I have a public bid project that specified PPG Duranar for a metallic flake finish over coil and extruded metal and aluminum materials. There is a LOT of coated material on this project. The project is located very near the ocean (within sight of water).
The contractor has submitted a substitution for Valspar, and I am looking for tangible feedback from others about the merits of one verses the other.
Specifics:
Duranar system is a 4 coat system comprised of A) Primer coat, B) Barrier coat, C) Finish/Color coat, D) Clear top coat. The finish color coat is true metal flake.
Valspar system is a 3 coat product (no barrier coat) and uses mica instead of metal flake.
The colors are similar enough that if used uniformly, is not a significant factor in this consideration.
Cost is a factor. The 4 coat metallic Duranar is a change from an originally specified 3 coat non-metallic Duranar finish. The Valspar system is thought to be a no-cost change, whereas the 4 coat Duranar reflects a cost increase to the client.
The origionally specified finish was a solid color, not metalic. 3 coat is adequate for the origional color/finish. When it changed to metalic, Duranar said a 4 coat is required for their product. I have sufficient history with PPG applications to approve it without any qualms. I do not have a similar history or familarity with Valspar. The technical comparisons appear similar other than the points I listed above. I do not know what the impact those differences will have. This is a public bid project, I have very limited abilitiy to hold a spec on an item where equivlants are allowed by law. As stated above, there is a substantial amount of coated material on this project. A failure would be unimaginably expensive to repair. It is difficult to accept and approve one over the other based on technical data alone. I rarely specifiy products based soley on technical data.
Aesthetics are a consideration, but if Owner and designer approve, that becomes a non-issue.
The major concern is the durability, which you have addressed with the 20 year warranty, to which both manufacturers agree.
Do they both state that harsh environments (salt water) are OK with the specific system?
the products are comparable, especially with the same warranty. in the original Duranar, the metallic “color” comes from metal flakes and its necessary to have a topcoat on that product to prevent corrosion. if the Valspar is using Mica, then corrosion isn’t a problem with that formulation. I’ve generally taken that substitution if the designers like the valspar product – the Duranar four-coat is a little more subtle and on some projects the designers care about that.