Author Topic: Potting Compound Removal from ECU  (Read 4271 times)

0 Members and 1 Guest are viewing this topic.

Offline Adam60

  • Regular Contributor
  • *
  • Posts: 79
  • Country: ca
Potting Compound Removal from ECU
« on: April 25, 2017, 01:57:53 am »
Good Evening.
I have an ECU from a marine engine that has a rubber epoxy type coating on the rear of it to seal and probably prevent people from looking inside it. I have seen videos where people have taken such units and boiled them in hot water to remove the coating. Does anyone have any experience doing this or used any other methods that might be better? I am trying to stay away from the stench that comes with heating it up and this sounds like a good method but never tried it before. The outer cover is just a polypropylene cover.
I have a pin or two that has corroded off and needs to be replaced. The unit is worth $2600 new so it is worth a shot.
« Last Edit: April 25, 2017, 03:28:00 am by Adam60 »
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 8117
Re: Epoxy Resin Removal from ECU
« Reply #1 on: April 25, 2017, 02:15:02 am »
First you need to identify the potting compound or at least what degrades it.  You'll need to cut enough away as samples you can try soaking in various solvents to see what, if any, can be used to soften it without dissolving the PCB and components.  Most epoxies are hard so the fact its rubbery means its more likely to be a silicone or urethane rubber based compound.  If it is epoxy, you are in for a world of grief as most PCBs use the epoxy bonded FR4 laminate and chip and other semiconductor packages are usually some form of epoxy so anything that attacks the potting epoxy is likely to damage the PCB and components.
 

Offline joeqsmith

  • Super Contributor
  • ***
  • Posts: 5911
  • Country: us
Re: Epoxy Resin Removal from ECU
« Reply #2 on: April 25, 2017, 02:33:55 am »
At first I saw Epoxy in the title, then I see rubber type epoxy.  I have never seen rubber type epoxy.  I have seen a lot of rubber sort of potting and it is easy enough to dig out with a plastic or wooden stick. Something about the size of a pencil with a wedge cut into the end like a chisel works well.   

I have had to remove some of the hard epoxy stuff to repair one of my ignitions.  I used a propane torch and a wooden stick.  Slowly heating it and scraping out sections.  Fairly quick,  maybe a few hours to get it cleaned up enough to do the repairs. 
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline Adam60

  • Regular Contributor
  • *
  • Posts: 79
  • Country: ca
Re: Epoxy Resin Removal from ECU
« Reply #3 on: April 25, 2017, 03:30:48 am »
At first I saw Epoxy in the title, then I see rubber type epoxy.  I have never seen rubber type epoxy.

I guess I had that coming. I do know the difference. It is more of a rubbery type compound like silicone based. I have cut around the outside of the compound and it cuts quite easily. I was hoping there was a way to remove it quickly rather than picking away at it. That is why I asked about boiling but that doesn't sound like a good method either now.
 

Offline james_s

  • Super Contributor
  • ***
  • Posts: 9836
  • Country: us
Re: Potting Compound Removal from ECU
« Reply #4 on: April 26, 2017, 12:59:38 am »
It sounds like silicone based potting. I haven't found a good way of removing it other than picking at it, silicone is impervious to practically everything, which is what makes it work well as a sealant and insulator.
 

Offline Teledog

  • Regular Contributor
  • *
  • Posts: 150
  • Country: ca
Re: Potting Compound Removal from ECU
« Reply #5 on: April 26, 2017, 03:19:03 pm »
If it's silicone, 99% IPA may help loosen it a bit.
It won't dissolve silicone, but it tends to weaken the bond.
Try to squeeze it in any gaps & then let it sit 30 seconds or so & carefully hack away.
IPA is the cat's ass for removing hot glue bonds, BTW!
 

Online CJay

  • Super Contributor
  • ***
  • Posts: 3413
  • Country: gb
  • M0UAW
Re: Potting Compound Removal from ECU
« Reply #6 on: April 26, 2017, 06:42:57 pm »
Dunno if this is safe for electronics or if it'd be suitable for your potting compound but:

http://www.screwfix.com/p/no-nonsense-sealant-remover-100ml/88987
M0UAW
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf