We made some benches and picnic table tops with 45 deg edges by simply cutting a 1x1 into a triangle that was about 3/4 by 3/4 on two sides and putting that on the bottom edge and top of the form. Then fill to the top of the triangle and use that as your "scraping" edge. D
Iv'e done a few concrete counter tops using GRFC or glass fiber reinforced concrete. I make my counter tops 1" thick and cast them upside down on a formica table. Any edge detail is possible and I usually do a 1 1/2" bullnose with a cove underneath. The edge overhangs similar to a granite countertop so that my concrete tops look like they are 3" thick but they are only 1" thick. I use a mix of pool grade dolomite, sand, riverside white cement and dry pigments throw it into the mold and then trowel it down so it is about 1/4'-3/8" thick and wait a few minutes for it t gell up. I add an acrylic glue called Forton to my water so the cement firms up a bit in half an hour. I then make my next mix with the same ingrediants but a bit wetter and add vinyl coated choped fiberglass that I buy from my local stucco supplier. I have forms around the edge that are 1" thick and I make the conter top to that thickeness with no rebar except in front and behind a cutout for a sink, I use piece of 3/8" rebar and have it extend about 6" on each side of the cut out. The surface on my counter tops comes out with a lot of small holes and I then back fill with a slightly contrasting color and end up with a counter then looks like stone. If I want it to look more like concrete I make the frst layer very dry like damp beach sand and pack it down. It is important to paint a coat of forton on the dry pack as you trowel on the next layer. As soon as I am done troweling I cover the wet cement with plastic. the next day it will be ready to de-mold and flip but it needs to be supported evenly or it will warp. Full cure takes a month. surface finishing is the same as any other conrete. I like to weigh my color on a triple beam balance scl\ale and run it through a fine mesh screen into the dry cement. I mix it throughly which enables me to control the exact color and to be able to match a whole kitchen. Pathcing color cement is tricky because if you use the same mix to patch with it will look darker. Do lots of samples and have fun with it.
Excellent post red. I'm not quite getting this part though and I like the illusory thickness idea. Do you have any pics?
Ok, new plan. Buying the DIY kit from Cheng! Seems pretty fool proof, even for this fool! Now I need a weekend with 40 degree weather so I can mix it in the garage but still hose off the mixer outside when I'm done.
I did concrete counter tops and a matching table for my house a few years ago and they turned out really well, although the next thing I do will be even better because of a couple of things I learned. At this point it's probably too late for advice, but the biggest recommendation I can give is to pour it upside-down and finish it outside. I know your piece is going to be huge but you can carry it with enough friends. Wet finishing is a big mess and must be done outside the house. I used Quikrete's countertop mix and it did a great job, although I didn't vibrate it quite enough. I couldn't find any stores that sell the stuff, but Quikrete was great and gave me the number of the local rep who delivers to the stores, and he ordered some for he and had it sent to the local Lowe's. All the Quikrete people were just fantastic to work with. I'm very happy with the project and enjoy them so much more than the played-out granite that everyone gets. They look great and feel great. Can't wait to see your results!
Don't think I have any at the moment. I know I didn't take any during the building of them. I'm not much of a picture guy. I just spent a week vacationing at Vail and didn't even take any pics. It's strange because I used to be all into it. Had a darkroom in the basement and everything.
We had them made so I can't help you with the process. Loooooove the look and feel but having problems with the finish. Anytime anything acidic get on them it leaves a mark. It's fairly easy to repair if you keep up on it. Looking forward to what you are going to use for a finish.
Do you know what kind of sealer they used on yours? I've heard that with some kinds you just have to accept that the counter will take on some "patina" over time.
I just did the grinding on my test piece, it was so easy, almost fool proof! Smooth a silk, pretty impressive actually. Now to seal it. I have the Pretecrete product, and the sealer from Cheng, I will do both sides and see which one looks and performs best! I will post my results in a week or two after some liquid and heat testing on both! Chengs sealer is looking for a wax after sealing to really shine it up and I am a little worried about that.
remodeling a bathroom, and haven't been happy with any of my countertop choices a friend mentioned concrete, which is interesting. watching and waiting!
oK, poured the counter top yesterday! I looks great! I followed the directions Fom Chng to the letter. The surprising part was how dry the mix was when we poured, and I use that term lightl. The concrete seemed barely wet, after working it in with our hands (wear gloves ) into all the corners and all around under the rebar etc. I was surprised again at how water came up to the surface! I will get all my pics of the process up by the end of the week. And then I will take lots of pics of the polishing process also. I am going let it set up for a week which I know is about three days more than necessary. But don't want to take any chances when removing the mold!
The water cement ratio is a big factor in strength. Any mix that can be worked at all will have more water than needed to fully hydrate the cement. This is the bleed water you see coming to the surface. The "self leveling" mixes most contractors use, can lose 25% of the design strength. They will be cracked later. rom your description is sounds like you used the correct amount of water. You should have good results. Rod
Ok, here's a link to all of the photo's, I have no time to upload them at this time, anyone else wants to do it for me, thanks, otherwise I'll get to it soon, maybe! link
I did concrete counter tops in my kitchen. After you pull the forms if you don't like the edge you can still trowel on more concrete, or grind them. You don't want a crisp edge. You'll be surprised how much you can do after to fix edges, holes, whatever. I sealed mine with a colored epoxy and after 10 years they still look like they did the first day. Make sure and use diamond mesh vs. wire or rebar.
Hey Guys, I was wondering if you have tried the mix from SureCrete? I do custom furniture,(steel and concrete) and this is the shit. It can be poured as thin as half-inch and has 7000 psi after about 12 hours. I will send pics to someone if they want at ptrentham3563@charter.net, just make sure and specify concrete questions. I just finished a 4'x4' coffee table, that has no mesh, no rebar. etc. and you can stand in the middle and it does not budge. It also is only 5/8's thick and only weighs about 140 lbs. You can find the website at www.SurecreteDesigns.com. This also is totally Eco-friendly and when sealed is very, very scratch resistant. My ole lady had finished this one with 600, 800, and 1000 grit automotive paper and we then used Maguire's auto wax and have a mirror finish that cold beer will dance off of. Just thought i would make a comment and Everybody, Ride , Ride, Ride. Hawghead
