|
|
Post by BenAlexanderT on Dec 27, 2020 9:45:22 GMT -8
|
|
|
|
Post by martyn on Dec 27, 2020 11:57:54 GMT -8
Most refactory mixes use cement fondue with crushed fire brick, the one I use also has nylon fibres and steel needles plus some un named (secret) ingredients !
You can use coarse silica sand and cement fondue for certain applications like bonding bricks but for casting, firebrick grog is going to be a better bet.
The strength and durability of the finished casting is dependent on a few different aspects like the mixing ratio, how much water is used, how well it is vibrated and how well it is cured. That is why I buy a good quality ready mixed product with accurate instructions.
Anything that is sub 500c is pretty easy to make up with one cement fondue and four parts crushed fire brick but from my own experience higher temperatures require commercial pre mixes !
|
|
|
|
Post by BenAlexanderT on Dec 28, 2020 9:33:07 GMT -8
Thanks for the response Martyn  So, ciment fondu for the batchbox core is a no go  |
|
|
|
Post by martyn on Dec 28, 2020 9:50:08 GMT -8
No I did not say that, the cement is good, will stand up to the temperature but it needs mixing with a suitable binder and that is not sand or not sand alone anyway.
What I was trying to say was that it is easier to buy a good quality pre mixed, dry refactory casting product than it is to make your own.
|
|
fuegos
Full Member
not out of the woods yet
Posts: 177
|
Post by fuegos on Dec 29, 2020 9:00:00 GMT -8
This is something that is more important than you would think .Working in construction i learnt that even pouring a 10 or 15 CM slab that using a vibrating poker was standard practice.My own experience casting test pieces with a pre mixed refractory mortar (i used clay/sand in the end ) showed a clear difference . |
|
|
|
Post by BenAlexanderT on Dec 29, 2020 11:38:26 GMT -8
No I did not say that, the cement is good, will stand up to the temperature but it needs mixing with a suitable binder and that is not sand or not sand alone anyway. What I was trying to say was that it is easier to buy a good quality pre mixed, dry refactory casting product than it is to make your own. Sorry, i misunderstood, i see your point now I will see what is available in my area |
|
