If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.
It will slump if you use too much water. Just get your mix right. Don't mix up too much in one go, it goes off pretty fast and is expensive to waste it. It's also thixotropic which means that it will go more runny with a little agitation. Follow Johnnys advice on the consistency.
Hi all, just a quick report on how the entrance casting went over the weekend. As a lot of people hinted the castable was pretty tricky to work with. The difficulty was the vertical walls. It seemed like it was either too runny or too dry but we quickly rigged up some forms and it all seemed to go quite well. It is obvious now that the dome will have to have outer forms for the verticals.
Other than that it was a success as far as I can tell. I ended up using a product called Silacast 145 which is the equivalent of the Densecrete 145. I added about 11% water by weight for best results. I didn't spend too much time
vibrating the concrete for the entrance but I'll definitely do that for the dome.
I'll spend some time casting the dome this coming weekend.
Thanks mate. The next entrance we did came out even better. We used a proper concrete vibrating tool and some outer forms. We have also made a couple of the dome pieces. Photos to follow after I remove them from the mould. They lift up ok so I don't expect any poblems.
Sure thing Sonomacast. We're on the verge of ordering 4 tons of castable provided we can get the right price. There will be photos aplenty !! We should have a full dome cast this weekend. I'll put up some photos of the mould pieces and the forms.
Mr G,
Be careful, the castable refractory has a limited shelf life, about 6 months I'm told. Make sure you convert it to finished product asap this stuff is expensive.
Excellent, can't wait. I was looking on the net to see how the comercial guys form the ovens. all I could find was a photo of the outer form (Steel with an open top for pouring) I have no idea what forms the inside or divides the segments. I would like something S shaped to form a male/female lip on the segments, this would be hard to form on the apex though, any ideas
Quick update with some photos - castable took a little longer to get delivered so this weekend should see us getting some serious work done. I've taken the first two pieces off the sand mould. They look pretty good but expect better results as we refine our process. I reckon by the tenth one it'll be beautiful.
Cheers for now.
Comment