Filing solder joints to make them less pointy

[EBK]

Just a little technique that I'm using on a tight build.  Maybe this would be useful to some, and maybe some of you have done this before. 

I find myself often insulating the solder side of my boards, or the portions of the enclosures that will be next to them, with gaffers tape or double-stick foam tape to prevent shorts.  On a recent build, I needed to go a bit further and file down the sharp points on the solder joints to ensure that they wouldn't puncture the tape.  This pic kind of shows this. 


A can of compressed air to blow away the electrically-conductive dust is probably also a good idea.  Probably also a good idea to delay soldering any trimpots to the board until after this step.
Anyway, I'm filing this away (no pun intended) in my collection of random building techniques and thought I'd share.

[bluebunny]

Interesting point (no pun intended).   

[anotherjim]

When I've had to a very low profile to fit the board, I've built it backwards, components on the copper side. Still needs insulation in case something pokes too far the holes. It's also possible to convert thru-hole to surface mount with short legs and a little bend so it don't have to poke thru a hole.

I agree with pointless joints, but use shear cutters, not diagonal wire cutters. You can cut very close flush to the board with those -  no need to file.

Maybe people think this type of cutter looks too cheap & nasty, but if only for cutting copper, they will last years. Don't try to trim steel guitar strings with them.

Ever have a soldered in chip that you think may be faulty on one pin & shorting things out? Clip the suspect leg with these shears (point is narrow enough) and test both ends. Turns out its ok? Bend the ends back in line and blob some solder over it. Nobody will know you did that unless they unsolder the chip.

[digi2t]

My first couple of vero builds, way back when, I had sitting on foam tape.

I hated it.

After that, every vero I laid out had a minimum of two mounting holes on opposing corners, in most cases four on all corners. I use 3mm nylon stand-offs for all builds.

I would rather sacrifice enclosure space/board size, rather than have a board sit on tape. That's my biggest gripe with the Tagboard effects layouts. God bless theirs souls for all the work they do, but I prefer to redraw than use one of their unholey layout. 

[Kipper4]

I have some of those Jim. Very handy too.

I hotmelt glue a piece of card on the underside of my builds. Then hotmelt to the back of pots.
with a few blobs on the sides and to the switch case.
No problems as yet.

The hotmelt to both sides of the card also acts as a layer of insulation for those sharp solder joints.

Said card also contains details of the pedal and most times a coded serial number.



Shhh

codebreaker

I use a ten letter word and give each letter a number.



serial number
first two numbers is the build number (also included in my Build Log, I know it's a bit anal.)
the next six numbers are the date. DD/MM/YY

[bluebunny]

I also got myself a pair of those flush cutters, Jim.  Much better than the previous pair that I'd been using for years.  I've been known to reflow the cut joint so that it becomes a beautiful shiny dome.  No sharp points. 

[davent]

...  I've been known to reflow the cut joint so that it becomes a beautiful shiny dome.  No sharp points. 

Me too.
dave

[armdnrdy]

I also use the "sheer cutters" for electronics....not side cutters for electrical work.

If you want a durable insulator which can be found in factory stompbox builds...search for "fish paper"

[Kipper4]

Maybe I'll draw a fish on it in the future too.






Thanks Larry.
You learn something everyday.

[davent]

Something i've use is the clear plastic from blister packs, like transparency film but tougher.

dave

[EBK]

I've used theatrical gels as thin and durable insulators before.  Expensive if you don't happen to have them on hand from a past hobby. 

[anotherjim]

Fish paper is , I think, what I know as "Elephant hide". Just found out it's probably actually a trade name "Elephantide".

[karbomusic]

I thought that any cutters that popped induced a shock/vibration into the joint potentially weakening it. I have cutters specifically made so they cut minus any pop/snap.

I also thought that you weren't supposed to cut them flush, maybe nasa manual or pace videos? I'm totally pontificating based on blurry memory.

[R.G.]

Use a hotter soldering iron so the melted solder is hotter, and remove the iron from the joint more quickly. The worst "pointy joints" are made when the solder is at or just above the "pasty" transition from liquid and the molten solder can't flow back into a non-pointy blob before solidifying. The hotter joint has more time to be liquid after the iron leaves, so it collapses back to more round.

Also, use less solder. And/or use 63-37 eutectic solder which is either liquid or solid, no middle ground.

[EBK]

Use a hotter soldering iron so the melted solder is hotter, and remove the iron from the joint more quickly. The worst "pointy joints" are made when the solder is at or just above the "pasty" transition from liquid and the molten solder can't flow back into a non-pointy blob before solidifying. The hotter joint has more time to be liquid after the iron leaves, so it collapses back to more round.

Also, use less solder. And/or use 63-37 eutectic solder which is either liquid or solid, no middle ground.

I assure you, the pointiness of my solder joints is due to the leads and not the solder.  I trim the leads after soldering.  Perhaps you do things differently?  Yes, I use eutectic solder, and although you can't stand over my shoulder while I solder, I need you to assume that I've got a handle on the basics after soldering for 25 years. 

Perhaps better cutters would be what I've been missing all along though....

Edit: I'm really sorry for my poor attitude above.  Outside stressors are affecting my writing today.  I do appreciate all feedback, whether it helps me directly or helps someone else.

[anotherjim]

I don't think you should cut totally flush. You can, but the joint is then seriously weakened. Just into the top of the solder "blob" should do it. Idea is to remove sharp ends only.
I find lots of near shorts in commercial stuff I'm given to fix - long lead tails bent over almost touching adjacent tracks. Even though they are not currently causing a fault, I always hunt them out and clip them back.

The real tool is the "cut & clench". The joint should have a mechanical basis and not rely only on solder. This also retains the parts before soldering. I don't have one myself, but remember them used on pcb assembly lines before machinery took over.
http://uk.rs-online.com/web/p/cutters/5402013/?origin=PSF_438811|alt

[Tony Forestiere]

anotherjim:
I had no idea such a tool existed. Rather clever.

[digi2t]

Edit: I'm really sorry for my poor attitude above.  Outside stressors are affecting my writing today.  I do appreciate all feedback, whether it helps me directly or helps someone else.

No worries bro. I was thinking to myself, "I wonder what he's like on a bad day?", and if that's all you've got, I think were all good. 

[R.G.]

I assure you, the pointiness of my solder joints is due to the leads and not the solder.  I trim the leads after soldering.  Perhaps you do things differently?  Yes, I use eutectic solder, and although you can't stand over my shoulder while I solder, I need you to assume that I've got a handle on the basics after soldering for 25 years. 

Edit: I'm really sorry for my poor attitude above.  Outside stressors are affecting my writing today.  I do appreciate all feedback, whether it helps me directly or helps someone else.

No offense taken, and none intended.
I have at times had pointy joints, of solder, not leads. If your points are leads, yes, the cutters will be one solution. Even then, if you get them too short, you may get solder connection to just the freshly cut end of the lead. I once had to track down an intermittent open caused by solder wettiing the end of a cut resistor lead, but not the sides.

There is an optimal lead length for through-hole leads - which is impossible to achieve consistently with hand tools.

My solution to the leads being prone to cutting through insulation under the board has always been to use standoffs, not just sheet insulation.

[duck_arse]

Xuron Micro-shears - they cost a bomb in the early 80's, I think they are still being made. they came with a cutting bar that would hold the cut lead from flying into the ceiling, and the blades were designed so's one rode over the other, to properly shear the lead.

and don't use them for guitar strings, kids.