I just repaired the engine control module from my 1991 pickup truck. It had a faulty electrolytic capacitor that leaked electrolyte and corroded a portion of the board despite it having a thin conformal coating. There was also an area on the opposite side of the board that was very slightly corroded but it appeared unrelated and likely from moisture that was sealed in during coating at the factory.
Anyway, after scrubbing like an archeologist for two days I finally got the board clean, the capacitor replaced and all remaining electrolyte neutralized with baking soda and rinsed away with cold water. I dried the board with compressed air and now it's sealed in a static shielding bag along with two huge packets of desiccant and some anti-static pink plastic between the board and desiccant (no idea if they're static safe).
Obviously doing all this work required removing the conformal coating from several areas of the board. I'm trying to determine if I want to repair the coating and if so what material to use.
The board will be installed in a vented metal box inside the plastic "kick panel" located in the cab of the truck beside the passenger's feet. So, it's not exactly a corrosive location. The board was mainly corroded by the electrolyte, not humidity or vapors or anything like that, so I'm thinking maybe it would be fine to not bother patching the coating in those areas and just reinstall the board.
I also thought about sealing up the metal enclosure with silicone caulking or gasket maker since I already have both of those here and wouldn't need to find a coating material. However, I really don't want to have to repair this thing ever again, so maybe it would pay to track down and purchase a coating product that I can put over the repaired areas.
Do you think I should repair the coating?
And, if yes, where in the world can I find a suitable product locally? I'd rather not wait for an order from an online retailer but according to their websites neither Radio Shack or Home Depot have conformal coating materials, tho I suspect there are suitable products being sold for other purposes, like maybe the polyurethane sealants in the paint section.
Thanks in advance for any advice you can offer
Anyway, after scrubbing like an archeologist for two days I finally got the board clean, the capacitor replaced and all remaining electrolyte neutralized with baking soda and rinsed away with cold water. I dried the board with compressed air and now it's sealed in a static shielding bag along with two huge packets of desiccant and some anti-static pink plastic between the board and desiccant (no idea if they're static safe).
Obviously doing all this work required removing the conformal coating from several areas of the board. I'm trying to determine if I want to repair the coating and if so what material to use.
The board will be installed in a vented metal box inside the plastic "kick panel" located in the cab of the truck beside the passenger's feet. So, it's not exactly a corrosive location. The board was mainly corroded by the electrolyte, not humidity or vapors or anything like that, so I'm thinking maybe it would be fine to not bother patching the coating in those areas and just reinstall the board.
I also thought about sealing up the metal enclosure with silicone caulking or gasket maker since I already have both of those here and wouldn't need to find a coating material. However, I really don't want to have to repair this thing ever again, so maybe it would pay to track down and purchase a coating product that I can put over the repaired areas.
Do you think I should repair the coating?
And, if yes, where in the world can I find a suitable product locally? I'd rather not wait for an order from an online retailer but according to their websites neither Radio Shack or Home Depot have conformal coating materials, tho I suspect there are suitable products being sold for other purposes, like maybe the polyurethane sealants in the paint section.
Thanks in advance for any advice you can offer
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