try ripping a length of pvc to incorporate into your edge moulding. if you can rip it straight, you'll have a perfect round edge.
cast the bullnose into the counter top, and once it sets up, and while it's green, gently remove the sides of the mold and hand polish the top and edges.( no power tools!) it takes quite a few day to atain full strength. 1/2 rebar sounds like too big to me, i think i'd used #10 wire grid, instead and see to it that is in the center of the cast. also if you have some cut outs to make, make sure that they are cast into the pour(stryofoam works good for this) good luck on the project
Fine Homebuilding has done a few articles on this. Type concrete counter top into their search bar and you will get lots of reading material. Good luck, concrete looks so nice polished. http://forums.finehomebuilding.com/
Regular cements tend to entrain air as a resistance to freeze damage. This is bad for counter tops. So I would strongly recommend getting a counter top specific mix. Use the exact amount of water the mix suggests, it will seem dry, but it will work. Don't use hot water for a faster cure. Slow is stronger. They also make 3/8 rebar, it would be a lot easier to work with. 1/2 will not hurt anything though. Rod
+1 on a slow cure. Haven't poured any countertops yet but I've poured lots of slabs and I keep them wet for a full month. People, mainly licensed contractors, laugh at the long curing time but my slabs do not crack. Skinners countertop looks big enough to build up significant internal stresses, so proper cure is really important. I don't know if rebar actually does a whole lot to prevent cracking, I think mainly it serves to hold the pieces together after it cracks. I think I'd go with wire mesh reinforcement over rebar in this case. Looks like a good and interesting project. Skinner are you going to stain or otherwise color the surface? I've experimented with etching stains on concrete and it sometimes looks very good. Bob
I will add color to the mix, the wire mesh sounds like a good idea also. I do have a product that is added to the water to help reduce air also, plus a densifier that is sprayed on top of the concrete after finishing that helps strengthen and seal. I'll add the names of them later as they are in the garge and I am on the couch right now. But both are from protecrete.
when not working on the countertop,keep the whole project wraped with plastic sheeting...and in close contact. water is part of the cure. i have seen fiberglass threads mixed into cement to improve the reinforcing. not entirerly shure how to do this without it showing up in the finshed surface
I'm following along here because I've always wanted concrete countertops. In my application though we could cast upside down in melamine forms, which supposedly gives a really nice surface without having to have any skill as a concrete finisher. I've read that you can deal with the glass fibers by playing a propane torch over the surface after it's cured to just burn away any that show up on the surface. I'd want to test that on a sample first though, obviously.
Cast upside down as above, and you use a bead of silicone smoothed into the bottom corner of the mold (this will be the top), with your finger to get the gentle round-over. That's the way I've seem it done.
Ok, I'm fully committed now! just ordered this concrete finishing set! Some of you have said you are going to try this project depending on my results. I don't see a need for this tool after this, so, depending on how much fun this is, the set may be for sale for half price after I'm done with it! Of course I hate selling bikes, guns or tools. so we will see.
I'm doing concrete countertops no matter how yours turns out! I bet if you're happy with your results that you may want to do them in your bathrooms!
There IS such a thing as an edging tool that'll give you a rounded top edge. Used mostly on sidewalks. It's used during troweling.
Yes I have one, but that leves other edges, I found on th site that bought the polisher they have a grinder/ profiling bit that rounds I off. But I am now happy with square edges. My test pieces have confined that. I won't proceed until I have successfully polished my test pieces.
I too am doing concrete counter tops in my house. I did one for my cabin and it turned out good. I poured it upside down with broken slate tiles in, they look like fossils when it was done! Do a goggles search and you will find edge forms of every kind, it will be a lot less work with an edge form. I'm just a DIY kind of guy but mine turn out good. Next I am doing the counters in the house. I think it is worth buying the books that were in one of the earlier post.. I will try to dig up some pics..
