Q: How long does it take silicone caulking to dry?
A: Silicone caulking does not “dry.” Instead, it “cures,” and the cure time will vary from product to product, so you will need to check the manufacturer’s literature for specific times. Generally, most silicone products will be mostly tack-free in about an hour. Substantial cure will require about 24 hours, and full cure can be 7 days or more. While temperature effects the rate of cure, a bigger factor in cure rate is the ambient humidity, because these products need exposure to water in the air to facilitate cure. The manufacturer’s data will usually list a specific temperature and relative humidity (RH) at which their data is valid. Temperature or humidity levels that differ from those specified can either retard or accelerate the cure process.
Q: What is the resin material used to make resin-coated slabs?
A: The slabs are not actually resin-coated. The resin is screeded onto the unpolished slab surface. After cure, the slab is sent through the polishing line in which nearly all of the resin is removed. Only that which is in crevice or a pit will remain. In most cases, only a fraction of a percent of the slab’s surface area is actually resin, although this is entirely dependent on the surface profile of the slab, so it can be significantly more. This process can take place in highly sophisticated equipment, using metered resin components forced through static mixing tubes, vacuum tables to draw the resin deeper into the slab, and ovens to accelerate the cure. The process can also be done manually, depending on the factory. In either case, we have no knowledge of the actual resin product that is used. Most of the factories that I’ve visited are using an epoxy, but they might also use a polyester or any other type of resinous adhesive. Most suppliers do not disclose the fact that a resin has been applied (although you can usually see it on the slab edges), much less the actual product that was used.