Hold a trimpot in place - Page 1
Forum section: electronics / beginners

author: nemo000111
author_rank: Contributor
timestamp: October 18, 2013, 06:13:08 pm
content: I need to be able to fix a trimpot in place. After applying a reasonable amount of force, the compound should shear allowing the dial to turn. I was thinking of something along the lines of nail polish, but wasn't sure if it'd be too weak. The goal of this is to have it not move during normal use and not as a tamper indicator. Any suggestions would me much appreciated. Thanks.

author: ThomasDK
author_rank: Regular Contributor
timestamp: October 18, 2013, 08:47:07 pm
content: Tamper laquer.Great stuff, looks like nail polish, but will let you retrim for several hours before it hardens.

author: David_AVD
author_rank: Super Contributor
timestamp: October 18, 2013, 09:53:32 pm
content: Cheap: nail polishMore expensive: Loctite (maybe one of the lower strength threadlocker types)

author: philpem
author_rank: Frequent Contributor
timestamp: October 19, 2013, 12:23:42 am
content: Quote from: David_AVD on October 18, 2013, 09:53:32 pmSomewhere in the middle: "Bloc'lube" (BLR) by Electrolube:http://www.electrolube.com/docs/maintenancemain.asp?id=148I don't use it often, but that's the stuff I use. I've also (ab)used it as a varnish for ferrite rod antenna coils, but I try not to make a habit of that...

author: mjrandle
author_rank: Contributor
timestamp: October 19, 2013, 12:33:29 am
content: SentrySeal, blue stuff is also better known as Smurf Poo

author: Stonent
author_rank: Super Contributor
timestamp: October 19, 2013, 02:49:46 am
content: I seem to remember as a kid, a lot of transistor radios had the RF section with trimmers, chokes and variable-caps dunked in wax or what felt like wax. Yuck.I tend to see blue Loctite style stuff used a lot.

author: Rerouter
author_rank: Super Contributor
timestamp: October 19, 2013, 05:26:52 am
content: cheap red nail polish at my work, one of the more pricy ones we tried had a very fine glitter that made it have a resistance close to 10K per cm which became a very big problem later on

author: David_AVD
author_rank: Super Contributor
timestamp: October 19, 2013, 05:56:29 am
content: Quote from: Rerouter on October 19, 2013, 05:26:52 amDid it lookfabulouson your nails though?

author: Rerouter
author_rank: Super Contributor
timestamp: October 19, 2013, 09:16:36 am
content: Well how else do you test it?

author: David_AVD
author_rank: Super Contributor
timestamp: October 19, 2013, 11:11:01 am
content: touché

author: GK
author_rank: Super Contributor
timestamp: October 19, 2013, 11:41:01 am
content: Nail polish is ideal as it has a thick consistency and won't run where you don't want it to go, unlike something like Loctite threadlocker or similar that has almost water-like viscosity.If you don't like the idea of having something girly like nail polish on the bench, you can buy the stuff with a more respectable label. This is what I use:http://australia.rs-online.com/web/p/epoxy-coatings/1965245/It's bottled like nail polish and smells exactly the same.

author: SeanB
author_rank: Super Contributor
timestamp: October 19, 2013, 11:55:14 am
content: Nice thing with nail polish is you can get different colours to use for different pots, so you can adjust, lock and next time use a different colour so you know which ones have been adjusted. As well it is available in a clear version so you can use it to lock panel screws so they will not come loose while being close to invisible.

author: Capital
author_rank: Newbie
timestamp: October 20, 2013, 01:42:40 pm
content: HOT MELT GLUE- it will hold the pot and can be easily removed by peeling. Its just low temp polyethylene so it does not bond very well.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 20, 2013, 07:30:15 pm
content: dont take your wife's nail polish if she is an active forumer.

author: peteroakes
author_rank: Contributor
timestamp: October 20, 2013, 10:33:11 pm
content: whatever you choose, it needs to dry brittle and should not be runny when first applied, I find superglue and the likes way to runny and it can easily work into the mechanics of not careful and permanently cease it so I avoid it. Similarly liquid tape used to waterproof crimp connectors etc. would work but may be too flexible for your purposes causing rebound while trying to fine adjust rather than crackingI would agree with the many forum reply's, Nail polish is a good and cheap choice, and you can even pick a favorite color lol. it dries brittle so when you need to re-adjust it will crack and not cause any springiness to the adjusting.Lock tight is a good choice too but more expensive than cheap nail polish and available in less colors

author: karchiba
author_rank: Newbie
timestamp: October 24, 2013, 07:25:01 pm
content: There's an enamel-like product called "Glyptal" (GE made it) that was used to coat transformer windings, that works well for locking trimmers.