RTV - Waterproof

[sbozy25]

What do you all think about using rtv as a waterproofing agent? I've got a small potted pressure switch that is only IP65 rated. Problem is, I need to submerge it (IP68 rating), and it does not quite work that well. For the most part it is waterproof, but there is one small press fit square piece of plastic that is allowing water through. My initial thought was to use a small coating of rtv to seal it for water resistance.

I have found no good reason to not do this. But wanted to see what others thought. No one in my organization really has any input on it....


Cabbages, knickers, It hasn't got A BEAK!

 

[MintJulep]

Might work. Then again it might not.

It will be highly dependent on surface preparation and goo application.

I would be unlikely to approve it if offered to me by a supplier.

 

[KENAT]

It's not just the 'does is work' initially, with these kind of things durability becomes a big issue from my limited involvement in similar issues.

If you can do some testing to demonstrate the durability that may make folks more willing to accept it.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[IRstuff]

We've never been specified for IP68, but we have had systems that seemed to attract water through (poorly designed) fastener holes. RTV was used to seal them, but we were not subject to full immersion. RTV is rather messy to remove, so disassembly should be considered, if required.

I'm wondering why you can cut a gasket to do this.

TTFN
faq731-376

 

[MikeHalloran]

A gob of RTV over a pressed-in plug probably won't seal well.
If the plug can be removed, coated with the RTV, and pressed back in, it has a better chance of working.

... all highly dependent on details, of course.


Mike Halloran
Pembroke Pines, FL, USA

 

[MintJulep]

I'm wondering what Loctite 290 might do.

 

[MikeHalloran]

Thin, penetrating grades of Loctite, like 290, might wick far enough to lock the switch internals. Or not, again depending on tiny details of construction and application.

Additionally, all of the anaerobic types will attack (craze/ crack) many/most plastics. I'd want my Loctite rep to bless the application before going ahead.





Mike Halloran
Pembroke Pines, FL, USA

 

[JohnnyB21]

I've used an RTV for waterproofing electrical fuse boxes in the past for work. This RTV also had very good chemical bond and was strong enough to hold vacuum as well.

Here's a direct link for the technical data sheet.

http://www.gtproducts.com/PDF_files/1partRTV.pdf

 

[Tmoose]

http://www.americanaquariumproducts.com/AquariumSilicone.html

 

[sbozy25]

Thanks everyone,
I think I have enough info between this trail, and my own research to intelligently make a recommendation to my customer that is favorable to my needs.

I appreciate all the feedback from everyone!

Cabbages, knickers, It hasn't got A BEAK!