PCB potting advice please

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sunndog
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PCB potting advice please

Post by sunndog » 21 Mar 2019, 11:29

So I'm building a new led headlight for one of my motorbikes and an aspheric lens set up I've bought as part of it came with a big old box containing the driver and stuff.

As usual with Chinese stuff a generally decent thing gets let down by a small part.
This box is really crap not in the least bit waterproof and the pcb is just rattling around in there

Image

This is for an off road bike too so it needs to be tougher.
Can I just fill the box with potting compound and seal it up?
I've never potted anything before so any advice would be welcome

Cheers......adam
when asking for advice, please include what n.v device and/or illumination you already have (if any) and what rifles you intend to use them on...cheers

phoenix
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Re: PCB potting advice please

Post by phoenix » 21 Mar 2019, 14:03

Make sure that whatever you use, it doesn't contain acid.
For example, most silicone sealants (which would do the job) contain acetic acid which would corrode the metallic parts of the circuit board and components
Personally, I'd go with a conformal coating applied by spraying.
Something like this would do it https://www.ebay.co.uk/itm/Ambersil-400 ... 3ebbe59727

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

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sunndog
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Re: PCB potting advice please

Post by sunndog » 21 Mar 2019, 15:25

Cheers Bruce I might get some of that anyway. However, the vibrations on a single cylinder 650cc dirt bike are white finger inducingly mighty :lol:
So if I can get away with setting the whole thing in a block of potting compound that will be ideal

I'll keep an eye out for acid contents too cheers
when asking for advice, please include what n.v device and/or illumination you already have (if any) and what rifles you intend to use them on...cheers

phoenix
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Re: PCB potting advice please

Post by phoenix » 21 Mar 2019, 15:46

Adam,
Sikaflex marine sealant - non acid and goes like a lump of hard rubber when set
https://www.amazon.co.uk/Sikaflex-291i- ... B004ZF8L0M
You wouldn't want to get into the circuit board again though!!!

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

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sunndog
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Re: PCB potting advice please

Post by sunndog » 21 Mar 2019, 16:17

You can use sikaflex?
I thought it was gonna be some special fancy pants compound. I've got sikaflex in stock for various jobs.
Brilliant I'll be using it next week anyway

Won't be needing to get to the board again. Assuming nothing overheats for being cast in rubber it will be fit and forget

Cheers mate
when asking for advice, please include what n.v device and/or illumination you already have (if any) and what rifles you intend to use them on...cheers

garfy
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Re: PCB potting advice please

Post by garfy » 22 Mar 2019, 07:06

They do sell a specific product for this at the electrical whole salers, its for filling in external connection boxes, cant remember the name though.

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sunndog
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Re: PCB potting advice please

Post by sunndog » 22 Mar 2019, 21:54

garfy wrote:
22 Mar 2019, 07:06
They do sell a specific product for this at the electrical whole salers, its for filling in external connection boxes, cant remember the name though.
Cheers, yeah i was expecting to buy something specifically for it but if i can use something ive already got i'm all for that.
Sikaflex is good stuff i've stuck all sorts together with that over the years
when asking for advice, please include what n.v device and/or illumination you already have (if any) and what rifles you intend to use them on...cheers

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Re: PCB potting advice please

Post by CustomRifleScopesUK » 24 Mar 2019, 10:01

Ive used sikaflex in the past for many jobs, but for potting its not advised, potting compound is specifically designed for protection from shock and or weather. When you use the potting compound, make sure the area your sealing is sealed itself ( no holes in the underside ) as it tends to leak through every orifice as its designed in that way. Not cheap but buy once, cry once !

Ash

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Re: PCB potting advice please

Post by sunndog » 25 Mar 2019, 16:30

Already gone the sikaflex route ash. I was careful to get a good seal and as solid a 'block' as I could sealing all around and into all the nooks and crannies.
I'll give it at least a week to go off and see what happens :thumbup:
when asking for advice, please include what n.v device and/or illumination you already have (if any) and what rifles you intend to use them on...cheers

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