Lacquer and Varnish

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MolaKule

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A. In what type of engine does Lacquer originate?

B. In what type of engine does Varnish originate?

C. Lacquer is drierived from what?

D. Varnish is derived from what?
 
Dang,
I was ready to launch in with drying oils, drying accelerents, resins, gums, and lac.

Better sit back and see how it happens in engines.
 
A. Diesel Engines
B. Gasoline Engines
(Credit to the Chevron Oronite reference section)

My best guess on the rest is:

C. Lacquer is from an organic source - lacquer coatings come from trees.

D. Varnish is a resin.

[ April 05, 2004, 11:42 AM: Message edited by: Blue99 ]
 
Yep, we're talking about engine related deposits since the questions says something about engines.

Laquer and varnish deposits are two different deposits.

Keep going guys, you're on the right rack.
 
I found a document from Shell Marine Products (actually an advertisement for a marine diesel oil) that described lacquer formation as the result of polymerization of unburned diesel fuel under high-heat/load conditions, combined with certain metal-containing oil additives and the movement of the piston rings that hardens the coating. I can post the link if anyone wants to see it.
 
The 10 years I spent in the coatings industry wasn't long enough ago that we were producing varnish for automotive use. I worked for Rinshed Mason that did supply lacquer to GM. The varnish and lacquer were meant for the body of the car. Even the paint for the engines was meant for the outside of them.

I suspect for things produced by a engine, we are talking the thin, dark coatings that build up on the valve covers and other parts contacted by the oil. These are commonly called varnish. It is deposited from the oil. Unsaturated materials, either not refined out of, or from oil breaking down, polymerize coat the engine parts. It is crummy stuff and can advance to sludge. I never saw any reference to lacquer forming in an engine. Perhaps it is just another name for varnish, like wishbones and A-frames in suspensions.

Lacquer once came from lac deposited on trees by insects. Later it was used to either mean a coating that dried purely be solvent evaporation, or a clear coating. Words like tools, take a beating when misused and become less useful.
 
Is the author perhaps referring to deposits in the combustion chamber and cylinder as lacquer? I would thing deposits there would be more sensitive to the type of fuel than ones in the lubricating system. On the other hand, I always thought the varnish that builds up in the lubricating system came from the oil. Could it be that it is a least partially due to the fuel? The same sort of short trips, cold engine, long OCI's, etc. that leads to varnish and sludge also leads to more fuel dilution.
 
Awright, I did some more reading about the Shell Gadinia AL product. Here is my next shot:

C. Lacquer in diesel engines is a resin deposit originating from components in the diesel fuel.

D. Varnish in gasoline engines is a resin deposit originating from components in the crankcase lubricating oil.
 
Excellent answers, and it is indicative of you guys doing your research.

The aldehydes and ketones form from the reaction of NOx with hydrocarbons at or above 137 C. These aldehydes and ketones undergo condensation to form polymeric compounds. These polymeric compounds further oxidize to form sticky oxygenates called 'resins."

This resin is a basic component to all precursors such as varnish, lacquer, carbon, and sludge.

Varnish, lacquer and carbon show up when resins separate out on hot surfaces and dehydrates . Carbon start to drop out of the resin when the resin is subjected to temps ranging from 300 C to 680 C.

At or below 200 C, such as the piston skirts, these deposits form a thin film of lacquer or varnish.

Lacquer is largely formed in Deisel engines from lubricant components. Lacquer froms on piston skirts, cylinder walls, and in the cooler parts of the combustion chamber.

In gasoline engines, Varnish is largely formed from fuel components. Varnish forms on valve covers, piston rings, piston skirts, valve lifters, and PCV components.

BTW, lacquer is water soluble and varnish is only acetone soluble.
 
One very interesting question - bummer I showed up so late.

No wonder synthetic oil REALLY doen't take varnish off.....but AutoRx does? (not really IMHO)

Does AutoRx touch Lacquer?
 
It was asked in the context of engine lubrication and technology:

quote:

A. In what type of engine does Lacquer originate?

B. In what type of engine does Varnish originate?

C. Lacquer is drierived from what?

D. Varnish is derived from what?

Generally, when I ask a purely chemistry-type question, I usually let the reader know up front.

[ May 18, 2004, 04:40 PM: Message edited by: MolaKule ]
 
quote:

Originally posted by MolaKule:
...

BTW, lacquer is water soluble and varnish is only acetone soluble.


This is why the original question really threw me. This statement is untrue in the context of the coatings industry.

Varnish resins "cure" by a chemical reaction, usually oxydation, while lacquers only "dry" by solvent evaporation. This is the reason I was having trouble with the original question.

Fully cured varnishes may or may not be acetone soluble, depending upon resin type, lacquer certainly is.
 
quote:

The aldehydes and ketones form from the reaction of NOx with hydrocarbons at or above 137 C. These aldehydes and ketones undergo condensation to form polymeric compounds. These polymeric compounds further oxidize to form sticky oxygenates called 'resins."

Having oils with excellent dispersant / detergent technologies prevent this varnish formation in gasoline engines. And by the way MolaKule, what does the Chemist say?

"Everything dissolves in everything"

How are Oilfilter media protected by degredation, what gives them mechanical stability? It has something to do with resins...

So, what is good for the oil, might not be good for the Oilfilter...
frown.gif
 
Most oil filter media and binders/adhesives degrade over time, which is one of the reasons you change the oil filter.

The resins or sludgy polymers formed by interaction of oils with combustion gasses are different resins than used for filter binders/adhesives.
 
quote:

Most oil filter media and binders/adhesives degrade over time, which is one of the reasons you change the oil filter.

It's the cellulose media which degrades under the influence of acids formed in the engine. So, high TAN values are bad for the oil, and they are bad for the oilfilter,too. They loose their strength over time until they fail under cold start conditions in the winter time.

In addition, water condenses into the oil. The water lets the fibers swell. The pressure loss over the media rises from 0,1 bar to more then 1 bar.

Most medias in Europe have phenolic epoxy resins as binder. Highly additivated oils with excellent dispersant/detergent systems degrade these binders earlier then more simple oils.

[ August 25, 2004, 11:02 AM: Message edited by: Callisa ]
 
quote:

mechanical stability?

Mechanical stability is a function of the mechanical design of the filter cage.

Some companies seem to use a lot of adhesive at the tops and bottoms, and the adhesive is usually some type of acrylate.

Synthetic media obviate the need for resinous binders in paper.
 
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