Some silicones don't hold paint well, however, and they don't bond to rot-resistant woods such as cedar, redwood and pressure-treated wood.
Can You Apply Silicone Rubber After Sealing a Wood Surface? If you seal the wood surface with at least two layers of a high quality clear acrylic spray (Krylon Clear Acrylic), both tin-cure and platinum-cure silicone should cure without signs of inhibition.
Generally, silicone RTV mold making rubber does not stick to anything, and nothing will stick to it. The exception is that it will stick to itself, other silicones, silica, and glass.
Loctite Polyseamseal Acrylic Caulk with Silicone bonds to wood, drywall, plaster, metals, brick, concrete, and masonry and can be painted within half an hour if you are using latex paint.
There are no guarantees with silicone - it is almost impossible to remove. If the silicone has migrated into the wood through cracks in the old finish, you may not be able to get it all removed.
You can't caulk with silicone when a surface is wet or damp, and it can be hard to ensure that porous materials like wood are truly bone-dry when they often retain moisture for long periods of time.
Silicone-based caulks are excellent for many applications, but they do not work well on wood. Silicones are formulated for use on non-porous surfaces like metal, plastic, or glass. However, wood is porous, and silicones do not adhere to either damp or dry wood.
When treating wood, you have the option of water-based polyurethane or oil-based polyurethane. Oil-based sealant takes longer to dry than water-based, but it doesn't require as many coats. It's also higher in VOCs than water-based polyurethane.
If desired, the polyurethane can be heat treated prior to being coated with the silicone-rubber material. The silicone rubber can be applied at room temperature immediately after the polyurethane has been heated.
Polyurethane has an excellent tensile strength and great abrasion resistance, whereas silicone has good tensile strength, but poor abrasion resistance. For dynamic applications subject to friction and wear, polyurethane would most likely be a better option.
Sealing joints on a damp surface should be strongly avoided, since silicone sealants generally do not adhere as well to moist substrates. If you want durable joints, never apply sealant in rain, freezing rain, snow or heavy fog.
The simple answer is yes, you can use silicone as glue. But you will need to consider how strong you want the bond to be and how much you want to spend on a high-quality silicone before using it to seal and bond.
Features excellent adhesion characteristics, high chemical resistance, and will not sag or shrink. The high temp "Red" can withstand intermittent temperatures of up to 650° F. All colors can withstand pressures up to 350 psi. Offers unmatched performance under the most severe operating conditions.
Painter's caulk adheres to wood, drywall, masonry, and other surfaces. And because it dries to a paintable texture in about an hour, it's a good choice for busy DIYers.
Although silicone mold rubber (Mold Max®, OOMOO® and Smooth-Sil®) won't stick to much and has the best release properties of the most common mold making materials used today, it may stick to surfaces with open pores (open grain wood, very dry plaster, concrete, etc.).
Caulking First
Under normal circumstances, you can apply caulk before priming; however, if you're working on certain surfaces, the caulk will not stick without a primer base coat. Caulk adheres very well to clean, bare wood and vinyl. Unfortunately, it will not stick well to stained surfaces.
“Sealant” is the general and correct term for the chemical used to seal. “Silicone” is one type of sealant. There are also acrylic sealants, polyurethane sealants etc. Silicone sealants are the most prevalent type of sealant.
Cyanoacrylate adhesives generally bond well to PU, with grades such as the Permabond 731 and Permabond 2050 being best suited for elastomeric PU.
Silicone sealants can stay waterproof for around 20 years, but this varies according to different factors including temperature, UV exposure and the chemical properties of the sealed materials.
Sometimes known as acrylic latex caulk, this type is best for use with drywall, wood and masonry. It's often called "painter's caulk." This caulk is inexpensive, easy to use, seals well without odors and cleans up easily with water.
Thompson's Water Seal 24101 Clear Multi-Surface Waterproofer
This product is highly versatile and can be applied to a wide range of surfaces, including pressure-treated wood. It will effectively seal it from water so you won't have to worry about any wood rot setting in.
* If cost isn't a consideration, the new tri-polymer or copolymer caulks are the best choices for versatility (about $4 to $6). Proflex by Geocel and Lexel by Sasho are multi-task sealants designed to adhere to dissimilar surfaces such as metals, glass and untreated and treated wood.
No. Silicone is not affected by extremes of weather – hot, cold, dry, wet, or humid. It also has excellent resistance to UV and ozone degradation.
You will not want to use the silicone caulk prior to finishing the top as the Waterlox® Tung Oil finishes may change the color of the caulk and will also not adhere to silicone.