Silicon gel

[multiweb]

Hi guys, I'm after some soft silicon gel. It has to be non acidic, neutral and fairly liquid to start with so I can apply it with a seringe. I intend to plug around all the USB/power connections in a QHY camera to seal around the holes. So some might get onto the PCB and some electronic components. TIA. :thumbsup:

[Auster1b]

Hey Marc,
what about liquid electrical tape, I have seen it used to totally seal pcbs and connectors.

http://www.jaycar.com.au/productView.asp?ID=NM2836

Neil.

[multiweb]

Thanks. Interesting. Would that get down to -40c? The camera cold finger will get that cold.

[wasyoungonce]

DOW corning 3145 RTV...probably the grey would be best and suit. probably not cheap either

an alternate, 3140 but IMHO 3145 is better. Both would be marginal to use thru a syringe depends upon the size. There are other methods of application

[multiweb]

Thanks Brenda. What's the difference between 3145 and 3140. Just curious. Also interested in methods of application. I was thinking of mixing inside a syringe then inject. Do you have a better idea? Open to suggestions.

[wasyoungonce]

From memory the 3145 has better tear strength. I have used the 3145 mil spec quite a lot with F111 hermetically sealed instruments and it worked well.

Might be best to explore DOW corning pages for hermetic seal on this.

Of course, JB weld will probably do is you do not want to remove the seals later. Install a purge port for re-purging.

[multiweb]

Thanks for the info Brendan. There are plenty of holes, in those cameras, that you can use to purge. Unscrewing the nosepiece, in most cases, will allow excess gas to escape with the QHY8. With the QHY9, there are two plugs on each side of the heat sink that can be used for this, or fitted with dessicant plugs also.

[Auster1b]

Marc,
FWIW

Star Brite from Jaycar -34 C
Permatex from SuperCheap -54 C ?

Neil

[multiweb]

Thanks Neil. :thumbsup: