from form to counter

I've spent the last couple of days working on the forms for the counter tops. We're doing poured in place counters. this way the large counter that is in an L shape can be seamless.
Also the cabinets make a nice level support for the forms and it seemed wasteful and expensive to build a bunch of sturdy temporary supports. We are now required to get it right the first time and the finish work will be a big deal. I spent 14 hours on Wednesday working on the form work and most of today was spent on the sink form though i only worked for about five hours and did some painting and a hardware run in between glue setting.

The forms look janky because they are built from scrap particle board. When shopping at Ikea for the cabs last year, i was snooping around the as-is section as usual. As i was snooping an employee rolled a doubled up cart loaded with scraps from cabinets and furniture that did not have a much individual value. The whole pile of of lumber, about 8'x2'x3' in volume was only ten dollars. I figured I could put it to good use and used just a fraction of it in the counter forms. Apart from four 8 foot 2x4's that we used to reinforce the legs of the cabs All the lumber is re-used scrap. I also ripped some of the wood paneling that we tore off the old kitchen and saved. less than $20 is a pretty good deal for 70 square feet of form work.

The inside of the sink was a little problematic. I thought some 1/8" masonite was going to work it seemed pretty pliable but it didn't quite get a tight enpugh radius before snapping. So architecture model making came into play. I had a bunch of chipboard left over (scavenged from the laser cutter room) also free and re-used. I didn't feel like cutting it into 2" strips by hand so I stacked up some pieces and ran them through the table saw! less than a minute to make 20 or so 4'x2 1/4" strips of card. The card is glued to the straight edges of the sink which is just wood blocks screwed into the sunken base. The base for the sink mold is just the cut out from where the old sink has been this last year. It's temporarily supported by a frame of 2x4's that are screwed into the inside of the cabinet. It is sunken below the rest of the plywood by 3/4 of an inch. after the concrete sets up, i'll unscrew the support and push the form out through the cabinet. This way the concrete cantilevers beyond the plywood base and there'll be a nice thick edge all the way around. The underside will be flush between concrete and plywood and supporting the undermount sink should be fairly easy. The mounting bolts are in place now and will become embedded in the concrete during the pour. The knockout for the faucet is a piece of 3/4 pvc pipe I found a 2 1/4"- 1" reducer bushing (PVC) and jambed a 3/4" straight coupling into the 1" inch end a snug fit! Then i sliced half of the bushing off and then half of the coupling. The coupling allows me to tightly fit the 3/4 inch pipe into the 2 1/4 inch bushing. A faucet only needs a small 3/4 or so hole to pass it's plumbing and fiting through but they aren;t manufactured to accomodate a 2 1/4" thick counter top. The bushing provides a enough room to get the nut a little ways up inside the concrete to deal with the short hardware.

Idealy the base for a concrete pour like this should be 1/2 inch cement board. But we needed countertops last year and cement wouldn't have held up. The plywood is sturdy enough but is prone to warping from the moisture of the concrete while it sets. however i did not want to endure the time and expense and waste of switching this elemnet out. especially seeing as it is really just a support for the counters while they set. I will place tar paper over the plywood before the pour and the small amount of moisture should be ok. All the wood is being taped with packing tape and caulked to deal with this issue also.

Cheung reccomends pushing plasticine into the screw heads so they don;t fill with concrete during the pour, and then become difficult to pull out. I used packing tape instead. it will hold up to concrete drips and when time comes to unscrew, the driver will just pop right through the tape, no picking out plasticine necessary! plus much quicker to set up.