prep for potting

[Tmoose]

We have had a few electrical issues that appear may be caused by metallic particle contamination before or during potting.

"Tack rags" are available for wiping surfaces before painting, and don't contaminate the surface to be painted.

Are similar items available that have been proven non-contaminating for items to be potted?

Thanks,

Dan T

 

[MikeHalloran]

Never heard of such a thing.

Better to find and eliminate the source of the particles.



Mike Halloran
Pembroke Pines, FL, USA

 

[PanelGuy]

Anti-stat blow nozzle

Vacuum

Sweep with a small niobium magnet.

I agree, have never heard of such a thing, but they have small robots that make other robots too so anything is possible.

Would need to know more about the substrates(skin, core and compounds) to help out, but still seems goofy, best off to just not let the "particle" be there in the first place.

 

[IRstuff]

Seems to me that you've got a bigger problem. Regardless of how you get rid of the particles prior to potting, how the heck did they get anywhere near your electrical assemblies? Why are there loose metal particles at all?

TTFN

FAQ731-376

 

[Tmoose]

"Don't let loose particles get in there"
We don't blast or abrade our product (although I think we should blast some surfaces). Here is a source of potting compounds that mentions creating particles as part of prep for good bonding (as does practically everyone, including MIL-HDBK-17). They also mention REMOVING the particles without being real specific. I'll squeeze them for particulate particulars.

http://www.anchorseal.com/anchorseal/epoxy_tips.html

Surface preparation: To obtain good adhesion, the surfaces to be bonded must be free of grease, oil, mold release, water and dust. For maximum adhesion, thoroughly clean all surfaces with a strong cleaner/degreaser. Roughen surfaces by grit blasting, grinding or with a sanding disk.
>>>Remove all dust and grit prior to application of the product.<<<<

 

[wes616]

If you are bonding directly to a composite surface, the easiest thing to do it to fabricat your parts with a peel ply on the bonding area. If that is not practical, or a metal surface you can simply sand by hand using a 120 Grit sandpaper. You are not trying to pit the surface or remove a lot of material, rather just scuff it up. Vacuum remove material while sanding. Wipe surface with alcohol and wait until alcohol is throughly evaporated before bonding.

Wes C.
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