Concrete counter tops

Ya I know nothing to do with boat building.Since boat builders are such handy type people was wondering if anyone had experience with making them?Looks easy enough ,make a mold,wax, pour in cement, vibrate.Not sure if Ill do cast in place or not.
Any tips? Thanks.

 

I've made quite a few of them. If you use Glass Fiber Reinforced Concrete use a mold so you get a clean face. Google GFRC concrete to find a supplier. You can make your own but some of the specialty mixes aren't mixed with water, they have their own solution. If you don't use a mold you will have all these little fibers sticking up so don't try it. The benefit to this concrete is you can pour it 3/4 thin and it's really strong.

If you go with self leveling concrete on top of a solid base, cast in place, you don't need a mold, only need to frame up your dams. This is an excellent product in that case - Industrial Coatings and Polished Concrete Flooring https://www.duraamen.com/

Vibrating is more important for the mold version but helps to break the surface tension on the cast in place as well. Check out the videos of what is possible, it's an amazing craft.

For cast in place, separate the base from the concrete with a sheet of plastic so the concrete can slip as it drys.

Use dyes to get color and seal with an epoxy, they have interior and exterior, some are rated as safe for food, forget how that goes. Duramen will suggest products for that.

 

This plastic stays in place i guess then?
The GRP seems to be all sprayed in?Ill just stick with cement and re bar.
My local Home Depo doesnt stock counter top cement but i may have found a supplier of the quickcrete stuff.
The acid wash look i dont like, almost looks fake,at least from videos,adding dyes to the concrete ill have to experiment with once i get the right concrete.

 

Season 1, Episode 7 of the DIY channel show Rock Solid had a good walk through. iIRC.

As for vibrating, it seems pounding the underside of the melamine mold with rubber mallets does the trick. I've seen it suggested as using a rub of olive oil as a releasing agent from the mold.

In addition to dyes you can use broken glass or pebbles of various colors, including the glow in the dark stuff if desired. You scatter these in the first layer of concrete and then once you demold and it is dry you grind the surface down to reveal them.

Don't forget to seal. Concrete isn't Paperstone or soapstone.

 

Yes, plastic remains. Any concrete will work, just depends on how heavy and thick you can go. This is my fishing shack in the keys. On the left is self leveling concrete with no dye, on the right I used black dye around the cooktop. You can't really see it but the left side has little patterns that form when you stir the stuff around. Both sides sealed with non toxic epoxy. Counter have lasted for over 6 years without needing a recoat and still look great.

 

Looks good.

 

Thanks!

 

The edges appear to be wood?

 

Actual concrete is only 3/4 thick, no rebar, no wire. I think I have 2 control joints total. The wood is an aesthetic choice, the rest of the house, including the furniture is built to match.

 

Rather than concrete countertops, consider stone veneer. You can now get stone cut so thin, it can be bend around bull noses, up backsplash fillets, etc. It looks like stone, feels cool to the touch like stone, needs to be cared for like stone, but is a fraction of the weight and cost, plus can be formed.

 

What is this stone veneer cut from, and if it needs caring for, how is it better than fake stone Laminex ?

 

Laminex is simply a high pressure laminate (Formica), while veneer stone is just as the name suggest, stone, sliced really thin often bonded to a 'glass or polyester scrim. It's real stone, usually about 2 mm thick (~1/16"). Look up flexible stone veneers.

 

Finding the proper cement at a reasonable price has been a challenge.I found a place for under $30 a bag so I;m off to the races.
Just need the proper tints now so i can experiment with the colors.

 

Lapsed civil engineering student here:
There are really only two kinds of cement: Portland and pozzolonic. Just about everything else is a variation of that, or an admixture. Pozzolons (fake sounding name) are what are responsible for Roman concrete (at least that's the current best guess). Volcanic ash mixed with sand, and possibly another alkali substance gives a different reaction than Portland cement.

What this means for you is that by adding some fly ash (there's a bunch of different stuff on Fishstone), your concrete will be significantly stronger, and significantly less permeable.

Other admixtures include:
- superplasticizer (concrete is stronger the less water you use. Superplasticizer helps it flow while keeping the % water down)

- set retarder/accelerator (just what it sounds like. Speeds up the set time, or slows it down)

 

A lot of things are used in concrete mixes to improve physical qualities. Silica and fibers are most common other than sand, metal and stone. Most of these are intended to improve compressive or elongative modulus. Plasticizers are common as are curing agents.