New build in Barnet

[bry]

K rend comes in 25kg bags (k rend is a brand rather than a specific product there are others like Webber), and there's normally a base coat one and a coloured top coat one, not sure on how much you'd need as we've only used it couple times as hate the shit, but I'd imagine 1 of each would be close so maybe 2 of each to be on safe side, expect some one who's actually used on their dome will clarify. The idea of k rend is when it's pretty much gone off you use a spiked float to scratch a "pattern" into but imagine this would be impossible on a dome, don't know how well it floats and sponges to a finish with old fashioned sand and cement method

[downunderdave]

Sept 3, 2016 11:40:22 GMT kaneabel said:

Thanks Bry, Oblertone and Dave,

A couple of followups:

- any estimates on how many 100ltr vermiculite bags would I need for a 36" oven? Is this the same as garden centre vermiculite? Similarly how much K rend would I need?
- should I start doing the build up fires now or after the insulation goes up?

Cheers,

Amount of vermiculite depends on how thick you make your layer.
Same applies to the K rend.
It is better to do the drying fires after applying the insulation layer IMO because the insulation layer helps even out the temperature. If you apply heat to one side of the refractory while the other side is cold, there is a huge difference in temperature and therefore expansion, stress and possible cracking. Uninsulated flue tiles or chimney pot flues that crack are examples of this, but the same applies to the refractory of the dome.
K rend is a brand name, one of many acrylic modified cement renders with some waterproofing added making it partially waterproof. This will tend to keep moisture in as well as keeping it out, so make sure all the water has been driven out of the oven before applying it.

[bry]

K rend is silicone

[downunderdave]

K rend is a polymer modified cement based render. The silicon gives it the waterproofing property. There are lots of K rend products. If it's dry stuff in a bag, then it's cement based, but if it's wet premixed and comes in a bucket then it's 100% acrylic.

www.k-rend.co.uk/technical-support/literature-library/technical-data-sheets-k-ren

[bry]

I'm aware, just saying it's got silicone in it, no acrylic as far as I'm aware

[downunderdave]

Read the data sheets. Polymer means acrylic.

[bry]

I was of the impretion that polymer was a reference to somethings molecular structure not necessarily acrylic, however I was not aware of k rend containing acrylic, I stand corrected. Regardless I still think k rend is a load of shit. In my humble none scientific knowledge

[kaneabel]

Hello all,

An update from me after a long time. I have finally finished the oven. Now the trick is to learn how to control and manage the temperature. Very pleased with how hot the oven get and the insulation is doing its job too, though I think the floor surface does not seem to retain heat as long as I would like it to. Perhaps a case of learning as I go along. Any tips welcome:

By the way, I am not being able to upload any images. The error message is: My IP address is blocked. Can somebody please help?

Regards,

Kaneabel

[kaneabel]

Hi all,

See attached the latest pics by way of an update. Learning everyday but quite happy with the results so far.