Coating for Epoxy substrate

[webrits]

Hi all,

I'm looking for some kind of coating for an epoxy encapsulated sensor we have developed for the downhole oilwell industry.

The sensor is approx 4" x 4" x 6" in size and is made from an epoxy that is able to withstand our individual tests of 177°C Temp & 15,000psi Pressure.

However, when we conduct combined pressure & temperature testing to the above values we are getting (what we think is) water migration into the epoxy that changes the composition into a very weak and chalky-type material. Then, post-testing the epoxy cracks and is then useless.

To increase the longevity of these sensors I am looking for a coating of some kind that would 'seal' the epoxy and prevent any moisture from migrating into it that subsequently changes its state.

I appreciate this is a long shot but hope someone could help in any way.

Many Thanks,

Paul

[loriolo]

Hi Paul
There is not coating applications in your case, maybe a high temperature capillar sealant from Loktite or you must change the epoxi, there are many others materials that resist at very high pressure and temperatures, like silicones, and other kinds of resins, I use many kind of resins on my artistic panels.

[Laurent]

Hi Paul,
We use RTV725 on composite material to repair cracks and/or surface delamination exposed to high temperature, such as 200-350°C.
The part is an inlet plenum installed on Auxillary power unit.
Manufacturer is Dow Corning.
Hope it helps
Cheers