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Chemtools PCT-7000Y Silicon Potting Compound - anyone familiar with?
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DTJ:
Has anyone personal experience with Chemtools PCT-7000Y Silicon Potting Compound?

I'm interested in how well it bonds to things, in particular the PCB & components and also to 304 stainless steel.
The data sheet does not mention its adhesive properties.


Data sheet: https://download.altronics.com.au/files/datasheets_H1620.pdf

I want to pour it down a 12mm ID x 100mm long metal tube to seal in a PCB (11.5mm x 80mm), the assembly will be immersed in water several meters deep.
It needs to be low viscosity (runny) so that the air bubbles all escape.

Thanks for any advice.



Muttley Snickers:
I haven't used the Chemtools compound you mentioned but am aware of some other similar products which are distributed by G.V. Kinsman. One type of potting compound is shown in the video below but they have other stuff as well. Someone in the comments section also asked about a submerged connection.

www.gvk.com.au

DTJ:
Thanks Muttley.

That stuff looks a little soft for my application but definitely interesting.

Lots of other useful items on that site, Cheers.

IDEngineer:

--- Quote from: DTJ on August 26, 2019, 11:15:33 am ---It needs to be low viscosity (runny) so that the air bubbles all escape.
--- End quote ---
Many potting compound vendors point out that you can evacuate air bubbles by putting the freshly potted module into a vacuum chamber with a slight vacuum. Obviously this requires some extra equipment but it might be an option for what you're doing.

I can also tell you from personal experience that epoxies are far easier to keep bubble free than urethanes, which are also often used for potting. The latter are often preferred due to their softer cure (less risk of fracturing SMD's, particularly MLCC's) but our experience has taught us that epoxies yield better overall results in production. You can get epoxies with lower durometers if you look around, which helps offset the risk, and using a slower cure compound helps too. The one we use has a pot life of around 30 minutes and a full cure time of 24-48 hours at STP.
DTJ:

--- Quote from: IDEngineer on August 26, 2019, 07:07:24 pm ---
--- Quote from: DTJ on August 26, 2019, 11:15:33 am ---It needs to be low viscosity (runny) so that the air bubbles all escape.
--- End quote ---
Many potting compound vendors point out that you can evacuate air bubbles by putting the freshly potted module into a vacuum chamber with a slight vacuum. Obviously this requires some extra equipment but it might be an option for what you're doing.

I can also tell you from personal experience that epoxies are far easier to keep bubble free than urethanes, which are also often used for potting. The latter are often preferred due to their softer cure (less risk of fracturing SMD's, particularly MLCC's) but our experience has taught us that epoxies yield better overall results in production. You can get epoxies with lower durometers if you look around, which helps offset the risk, and using a slower cure compound helps too. The one we use has a pot life of around 30 minutes and a full cure time of 24-48 hours at STP.

--- End quote ---

I've got the basics for degassing if  I need to.

I'm using a urethane now (70A shore) and I'm worried its a bit hard. I've used harder epoxy on other jobs and it worries me.

I found a better data sheet on the PCT-7000 on the chemtools website that clarifies the adhesion question. They promote it as an adhesive in that data sheet so it should do the job.
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