Silicone and cap replacement

Post by **Eric D** » Sun Aug 01, 2010 11:13 am

For those of you who are replacing your caps or plan too on one of your amps, I highly suggest against gluing the caps to the board with silicone. It is just fine to glue the caps to each other with silicone, but using a dab to glue them down to the board is a bad idea.

I am working on an amp right now in which the caps were replaced, but they were not soldered in properly (damaged vias), and the installer used silicone to glue the caps in. Well, removing them will destroy the board, as there is no way to get the silicone loose without de-laminating the copper plating off the board. I may try slicing them out with a very thin blade, but there is not a very good way to get one in with all the other components in the way.

The other downside to gluing them down, is later if they ever did fail again (in another 20 years), removing them becomes significantly harder, if not impossible, than the original way they were installed.

marko · Post by **marko** » Sun Aug 01, 2010 12:15 pm

agreed, just gluing them together with a dab of silicone will give them plenty of damping against vibration (just like in the zx amps).

money-b · Post by **money-b** » Sun Aug 01, 2010 12:27 pm

just out of curiosity...how do i identify what size/or make (if that's even technically correct) i need on my 20 farad powercore...i know it's alot of them....but changing them out might be a good investment,since thats the only complaint i seem to see on the phorum....mine aren't leaking...but if i change them all out to brand new,then they shouldn't leak for years i'm guessing.

Post by **ttocs** » Sun Aug 01, 2010 12:48 pm

I will be using a dab here-n-there when I replace the caps in my octane le.....

eulogious · Post by **eulogious** » Sun Aug 01, 2010 1:19 pm

money-b wrote:just out of curiosity...how do i identify what size/or make (if that's even technically correct) i need on my 20 farad powercore...i know it's alot of them....but changing them out might be a good investment,since thats the only complaint i seem to see on the phorum....mine aren't leaking...but if i change them all out to brand new,then they shouldn't leak for years i'm guessing.

If you are referring to your caps, it *should* have it written on the side, usually around where the leads come out of the cap. The problem you will probably run into is that you need "super" caps. I believe they are called that, but they are a special, more expensive cap, and might be more difficult to source. That's all the help I got for you

As to putting silicon on the board itself to secure caps, all I have to say is

Why would anyone want to do that? Sticking them to themselves is all good and probably a good idea, but to the board, are you kidding me! The SOLDER is what is suppose to secure the caps, not glue! What a tool...

Post by **Eric D** » Sun Aug 01, 2010 1:50 pm

I won't go so far as to say this guy is a tool, as other prominent members here told him to glue the caps down. I just made this post so those of you thinking of gluing the caps down will realize the consequences of doing it.

In a perfect world I think gluing them down would not be all that bad. However, once you glue them you are screwed if things later on are not so perfect...

eulogious · Post by **eulogious** » Sun Aug 01, 2010 2:15 pm

Eric D wrote:I won't go so far as to say this guy is a tool, as other prominent members here told him to glue the caps down. I just made this post so those of you thinking of gluing the caps down will realize the consequences of doing it.

In a perfect world I think gluing them down would not be all that bad. However, once you glue them you are screwed if things later on are not so perfect...

Fair enough, and I also agree. If you plan on getting rid of the amp, or tossing it at some point, then who cares? But I plan on keeping these amps around, and they will work for a very long time if properly maintained, so I would never do something that is so permanent on parts that might fail again.

So I agree in a perfect world/throw away world it would work great, but on quality PG amps that can be fixed and are worth fixing

No way would I do that! Just makes sense...

Of course it could also depending on the type of silicon used as well. Some stuff will peel off easily and not leave damage (like a true, pure silicon), where others are almost a glue that is not meant to come off. So I guess calling them a "tool shed" might be a little harsh

It's good know what might happen though, so thanks man!

dBincognito · Post by **dBincognito** » Sun Aug 01, 2010 2:33 pm

When you say silicon......are we talking about hot glue from a gun, or something different ?

tonym · Post by **tonym** » Sun Aug 01, 2010 3:00 pm

dBincognito wrote:When you say silicon......are we talking about hot glue from a gun, or something different ?

something different......

Typically heat-resistant and rubber-like, they are commonly used in cookware, medical applications, sealants, adhesives, lubricants, insulation, and the best use breast implants.

Post by **Eric D** » Sun Aug 01, 2010 3:10 pm

Silicon, or silicone?

I have been referring to silicone, as in from a tube, and in a gel form. Extremely stinky while setting up and corrosive to some materials as well.

Which reminds me, I never use pure silicone on these amps, and instead go with latex with silicone in it, or epoxy. I like the quick setting of epoxy, and the rigidity of it. Plus if you have to pull the item later, the epoxy will be brittle enough to break it up and then desolder the item.

eulogious · Post by **eulogious** » Sun Aug 01, 2010 3:30 pm

Sorry, I meant silicone, the stuff from the tube. Forgot that that "e" at the end actual DOES make a difference

I like the epoxy idea, that's good stuff! I have never really even contimplated "glueing" the caps to anything, but I might do that from now on. Thanks for the tip dude!