Resin to protect circuit boards

[StefanSG]

Does anyone know of a rubbery resin that I could pour into a the base of a cheap LED lamp (with a touch switch) to try and protect the circuit board from salt corrosion ? My last lamp lasted less than a season. Something that starts out more liquid than hot glue.
TIA

StefanSG

 

[Fr J Hackett]

There are proprietary casting resins for electrical circuit boards have a look in the RS catalogue.

 

[justanothersailboat]

I think the word you're looking for is "potting compound".

EDIT for later readers: this will definitely protect, but is a messy and drastic approach and some of the suggestions below for conformal coating products seem like a better choice for most purposes.

 

[StefanSG]

Excellent info thanks

SSG

 

[ash2020]

Conformal coating is what it's called.
70 for 'conformal coating' | RS

 

[jamie N]

 

[trevbouy]

You could also try 'liquid rubber'. I've used it for many sealing purposes, particularily antenna connectors subject to harsh conditions.
I've also used it to build up a coating on a microphone lead grommet that kept splitting. Still working well and flexible.

Liquid Rubber

 

[Refueler]

Corrosion X ..... it coats with a thin film ... allows switches etc to still function ...

Spray and forget for a year .. spray again year later !

Advantage is that if the item ever needs attention - you can work without need to break out potting compound etc.

 

[DinghyMan]

You could also try 'liquid rubber'. I've used it for many sealing purposes, particularily antenna connectors subject to harsh conditions.
I've also used it to build up a coating on a microphone lead grommet that kept splitting. Still working well and flexible.

Liquid Rubber

Need to carefully read the label on liquid rubbers, RTV's and similar - they often contain acetic acid which you can smell as they cure - which nicely destroys components as they set....

We use an epoxy based two part potting compound on some of our products and its proven to be good and works even when things have been flooded at depth

 

[AngusMcDoon]

Conformal coating is the product specifically produced for this application. It's easily available, not expensive & easy & quick to apply. It's pretty much guaranteed to be compatible with what you wish to apply it to & is widely used in industry for corrosion protection of circuit boards in applications that do not need to go to the length of potting. Using a product not intended for circuit board protection is a bodge.

 

[The Q]

Conformal coating is the product specifically produced for this application. It's easily available, not expensive & easy & quick to apply. It's pretty much guaranteed to be compatible with what you wish to apply it to & is widely used in industry for corrosion protection of circuit boards in applications that do not need to go to the length of potting. Using a product not intended for circuit board protection is a bodge.

100% agree on this, I worked for a company producing electronic test equipment to a very high standard, our top DMM was £17,000 . Conformal coating is definitely the way to go.

 

[AngusMcDoon]

I think the word you're looking for is "potting compound".

That will do the job, but is extreme and there's no going back. It can be a messy faff as well.

 

[justanothersailboat]

Fair point Angus, and looking at some of the other electronics-dedicated products linked, my suggestion also seems a bit out of date. When I read the description of pouring in something rubbery to fill the case, potting was what came to mind, but conformal coatings probably offer a more convenient way. Also it's not as though this needs extreme shock resistance.

 

[trevbouy]

Liquid rubber does not contain acetic acid (vinegar) ! That's usally the domestic sealant stuff.

As for conformal coating, yes great on a pcb post production but not what I envisaged the OP wanting for an led light.

I'm probably wrong but it sounds to me like he wants a pourable liquid that sets inside the fitting which liquid rubber does but is totally flexible as well as waterproof.

Potting compound. great but never to be touched again, virtually impossible to be removed without major damage.

 

[Stemar]

If it's only a cheap light, I'd just get some Pound Shop epoxy - the type in a double syringe. No need for the fancy products that will probably cost almost as much as the light!