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 Post subject: Calico coatings
 Post Posted: Thu Jan 19, 2012 8:04 am 
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Anyone have anything to share ?? Just had the piston skirts done..

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 Post subject: Re: Calico coatings
 Post Posted: Thu Jan 19, 2012 3:30 pm 
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Why Parts Get Coated, Dave Emanuel, Automotive Rebuilder, February 1998
I never would have believed you could get those kind of results from a glorified paint job. With those words, another skeptic (in this case, a NASCAR Winston Cup engine builder) had come to accept the value of special coatings applied to engine components.
At the time, such skepticism was not totally unwarranted. Like any emerging technology, the coating of metal parts, with fluoropolymer, metallic/ceramic and graphite materials underwent a painful teething process before it was perfected. But the worth of various coating processes has been repeatedly proven over the past 10 years, so doubting Thomases and Thomasinas are out of step with reality.
Even Ford and General Motors have embraced the process with both companies using coated pistons in some applications. A major supplier of aftermarket engine components has also embraced the worth of coatings and offers pistons with moly-based, graphite-coated skirts for a wide variety of engine types.
If there's a rub with friction reducing and heat blocking coatings it's their time and expense. Although most applicators offer quick turnaround, shipping usually takes at least one day each way. If time isn't a major stumbling block, additional expense may be the hurdle that can't be jumped.
Like your gas mileage, prices vary, but custom coating a set of pistons and bearings can add substantially to the cost of rebuilding an engine. Charges of $10 to $40 per piston, $5 to $10 per valve and $40 for a set of bearings, plus shipping charges, are not unusual.
When customers are receptive to those additional costs, an engine rebuilder's life becomes somewhat easier because engines with coated components demonstrate greater durability and occasionally generate more power. But in price-competitive environments, selling the worth of coatings can be difficult.
With the recent advent of do-it-yourself coatings, cost considerations may diminish dramatically. But proper coating of engine parts is a bit more involved than simply spray painting, so in-house coating operations may or may not be viable. The performance of coatings also varies significantly according to their composition and the applicator's capabilities and experience.
New applicators will have to learn to avoid the same pitfalls that initially earned coatings a reputation for poor performance. In the late 1960s and early '70s, when coating technology was in its embryonic stage, applicators were still experimenting to a large degree. Many didn't understand coating and base material compatibility issues, nor did they realize that proper preparation is vital to adhesion. Consequently, coatings cracked, flaked off, didn't perform as advertised, or even all of the above.
Most commercial applicators are religious in their adherence to pre-coating preparation techniques that leave a component surgically clean. Some applicators use a five-step cleaning process that includes the application of heat along with mechanical and chemical cleaning. After the parts are sprayed, they're cured in an oven at between 350 to 500F.
Similar techniques are used by virtually all commercial applicators; in-house coating operations must also adhere to the "cleanliness is next to Godliness" gospel to achieve success. The logical question is, therefore, what benefits do coatings offer to justify the trouble and expense?
Although claims and speculation abound, there's little documentation available to provide substantial proof of significant power increases derived from anti-friction coatings. A principle advantage of such coatings is that they're dry film lubricants and provide back-up lubrication in the event engine oil is absent. Secondly, since they retain engine oil under conditions of extreme heat and pressure, they offer an extra margin of safety in the event of oil starvation. These types of coatings are typically applied to piston skirts, bearings, valve springs, camshafts and lifters.
Builders of professional-level race engines were among the first to use coated parts extensively. The extremely high loads under which these engines operate make them prime candidates for failures arising from scuffing and galling of internal components. In many instances, coatings are used as a means of extending a component's useful life even when hard failures are rare.
As one sprint car engine builder stated, "I won't install uncoated pistons. The coated ones look so good when they come out of an engine it's hard to believe they've been run for more than a race or two. We're now able to use a set of pistons for a whole year and that really cuts down on maintenance expense."
For many production engine rebuilders, such considerations may be irrelevant because a quality rebuilt engine can now run for more than 100,000 miles - far longer than a typical consumer expects. But for rebuilders who deal with fleets and stationary power plants, where durability expectations are high and closely monitored, measurable improvements in engine life can lead to increased customer loyalty and satisfaction.
On the surface, taking steps to increase engine life beyond customer expectations may seem like biting the hand that feeds you. After all, shorter times between overhauls translates to more business. From a myopic perspective, that's true. But when viewed through corrective lenses, a more ethical and ultimately more profitable viewpoint comes into focus.
People tend to talk, especially to other people in similar professions. When one fleet manager converses with another and finds his engines need to be rebuilt more frequently, he just may decide to take his business elsewhere. Similarly, if your customers' engines are enjoying above average life spans, word is likely to spread, resulting in new customers and increased profits.
Metallic/ceramic thermal barrier coatings applied to the exhaust headers provide two advantages. They protect the headers from rust and corrosion and reduce heat loss which translates into high power output. Thermal barrier coatings are also applied to piston crowns, combustion chambers, intake manifolds and exhaust parts.

In addition to dry film lubricant-type coatings, oil shedding coatings are also available. Like the TeflonĀ® used to create non-stick frying pans, oil shedding coatings resist the adhesion of fluids to their surface. Many race engine builders spend a good deal of time and money attempting to minimize the power losses associated with oil windage in the crankcase. Coating connecting rods, crankshaft counterweights and windage trays with a non-wettable compound enables oil to leave the premises quicker. Since it has less time to hang around in the way of a spinning crankshaft, engine oil interferes less with the creation of horsepower.
Another area in which non-wettable coatings can be found is the intake tract. Some engine builders coat intake manifold plenums and runners in an attempt to reduce fuel puddling and reduce surface friction.
Applying dry film lubricant coatings to main and rod bearings adds an extra measure of insurance against damage caused by oil starvation. Reduced friction is another benefit that offers horsepower and durability improvement potential.

Many of the power-enhancing effects of friction reducing and oil shedding coatings are highly debatable because their effects are rather subtle. Everything else being equal, the difference between two engines, one assembled with coated components, the other without, may only be a few horsepower. But many engine builders have found that coatings allow them to make other changes that deliver more significant power increases.
As an example, coated bearings typically allow tighter clearances which in turn mean reduced internal oil hemorrhaging. With less oil slipping out between the crank journals and their bearings, adequate oil pressure can be maintained without the need for a high pressure oil pump (and its attendant parasitic power loss).
Obviously, many of the benefits derived from friction reducing and oil shedding coatings are most applicable to hard core race engines. Metallic/ceramic coatings (silicon and zirconium based) are more universally beneficial. The most popular use of these types of coatings is on exhaust headers, where they provide a two-fold benefit.
When headers are coated, they don't transfer heat as quickly so exiting exhaust gases stay hotter and maintain higher velocities. That improves engine efficiency because less residual exhaust gas in the combustion chamber leads to a reduction in intake mixture dilution. In turbocharged engines, higher exhaust gas temperatures equate to more boost and higher power output.
Secondly, with less heat transfer through the header tubes, the engine compartment stays cooler so the incoming intake charge doesn't have its temperature raised as much as it would were the headers not coated. For racers working on hot engines, cooler headers mean fewer burnt fingers.
Then there are the cosmetic considerations. Being constructed of mild steel for the most part, exhaust headers have a marked tendency to cultivate a layer of iron oxide on their exterior. Metallic/ceramic coatings won't rust, so coated headers maintain their appealing appearance longer. Most headers are coated inside and out as a means of sealing out rust, but the interior coating also improves durability because it reduces the thermal shock of hot exhaust assaulting the steel.
Inside an engine, metallic/ceramic coatings are frequently used on piston crowns and valve heads to reduce heat transfer and its attendant power losses. A metallic/ceramic coating material, specifically formulated for high temperature applications, can withstand typical combustion chamber temperatures even though they're only .001" to .0015" thick.
In addition to keeping heat in the chamber where it can produce power, metallic/ceramic coatings, by virtue of the fact that they present a barrier to heat transfer into a piston, reduce skirt expansion. Some engine builders have found enough of a difference in skirt expansion to allow a tightening of piston-to-wall clearances.
The underside of a piston with a coated crown speaks volumes about the effectiveness of thermal barrier coatings. After any length of service, the underside of an uncoated piston typically has a brownish color to it, like the inside of an aluminum pan that has been used for frying. The underside of a coated piston looks brand new because it didn't cook any of the engine oil that contacted it.
Many engine builders have clearly documented significant horsepower increases resulting from the use of metallic/ceramic coatings. The effect is greatest when piston domes, aluminum cylinder head combustion chambers, exhaust ports and headers are coated. Measurable power increases should result from the application of metallic/ceramic coatings because regardless of the method, the payoff for maintaining combustion heat is more power.
Frequently, the amount of spark lead required for maximum power is less when thermal barrier coatings are used. One caveat does exist, however. The use of thermal barrier coatings in some engines, particularly those with cast iron heads, may lead to detonation because too much heat is retained.
Should you decide to experiment with coatings, you can purchase aftermarket replacement parts that have already been coated, contact a commercial coater or try the do-it-yourself route. Tech Line Coatings & Lubricants and Extreme Performance Coatings both offer a variety of coating materials suitable for do-it-yourself applications. These materials are typically applied with an air brush and can be cured in a home oven. The air supply to the air brush should be filtered to remove moisture and any other accursed foreign elements.
Curing temperatures vary according to the composition of the component being coated and the coating material. As a general rule, aluminum parts are cured at 350 F and iron parts are heated to 425 F; metallic/ceramic header coatings usually require curing at 500 F. Usually a baking time of one-half hour to an hour is specified. But, coatings can be allowed to air dry; a running engine provides the heat for curing after the component is installed.
Custom coatings are usually sprayed on a component with an air brush. Carl Benton of Polymer Dynamics is shown here coating a piston. Note that Benton is wearing the necessary safety equipment, i.e., safety glasses and a mask protect him while rubber gloves protect the part being coated. Finger oils can interfere with proper adhesion of the applied coating.

Virtually all types of coatings, including thermal barriers and dry film lubricants, are available for do-it-yourself application. As opposed to the coatings used by commercial applicators, the materials sold by Tech Line and Extreme Performance are largely water-borne as opposed to solvent borne. The latter-types of coatings cannot be cured in a standard oven because of the hazards associated with solvents.
As might be expected, inhaling any of the mists or fumes that are part of the coating or curing process should be avoided. Water-based coatings don't emit any harmful fumes during curing, but some mist undoubtedly fills the air during a spray application. The proper protective equipment should be worn when any coating materials are applied. Extreme Performance Coatings offers some coatings that can be brushed on, thereby eliminating concerns associated with inhalation of a spray mist.
Prior to the actual application of a coating, a part must be absolutely clean. A light, low pressure sand blast with fine aluminum oxide or sand is recommended. Blast pressure should be set to 30-40 psi in a siphon-type sand blaster.
The question of the day is, of course, whether self-applied coatings are of the same quality as those that are commercially applied. Answers vary according to the allegiance of the answerer. Commercial applicators obviously view the integrity of self-applied coatings with skepticism and disdain. Representatives of companies selling coating materials see things in a somewhat different light.
Objectively, the nature of the application and the volumes involved will determine whether commercial or self application is most advantageous. But irrespective of application method, coated engine parts appear to have a silver lining.


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 Post subject: Re: Calico coatings
 Post Posted: Thu Jan 19, 2012 4:58 pm 
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OK then!!!!!!!! Thanks =;

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 Post subject: Re: Calico coatings
 Post Posted: Thu Jan 19, 2012 10:51 pm 
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It's a bit dated, but does cover most of it.


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 Post subject: Re: Calico coatings
 Post Posted: Fri Jan 20, 2012 6:20 am 
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I had my piston's done...I will get some pic's later and post them..
http://www.calicocoatings.com/industrie ... ve-racing/

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