Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: six el six on May 05, 2012, 12:17:13 pm
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Many amps have glue holding together filter caps both to other caps and to the circuit board.
When replacing caps,
1. How do you get the glue off? Is there an easy way to remove the stuff?
2. Do you replace the glue with new glue once the new caps are in place? If so, what kind of glue is typically used?
Thanks,
six.
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most is just silicone kit and is easy to cut. if the new caps are a bit loose add hot glue or silicone kit again.
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Same stuff as silicone window/crack sealant?
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Yep. :icon_biggrin:
BUT! Let it dry compleatly before you fire it up. It's conductive untill it's fully cured. :w2:
Brad
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Not a huge fan of silicone and electronics. Until it cures, silicone may gas off acids. Copper and acids not always compatible.
Isn't this one of the reasons we use resin flux solders.
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the acid in silicon is acetic acid. Vinegar, tha's all. Just add french fries and you're done!
No joke, I was fixing a SOVTEK amp the other day and I was surpised seeing the filter caps stuck together with silicon. Any purpose other than holding ''loose'' caps ?
Colas
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The GE Silicone II doesn't produce acetic acid as it cures. It's also sold everywhere and doesn't cost an arm and a leg.
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all silicons are acetic acid based. and there is cheaper than GE
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Now I'm just confused.
I guess I'll just continue scraping the stuff away and then not reapply it when I replace caps.
I thought maybe it was used for some good reason but no one has mentioned that.
I've heard e-lytics can rattle and I certainly know how to tap on them to hear a little thump.
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silicone not all silicone adhesives off gas acetic acid, or I would have said that. Check out the MSDS on the particular brand of adhesive you use, I checked out four or five and not all had acetic acid as a component.
Some of the silicone have real decent dielectric properties. My RAV4 has silicone covered spark plug wires for example.
As an adhesive, some mixtures can take some real temperatures, say 300 degree C.
I guess we go over to the hobby shop and get some glue guns stick every thing together that way.
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I gotta say, the stuff on the caps in my TRRI is not silicone rubber, RTV, etc. It's hot melt glue. Gets hard. It's not pliable like silicone products.
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:think1:Follow Sluckey's advice, use hot glue and glue gun. :think1:
then you have goo-gone, acetone, and a few other solvents you can use for clean up.
I guess you don't want to be using contact cleaner around the caps, :think1:
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I guess I'll just continue scraping the stuff away and then not reapply it when I replace caps.
+1... I never understood the use of this stuff. And it's damn ugly and a pain to remove if you need to...
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Hey Now Everyone,
I have good luck with Industrial Self-Stick Velcro.
The Hook part is very well made and strong, so much
better than the regular type. I buy a 25' foot roll of the 2"
and it last a long time. From sticking them to a filter cap cover
or side by side, it's great because you can easily remove a cap
to replace it in the future and it stops buzz problems. I also use
it to slice-off the old paper Filter Cap covers and velcro-in the
new sometimes smaller Sprague Atom Caps inside.
Just a small piece of velcro holds caps and stops the buzz issues.
The old Tweed filter cap covers, I just put velcro on the cap cover
(Hook-type on cover) and I put the Loop-type velcro on the cap itself.
So when I pull the cap cover off a tweed type amp Bassman 5F6-A for
instance, the caps are fastened to the cap cover with the velcro and do not
flop around loose inside.
After using the Industrial Velcro (The regular type sucks) I have never used
silicone again. No need to wait for anything to cure.
All the best to your builds, And thanks Doug for all the great deals.