DURHAM'S Rock Hard Water Putty - 4lb Container

This works really great. But a little goes a long way. I probably only needed to buy a 1 lb container. This price was so good that I had no idea that it was a 4 lb container when I bought it. I did not look close enough. This thing is huge! A four pound container of this is going to last me the rest of my lifetime. But I'll take it it's really great. Which is pretty easily just keep adding product if you have too much water vice versa. Goes on really easy. I had to fix a door jamb that was riding away and I didn't want to replace it because I have no idea how to check all that project. This was good for a quick fix. It's been about a year and holding up well. It really does dry like cement. Highly recommend.

This is a great product that should be in any DIY arsenal, especially at the outstanding price with the add-on program here. Costs at least double this at the local orange home center. This is a fine cream colored powder, you mix it with water. Mix it thin, it is a great pore/ grain filling skim coat. Mix it thicker, it's putty that will fill knot holes, etc. It says that it does not shrink but of course as it dries it will shrink a little, necessitating more than 1 application on deeper holes, etc. It also sands very well, you can get a great smooth finish on it. As with any putty it will take stains, etc but you always need to experiment prior to using it on your final project- it'll take stain, but differently than the surrounding wood. I mostly use it as a skim coat on plywood that I'll paint. I can save money with lower grade plywood, build my shelf/ cabinet etc, fill the grain and imperfections with this, sand it back flat and get a perfectly smooth & flat surface for painting. As the name says, it does dry rock hard, no joke. I would not say that it is structural- I guess you could mix in some fibers or aggregate to strengthen it, but I have not experimented with that yet. Anyway, if you build stuff, especially if you're a woodworker, you should have a tin of this stuff on the shelf. I just finished a tin that I bought 5+ years ago and it was still good.

Great product and works as it should. Much cheaper than other kinds of wood filler. I’ve been using this since I was in junior high in the 60s.

This stuff is great. Been using it for a long time and the results are always consistent. It doesn't shrink or crack. Easy cleanup. Nice and smooth, sands down easily, paints well. I dont stain filler so I cant comment on that. But i would assume you can get good results with a little experimentation. It dries a light pine color. Powder doesn't dry out in the containers like pre mixed, it mixes very easily and applies smooth. You dont need much water with this.

good stuff but you need to be aware of some realities of using it. the thicker you make the mixture the faster it dries to its rock hard final state. add water in very small amounts until you get a feeling for how much water to use because it is far too easy to add too much water and wind up with a mixture that is too thin for your need. it washes off skin very easily, but not clothes. you can use a wet towel to clean an area before the stuff dries but there will be a white haze when the area dries, the haze comes off with a second wiping with a wet cloth. if you use it on outside wood be aware that the wood expands and contracts with temperature change. this stuff does not. the end result is that there will be a fine "crack" where the putty ends and the wood begins. i suggest using a flexible caulk to seal the crack but you need to minimize the area the caulk is spread on (or paint the caulk when finished.) a tip: if you want to work on multiple filling points have a wet (not damp) cloth that you can use to wipe off the instrument you are using to apply the putty, otherwise the putty will dry on the instrument and make it impossible to immediately reuse. you will not be able to wash the cloth and get the putty off. update 10/10/20 it sets up rather quickly depending on how thick or thin the batch is. make small batches if you need to use it for an extended period (say longer than 15 minutes). you can salvage some of a batch that is starting to setup by adding small amount of water - but not the entire batch. since it is water based, drying time will depend on humidity and temperature. the more you use in one place the longer it will take to completely dry. it is readily dissolved by rain so when the top is dry and you expect rain, put a THIN coat of waterproof caulk on the surface to repel rain; you may want to sand it off. something i learned is that when using it outside temperature variation causes some, not much, edge separation. since the stuff dissolves in water, unless there is good drainage, seal (like using clear caulk) the edge to prevent water from standing in contact with dried putty.

Great stuff! I have used this over the years and have never been disappointed. It is easy to mix up just the right amount and not have any waste. Tool with any putty knife. Indeed, dries rock hard. But wait; there's more! It can be sanded smooth and re-coated, if necessary. I allow it to dry for 24 hours just to be sure, but that may be overkill. Keep container tightly sealed and it will last for years. Picture shows a knot-hole I patched in the bottom of a bathroom cabinet I repurposed as a paint-can cabinet.

This product is amazing stuff. Like the directions say its 3 parts powder to 1 part water which was pretty close to where i wanted it to be. I went for a light thick consistency that was able to stay in the mixing bowl when turned upside down but very easy to spread. This stuff has a pretty decent working time and dries pretty quickly once applied; My particular surface was dry to the touch within 30 minutes. Once this stuff dries, it is hard as a rock, which is exactly what I wanted. I have also not observed any shrinkage like with other products. It sands down nicely and doesn't fall apart and doesn't look half bad with poly on it either. I am super happy with this product!

This is a great material. I've used it on wood of various types. It dries very hard, so you want to make sure it is a smooth coat. My last can lasted for 20 years before I used it up. It never goes bad like regular wood putty. No smell, dries slowly.