potted BMS

[miro13car]

Hi all!
I have a question about potted BMS boards like one found in Milwaukee V18/V28 battery packs.
What is the best way to remove gummy, spongy potty compound covering comonents .
I tried to remove black spongy compund from Milwaukee BMS with little sucess.
Any advice appreciated.
Miroslaw

 

[Doctorbass]

Search on this forum or on RCgroup forum about :dewalt bms

you will find some people that toke pics of inside BMS

http://endless-sphere.com/forums/viewtopic.php?f=14&t=1427&hilit=+dewalt+bms

And about a mixture called: "magic sauce" that can melt the potting. Hard to find on the internet!!

it's made of _ _ _ _ _ _ _ chloride.....

or a dremel can do the job.. just a bit of patience!

Doc

 

[Ypedal]

The liquid wash is likely the " easiest " in way..

A heat gun and sharp metal " dental picks " work, but i'm not sure how much heat the BMS components can handle before they cook.. once the potting material heats up it softens up.

My technique was described as " Harsh " by deepkimchi on the flintstone chargers lol

 

[miro13car]

Doctorbass, Ypedal,
thank you for answers.
Milwaukee potting is already pretty soft like sponge. I tried to scrub, peel it and damaged board of V18 pack
it still charges fine, but
SOC LEDs don`t lit up any more. I measured voltage after damage it is still there.
Solvent would be great, but where to find one. It would have to be safe for components.
Miroslaw

 

[Doctorbass]

I finally found the file explaining the "Secret Sauce" for potted electronic:

here it is the original:

Heatgun and a dentist's tool set, followed by generous agitation in a

50/50 mix of Methylene Chloride and Formic acid. Also known as "secret

sauce" for when you need to look into a competitors epoxy packaged

semiconductor IC. And it worked afterwards.

Doc

 

[paultrafalgar]

I finally found the file explaining the "Secret Sauce" for potted electronic:

here it is the original:

Heatgun and a dentist's tool set, followed by generous agitation in a

50/50 mix of Methylene Chloride and Formic acid. Also known as "secret

sauce" for when you need to look into a competitors epoxy packaged

semiconductor IC. And it worked afterwards.

Doc

Methylene chloride is extremely toxic. Don't breathe it. Formic acid is fairly corrosive.
I would guess that most of the encapsulation of electronic components would be damaged by exposure to whatever you used to get rid of the potting compound. But I could be wrong.

 

[iberkt]

I was on another forum and someone suggested using a solvent called De-Solv-it. It is a citrus based solvent so it is not as toxic (supposedly) as some of the other solvents on the market. You can get it online. Here is the link.

http://www.orange-sol.com/miva/merchant.mvc?Screen=PROD&Store_Code=OO&Product_Code=10022&Category_Code=OSHH

***Disclaimer I have not tried this yet so I have no personal knowledge of how well it works (or if it does at all) or how safe it is (like I said I just read it on another forum).

 

[TylerDurden]

I used some small screwdrivers... not the best job, but perhaps some brake-parts cleaner or orange stuff would tidy things a bit.

http://endless-sphere.com/forums/viewtopic.php?f=7&t=355&p=7317&hilit=ratty+gunk#p7317

(The Ridgid bms is the almost the same as the MilW... different voltage)

 

[miro13car]

Tyler,
You are very patient man if you clean the board that clean and it still works!
Seems to me from my serching, that PCB conformal coating stripper can desolve black gunk.
I use it at work sometimes . I want to strip gunk from 3 boards of V18 batteries.
Anyone any other ideas?
Miroslaw