New build in Woking

[DuncanM]

Nope I've not been looking on Forno Bravo, why'd you ask?

yeah I knew I would need to fill the air pockets with a concrete slurry, then re-polish but as these were tests I haven't bothered. It's shown me what I needed it to. Plus if I had vibrated the concrete properly (read: at all) it would have reduced them number of air pockets greatly).

I have decided on a sealer for the main countertop yet, will look into that more in the future.

I glued the aggregate (glass and glow in the dark aggregate) to the bottom of the form with the same silicone sealant I used around the edges of the form, then during polishing it gets removed.

[turkey]

Apr 15, 2013 15:26:55 GMT DuncanM said:

Nope I've not been looking on Forno Bravo, why'd you ask?

I suspect its because the level of detail you are going to is very similar to the FB boys who can often go all out. Its a good thing, especially for us reading along

never saw polished concrete till the posts on pizza forums, it does look very good for what sounds like a "cheap" material.

[bookemdanno]

Those guys across the pond went for it big time last year!

All sorts of versions.

[DuncanM]

While I bide my time waiting for the glow in the dark aggregate to be shipped over from the states, I cast another test slab at the weekend to test two more aggregates:
1. Flaked mica
2. Mother of Pearl Chippings

I had high hopes for them both, but unfortunately the mica wasn't even worth my time. The mother of pearl on the other hand is beautiful. It was difficult to capture the luminescence properly in the quick photo I took this evening after a very quick polish.

Note, I did attempt to vibrate this test slab (partly anyway), but it doesn't appear to be much less air-holey than my first 2. I'm not bothered as I'll be hiring a proper concrete vibrating wand for the proper countertop.




Also took one more photo of the glow in the dark aggregate (inside) after letting it charge in bright sunlight for a good few hours. I think it looks great.



More test slabs to come (not yet decided which other aggregates to test).

[cannyfradock]

Duncan

I've probably already mentioned...that's something I always wanted to do, but not got round to it. Love those test panels. It seems a shame that you will eventually be prepping food on such an interesting surface.

I can see you finding the perfect stone for your mix, then going into full production making polished marble top garden tables.

Terry

[spinal]

Love these - I've been struggling to decide between polished concrete and a marble or granite countertop...

I think the glow in the dark aggregate has made my choice for me... but that MOP looks stunning too.

Any chance you can do your countertop before June/July? Failing that, would love so see some pics of your test slabs next to the brick oven so see what the color matches like.

As to the larger air holes - you can use that to your advantage. If you were to mix something lighter/white (I'm thinking white cement slurry?) and pour it over before repolishing, you could get some more marbling on the surface...

M

EDIT: You've got me thinking... I'm thinking mother of pearl mixed with whole shells (trochus type) in black concrete... the shells should, in theory, when polished, but to reveal their internal workings, which can then be filled with the slurry...

[DuncanM]

I'm hoping the countertop will be done by July for sure. The exact date I'm not too certain on but hopefully mid-June.

I can take a picture of test slab 3 next to the oven, albeit this is slightly lighter in colour then 1 & 2. Number 1 & 2 I took back to Yorkshire to show my parents, and they wanted to keep them so I left them there.

I do plan on doing some more test slabs, filling the holes with a cement slurry (of different colours) to see what sort of look it will give. I'll add the updates on here along with other test slabs I do (waiting for more test-aggregate through the post). I will also be testing how I seal the countertop.

[spinal]

Cool, thanks I need to finish the roof of the oven first, so hopefully I can wait until you're done before doing mine

M.

[DuncanM]

Another update on test slabs.

I received 5 more test samples through the post (from specialistaggregates.com - a UK supplier) which consisted of glow in the dark aggregate, grey marble chippings, purple mirror pieces, gold mirror pieces and silver mirror pieces:



I had high hopes for the silver mirror pieces and possibly the glow in the dark aggregate, but it was slightly too late anyway as I'd already ordered from the Canadian based AGT after being impressed with their aggregate.

The image below shows a sharp sand based concrete with glow in the dark aggregate (as mentioned above from specialistaggregates.com) and one large blue glow in the dark pebble from CoreGlow (again UK based). In addition, I also used some of Wickes glass fibres and powder mixture for "no crack concrete". It was my intention to use a GFRC (Glass Fibre Re-inforced concrete) as my final mix. However, I found the mix a strange consistency, it was certainly wet enough, but still maintained a crumble like texture. It went into the form easy enough though. Removing it was a different matter, I'm not sure if it was the concrete mix or the fact I've re-used the forms many a time now without completely cleaning the melamine board (probably a combination of them both) but there certainly was difficulty removing it.



And after most of the day in the sun.



Once given a very brief polish at 50 grit, I wasn't very happy with the appearance, I could see the fibres everywhere, as seen below, and the concrete wasn't giving as smooth a finish as it was at this stage with other mixes.

Glass fibres are visible in this shot towards the corner.




I will come back to the mirror pieces and granite later...

Another two tests, using some sea-shells (some I used whole, others I smashed) I picked up a few weeks ago. I've not actually polished them yet - will update post when I do, but I like the potential shape of a half buried hermit crab shell or whatever it is (once filled in with more concrete that is). Top and bottom pics of sea-shells slab 1.






Again this mix was the GFRC concrete, and once again I didn't like the consistency of it, and it was difficult to remove from the mold, as seen below - despite having been left in the mold for 7 days, when normally I have left them in for 3. The concrete felt very brittle and crumbly in parts. The unfortunate test slab 2 for sea-shells




Now... back to those mirror pieces. As I've mentioned twice above already, I really don't like the feel of this GFRC concrete, I must be doing something wrong because the only thing it's addition has successfully done so far is weaken my mix. The two slabs with the different mirror pieces in removed from the forms terribly - albeit in one piece, but left most of the aggregate stuck to the forms and not the slab, I gave a very brief attempt at polishing (again 50 grit) but the few remaining pieces were so poorly bonded to the slab they flew off rather than be polished. So I improvised with some spare non GFRC mix, and added on a 2nd helping to see if the bond would help. It is probably a bit too thick but I didn't have anything to lose.

mirror test slabs 1 & 2 with additional layer of concrete added. Again these need re-polishing to see if I can see any of the aggregate I was hoping to test.






It was difficult to get a consistent light setting for these pictures and the other glow in the dark products to compare side by side, but ultimately the one I chose (AGT from Canada, shone much bright and outlasted the others by 3-4 fold).


So basically I've decided on all the decorative aggregate I want in my final mix, 4 of 5 I have created a test slab I'm very pleased with, the 5th I still have enough hope it is worth including.

• AGT Glow in the Dark Aggregate (Turquoise and Blue colours)
  
• Blue glass
  
• Turquoise glass
  
• Mother of Pearl
  
• Silver mirrored glass pieces
  

And here they all are after being delivered today, albeit the stuff from Canada took 6 weeks (I chose snail mail, and it got held up in customs with a £26 bill )


And after a few hours in the sun:



2 colours of glass, small bag of silver mirrored glass and a large bag of mother of pearl.




For reference, I also received another sample pack from AGT showing their full range - so I thought I'd show you guys what's on offer, as my initial slabs didn't show this clearly.

Yellow aggregate
1 = AGT-EY 3/4"-1"
2 = AGT-EY 1/2"
3 = AGT-EY 1/4"
4 = AGT-EY 1/8"

Blue aggregate
5 = AGT-SB 3/4"-1"
6 = AGT-SB 1/2"
7 = AGT-SB 1/4"
8 = AGT-SB 1/8"

Turquoise aggregate
9 = AGT-AB 3/4"-1"
10 = AGT-AB 1/2"
11 = AGT-AB 1/4"
12 = AGT-AB 1/8"

By Day:


By night (or slightly darkened room in this case):



So I need to wait 2-3 weeks until I have the melamine sheets, re-inforcing steel and pre-bagged 40n High strength concrete to be delivered. I'll make my forms, cast a few samples again with the final product to make sure I'm completely happy then take the plunge.

[DuncanM]

Later than I'd originally planned (I keep saying that with every post ) but I've got some updates to share on the countertop.

Had the past 3 days off work to do this all, some parts took a lot longer than expected.

Created a very strong and level base with 4 saw horses and lots of 4x2's.



Template made in situ (using pallet timber from the melamine boards)


Showing the two seperate pieces of the template / mould. I originally was going to do this as one giant piece, but then the logistics of flipping over then moving such a heavy piece made me split it into two (which will still prove difficult to move).



Templates made from 2 8'x4' sheets of melamine from Travis Perkins, made to fit the templates... except a last minute decision to reduce the width by 5cm for ease of measurements with the melamine.


Forms secured to the timber base, side walls reinforced and all corners silicone caulked. Aggregate put in one piece and glass rose caulked in place in the other.


Rebar (ss brick ladder, 3mm wire x60mm wide) used as "normal" rebar is way too thick for a 2" slab.


Rebar and aggregate.


1st form almost filled. Missing pics of the rebar, but it's in there


Aggregate in the 2nd piece ready for the slop.


1st piece levelled (but not yet skimmed).


2nd almost fully filled, showing the rebar in place (15mm from the bottom of the 50mm slab) - which when flipped will mean it's in the top 3rd of the slab which is where the tension will be given the 12" cantilever from the supporting brickwork.


Just in case you like pictures of cement and rebar



Now it will be a few weeks until I have any more updates as I need to wait for it to set, get friends over to help flip it, polish it, then get an army over to help lift and set it in place.

For the record the concrete mix was:
Prebagged Hanson 40N concrete (I wanted a strong mix)
100ml Sika Black liquid colouring per 2 bags of concrete
20ml Sika concrete waterproofer per 2 bags of concrete
100ml superplasticiser per 2 bags of concrete.

[spinal]

Love it! Can't wait for the next update...

Did you end up putting any shells? I quite liked the hermit crab shell...

[cannyfradock]

Duncan

I'm looking forward to seeing the finished product.

Terry

[DuncanM]

I liked the hermit shell as well, but unless I could manage to slice it a few mm thick it would have weakened my slab too much casting a largeish one in place with the void it would have left until it could have been filled. That being said, specialistaggregates.com does offer some, I just didn't want to buy any at the time:

www.specialistaggregates.com/mother-pearl-nautilus-motif-p-1954.html

www.specialistaggregates.com/mother-pearl-shell-slices-p-1980.html

looking back they would have been quite cool to look at, but once again it was added expense to something that had already spiralled pretty high.

I will consider them for future casting though.

[rivergirl]

Love these test pieces, I wanted to do concrete work tops years ago . Hopefully in my next outdoor kitchen I will get them! Especially if they look as good as yours

[DuncanM]

More updates for you all

Removed the sides after 4 days, the concrete set incredibly quickly so I had no reservations about doing this:



Very roughly polished/grinded out the peaks from the (eventual) bottom of the slab, didn't spend long, maybe an hour. At this point my US purchased wet polisher died. After lots of investigation and a call to an electrician who has done some previous work for me, I realise I was incredibly stupid (and lucky) to have it last as long as it did. I essentially plugged it in to the UK mains without a transformer - that's a 110v designed power tool being supplied with 230v. Great.

After lots of investigation, I couldn't hire one for a decent price - I was looking at £70+ per day by the time it included transformer and VAT. So I happened on this (http://www.eibenstock.co.uk/acatalog/Polishers.html - EPN1310) which is the same one that was being rented out, except it also came in a 230v version - woohoo. £250 and 2 days later a brand spanking new polisher arrives. At this point I realise the build quality is about 800x better than the one from the US. I should have got this in the first place - I would have if it was easy to find.

Anyway, roughly polished:


Here's the other piece - which I somehow managed to flip on my own without breaking my back. I estimated by the concrete volume this weighs in the region of 200kg. The bigger piece in the background - 250kg.
Note the small black dots - ghosting. This is usually undesireable, however it's not important given I always meant to grind the cement cream off. The ghosting was a result of the aggregate being placed in the form, concrete on top and then vibrated meaning the cream didn't remix properly on the surface.




The glass embedded rose - with the silicone caulking used to hold it down showing.



Started to grind away at the cement cream with 50grit diamond pad. You get ludicrously wet using these things - you'd be less drenched taking a shower - seriously!


Et voila - the caulking and cement cream have been removed to reveal the rose. I love it.


Once I completed the whole slab @50grit - (which took about 8 hours!!) I then applied a cement slurry to fill whatever tiny air-holes were present. Let the slurry dry for 2 days then grinded off again - it was much quicker to do then the initial exposing.



Whilst waiting for the slurry to dry, I built and cast two more slabs, 1 on the left for the chimney transition from brick to pot and the one on the right as the entrance to my oven.



Oven entrance removed - I didn't add enough water to this mix, nor did I vibrate at all so the corners were not very well finished. I corrected this by using a cement slurry to fill in all the gaps. This slab doesn't need to be strong, it will be fully supported.



Checking the transition works OK



The plant pot was the perfect size to cast the hole which will let the chimney sit on the outer rim.



The slab with the rose polished up to 3000 grit - with a brief stop off at 400 grit where I did another slurry to get the remaining fine holes. It was difficult to get a decent photo at about 7 this evening as the sun was going down, but hopefully this photo shows the reflection on the slab.



More light reflecting to the left of the rose:



Top down picture:



The larger slab still not fully exposed. Hopefully that will happen this weekend - but an expected 6 hours left just with the 50grit pad alone!



Close up of the rose. The light grey streaks is just dust on the surface of the slab.



Oven entrance slab having had the holes filled in with slurry, then repolished to expose aggregate on the front lip. I decided that I didn't want to expose as much aggregate on this one (I didn't put any decorative pieces in it either). It's not yet levelled or mortared in yet, that will come at a much later date when I've got the chimney in place (to avoid mortar splashing it).




I expect a month or two delay between the next post as it will show the finishing of the largest slab, sealing of both slabs and oven entrance, details on sealer, fitting of chimney slab and pot and the installation of the two behemoths into position.