Kohler does have touch up paint they can send you. I asked for it when my second tub from the arrived chipped on the edge. You just paint it on but in my case, they sent two colors that have to be mixed together. I have the sea salt color cast iron jacuzzi tub.

Only a two part epoxy type substance will have a prayer of holding, and even that is not a permanant solution. Porcelain over cast iron is basically glass that's sprayed on in powder form and then heated to liquify. When it cools, it's a solid glass coating over the steel. Glass, although strong, is brittle, as you've discovered. And, glass is very very difficult to bond anything to. Once the porcelain chips and the iron has come into contact with air and water, it's gonna rust and eventually that repair is gonna come out. The good news is that it takes a really long time for a cast iron tub to rust enough to become a leak issue. The bad news is that spot will be ugly (and expand) the whole time until you can't stand it anymore and replace it.

You should be able to get an idea of the weight from a spec sheet. Kohler could also tell you, if all else fails. UPS may have a max weight they can handle (since their delivery drivers couldn't handle a 150 lb item by theselves.) But they might have a deal to package the item and get it to a motor freight company - for a fee, natch!. I'd be surprised if the sink actually weighs as much as 150 lbs, unless it's some kind of vintage behemoth. Modern stuff is usually designed to be shippable. I have several heavy cast iron sinks and none weigh any where near that much. I know because I just shifted my stash around in the barn last month and while some were heavy, none were beyond my strength. And I am a 63 yo female.. The sellers will probably be happy to take it someplace that will see to packing and crating. Then they'd not be liable for any damage claims during transit. Good luck! L..

We inherited a Kohler Heartland cast iron sink when we bought the house and I love it. I decided to keep it when we changed out the countertops and I had the undercount sink in our other home and this one has A lot of room inside. When I need to clean it I use Mrs. Meyers llama purpose cleaner, baking soda scrub, or the vinegar scrub. It’s holds up very well. Most of the time I just use Dawn detergent. Good luck! If you are worried Joseph Joseph makes some fun tubs with a drain you can wash or dry your items in but you still have to clean those really well at times.