Porsche Transaxle Powdercoat - How much heat?

[doozer]

I want to powdercoat a Porsche Transaxle but I dont want to tear it down to do it.

How much heat can a Porsche Transaxle take before it starts to have problems with seals, etc... ???

I can do a slow cure bake at 275F - 300F



This is the powder I am using " Near Chrome "

[Rot 911]

Todd personally I would never powder coat something that needs the air cooling to keep the fluid cooled down. On the other hand, I have no idea if the materials in powder coating transfer heat at a lower rate than bare aluminum of magnesium.

[doozer]

It has a ten pass external oil cooler with fan and Tilton pump so cooling should not be a problem with the minimal insulation of the powdercoat. Good point though..

[doozer]

Anyone know the material that Porsche uses for its seals???

Sealing Element or Lip Material
Many seal manufacturers use their own proprietary material. Where possible, these materials have been categorized into the generic equivalent or material family. Consult with manufacturer for proprietary material specifications._



__ Rubber or Polymer: ____ A polymer is a_solid, nonmetallic compound of high molecular weight the structure of which is composed of small repeat units (mers). Plastics and elastomers are polymers.
__ Your choices are...
_ ____ _
_
__ Ethylene Acrylic (AEM - Vamac®, etc.)
_ ____ Ethylene acrylic compounds provide high-heat aging resistance while providing good physical properties. They offer a high degree of oil, ozone, UV, and weather resistance along with good low temperature flexibility. Suggested operating temperature (-20° to 300° F). Manufactured under the trade name Vamac® by DuPont Dow Elastomers.
_
__ EPDM
_ ____ Good resistance to sunlight, weathering and ozone. It has poor resistance to petroleum oils and fuel. Good heat and compression set resistance. Suggested operating temperature (-70° to 275° F). Trade names include Nordel® (DuPont Dow Elastomers), Vistalon® (ExxonMobil Chemical), Epsyn® (DSM Elastomers), Royalene® (Uniroyal Chemical), and Epcar® (B.F. Goodrich).
_
__ Fluoroelastomer (FKM - Viton®, Fluorel®, etc.)
_ ____ A range of fluoropolymer elastomers whose formulation can be tailored to a reasonable extent to meet the needs of individual end-uses. They are normally black and have high heat, oil and chemical resistance but indifferent low temperature performance. With the exception of Kalrez® perfluorinated elastomer, they are about the most highly temperature resistant of all commercially available elastomers. Trade names include Viton® (DuPont Dow Elastomers), Fluorel® & AflasTM (3M Corporation), and Technoflon® (Montedison).
_
__ Flourosilicone (FVMQ, FMQ, FPM, FSI)
_ ____ The mechanical and physical properties are very similar to silicone. However, Flourosilicone offers improved fuel and mineral oil resistance but poor hot-air resistance in comparison. Suggested operating temperature (-100° to 350° F). Trade names include FSE® (General Electric Co.), Silastic® (Dow Chemical), and Sylon® (3M Corporation).
_
__ Nitrile (NBR - Buna-N)
_ ____ Good resistance to petroleum hydrocarbons and fuels. Widely used with most oils, hydraulic fluids, and alcohol. Many compound variations are available for specific applications. Suggested operating temperature (-30° to 275° F). Trade names include Breon® (BP Chemicals), Chemigum® (Goodyear), Hycar® (B F Goodrich), Krynac® (Polysar Ltd.), Nipol® (Zeon Chemicals), Nysyn® NBR, (DSM Elastomers), Paracril® (Uniroyal Chemical), and Perbunan® (Mobay).
_
__ Nitrile - Highly Saturated (HNBR)
_ ____ Nitrile has good mechanical properties when compared with other elastomers and high wear resistance. Nitrile is not resistant to weathering and ozone. Suggested operating temperatures from (-40° to 300° F). Trade names include Therban® (Mobay), Tornac® (Polysar), and Zetpol® (Nippon Zeon Company).
_
__ Nylon / Polyamide
_ ____ Nylon, comprising several grades of polyamides, is a general-purpose material in wide use; it is tough and resistant and has good pressure ratings.
_
__ Polyacrylate (ACM)
_ ____ Polyacrylate elastomers are well suited for use with extreme pressure (EP) lubricants and have high resistance to oxidation and ozone. Polyacrylates are not recommended for dry running applications. Suggested operating temperature (-25° to 350° F). Trade Names Include Cyanacryl® (American Cyanamid), HyTemp® (BF Goodrich), and Thiacril® (Uniroyal).
_
__ Polychloroprene (CR - Neoprene)
_ ____ A synthetic rubber that resists degradation from sun, ozone, and weather. It performs well in contact with oils and many chemicals. Neoprene remains useful over a wide temperature range, displays outstanding physical toughness, and resists burning inherently better than exclusively hydrocarbon rubbers. Neoprene also offers resistance to damage caused by flexing and twisting. Suggested operating temperature (-45° to 230° F). Trade names include Neoprene (DuPont Dow), Baypren® (Mobay), and Butachlor® (Ditsugil).
_
__ Polyetheretherketone (PEEK)
_ ____ PEEK is a high temperature resistant engineered thermoplastic. It has excellent chemical and fatigue resistance, and thermal stability. PEEK has superior chemical resistance, is inert to all common solvents and resists a wide range of organic and inorganic liquids. PEEK has a maximum continuous working temperature of 480°F and retains its mechanical properties up to 570°F in steam or high-pressure applications.
_
__ Polyoxymethylene (POM, Acetal)
_ ____ Acetal polymers are semi-crystalline. They offer excellent inherent lubricity, fatigue resistance, and chemical resistance. Acetals suffer from outgassing problems at elevated temperatures, and are brittle at low temperatures. Glass filled, and added lubrication grades are available, flame-retardant grades are not. Brand names include: Celcon (Hoechst Celanese), Delrin (DuPont), Thermocomp (LNP), Ultraform (BASF).
_
__ Polytetrafluoroethylene (PTFE- Teflon®, etc.)
_ ____ PTFE is an insoluble compound that exhibits a high degree of chemical resistance and a low coefficient of friction. It is sometimes marketed in proprietary classes of materials such as Teflon®, a registered trademark of DuPont Dow Elastomers.
_
__ Polyurethane / Urethane
_ ____ Polyurethane is a diverse class of materials exhibiting good elongation, recovery and toughness properties. They are flexible and have good abrasion resistance. (NOTE: The urethanes of the plastics industry are so named because the repeating units of their structures resemble the chemical urethane.) Trade names include Texin® (Bayer), Adiprene® and Vibrathane® (Uniroyal Chemical), Estane® (B F Goodrich), Genthane® (General Tire and Rubber), Millathane®, and Pellethane® (Dow Chemical).
_
__ Rubber - Natural (NR)
_ ____ Natural compounds such as gum rubber (polyisoprene) and latex.
_
__ Search Logic: ____ All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.

[doozer]

Called a buddy at p-car and he did verify that they are Nitrile (NBR - Buna-N)

[doozer]

Anyone know the operating range on a pcar tranny?

[randywebb]

There's a thread that talks about this. I don't think anyone knew - you could put a thermocouple in there and measure.

Also, find out what temp. Porsche was seeing right before they put coolers on their trannys.

[lateapex911]

are you doing the powder coating yourself, or using a shop?

[greglepore]

Most powder requires what, 350 or so to kick, so I'd avoid this on principle, not that I know anything about the seals etc involved.

[Jim Smolka]

To powder coat a gear box w/o disassembly will not work that well. To cure powder coating, the gear box metal (not oven temp), must reach 400 Degrees F for ~20 Minutes. Also, to get decent results, the parts must be cleaned and free of oil. Then the part must be preheated to allow gasses to escape. If you have an alum case, cleaning with a qlty brake cleaner and a brush will yield amazing results.

[doozer]

I have done low temp (275F-300F) long run with this powder and had good results.

I am doing it myself.

The seals I found have a maximum opp temp of 275F so I would be right on the borderline and I would have to really keep an eye on my temps.

The tranny is empty ( no oil ) and I would not think the temp would have an effect on the mech. of the tranny.

It is one of those things I know would work but would be a pisser if I messed it up.

[Jim Smolka]

Columbia coatings has a great book about powder coating. Worth reading. Yes, the powder will flow out around 250 degrees, but it does not bake into the metal untill around 400 degrees F.