Brown Mystery Adhesive on PCB - Page 1
Forum section: electronics / beginners

author: savagemadman
author_rank: Newbie
timestamp: July 05, 2017, 11:39:03 pm
content: Any suggestions how to remove this evidently slightly corrosive 40 year old brown glue from the pcb? It's very tough stuff, hard but not brittle. IPA does nothing to it and I'm not sure what else I can safely use as a solvent. I can sort of brute force it off from the trace side of the PCB, but there is a couple of large capacitors secured with it component side that are too inaccessible for that.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 06, 2017, 12:06:16 am
content: Oh yes, this is easily my favorite PITA repair headacheI've tried everything 'fast n easy' with great FAIL, including bathing the area with IPAandWD40The best I have come up with is to heat up the affected area with warm to hot air till the crap softens a bit,and pick, chop, twist, cut and pluck away patiently,and very carefully to not slip up or cause damage, with whatever tools availableThis works well for me, and many dead/faulty boards have come back to lifeIf the CB corrosion is really bad, some bodge wire links come to the rescueI don't know if a cheap soldering iron directly applied to the glue would speed things up,I can't remember trying it or maybe I did and it was a fail too and forgotAnyway it's a good post, and hopefully some member/s here will have a fast fix method to get this temperature sensitive conductivesaboteurial time b0mb gunkoff,that some assembly line neanderthal bosses still use

author: alm
author_rank: Super Contributor
timestamp: July 06, 2017, 12:15:05 am
content: Quote from: Electro Detective on July 06, 2017, 12:06:16 amI think you should go back and redo that test. I find it hard to believe that there is somethinga hammerWD-40 in your hands does notfixloosen.I have occasionally run into that stuff, and mechanical means usually worked for me. Adhesion was quite poor, so with some mild pulling I could usually get the caps / wires off after desoldering the pins. Then I would scrape the glue residue off the board. It may be that I have been lucky, however, and ran into a particularly crappy version of this crap.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 06, 2017, 12:25:40 am
content: This amber/brown glue I always seem to scorewill pull tracks off boardsand rip component legs off if only brute force is appliedIf it's been on for 15 to 40 years, it won't leave the building without a fightSometimes you get lucky if it hasn't dug in too much,9 out of 10 times it hasI wonder if the Dremel tool co. offers an optional special order _mini jackhammer_ attachment ?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: July 10, 2017, 09:18:42 pm
content: That stuff has caused lots of problems over the years.Mitsubishi used it extensively on their PCBAs, VCRs in particular.I told a customer back in the late 80's that if the goo was not removed it would begin corroding the traces on the circuit board. He declined that repair. I did however receive a small claims court lawsuit, later when my prediction came true. Fortunately Mitsubishi was contacted by the Judge, and they admitted there was a problem with it. Successfully defended the case.The lesson here, is if you see it, run the other way, as fast as you can!