I pored a new floor for one of my forges 3 days ago, 3/4 to 1in thick, the satinate was as thick as heavey stickey mud. 18 hr after poring it was still damp [over night] and soft 36hr ago I put two 100 watt light bulbes in the tunnal 5"high 6" wide 30" long now it is getting hard but I have large cracks 1/8 " wide
across the floor and around the edges and the peces are loose. What now, I have thought about using a thinner mix just thin enougt to poor and fill up the cracks, any and all sugestions welcom. Tempture in the 60's in the day and below frezzing at night Gib

Gib, sounds like you did the same thing I did by going to heavy all at one time. I went ahead and lit it up and filled in the cracks once it was dry threw. If you don't do that all I can say is have patients...<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/ohwell.gif ALT=":\"> ... I'm assumming you did this to stop the borax from burning threw your insulation. I've been thinking about going castable on my next forge. Ray

Thanks Raymound you are right I was trying to stop the flux
from melting the fire brick. I will light the forge and see what happens. Gib

I'm a refractory fan, myself.

I have a friend who put the wool around the top and sides of his forge, but the bottom was fire brick that could be replaced as neccessary. The brick tucks the wool in, at the bottom.
It may be easier than working with that goop.

Gene, the goop really isn't that bad. I've found the best way to work it is to wear latex gloves instead of trying to trowel it or smooth it out with a stick. Isn't one of forges made out of castable? If so, whats the drying time like? I know you got some words of wisdom. Ray

I use castable refractory in all mine, now.
A day to dry, then slow start it, running it cool first, then gradually getting it hotter.
Ready to go!

Merry Christmas Geno, On the castable how thick do you need to go with it? What temp. is an inch of castable rated at? Are all the castable the same or is one better than another? I'm planning on another forge in the future and have been thinking on going this route. Ray

Ray, there are several kinds of refractory plaster. Density and temperature ratings fluctuate by manufacturer.
My forge is 2 1/2" thick per wall (in the middle)@2600' rating.
I have lost less than an inch of wall thickness in over a year of heavy use now.(started out 3" per side)
Q tran is where I get my stuff.# 817 870 1855, in Ft Worth.
They can help you out with any questions you have about thier products.
I think they recommend 3" for that kind of heat.Be Blessed!

I had the same question when I got a fifty pund bag of the stuff... so I called the manufacturer and they told me to fire it wet. Our use is a little different, but it is actually meant to be used as a mortar between bricks in a ceramics kiln, for example. I can't remember the exact temp, but somewhere around 2300 F it becomes 'sticky,' mostly to itself but also to surrounding material.

I have been firing mine wet every time I clean up or rebuild my forge with no problems.