electrolyte caps fixed by hot glue?

[yeeshkul]

I've seen in quite a few boxes that there was a blob of hot glue on electrolyte caps. Is there any reason for that?

[Paul Perry (Frostwave)]

Yes, electrolytics are heavy enough that in a high vibration situation, the legs can get metal fatigue from the cap vibrating back and foward.
A whole bunch of radios failed on some earthmoving equipment out here once for that reason.
In fact, I have an oscilloscope from a university teaching lab that had a filter cap break off the board.

[soulsonic]

Yes, but you have to be careful with the quantity and location of the hot glue. If you block off the vents with the hot glue, the cap won't be able to properly release the gases formed within itself. This is a proven cause of early cap failure. The cap must be able to breathe.
This is the #1 reason why I find that stupid goop to be so totally offensive and ignorant. Pouring goop all over the caps not only increases the chances of early failure, but also makes it nearly impossible to replace them when they do fail.

The best solution for high-vibration environments is to use multi-legged caps; the kind with 3 or 4 legs for added stability. Clamps are also an excellent way of properly securing them.

But I see no reason to do any of this in a stompbox.

[DougH]

I've never even done this in amps I've built. Maybe it hasn't been long enough for a failure but I've never had a problem.

[Dragonfly]

just a drop of hot glue on one side is more than enough to stabilize a cap for stompbox use.

[drewl]

It's quite common in almost all new/cheap solid state amps.
Reflowing or adding solder to the pc board connection would be a better fix, and something that fixes most of the broken equipment I come across- but it's probably easier/cheaper for them to just glue the caps to prevent movement/lead breakage.

[Processaurus]

Most of the time you see them (correctly) kinda half glued, so they can still vent.  Boss pedals do it, with some kind of stuff I don't think is hot glue.  They like gooping the wire connections too (so they don't break where they got stripped).  Anything that increases reliability is a plus in music gear, just get it working before the hot glue gets gooped on.

[BubbaKahuna]

I've never been a fan of hot glue on anything electrical, especially caps.
A drop of clear silicone works better, doesn't shrink or get hard and is infinitely easier to work on later.
It also doesn't cook your components putting it there. 

Cheers,
- JJ

[Processaurus]

not a bad idea, the hot glue is regrettable if something needs to get fixed, or modded, even with a heat gun to soften it up.  It is really nice to have something goopy on the wires though, the only general trouble I've had with pedals I've built (once debugged) is with wires breaking from getting handled.

[DougH]

Yeah, that's usually the biggest cause of wiring failure in a stompbox- taking the crap out of the box and working on it!! Haha!

[petemoore]

  Heck Yea...
  Them Hartke's I've worked on, the big filtercaps had no glue, but I was able to re-flow those nodes and re-inforce the top-heavy capacitors to the board with...I used little bits of epoxy.
  Another routine I like to do with amps that have 2 input jacks on a PCB is make sure the jacks and nuts stay secured, a bit of glue here can help resist the massive plug leverage on the weak point...and helps keep Both nuts tight...input jacks in PCBs...you wanna make Sure those nuts are securely fastening.
   If dabbed just right, [hotmelt glue..whatever], it can have morganenough 'stayput' strength, but relatively little 'shear' resistance [ie you can twist it mostly off with needlenose pliers, without really pulling hard on the traces].
  Even hit lightly with glue at radial points [ie three or four places around the bottom] adds amazing amounts of strength compared to no glue.
 

[DougH]

Another routine I like to do with amps that have 2 input jacks on a PCB is make sure the jacks and nuts stay secured, a bit of glue here can help resist the massive plug leverage on the weak point...and helps keep Both nuts tight...input jacks in PCBs...you wanna make Sure those nuts are securely fastening.

I've started using lock washers on pots and jacks.