What is safe to clean alternator windings with?

contessaman

contessaman

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I was going to throw away the old alternator that was attached to my dead old volvo penta. Now I've realised it's about 900 quids worth of mastervolt alpha pro I think I clean it up and fit it to my new engine! The alternator works but it's pretty gunked up and the paint is all flaking off so I'm going to strip it, clean it and repaint it before fitting it to my new engine.

Having got it apart the inside is filthy with general black engine grime.
Normally paraffin would be my first port of call to remove such grime but can anyone tell me what is safe to use with the enamel wire windings of the alternator. I don't want to dissolve the enamel and break a working alternator in the act of cleaning it up.

Any other alternator refurbishing advice also taken gladly. There's no play in bearings. Brushes look okay but I'm going g to be spinning it the other way so I'll fit some new ones. Fan is omni directional so no worries there. Cheers.
 
contessaman said:
I was going to throw away the old alternator that was attached to my dead old volvo penta. Now I've realised it's about 900 quids worth of mastervolt alpha pro I think I clean it up and fit it to my new engine! The alternator works but it's pretty gunked up and the paint is all flaking off so I'm going to strip it, clean it and repaint it before fitting it to my new engine.

Having got it apart the inside is filthy with general black engine grime.
Normally paraffin would be my first port of call to remove such grime but can anyone tell me what is safe to use with the enamel wire windings of the alternator. I don't want to dissolve the enamel and break a working alternator in the act of cleaning it up.

Any other alternator refurbishing advice also taken gladly. There's no play in bearings. Brushes look okay but I'm going g to be spinning it the other way so I'll fit some new ones. Fan is omni directional so no worries there. Cheers.
Click to expand...

I used carb cleaner on mine. Not to say that is recommended, but it's designed to be OK for rubber parts and really did a good job. Easy to squirt everywhere from a high pressure / flow can. Dries quick too with no residue. Seemed to have no ill effect.
 
White spirit won't dissolve the enamel of the wire so I can't imagine that paraffin would although it's many years since I used parafin rather than white spirit. You could try a quick rub on a connecting wire first just to check.

Richard
 
You don't want to degrease the bearings!
Any reasonable solvent should be OK on the rest of it.
How far does it come apart easily?

You could consider a foam aerosol cleaner then rinse with water and dry in a warm oven for parts of it.
It may be full of a lot of brush and belt dust which will take a lot of solvent to flush out.

I recently fixed a friend's Land Rover alternator, full of a mixture of oil and mud.
No option but to wash it out, keeping the bearings as dry as possible!
 
There are lots of options.
You could try this, or equivalent from other sources, designed for the job:-

http://www.maplin.co.uk/p/maplin-pcb-cleaner-200ml-n64an
or this http://www.maplin.co.uk/p/maplin-contact-cleaner-200ml-n61an

or this
https://www.cromwell.co.uk/shop/lub...-129f235df603&istItemId=aqrxxplai&istBid=tztt

or this https://www.cromwell.co.uk/shop/lub...-129f235df603&istItemId=aqrxlilxl&istBid=tztt

Brake cleaner would probably do the job just as well, I think it's effectively the same or very similar
 
Isopropyl alcohol (aka Isopropanol). Commonly used for cleaning electronics, including circuit boards. Evaporates without leaving a trace and is non-conductive. Got this handy spray bottle on board. Use a q-tip (cotton bud) to get into the corners.
 
Now to be controversial.

Remove the rotor with the bearings mounted, although for a few quid I would change these.

Then for the stator, very warm water with plenty of detergent. Thoroughly soak to remove the crud, and if necessary change the water and detergent, then rinse in more warm fresh water. Blow dry the majority of the water off then discreetly place in the airing cupboard for a week, or for a more speedy result bake in a very low fan oven (~ 80 to 100 oC) for a few hours.

Once dry if you have a megger buzz it at 250volts coils to casing, but do not megger across the diodes. You are looking for > 2 Megohms, and ideally infinity.

None of the solvents mentioned will touch wire insulation which is normally a plastic coated wire, but water washing is very effective as long as it is thoroughly dried afterwards
 
superheat6k said:
Now to be controversial.

Remove the rotor with the bearings mounted, although for a few quid I would change these.

Then for the stator, very warm water with plenty of detergent. Thoroughly soak to remove the crud, and if necessary change the water and detergent, then rinse in more warm fresh water. Blow dry the majority of the water off then discreetly place in the airing cupboard for a week, or for a more speedy result bake in a very low fan oven (~ 80 to 100 oC) for a few hours.

Once dry if you have a megger buzz it at 250volts coils to casing, but do not megger across the diodes. You are looking for > 2 Megohms, and ideally infinity.

None of the solvents mentioned will touch wire insulation which is normally a plastic coated wire, but water washing is very effective as long as it is thoroughly dried afterwards
Click to expand...

No, not controversial, personally that would get my vote as well ! You need a lot of liquid in inaccessible places and hot water/detergent to flush dirt out of the stator. Providing dried well, cannot see a problem. And yes, would change bearings as well. I would however tackle the brushes, brush holders, diode pack, commutator, rotor etc gently and certainly avoid water near any unsealed electronics like an inbuilt regulator.
 
In a previous life I was Assistant Manager at the largest Lucas Service depot in the UK. We had an alternator reconditioning production line for Lucas product and a busy repair shop that could-and did-fix any alternator.

White Spirit was the solvent used for cleaning. The parts was then blown dry with LOW pressure air and any residue evaporated away naturally in the warm envioroment.

I hope this helps.
 
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