Felt Sealing Washers

[Tom S]

I'm getting ready to re-assembly the headstock on my Ames, and it has a couple washers in the front bearing assembly that appear to function as dust seals. They sit on a slightly tapered surface, don't appear to be under any real compression in the assembly, and protect the open front bearing from debris entering via the spindle. Spindle is greased, not oiled, so these washers do not function as lubrication, just seals. The ones I took out of the headstock disintegrated, I believe the grease hardened up in them and caused them to become brittle. I'm thinking to replace them with felt rings, but am wondering what grade of felt I should get for this. Do I go with something more solid like an F1, or something a bit softer like an F3 or F5?

As an aside, while looking through my diagrams of the headstock (from 1949) I noticed that a price list was attached. This lathe, a standard bench, and the collets I just purchased would have run somewhere in the range of $1,101.50 USD at the time, running through an inflation calculator that's about $11,866.078 USD. Pricey piece of equipment.

[CarlByrns]

They may be "flocked" seals (insert pun here) and they're used on turf equipment for keeping grease in and clippings out.

[J Tiers]

Not knowing how they are held in place, nor what force is placed upon them, my inclination is softer, since unlike a wiper, they run on the same portion of the surface all the time. Do you have a picture?

Modern versions would be a pressed-in-place metal holder with a rubber seal. Those used to be felt seals with the same metal ring holder. I replaced several felt types on a Benchmaster vertical head which wee felt, in some cases assisted by a spring.

Leather seals were also used, often with a "garter spring".

[Tom S]

Here's a screenshot of the area in question. Moving from right to left, there is a plate through which the spindle protrudes, threaded into the headstock casting. It presses against a cupped washer, which presses against the outer bearing race, which presses against another cupped washer, which seats against the headstock casting again. So when the plate is tightened up it securely holds the outer race in place without touching the inner race. The black pieces are the sealing rings, which have tapered seats and ride against a pair of collars, one built into the nose of the spindle and one assembled to the spindle. I'm thinking it the felt should have some ability to compress so that it can form to the tapered seat.

[JoeLee]

When I restored my KO grinders I put felt dust seals / washers in front and in back of the bearings. The rear felt seals just pressed into the hole that was machined through the casting. No force pushing against it. It was a snug enough fit so it wasn't going anywhere. The front ones are between the bearing and the hub of the hand wheels, they fit inside the spanner nut, not between the nut and the bearing. They weren't originally there but the bearings were shielded and pretty rough because of the grit and crud that had gotten into them over the years. Been about 20 years and no issues. This was my idea of adding some extra protection to the bearings.

JL.............

[J Tiers]

That is a standard old way of sealing, and about what I expected you had. The angle of the recess gives a bit of a push inward.

New Departure handbook suggests felt "of a firm structure, generally known as medium felt". So not the firmest, somewhere in the middle.

You can either punch rings, or cut strips that are bent around to form a ring, and then stapled, etc. If they are cut the suggestion is to angle cut the felt so there is an overlap.

[Tom S]

Thanks. I’ll probably go with an F1 then, the softest of the firm felt I saw. I was planning to cut out rings rather than strips, seems like there is less to go wrong that way.

[rickyb]

I add felt seals on a lot of machines where there were none. My surface grinder for one. It is a nice way to protect the existing seals from dust and debris buildup. I use felt weatherstripping. Contact cement to make the strips as wide and thick as I need. My guess is any grade will work and thicker would be better.

[larry_g]

Thanks. I’ll probably go with an F1 then, the softest of the firm felt I saw. I was planning to cut out rings rather than strips, seems like there is less to go wrong that way.

https://www.mcmaster.com/felt/firm-felt/

Might I suggest that you use cord or discs listed above. You have a known product of a known size.

lg
no neat sig line