Using silicon to glue down components

[Mark]

I'm putting in 6PS Orange Drop onto a Garolite card and I'm wondering if it is still "wise" to glue them to the board as was done in the Mark 1 Boogie amps?

I understand the reason for doing it is to minimise vibration and thus stop dry joint occurring.

What do you think?

[pompeiisneaks]

I don't think it's ever a bad idea for larger components, yes it basically keeps them from vibrating and causing stress fractures in the leads, which can eventually lead to breaks. also some forms of noise transmission are vibrations. If the silicone is there, it can eliminate vibration as well although vibration transmission should usually only be caused by microphonic components, so that's more a failure of it's own anyway

~Phil

[Mark]

Thanks for your reply Phil. How big are larger components?

0.1uF @ 500V cap?

[xtian]

I might use RTV silicone to stabilize components, but only for amps slated for hard touring. Not for amps meant for home use or local gigs. Such a PITA when it comes time to mod or replace parts.

[The Ballzz]

Might I suggest the highest temp hot glue available? You're merely striving to create a "pad" to eliminate movement/vibration and hot glue will stay put and hold it's shape, yet is quickly and easily removed when necessary. It does not really adhere very well to non-porous stuff. On the other hand, it can bond surprisingly well to certain types of plastic type materials!
Just My $.02,
Gene

[SoulFetish]

If you go with silicone, RTV (room temperature vulcanizing) silicone comes in two types. Acetoxy RTV and Neutral Cure RTV. Many Acetoxy RTV silicones use acetone in the curing agent and all release acetic acid when they cure, which can break down certain plastics/materials.
Its best to use Neutral Cure silicone on electronics if you can get it. Electronics manufacturers use this type.
Having said that, I've used Acetoxy RTV silicone in amps before. I let it cure uncovered to allow for airflow, and there didn't "seem" to be any issues with component breakdown that I could see with the naked eye.

[Mark]

The closest I could get is Selley's bathroom sealer. Same deal, clear and rubbery and sticks to stuff like XXXX on a blanket. Is this a bad thing?

I read up on it and GE RTV is the ticket. I'll give the gluing a miss this time.

Your normal every day RTV silicone is 'Condensation cured' where atmospheric moisture is what makes it cure. There are 3 general kinds. Acetoxy cure, which is the cheapest, bonds well, but releases acetic acid on curing (the acid ingredient in vinegar) And corrodes copper and lots of other metal. Even sealing an enclosure with it, the trapped fumes inside can corrode the items. The other two kinds are neutral cure, but still slightly different. Oxime cure which releases a ketone on curing. This can corrode copper on contact, but isnt as bad to use near electronics, just not directly on copper. The most desirable for electronics is Alkoxy cure, which releases methanol. Mind the fumes from all of them, but if you have a large surface area covered, Acetic acid fumes can be pretty nasty. Though your nose will give you plenty of warning that something isnt right.

Thanks for you help.

[pompeiisneaks]

Might I suggest the highest temp hot glue available? You're merely striving to create a "pad" to eliminate movement/vibration and hot glue will stay put and hold it's shape, yet is quickly and easily removed when necessary. It does not really adhere very well to non-porous stuff. On the other hand, it can bond surprisingly well to certain types of plastic type materials!
Just My $.02,
Gene

The big problem I can see with this is even the highest temp stuff gets brittle and releases/breaks the hotter the environment it's in. Tube amps are hot environments. I know it probably does well for a few years, but it will invariably fail. I've seen hot glue in electronics that weren't very hot and the glue was useless after about 4 to 5 years.

~Phil

[pompeiisneaks]

Thanks for your reply Phil. How big are larger components?

0.1uF @ 500V cap?

I'd guess the ones I'd think are more prone to this are the 0.1uF and higher yes. I don't know if there's a good rule of thumb, but from my point of view those seem big enough to me to be problematic, yes.

~Phil

[Mark]

Thanks for your assistance Phil, I appreciate it.

[AustinKid8675309]

Go to Amazon and buy ACI Clear Electronic Grade Silicone. 2.8 ounce. $10.99 in stock. Anything else will degrade your caps. ALWAYS USE ELECTRONIC GRADE SILICONE. THAT'S WHAT IT'S MADE FOR. Sorry. Didn't mean to yell. Pricey, but you get what you pay for. Not affiliated with any company. I'm retired and work on guitars, amps and turntables.

[pompeiisneaks]

I've used ge silicone II for a long time because it explicitly does not have acid in the curing and is safe for electronics. There are likely many more... Is there a specific reason you're recommending ACI vs any other? Personal preference, or vested interest in the company?


~Phil

[Mark]

Thanks for your replies. Yeah, it has to be electronics grade due to the acid is the bathroom stuff.

[TUBEDUDE]

Also the hot glue is rigid, not providing the
vibration damping of silicone.

[Leo_Gnardo]

I've used ge silicone II for a long time because it explicitly does not have acid in the curing and is safe for electronics.

Same - GE silicon RTV since college days 45 years ago. NEVER a problem with corrosion or any other form of degradation. Claims to the contrary are fake news imho. College lab use subjected clear GE RTV to voltage beyond 25 KV as well, once cured overnight it always worked fine as an insulator. In more recent years industrial use of GE RTV in systems carrying up to 200 KV, again never a problem. Color varieties maybe not so resistant to high voltage due to added pigments so stick with the basic (clear) product.

FWIW Rivera has been using a product that resembles black weatherstrip glue to paste down caps and anything else in their chassis for decades now. Maybe that stuff is a tougher glue than RTV but it sure is a pain to pry away anything stuck down with it. However - never seen any corrosion from their adhesive either.