Join Date: Dec 2002
Thanked 0 Times in 0 Posts
Rep Power: 13
Teak deck sealing
I''m not specifically familiar with the TDS product, however, I’m not certain how valuable an “Oxime Cure” system would be in a deck sealant application. I don’t think the deck sealant should come in contact with (or close proximity to) any metals (susceptible to acetic acids) .
Acetoxy-cure silicones are one-part, solvent-free adhesives that react (catalyze) with moisture to form a thermoset elastomer with excellent flexibility at low temperatures and thermal resistance to 600̊F (316̊C). Upon cure, these adhesives produce acetic acid as a by-product, which can be corrosive to some materials.
Single part silicone sealers generally contain a cross-linking catalyst (such as a tin compound) that is activated upon exposure to moisture in the air.
Since the acetic acid is released during curing, it can attack the underlying substrate material. This can cause corrosion of certain metals and prevent the proper adhesion of the silicone. However, on other materials, the acid can etch the surface slightly and increase the adhesion. Aluminum is one such material. Copper and zinc, however, are
corroded by the acid. Thus brass and galvanized steel should not be used with silicones which release acid. Dissimilar metals can form electrolytic couples and corrode severely underneath a covering of acetic acid releasing silicone.
A catalyzed moisture cure system, Oxime-cure silicones are also one-part adhesives that react with moisture; however, they produce an oxime (alcohol methylethyl ketoxime) rather than acetic acid. This byproduct smells like latex paint. Consequently, their by-products do not corrode ferric substrates, and generate a less pungent odor than does acetic acid.
A condensation cure system which liberates no corrosive (to metals) by-products upon curing. Alkoxy/Alcohol cure systems (Oxime) are neutral cure.
Dow Corning Construction Americas Technical Manual
Synthetic Rubber-Based Adhesive Sealants
From "The Practical Sailor Library - Volume IV - Do-It-Yourself Improvement Projects"