Adhesives and Sealants — FAQ
What's the difference between 5X and 7X adhesion?
The 7X formula contains higher concentrations of silicone polymers and adhesion promoters. For high-movement joints and constant water exposure, 7X provides extra insurance against failure. 5X works fine for standard applications.
Can I apply new silicone over old caulk?
Never. Old caulk must be completely removed with a utility knife and caulk remover tool. Clean the joint with alcohol, let dry fully, then apply new bead. Overcaulking guarantees premature failure.
How long before water exposure?
Wait full 24 hours for cure. While silicone skins in 30 minutes, internal curing continues. Early water contact causes whitening and adhesion loss. For shower enclosures, wait 48 hours before first use.
Why do my caulk beads crack after 6 months?
Generic sealants lack elasticity modifiers. Use contractor-grade silicone with crack-proof guarantees. Also check joint depth—caulk performs best in 1/4-inch gaps. Deeper joints require backer rod.
Clear or white silicone for my project?
Use clear for natural stone, glass, and when you want an invisible seal. White works for porcelain fixtures, painted trim, and standard tile. Never use white on marble—it will stain.
Do I really need a caulk gun for 10 oz tubes?
Yes. Squeeze tubes lack the pressure control for consistent beads. A quality dripless gun costs $15 and pays for itself in one job by preventing waste and blowouts. Essential for pro results.
