Finding fibreglass fibres for render in Oz

[Muhindo]

Hi All,

This is a general question for all but especially Aussies. I'm in north Qld and am looking for where to source the fibreglass fibres @davids speaks of (3:2:1) recipe on @sergetania's build post. I'm currently in the process of waiting for my perlcrete layer over the superwool to dry. I have about a week before it's ready for a final render and waterproofing. I'd like to source some fibres as I want to make a very hard, water-resistant shell for the oven as it will be exposed to the intense wet season in the tropics--at least on those days I forget to roll the cart under the patio roof. Local suppliers here in the Ville include the ever useful Bunnings and Lyndons but neither seem to carry these fibres that I can tell. Perhaps theres an off-the-shelf, pre-mixed product that's modestly priced instead?

Further, from the photo you can also see the imperfect shape of the dome, i.e. the rear sidewall. Should I add more perlcrete to buildup up these low spots, or let the render fix it?

Also, I must add, this forum is a fantastic resource for learning how to make a pizza oven. Thanks to all of you for your posts, wisdom and sharing your mistakes!

[david s]

I also happen to be in Townsville. You are correct in that our local suppliers don’t stock the AR fibres. I get mine from Domcrete in Sydney.
Regarding your perlcrete you should be able to shave it back where it’s too high and add more over the top where it’s too low. I currently have one built at the same stage if you want to look.
Give me a call if you want 0449132608

[Muhindo]

Oh wow David, you are very close. Thanks for the quick reply.
I'll check out the domcrete website. BTW, when you say "shave" is that angle grinder shaving, a sharp machete or something else--I'll note the perlite is likely only 20-30ml thick in someplaces and due to the superwool underlay, there not much structural integrity here.

Thanks for the number, I'll give a call this eve if your home.

[Muhindo]

Hi David (@davids),

I hope you're on the mend now and feeling fit!

It was great to catch-up in person with my son the other week-we both really enjoyed the visit and getting to see all the work you are doing in the yard. My son is even talking about picking up ceramics as a hobby now.
I could just sent you a text message but i thought users on the forum might benefit from the following question, and your advice. Over the last few weeks Ive been gradually bringing the oven up to cooking temps now that the perlcrete has fully dried. All looks good. The exterior is not hot when the oven is fired, and not cracks in the perlcrete shell even though I got the internal temp to 450C and the white hot effect on the inner dome-- a few minor hairline cracks in the interior, but nothing that's concerning.

I have finished a couple thin layers of a finishing render (consisting of homebrew, 3:1:1 and a handful of the fibreglass). It looks to be setting up as a nice hard shell. It's currently under plastic for the next week to cure. You had recommended using a product called Flexible Pointing, diluted with 20% water and brushed on with three coats for a weatherproofing layer. So my question is, would it be expedient to paint on the flexible pointing while the render is still setting, like in 24-48 hours?

My reasoning is as follows; if im going to cure the render for a week anyway, why not seal some moisture in with the flexible pointing to aid the curing.


Thanks for yours or anyone elses input!

[david s]

Although that sounds logical if you paint the flexible pointing over the render while it still contains moisture you risk blistering of the coating. Better to wait around another week after removing the cover to ensure it’s completely dry.
For ceramics classes for Felix try Nth Qld Potters Association, Flowers St Sth T’ville