The Aluminum Restoration System

OR-80SLM Silver Lining Membrane is a pure polyurea — an amine-terminated resin reacting with isocyanate, with no polyol extender and no catalyst. That chemistry matters on a roof for one reason above all others: it is not moisture-sensitive during cure. It will spray on a damp deck at dawn and it will not foam or blush.

The two components meet at the gun at roughly 2,000 PSI and 160°F, impinge, and gel in 3 to 6 seconds. Tack-free follows in 10 to 30 seconds. The practical consequence on an aluminum roof is that a crew can spray a full day's section and have it weathertight before an afternoon storm — no overnight exposure, no partial-cure washout.

Because it is 100% solids there is no shrinkage on cure and no solvent to entrap. Every wet mil is a dry mil. On a substrate that is already moving under the film, eliminating cure shrinkage removes one of the two stresses on the bond line; the elastomer's 300–400% elongation absorbs the other.

Do not spec SP6. A commercial blast profile is the right answer on structural steel and the wrong answer on 0.032" aluminum panel. The panel will oil-can, distort at the ribs, and in bad cases perforate. Aluminum wants a uniform matte, not a 3-mil angular profile.

Degrease first, always. Mill oils, roll-forming lubricants, and years of atmospheric film all sit on aluminum without visibly staining it. Detergent wash and rinse before any mechanical work — abrading a dirty panel just drives the contaminant into the new surface.

Abrade, then beat the oxide clock. Brush-blast at low pressure, or use abrasive pads on smaller roofs, to break the existing oxide and give the primer something to key into. Aluminum begins re-oxidizing immediately and has a meaningful skin back within the hour. Prime the same working session — not the next morning.

7001 Primer is required. On blasted steel, polyurea can go direct. On aluminum, it should not. 7001 is a quick-set, multi-surface adhesion primer that bonds through the thin fresh oxide and also blocks bleed-through when you are going over old aluminized asphalt or a failed acrylic.

Coastal roofs: verify chlorides. Salt below 7 µg/cm². Soluble chloride trapped under any membrane will osmotically blister it, and marine-exposure aluminum roofs are the most common place we see that failure. Wash, test, and retest if needed.

Detail the dissimilar metals before you spray. Steel fasteners, galvanized flashing, and steel curbs get primed and stripe-coated first so the membrane fully encapsulates the junction rather than terminating at it.

On low-slope aluminum industrial roofs, closed-cell spray polyurethane foam is often applied first and OR-80SLM becomes its weather surface. Two problems get solved at once: the foam adds R-value across the whole deck with no thermal bridging at the fasteners, and it can be tapered in the field to re-slope ponding areas that were never going to drain as built.

Foam has no UV resistance and no impact resistance on its own — it must be coated. Pure polyurea is the ideal weather layer over it because it goes on thick in one pass, moves with the assembly, and is walkable the same day.