** Durham's Rock Hard Water Putty** ** **I have worked construction for many years now and have seen so many products come and go. There are so many needs in a job such as building goes.The way things are done or held together changes every day.I have nailed wood, screwed it together and even glued it together. There are always small defects no matter what way you do the job. So you have to make up for these. Well I am 56 and this product was created before my time even.It is not a glue nor is it an abrasive substance that can be harmful and is so easy to use.The product comes in a cylinder canister and is just powder. You use it to fill cracks in floors walls small dents in wood, plaster, tile,and concrete. The product will not shrink and dry it is rock hard. I have used it for years in new and old houses.They say they have a new one to fix some plastic. This I have not used so I can't tell you about that.On a unlevel floor you can smoothit out to make ready to put flooring down or walls in cracks for painting and or tile. You can find many uses and it is water activated so just mix it thin or tick depending on use on a wall or floor but dont over mix if you make a lot you need to be ready to use it.You can not add water to thin it back again.Very practical for self home repairs do not need gloves from any type of abrasive.Would still not put for a small child to mess with.This is a very good product that does what it is intended to do. I have had it to use myself not just at a job and would use again. Will not go bad if kept dry.