3HP Motor Tear-Down Clean-up and Bearing Replacement #2: Clean-up Time and Painting Time!

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Blog entry by RichmanNot posted 01-29-2017 12:53 AM 893 reads 0 times favorited 1 comment Add to Favorites Watch
« Part 1: 3HP Motor Tear-Down, Clean-up and Bearing-Replacement Part 2 of 3HP Motor Tear-Down Clean-up and Bearing Replacement series Part 3: Re-assembly Time! New Bearings Installation-3HP 1Phase PM 66 Motor »

OK last time I had completed the “tear-down” of the motor, completed the removal of the bearings and checked everything out.

I used the shop-vac on and off during the disassembly which helped get rid of the loose sawdust. Depending on your motor the sawdust may be a little worse or a little better than what I have shown. But in any case there may be a need to do some removal of “caked-on” sawdust and a need to clear the dust out of the motor housing from the “windings” and in my case a small J-box that holds the capacitor.

With a rubber-tipped blow-gun and my air compressor, I proceeded to clear the embedded sawdust from the parts.

(The ‘rubber-tipped’ blow device is best when working close to the winding to prevent damage)

There was a lot of dust stuck in the motor winding. So as not to make a big mess in the shop, I took a cardboard box, stood it on end, then cut a hole in the end of the box so I could lower the motor down into the box. Before I put the motor in the box, I took a piece of an old bath towel, dampened it with water, and laid it in the bottom of the box.

That way it would help trap some of the dust as it was blown through the motor winding.

I also had my shop-vacuum hose at the edge of the box to catch the flying dust.

Here are the two ends after they were blown out with the compressed air.

Jbox got blown out also!

On the side of the motor housing is the “Motor Tag” or data plate… (In my case it is a sticker label). In some of the previous posted pictures you will see that this label is brownish in appearance? I wasn’t sure what was on the label but I thought I would try and clean it up anyways. I was near the laundry in the basement so I took a dryer sheet, poured a little laundry detergent onto the dryer sheet and “viola” that did the trick! The label looks brand new again!

I also used a bit of “brake-clean” on a rag to wipe and clean off the painted surfaces staying away from the label .

You may recall I mentioned earlier that the “CONTACTS” would need to be cleaned? OK here is how that is done….

I used some emery paper (fine grit) and cut some thin strips (about 5/16” wide). The emery needs to be able to get into the contacts and to be honest it is a bit difficult… You could use an ignition point file…. (if you have an ignition points file and experience with using one – not only are you “dating yourself” but you’ve worked on classic cars!).

I took a small piece of thin cardboard (from the sandpaper packaging) and put it between the folded over emery paper to give my “file” a little stiffness.

As you see here it is a tight operation!

Gently “squeeze” the contacts together as you mildly abrade the contact surfaces. Just get them shining again and you are finished.

The next thing is to take a look at the J-Box. Look over the wiring look for any burned or melted wiring. Take a good look at the capacitor . Check to see if there is any “leakage”, also look at the small light colored round spot on the top. If there any “swelling” there, it may indicate a failing or failed capacitor. (If so, you will have to replace it – most motor supply houses can help)

Also look at the small “resistor” that stripped color gizmo on the top of the capacitor. Check the “links of wire” and see that there are still connected and the resistor is not swelled (swelling may indicate it is bad).

Here is a close-up of the top of the capacitor showing “the light colored round spot” and the small multi colored resistor.

If you had no starting or run issues prior to the bearing replacement then your probably OK in the capacitor department.

OK… On to a bit more clean-up and then the painting!

I found that “Simple Green” (trademark LOL) worked pretty well to clean the casting parts. I took them to the laundry sink, sprayed them down with some diluted solution and let them soak a while then rinsed them off and dried them with an old towel.

Note: I did have to use a wire brush on some of the cast parts to get them cleaned up. I used my 4-inch grinder with a fine wire wheel. Just be careful wear PPE (personal protection equipment) those darned wires are dangerous when they come flying at you!

What I did next was clean up the rotor shaft… There was some corrosion on the shaft on both ends, and I used some fine emery paper again to lightly “sand off” the old residue and rust.

NOTE: I carefully mounted the rotor in my vice using some some wood on the jaws to hold the rotor while I cleaned up the shaft ends. No need to go wild on the shafts, just be sure to keep one hand on the rotor while you clean-up the shaft ends!

Cleaning up the rotor shafts takes only a little time and is easy – no need to go crazy – a little scrubbing is all you need to do. If you want to – use some acetone and steel wool that works good too!

Do you remember the first thing we removed when we started? Yep, it was the V-Belt Pulley! Mine was really rusty (seems they never bother to paint them?) So… to get the rust cleaned off I used some Muriatic Acid. Now beware you are dealing with a potential deadly solution so precautions are needed. Wear PPE and especially a face shield and rubber gloves when doing anything with Muriatic Acid.

What I did was go to the laundry sink (best to do this outside actually), I took an old plastic distilled water jug, cut the top partially off so I could hinge it back and set the pulley inside. Then I poured in enough acid to cover the pulley and re-closed the plastic jug and taped it closed. About an hour or so later, I retrieved the pulley washing it off in water and rubbing it with a rag to get the residue off.

Once it was clean and dried I masked off the valleys and gave it a coat of “Hammered Grey” Rust-Oleum (trademark LOL).

On to the next steps…. and the rest of the parts.

Here we have some parts ready to be masked-off for painting!


Then I prepped and masked off the casting pieces, and gave the sheet metal parts and the motor housing a light sanding with some fine sandpaper, masked them off where I did not need any interfering paint, and gave them some new coatings.

HINT: A friend of mine taught me a good trick… use a heat gun or a torch and pre-heat the metal parts prior to spray painting…. It seems to help prevent runs?

Here they are on the paint rack!

There we have it… Everything is cleaned-up, painted and we are ready to re-assemble the motor! (Oh.. wait! I’m going to have to let the paint dry – so… I will continue in a day or two!)

-- "can't died in the poor house" (Because he always went around saying... "I can't")

1 comment so far

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3201 posts in 1826 days

#1 posted 01-29-2017 03:20 PM

Great refurbish!

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