Solder as glue

Started by amz-fx, November 25, 2019, 12:23:25 PM

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amptramp

I'm with the OP - make the mechanical connection first then make the solder connection to the mechanically stable wire connection.  Solder is soft and weak - you cannot use it reliability as a glue for putting things together.

italianguy63

Quote from: tubegeek on November 26, 2019, 09:11:16 PM
Quote from: italianguy63 on November 26, 2019, 01:54:45 AM
We actually had one of these irons up until late.  My dad had one, and it disappeared after he died.  We think the neighbor came over and stole it from his tool shed....  (other things went missing too).

That is one f'ed-up neighbor - even if you only SUSPECT them of this, there's got to be some kind of horrendous backstory to it.
[/quote]

Yes.  Dude is a total tool.  He was good friends with my dad.  He watched over my parents house when they were away and had keys to the house.  When my dad died, and my mom was away for the winter.. he went into the house and lifted things.  He was bragging to the neighbors he was going to "get the house" (from the widow) for his adult child.

When I got up there in the summer I changed the locks, and we did some major renovations to the house.  We plan on keeping the property.  Let's just say we do not speak anymore!

MC
I used to really be with it!  That is, until they changed what "it" is.  Now, I can't find it.  And, I'm scared!  --  Homer Simpson's dad

tubegeek

Quote from: italianguy63Let's just say we do not speak anymore!

MC

Ouch. My condolences.
"The first four times, we figured it was an isolated incident." - Angry Pete

"(Chassis is not a magic garbage dump.)" - PRR

Mark Hammer

In all seriousness, though, I think the take-home message here is to own, or get yourself, a pair of suitable needle-nose pliers that allow you to get into tight spaces and twist leads appropriately to produce a secure joint.

Govmnt_Lacky

I ALWAYS cringe when I see someone post "Here is the new pedal I finished for a customer" and I see the LED power or ground just solder-blobbed to a wire and exposed.  :o :icon_eek:
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anotherjim

There really are places where a mechanical joint isn't the best option.

If you make a mechanical joint too good, you will probably wreck the part/s if you have to replace them or make a temporary disconnection for testing purposes.

Inline lap joints are perfectly good provided -
The parts were pre-tinned 
There is sufficient overlap - end to end butt joints won't work at all.
You keep the lap tight and parallel while soldering together.

A wired to panel-mounted LED is a perfect example of where I would always use lap joints - but then they would be sleeved over and preferably, not with heat shrink.



amz-fx

Quote from: anotherjim on November 27, 2019, 10:05:35 AM
You keep the lap tight and parallel while soldering together.

A wired to panel-mounted LED is a perfect example of where I would always use lap joints

Instead of a lap joint, why not form a small hook on the end of each wire, then crimp them together when the hooks are in place? I even do this on LEDs before I put the shrink sleeve over it.

regards, Jack

tubegeek

#27
Quote from: Mark Hammer on November 27, 2019, 09:15:13 AM
In all seriousness, though, I think the take-home message here is to own, or get yourself, a pair of suitable needle-nose pliers that allow you to get into tight spaces and twist leads appropriately to produce a secure joint.

I'm a big fan of locking forceps. You can either snag them when the ER doc isn't looking (not really recommended!) or order them online fairly cheaply - get a few sizes and shapes. Not a replacement for needlenoses but an essential supplement. Get a scalpel and some replacement #10 and # 11 blades while you're at it - sharper and cheaper than an Xacto although not as tough/long-lasting.
"The first four times, we figured it was an isolated incident." - Angry Pete

"(Chassis is not a magic garbage dump.)" - PRR

KarenColumbo

Solder is the glue that binds my soul to earthly matter.

[philosophical metaphor mode off]
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j_flanders

#29
I'm not sure I understand.
Do you consider all these joints in this random google image to be glued rather than soldered?

And, since the wire to a pot lug (apparently) needs to go through and then run back, aren't all through hole components (resistors, caps, diodes etc) glued instead of soldered?
Just trying to learn and understand to solder better.

I often do point to point and twisting leads of components before soldering is often virtually impossible and a nightmare when modding/replacing stuff afterwards.

anotherjim

I'm not a fan of hook & loop joints, especially with stranded wire - and they don't sleeve over neatly. Any forces that can break a decent lap joint are going to be strong enough to break something else instead. Another way of looking at it is that joining tinned parts with a solder of similar metal is more like welding than glueing.


iainpunk

idk, i have more problems with vero than with bad solder technique
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

EBK

Would a lap joint covered in heat shrink meet the approval of our wise elders?  Asking for a friend.   :icon_wink:
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amptramp

Of course, surface mount components are designed so the solder is the only thing holding the components together.  But in this case, the components are low mass and the worst problem they would have is if the board flexes for any reason and breaks the solder joints.  In some cases (like spacecraft), I have seen surface mount components glued down to the board with Solithane 113, a flexible glue that is somewhat like RTV.  Gullwing leads tend to absorb stress better than flatpacks.

Rixen

I've always found a lap joint is stronger than the wire anyway.

tubegeek

Quote from: Rixen on November 27, 2019, 10:46:19 PM
I've always found a lap joint is stronger than the wire anyway.

And sometimes a lap dance can be stronger than a relationship!
"The first four times, we figured it was an isolated incident." - Angry Pete

"(Chassis is not a magic garbage dump.)" - PRR

vigilante397

Quote from: amptramp on November 27, 2019, 04:45:11 PM
In some cases (like spacecraft), I have seen surface mount components glued down to the board with Solithane 113, a flexible glue that is somewhat like RTV.

At work when we're just doing prototypes we let the components stay as they are, but for anything going into production we epoxy down the components and do a conformal coat over the top of everything.
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amptramp

The epoxy we used on spacecraft was Epiphen 825A and it sets up hard as a rock whereas Solithane 113 was somewhat flexible.  We used a conformal coat that was locally removeable so you could fix things.  I don't know how much has changed - spacecraft use trailing edge technology because everything they use has to have an established reliability or you have to file a NONSPAR (non-standard part approval request) and do extensive component, part or process qualification testing.  Someday I may tell you the story of what Canadian Tire has in space and how it got there.

One consideration that made Epiphen 825A and Solithane 113 suitable for spacecraft was the low outgassing - the vapour pressure was low enough that it could be used in a vacuum whereas we couldn't plate anything (like connector shells) with cadmium or zinc because these metals have a high vapour pressure and the vapour tends to stay around the spacecraft and deposit itself onto the optical sensors.

Rixen

Quote from: amptramp on November 28, 2019, 09:01:40 PM
.. Someday I may tell you the story of what Canadian Tire has in space and how it got there...


Curiosity piqued...

PRR

> all these joints in this random google image


That's "Art". It can't be expected to stand-up to a grueling road-trip like our gear should.

I've stuck lots of things together. Some as quick-test. I've also "SMD-ed" thru-hole parts onto large pads with a J-bend in the lead set flat and soldered all around for light-abuse gear.

But there's soldering where the worker applied time, thought, and experience, and solder globbed-on thoughtlessly and recklessly. I think the later is what this rant is about.
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