Powder Coating vs. Fluoropolymer Fini...

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Author Message Peggy White, CSI, CCS, CCCA, LEED AP Senior Member Username: peggy Post Number: 42 Registered: 07-2007 Posted on Monday, August 20, 2012 - 02:52 pm:    Hello Is there a published comparison of the performance and long term value of powder coating vs. fluoropolymer finishes? Or, does someone in this forum have an educated opinion? The application is exterior aluminum window assemblies, for the most part. Thanks in advance.... William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 868 Registered: 10-2002 Posted on Monday, August 20, 2012 - 03:03 pm:    Peggy, It depends on what the powdered coating really is. You can actually get powerized fluoropolymer. PPG markets this as their highest performance product for the most severe conditions, 30 year warranty. Their typical spray/coil coated 70% fluoropolymer (Duranar) is a 20 year warranty. For the most part, powder coatings are polyester or polyurethane based, and their warranties range from 5 to 10 years. And, you can't get the mica or metallic based colors in powder that you can get in the wet applied fluoropolymer coatings. William C. Pegues, FCSI, CCS, SCIP Affiliate WDG Architecture, Washington, DC | Dallas, TX Dave Metzger Senior Member Username: davemetzger Post Number: 440 Registered: 07-2001 Posted on Monday, August 20, 2012 - 03:05 pm:    Peggy: Powder coating is a method of paint application, not a specific paint type; different paint types can be applied using powder coating. I understand that fluoropolymer resin systems (PVDF) can be applied by powder coating and that they can be formulated to meet the requirements of AAMA 2605. I don't know whether there is a difference in performance between PVDF systems that are spray/solvent-applied and those that are powder coated applied; I'd be grateful if someone with more experience in this than I have could advise on this. The most-used powder coating paint types have been polyester. They do not have the weathering performance of PVDF systems but they are harder and resist abrasion better than do PVDF systems. Robert E. Woodburn Senior Member Username: bob_woodburn Post Number: 10 Registered: 11-2010 Posted on Monday, August 20, 2012 - 03:44 pm:    I don't know of a published comparison, but here's an "educated opinion" based on what I learned some years ago from a client of mine that was a leading powder manufacturer (later bought out by DuPont): Keep in mind that powder coating is a process, and the powder itself can be based any of a number of very different resin "families" (epoxy, polyester, etc.), each of which has potentially infinite variations, and not all of which are UV-resistant enough for exterior exposure in the first place, let alone for a long time. In fact, the powder coatings available at that time were intended solely for use underground (e.g. epoxies, for pipeline coating) or interior use (polyesters, for furniture, office machines, etc.). In contrast, the fluoropolymer coatings used architecturally are essentially a single product; Kynar 500 and Hylar 5000 are basically identical, but they are made by two different manufacturers to avoid the need for sole-sourcing. And fluoropolymers have a long history as the coating with the greatest longevity--some are now warranted for more than the 20-year term that they originally were thought to be capable of, because experience has verifed they last longer--at least 25, maybe even 30 or 40 years or more, depending on the application, etc. Though powder coatings have one main advantage over liquid-applied coatings, in that since they are fused or melted in place, there are no microscopic internal pores or pathways formed by the solvent evaporation common to liquid coatings that eventually let corrosive elements reach the substrate, the powders developed for exterior UV-resistant use just haven't been around as long as Kynar/Hylar have. Robert E. Woodburn Senior Member Username: bob_woodburn Post Number: 11 Registered: 11-2010 Posted on Monday, August 20, 2012 - 03:51 pm:    Duranar is, I believe, PPG's trademark for its coatings based on Kynar or Hylar resin (other manufacturers have other tradenames for their coatings--but they all, as far as I know, use the same basic fluoropolymer resin). Combining the powder coating application process with a powder based on proven Kynar/Hylar chemistry would seem to combine the best of both worlds. Wayne Yancey Senior Member Username: wayne_yancey Post Number: 536 Registered: 01-2008 Posted on Monday, August 20, 2012 - 04:16 pm:    Peggy, E-mail me at wayne.yancey@callison.com for a PowerPoint persentation by Tiger Drylac powder coatings. It has side by side comparisons of power coating vs. liquid coatings. It is what is is. Wayne J. Peter Jordan Senior Member Username: jpjordan Post Number: 480 Registered: 05-2004 Posted on Tuesday, August 21, 2012 - 10:57 am:    New "Kynar" coating lines will almost certainly be lines for powder coating. It is my understanding that there are a lot of EPA hurdles to pass to install a new liquid-applied line. Scott Piper (Unregistered Guest) Unregistered guest Posted on Monday, August 20, 2012 - 04:45 pm:    In our experience the only advantage of powder coating on an exterior product is for the abrasion resistance. We have used some powder coating on metal hand rail systems with success (thus far anyway. more years of wear and tear are required before we will know for sure). Of course the type of material you are powder coating does make a difference as already stated above. For windows, roofing metal, etc. there does not appear to be an advantage that would make it worth our trouble. I admit this is only anecdotal evidence but I figured I would put my two cents in anyway. Lynn Javoroski FCSI CCS LEEDŽ AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 1541 Registered: 07-2002 Posted on Wednesday, August 22, 2012 - 10:12 am:    This just in: http://www.durabilityanddesign.com/news/?fuseaction=view&id=8265&nl_versionid=2292 "Professionals who are looking to improve good technical practice in specifying and using coatings on architectural metals can get free expert guidance from a new eBook by Durability + Design." Peggy White, CSI, CCS, CCCA, LEED AP Senior Member Username: peggy Post Number: 44 Registered: 07-2007 Posted on Friday, August 24, 2012 - 12:47 am:    Thanks everyone - this came from a project contractor looking to save some money. My impression was that they are not planning on powderizing fluoropolymer, but rather that they are going with a polyester based powder coating application. bhargav.admar (Unregistered Guest) Unregistered guest Posted on Monday, March 24, 2014 - 04:22 pm:    is powder coating & p.v.d.f coating process are same? if not then plz guide me for p.v.d.f coating. J. Peter Jordan Senior Member Username: jpjordan Post Number: 710 Registered: 05-2004 Posted on Tuesday, March 25, 2014 - 07:31 am:    Not to belabor the point made by others above, but PVFD is a product, more specifically a type of coating resin, while "powder coating" is a process. Resins used in powder coating include PVDF as well as polyester, urethane, and epoxy (not typically used for exterior applications). Not all powder coating applicators will offer all resins. In my experience, polyester is the nost common, but the epoxies are used in lab applications. Moreover, gloss will vary. The powder coated PVDF finishes will be the most durable in term of color and gloss retention so are typically used for exterior applications. Not to muddy the waters too much, but powder coating is confused with electrostatic painting in which a liquid paint is used. Brett Scarfino (Unregistered Guest) Unregistered guest Posted on Tuesday, April 22, 2014 - 06:18 pm:    Peggy to your original question, for aluminum window extrusions we recommend a PVDF paint. It could be applied with wet spray or powder coated as long as it meets spec requirements, and your happy with how the finish looks. In either case, PVDF is typically baked/fused to the surface at high temperatures (500-degrees) after it has been applied. You could consider allowing a polyester or some lesser paint product for interior portions of the frame where UV exposure is minimal.