Old Merritt's clock oil vs synthetic 0w-40

Elliott Wolin

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An NAWCC article recommended using fully synthetic 0w-40 for oiling clocks (10w-60 for springs and heavier pivots). I just purchased a twenty lifetime supply of Mobil 1 0w-40 for about $7 and am wondering if I should stop using the older oil.

I got a tube of clock oil with needle applicator from Merritts maybe 20 years ago. They still list it on their web site but don't say what kind of oil is in it.

I'm wondering if I should just dump the Merritts oil and fill the applicator with the Mobil 1 0w-40.
 

wow

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Yep. Dump it. I use Mobil 1 on everything in clocks except the mainsprings. Harold Bain got me started on Slick 50 One oil for mainsprings years ago. Iv never seen either of these gum or get sticky. IMHO.
 
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Elliott Wolin

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I read there are two types of Slick 50 One oil, the original Teflon-based version and the new, improved non-Teflon version. All the good results were from the original version, with mixed or not great results from the newer version, if I recall. I purchased the newer version (not knowing the difference at the time) and used it on some mainsprings, we'll see.

Since the NAWCC bulletin article recommended using full synthetic 10w-60 on mainsprings, that's what I'm doing now.
 

Elliott Wolin

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I just dumped the old Merritts clock oil, so now I'm using fully synthetic 0w-40 for most clock pivots, 10w-60 for mainsprings and heavy pivots, and Nye watch oil for watches and very small clock pivots and other delicate parts.

OTOH I use whatever grease I have handy for clicks and other heavy parts needing grease. I switch among bike wheel bearing grease, auto wheel bearing grease, white lithium grease, etc. Is there a problem with any of these?
 

wow

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I just dumped the old Merritts clock oil, so now I'm using fully synthetic 0w-40 for most clock pivots, 10w-60 for mainsprings and heavy pivots, and Nye watch oil for watches and very small clock pivots and other delicate parts.

OTOH I use whatever grease I have handy for clicks and other heavy parts needing grease. I switch among bike wheel bearing grease, auto wheel bearing grease, white lithium grease, etc. Is there a problem with any of these?
I dont know the answer to the grease question. I don’t use it at all on clocks.
 

Bruce Alexander

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I use this #163 Clock Grease 1 Ounce
Not cheap but a little goes a long way.
I don't do a high volume of work but I'm fairly steady now.
I've been using my original 1 ounce container and still have about a 3rd of it left. I use it mostly on sliding surfaces in strike and chime trains.
 

R. Croswell

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An NAWCC article recommended using fully synthetic 0w-40 for oiling clocks (10w-60 for springs and heavier pivots). I just purchased a twenty lifetime supply of Mobil 1 0w-40 for about $7 and am wondering if I should stop using the older oil.

I got a tube of clock oil with needle applicator from Merritts maybe 20 years ago. They still list it on their web site but don't say what kind of oil is in it.

I'm wondering if I should just dump the Merritts oil and fill the applicator with the Mobil 1 0w-40.
Yes, you were right to dump the old Merritt's oil but I have found that these cheap pre-filled applicators will soon crack and make a big mess, plus the usually deliver too much oil. I now use Mobil-1 0W-20 for most general clock work. I sometimes use Nye-140 synthetic for tiny pivots. I not sure how 0W-20 compares to 0W-40 at room temperature. I've had good luck with Mobil-1 75W-90 gear oil on main springs but I think any heavy weight synthetic oil is fine for main springs. I use The System synthetic grease from timesavers on cams and places that should be greased. If you search hard enough on-line you can fine a copy of the Hermle Service Manual (an older edition) that has a very good section on lubrication, what to oil, what to grease, what not to oil, etc.

There is one thing that you can be sure of is that there is little agreement on what is the best oil for the various parts of a clock.

RC
 

Elliott Wolin

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The article on clock oils is here: https://www.kensclockclinic.com/wp-content/uploads/2015/02/Clock-Oils.pdf

I think I've had the Merrits plastic oil applicator for about 20 years now, haven't used it much until recently, but it still seems good (I squeezed it hard lots of times before refilling it).

I can't find a downloadable pdf of the Hermle Service Manual that I can print out, only versions where you have to read it online. If anyone knows of a downloadable pdf for the manual please let me know.
 

R. Croswell

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The article on clock oils is here: https://www.kensclockclinic.com/wp-content/uploads/2015/02/Clock-Oils.pdf

I think I've had the Merrits plastic oil applicator for about 20 years now, haven't used it much until recently, but it still seems good (I squeezed it hard lots of times before refilling it).

I can't find a downloadable pdf of the Hermle Service Manual that I can print out, only versions where you have to read it online. If anyone knows of a downloadable pdf for the manual please let me know.
That article on clock oils has been around for some time and is interesting reading but it is not the whole story, and, like many articles one finds on line and stuff in the mainstream media, the research seems to be designed to support the author's narrative. There is no one best oil for all clocks and whatever product product anyone thinks is best is probably a compromise between correct viscosity at room temperature, ability to stay in place, ability to reduce wear, ability to reduce friction, ability to last a long time without drying out, and on and on. We often sacrifice one property to get an advantage from another.

Perhaps the pre-loaded oilers Merritt's sold 20 years ago were made of better stuff.

Try this link for the Hermle Service Manual; Hermle Service Manual Looks like there is a download option. It is a .pdf file.

RC
 

Elliott Wolin

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Thanks, I had found that site, but the "download" option is disabled.

As concerning clock lubrication, I suspect such discussions will never end, and will always generate passionate opinions about which lubricant is best to use, and where. This gives us something to talk about in retirement, of course. :)

As I currently have enough synthetic automotive oil to pass on to my great-great-....-great-great grandchildren, I'll be using it until something definitively better comes along.

Actually, I read about Teflon powder recently...
 

rgmt79

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You can read the manual online from this link: Hermle Service Manual

Reading the section on "cleaning and lubrication" I'm intrigued as to why they say "do not clean the mainspring in an ultrasonic cleaner" without explaining why...can anyone enlighten me please?

Richard
 

shutterbug

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I use the US for cleaning mainsprings and it works fine. I can't imagine why they would think it would hurt a mainspring. But I does negatively affect hairsprings. Maybe that's what they meant.
 

R. Croswell

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The main problem I see with cleaning main springs in the US is that they are usually pretty dirty and can quickly mess up a clean (and expensive) batch of cleaning solution so that I wouldn't want to use it for movement parts. I usually soak mainsprings is Super Clean (a purple automotive degreaser sold at Wal-Mart) overnight or even longer while I work on other things. A little brushing, a good wipe down and quick rinse is usually all that's needed followed by a quick dry. The caustic cleaner won't attack the steel and the spring and it isn't likely to rust while in the cleaner. But do rinse and dry quickly because the now clean steel will rust.

Of course some uncoiled springs (especially 31-day Korean type) won't fit in teh US unless you have a really huge one.

RC
 

Elliott Wolin

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I just soak and then wipe mainsprings down with Naptha multiple times until the cloth comes off clean, then lubricate with 10w-60 after it dries. Am I missing something?
 

R. Croswell

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I just soak and then wipe mainsprings down with Naptha multiple times until the cloth comes off clean, then lubricate with 10w-60 after it dries. Am I missing something?
Are you missing something....... I hope not but no one mentioned that you need to inspect the spring carefully for any hairline (or larger) cracks that may be starting, especially near the hole and inner coils of all springs, and also around hole in the outer end of hole-end springs. Any deep rust pitting would be a reason to replace the spring.

RC
 

Elliott Wolin

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I'm embarrassed to say I tend not to inspect springs as carefully as RC suggests. In my (weak) defense I'm working on clocks for myself, so having to repair something later is not a big deal. And often I'm so anxious to get a clock out of my garage after weeks of work and waiting for parts to arrive I rush through some steps.

In the past I'd notice any serious problem with a spring, but perhaps not a tiny hairline crack that is barely visible. I will look more carefully in the future.
 

Bruce Alexander

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having to repair something later is not a big deal
Hi Elliott,

I currently have a Seth Thomas #120 on my bench which helps to illustrate and emphasize the excellent advice that RC has shared with you.

As found, there was a tear out of one of the hole end mainsprings. I think that this may have resulted in significant damage to the Great Wheel. As bad as the wheel looked upon initial inspection, I was able to straighten most of the bent teeth. One was bent almost 90 degrees and I replaced it. The other Mainspring looked okay initially, but looking at the end under magnification revealed micro-cracks around the hole-end. I removed the damaged ends, annealed where necessary and punched/filed new hole ends on both springs. I've read that one should be able to remove up to 10% of a mainspring's length without affecting strength or run time. If a failing end looks like it has already been re-shaped, I think you should seriously think about replacing the spring. Measure the existing spring and use a mainspring calculator to check its length when ordering a replacement.

The point I want to stress is that you've already decided to do the heavy lifting of a proper overhaul. Don't overlook close mainspring inspection. Mainspring failure can be catastrophic and this may be your only chance to head it off.

The missing washer didn't help matters any, but it probably didn't significantly contribute to the damage caused when the spring tore out. In any case, the split plate needs to have that washer so that it remains parallel to the other plate components. It keeps the Great Wheels perpendicular to the plates. The Seth Thomas 124 uses similar washers too. In this movement, I've fabricated a replacement washer and fastened it securely in the proper position with Loctite 680. It will be one less thing for a future repair person to worry about.

Regards,

Bruce

TearOut.JPG Great Wheel Damage.JPG Spring Ends.JPG Springs Repaired.JPG Missing Washer.JPG
 
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