only a chapter is devoted to things that aren't strictly welding, but maybe that will be enough.
> 
> The AWS website was a good idea, but I don't see anything there that isn't about welding.



Drysdam,

Your not looking very hard.  Here's one article I found in 4 minutes of my time. I suggest you spend 4 of yours investing in your education and look a bit harder.  

http://www.aws.org/pr/WJ_October_2010/eMagFiles/source/WJ_oct2010.pdf

My reference for my post was from AWS....

Best of luck to you

Dave


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## steamer (Jun 28, 2012)

Or perhaps here

http://www.harrisproductsgroup.com/en/Products/Alloys/Brazing.aspx


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## drysdam (Jun 29, 2012)

<i>Your not looking very hard.  Here's one article I found in 4 minutes of my time. I suggest you spend 4 of yours investing in your education and look a bit harder.  </i>

I've spent a lot more than 4 minutes looking for this kind of information. The reason I'm asking here is that the information I find seems to assume you already know *something* from *somewhere*. I'm trying to identify that something and where I can get it.

Your PDF is a welding journal. The table of contents has nothing about soldering or brazing.


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## drysdam (Jun 29, 2012)

panofish, where did you get that microtorch? That might not be sufficient for all future jobs but it'd be more than enough for my current project. (No wait--I found it. Harbor Freight.)

I guess I'll have to just experiment with joining aluminum/brass because if you ask 3 people you get 4 opinions on if it can be done.


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## Blogwitch (Jun 29, 2012)

> I guess I'll have to just experiment with joining aluminum/brass because if you ask 3 people you get 4 opinions on if it can be done.



I am not being nasty at all, but your attitude from the very start has not been very conducive to people wanting to help you.

People on the whole on this site will bend over backwards to help someone, and I must admit, I am a bit of a master when it comes to silver soldering, but the way you started off and moaned ever since, has made me back away very quickly.

John


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## panofish (Jun 29, 2012)

I've never joined brass and aluminum, but I would guess it isn't possible?


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## Bustedbricks (Jun 29, 2012)

There are flux/solder products on the market that claim to be able to join copper and brass with alu:

http://cupalloys.co.uk/joining-aluminium-c100014.html

I agree with Bogstandard - OP does have a bit of an attitude and seems to want everything served on a silver platter. The truth is that there are so many variables that you really need to do detailed studies on each application. All the information is out there and easily accessible if you take the time to look.


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## drysdam (Jun 29, 2012)

Let's try this again.

I have a small block of aluminum with a 3/32" hole in it that I cannot make smaller. I also have a 3/32" piece of brass tubing that I cannot make larger and is a loose fit in the former. I want it to stay in there. The temperature of the whole deal theoretically won't go above about 220°F but could if something goes wrong, so higher heat resistance is better. I do not want to use glue if it can be avoided. Other than a setscrew or similar, what are my options wrt soldering/brazing, if any?

I also have other pieces of aluminum and brass of a similar scale (up to about 1/4") that may need attaching in all possible configurations (Al/Al, brass/brass and Al/brass), so a solution that covers all cases would be ideal.


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## Rayanth (Jun 29, 2012)

machine down the OD of the tube slightly, and make a bushing that is a tight fit for both, to go between them?

Just a thought. at that size it might be tough. maybe a ring more like a piston ring would be easier - a bushing with an open end so it will adjust to meet the tightness needed.

- Ryan


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## drysdam (Jun 29, 2012)

Ah yes. Now that you mention bushings, some of my fastenings will in fact be interference fit bushings themselves, so I don't need as much soldering as I was thinking when I wrote that. 

On the 3/32" tubing, though, I think the bushing idea has two problems. One is the tubing wall thickness preventing going down too small (not sure what the wall thickness is). 

The other problem is making the hole in the bushing. The reason the hole in the Al block can't be made smaller, is that I don't have a full set of tiny drill bits. I could step down by 1/32, but that's way too much for a fit. Thus I can't make the bushing either.

If I scared up a #42 drill bit (.0935) that might work for the 3/32" (.09375) tubing though. I'll see if I can find one around.


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## sunworksco (Jun 29, 2012)

rhitee93  said:
			
		

> There are many mechanical methods. Fasteners of all kinds, or interference fits as Marv mentioned. Regarding adhesives, some of the epoxies out there are amazing!
> 
> There is no metallurgical way to bond brass and aluminum that I know of. If this is what you are needing to do then I thik you are stuck with mechanical connections or adhesives.




[ame]http://www.youtube.com/watch?v=lGy7pHx6P3Y&feature=youtube_gdata_player[/ame]


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## panofish (Jun 29, 2012)

Wow!... there's your answer and great technique for brazing aluminum to brass!


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## drysdam (Jun 29, 2012)

Yeah, I found those guys. But with all the naysaying on Al vs brass, and being ignorant myself, I couldn't tell if it was a crock or what. They've got comments disabled at YouTube which could be a bad sign...


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## Rayanth (Jun 29, 2012)

drysdam  said:
			
		

> Ah yes. Now that you mention bushings, some of my fastenings will in fact be interference fit bushings themselves, so I don't need as much soldering as I was thinking when I wrote that.
> 
> On the 3/32" tubing, though, I think the bushing idea has two problems. One is the tubing wall thickness preventing going down too small (not sure what the wall thickness is).
> 
> ...




Can the hole that the tube is going into be made BIGGER, so a bushing can go the other way?


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## bearcar1 (Jun 29, 2012)

Hi DS, Not to sound condescending, but the purchase of a small set of number drills would seem to be a prudent thing to do. Doing so would certainly allow you the flexibility of using parts at hand or making pieces to fit a whole lot simpler. Not to mention they would also be very useful in those tapping situations you mentioned earlier. I'm thinking of getting an extra set to augment the full monte set I have as I searched all over the other day for a #50. Finally found it underneath the drill press it had rolled under.


BC1
Jim


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## drysdam (Jun 29, 2012)

Oh, I'm definitely picking up small drill bits. But I'm getting nice ones piecemeal from a quality used source, so I can't predict when I'll have a particular size. Besides, I'd like to solve the "general problem" not just my current 3/32" issue. That's why I started in a general way.

Making the holes larger to fit bushings the other way. That's 100% genius. I might just be able to do that.


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## steamer (Jun 29, 2012)

drysdam  said:
			
		

> <i>Your not looking very hard. Here's one article I found in 4 minutes of my time. I suggest you spend 4 of yours investing in your education and look a bit harder. </i>
> 
> I've spent a lot more than 4 minutes looking for this kind of information. The reason I'm asking here is that the information I find seems to assume you already know *something* from *somewhere*. I'm trying to identify that something and where I can get it.
> 
> Your PDF is a welding journal. The table of contents has nothing about soldering or brazing.



Try page 18....


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## Rayanth (Jun 29, 2012)

drysdam  said:
			
		

> Making the holes larger to fit bushings the other way. That's 100% genius. I might just be able to do that.



Of course, you still have the problem of your 3/32" bit drilling too big for the tube. you'll have to drill the hole in the bushing some other way, to get a slightly smaller hole.

- Ryan


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## steamer (Jun 29, 2012)

Can you provide a sketch of what your trying to do?

Dave


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## Troutsqueezer (Jun 29, 2012)

drysdam  said:
			
		

> Oh, I'm definitely picking up small drill bits. But I'm getting nice ones piecemeal from a quality used source, so I can't predict when I'll have a particular size. Besides, I'd like to solve the "general problem" not just my current 3/32" issue. That's why I started in a general way.



Unless you have money waiting to be spent you can just buy a complete drill bit set from Harbor Freight for 30 bucks. Get a Drill Doctor to sharpen them when they get dull. That's what I did and I've only had to sharpen a couple of them after three years. The holes they drill are every bit as accurate as the more expensive bits. 

-Trout


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## xatxtal (Jun 30, 2012)

Hello folk
I have just looked up Brazing in a 1850 Mech handbook it is spelled Brase as in Brass, fillers were described as copper zinc mixtures IE Brass.
It seems that our USA friends changed the spelling and brought it back to the UK in the first World War as Braze.
I hope this confusion may help.
Trev. :big: :big:


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## Dunc (Jun 30, 2012)

Have a look at www.brazingbook.com

Some years back I had d/l a pdf version, "The Brazing Book" from Handy & Harman Canada but that website has disappeared.

It is now available from:
www.fpga-faq.org/sb-metal_hold/CD_08/&#8203;TheBrazingBook.pdf


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## Bastelmike (Oct 14, 2012)

As I'm not native-english speaking this thread was pretty interesting as I always was confused with the terms brazing and soldering.

But its still somewhat confusing to me. If I look at a drawing requiring silver soldering, I still dunno what to do

1) soft soldering with low temp. and lead or tin-based solder and a propane torch,
 or
2) hard soldering with silver or brass solder and taking out the acetylen-oxygen torch ?

Thats still not clear 

Mike


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## velocette (Oct 14, 2012)

Hi there is more information posted elsewhere on HMEM please go to 

http://www.homemodelenginemachinist.com/f25/brazing-advice-needed-15662/

Eric


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## kquiggle (Oct 23, 2012)

Just wanted to weigh in with my limited experience is this area: I have tried alumiweld from Harbor Freight (possibly also available from your local hardware store) - I found that it works as advertised. But - you have to keep its limitations and properties in mind:

First: your "weld" will be harder than the aluminum you are "welding" (it's really more like soldering), which may or may not be an advantage. The joint will also be more brittle - it will crack before it will bend.

Second: if you are joining more than two pieces, you will need to clamp everything together and join all pieces at more or less the same time, because your second join will likely cause the first join to melt.

I have not tried alumiweld will brass and aluminum both, so I have no idea if this will work for this combination or not.

By way of background, here are a couple of things I did with alumiweld: 

One: I had a gas barbecue with a rusted out drip pan; I built a new drip pan out of aluminum sheet by bending into a shallow rectangular pan; I soldered the corners with alumiweld and this worked very well. 

Two: I needed a small aluminum box for a project; I cut aluminum rectangular bar into appropriate pieces and used alumiweld to solder the interior joints. The first time I tried it the first two pieces fell apart while I was soldering on the third piece - this is when I found I needed to clamp the whole box together and solder all joints at once.


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