Cleaning Electric Motors

Old 09-11-15, 05:19 PM
Thread Starter
Join Date: Jun 2003
Location: USA
Posts: 156
Upvotes: 0
Received 2 Upvotes on 2 Posts
Cleaning Electric Motors

Many years ago there was a guy in my neighborhood who repaired electric motors.
Thinking back, I'm totally amazed how he could fix electric motors that most people
(including me) would throw in the trash.

He had buckets and trays with motors soaking in some chemical. I don't remember
any really bad odors, so he wasn't using gasoline. Back in those days, people used
gas to clean almost anything. Prolonged exposure to the vapors could kill you, and
there was that little problem of a fire or explosion!

I've got an expensive electric motor that runs ok, but it must be cleaned and lubed.
It has oblong slots in the case, so it's an open frame design. I've got traditional
electric motor lube. It's recommended for 1/4 HP motors or larger (SAE 20) which
should be fine for my motor. The brand is 3-in-One Motor Oil. I'm sure this stuff
has been replaced by better, synthetic lubes. Tell me what to buy.

It definitely needs a thorough cleaning. I've got plenty of grease dissolving chemicals,
but I don't know which one is safe to use. Whatever chemical that guy used several
decades ago, must have been good. Everyone thought he was an electric motor genius.
Old 09-11-15, 05:26 PM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes on 0 Posts
I remember people using carbon tetrachloride. It was great for cleaning all kinds of things. However, it wasn't very good, for one's liver. Wikipedia has a page, on it.
Old 09-11-15, 05:57 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes on 30 Posts
Here is one product I found via a Google search using the term electric motor cleaning solvent.

Old 09-12-15, 10:38 AM
Join Date: May 2006
Location: upstate New York
Posts: 375
Received 4 Upvotes on 4 Posts
motor cleaner

Yeah, carbon tet was what we used to use to clean lots of things. Hate to think about how much of that stuff I came into contact with! (along with lots of other
no - no chemicals. Furd's suggestion looks pretty good-

Old 09-12-15, 03:45 PM
Thread Starter
Join Date: Jun 2003
Location: USA
Posts: 156
Upvotes: 0
Received 2 Upvotes on 2 Posts
I've got a spray can of CRC QD Contact Cleaner. It's sold in Home Depot.

I just scooped a blob of very thick wheel bearing grease into a tray and sprayed
the contact cleaner into the grease. It turned into a thin soup. Seems like the
right product for the job. Also, it won't damage most plastics.

This motor is kind of big and heavy. It was purchased new, surplus from a factory.
It's a full 1 HP. I was hoping to immerse the entire motor into a bucket with some
chemical. I keep thinking that most petroleum based weak solvents would be ok,
like cheap paint thinner. I frequently clean mower components with paint thinner.

The contact cleaner dries very quickly. That's required if the equipment must be
put back into service immediately. I won't be using this motor for a few weeks.
After soaking in a bucket, I'll let it dry for several days before applying the lube.
Old 09-12-15, 07:02 PM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 19,281
Received 6 Upvotes on 6 Posts
You don't want to use anything that might remove the lacquer on the windings. If the motor is new, why would you need to immerse it in something? Blow it out, clean it up on the outside, and it should be good to go shouldn't it?

Thread Tools
Search this Thread
Ask a Question
Question Title: