Dowsil 795 Silicone Sealant
Description
Dow-manufactured one part cold-applied non-sagging silicone material that cures to medium modulus silicone rubber upon exposure to atmospheric moisture. The one-component room temperature vulcanizing (RTV) silicone was introduced in 1960. It has typically been used for case manufacturing in case construction and sometimes mount fabrication. Designed for setting glass in mounting systems and allowing for some movement of the glass within the structure.
Synonyms and Related Terms
Diisopropoxydi(ethoxyacetoacetyl)titanate -Concentration >= 0.5 - <= 1.1 %, Silicone elastomer Adhesive, silicone elastomer, room temperature vulcanizing (RTV) silicone
Applications
Building sealant/adhesive Metal-to-metal bonding Glass-to-metal bonding Glass-to-wood bonding Metal-to-wood bonding
Personal Risks
Wear eye, hands, and respiratory protection. SDS: [1] pdf
Collection Risks
Silicone is said to have no significant volatile components. Some silicones have curing byproducts of ethanol, peroxides or ketones. Risk to museum collections could occur if an object comes in contact with the sealant causing possible staining or adhesion (if not fully cured).
Physical and Chemical Properties
The cured sealant is durable and flexible enough to accommodate a +/- 50% movement of original joint dimension. A one-part neutral cure RTV (room temperature vulcanizing) silicone sealant. Excellent weatherability virtually unaffected by sunlight, rain, snow, ozone and temperature extremes of -40°F (-40°C) to 300°F (149°C).
Working Properties
It is good to use when a flexible adhesive is required. Curing time depends upon humidity and it will initially cure (to the touch) quickly, but the full cure can take a long time. In 50% relative humidity (tack-free to touch: 4 hours, curing for handling: 7-14 days, full adhesion: 21 days). If you are trying to create a sealed case with a low air exchange rate then the flexibility of the sealant may make this difficult. It can be difficult to work with and keep everything clean.
Forms and Sizes
Black, white, gray, dusty rose, charcoal, spruce, etc. (colored) - Available in 15 standard colors and can be ordered to match any substrate. DOWSILTM 795 Silicone Building Sealant is supplied in 10.3 fl oz. (305 mL) disposable plastic cartridges that fit ordinary caulking guns, 20 fl oz. (590 mL) sausages and 2 and 4.5-gal (7.5 and 17 L) bulk containers.
Resources and Citations
Dow corporation technical data sheet - https://www.dow.com/en-us/document-viewer.html?ramdomVar=6429995798660647799&docPath=/content/dam/dcc/documents/en-us/productdatasheet/61/61-885-dowsil-795-silicone-building-sealant.pdf
Dow corporation product sheet - https://www.dow.com/en-us/pdp.dowsil-795-silicone-building-sealant.01595717z.html Skeist, Irving, Handbook of adhesives, second edition.Van Nostrand Reinhold Company, New York, 1977 Comyn, John, Adhesion Science, The Royal Society of Chemistry, Cambridge, 1997 Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002[[Category:]]