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Wdc

100% Lacquer Thinner for cleaning YES/NO

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Does anyone have experience or knowledge if 100% Lacquer Thinner will hurt watch parts as part of a cleaning routine? Excluding of course plastic parts or the pallet fork.

I have been using it for years a a strong solvent for tough cleaning and I know it will not hurt metal, ferrous or non-ferrous but I am not sure about the synthetic jewels.

I have been using the following regiment, right or wrong.

10min - 100% Lacquer Thinner soak (cut grease & grime

30 mins – ultrasonic in water 4-5 cups, dish detergent 2TBS, Ammonia 1 cup

5 mins -  91% alcohol rinse

 

Reason I ask is I am thinking to skip step 2 water, ammonia and add 100% Lacquer Thinner into my stainless ultrasonic cleaner.

 

So how many gasp & shrieks do I hear out there?

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Hi Wdc.

Many base metals react chemically with thinners. Some thinners are just kerosene, no harm, however,  Various thinners of different chemical base and strength are out there, and with short soak time you may not observe the damage to the base metal but it is there, the fluid penetrates through pores of gold or nickle plating.

I test the long term soak with junk pieces, to find the answers for me, since not all brands are available to me, If available to you, You already got best advice from OH.

Regards joe.

 

 

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10 hours ago, Wdc said:

5 mins -  91% alcohol rinse

This is ok for most watch parts but I wouldn't use it for balance wheel or pallet fork as both these components have jewels glued in place using shellac which is soluble in alcohol.

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It's OK to rinse in alcohol but it will dissolve the shellac if left long enough- 5 mins would certainly soften it. Try rinsing in distilled water after cleaning, then in alcohol (which will basically remove the water), but only leave the balance/fork maybe 30 seconds.

I don't know about lacquer thinner, but it sounds to me like your ammonia percentage is too high. I use a clock cleaner that has about 100ml, ~ half a cup, of 24% ammonia (quite strong, yes) to 4 liters of liquid. In this mix the ammonia reacts with oleic acid forming a soap, so the ammonia effect is even less pronounced. In a strong ammonia solution you'll see it has a rather severe effect on brass parts and can start to strip plating as well if left long enough. Also, 15 mins should be plenty of time in the cleaner.

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  i believe, any solvent will desove shellac.  thats why you remove those parts before cleaning.   at one time, paint thinner and lighter fluid were the only solvents available (or cheeep) for "cleaning".    for manual cleaning,  iso  alchol is available,  at the chemist,  usially at 75% solution.  and the warning "do not drink".   it is the best solvent for oil or grease.     if you buy a cleaning machine;   use their sugested cleaners.    cheers.  vin

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26 minutes ago, vinn3 said:

  i believe, any solvent will desove shellac.  thats why you remove those parts before cleaning.   at one time, paint thinner and lighter fluid were the only solvents available (or cheeep) for "cleaning".    for manual cleaning,  iso  alchol is available,  at the chemist,  usially at 75% solution.  and the warning "do not drink".   it is the best solvent for oil or grease.     if you buy a cleaning machine;   use their sugested cleaners.    cheers.  vin

A little off topic but..

Not all solvents work the same way. Alcohol is what is known as a polar solvent, hydrocarbons (like naphtha) are nonpolar solvents.

Polar solvents are great for dissolving ionic compounds (which is why they are good for drying water off components).

Nonpolar solvents are great for dissolving oils and greases (which is why they are great for cleaning)

Generally speaking things that are highly soluble in polar solvents are much less so in nonpolar solvents, which is why shellac is perfectly safe in (nonpolar) cleaning solutions but very much at risk in (polar) solvents like alcohol.

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21 minutes ago, Marc said:

A little off topic but..

Not all solvents work the same way. Alcohol is what is known as a polar solvent, hydrocarbons (like naphtha) are nonpolar solvents.

Polar solvents are great for dissolving ionic compounds (which is why they are good for drying water off components).

Nonpolar solvents are great for dissolving oils and greases (which is why they are great for cleaning)

Generally speaking things that are highly soluble in polar solvents are much less so in nonpolar solvents, which is why shellac is perfectly safe in (nonpolar) cleaning solutions but very much at risk in (polar) solvents like alcohol.

    alcohol is the simple answer.  if not sure consult a chemist.

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As always thanks for the advice.

A couple quick qualifications

I was estimating at the quantities in my #2 solution. I generally pour everything into a bucket and dump it into the cleaner. I may have estimated my Ammonia a bit high likely somewhere between ½-1 cup. I do understand there is a diminishing return where brass will tarnish black. Thankfully I discovered this on tools not watch parts, something easily buffed out.

This discussion has uncovered a BIG oversight on my part, the “Pallet Wheel Jewel” . the whole reason I leave out the pallet fork is the jewel and shellac. Point taken on a shortening the alcohol rinse. It may even be good practice to stop re-attaching the balance to the bottom plate and running it though the Ultrasonic cleaner (USC) as I have seen many do. Dip the balance and HS into a solvent to degrease, quick alcohol rinse and call it good. I like an alcohol rinse because of the quick evaporation and at 91% there is very little water to corrode and/or stain. Hit it with a little defused hot air from a heat-gun  and it’s almost instantaneous.

Whereas everyone has a good point @vinn3 raises an important on solvent classifications polar and nonpolar. I am sure Lacquer Thinner (LT) falls into polar along with alcohol. I’ll need to do more research on the two categories to understand them better and ID what fall where.

In closing I would like to say that @oldhippy point is well taken.  After doing more research on watch cleaning solutions, including Lacquer Thinner on a number of watch sites, it is clear this can be a charged subject. Ironically, I did find someone that writes he’s been using LT for year with great results but he did warn, "do not to run it in the USC and heat it". Heating it is common since and my experience is you don’t need to, it degreases fast at room temp.

Lastly @Nucejoe had a good point, run some test. When I decided to take up this hobby, I purchased 65 misc. movements, so I have plenty to test with. Sometimes the proof is in the pudding…lol

Thanks again to all

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