Refractories have a shelf life but..........

[Roy]

Don't know how many of you knew this, but refractories all have a shelf life. Most plastic ramable types have approx 6 month span from date of manufature, and the castables can go as high as 12 or 13 months. What this equates to is that most foundries will not purchase refractory that is out of shelf life. Distributors have to get rid of it........as no one will purchase it (on the assumption that they are reputable dealers / distributors). So just what does this mean...Well the refractory may have started to setup in the bag/box, and may contain clumps of hardened material, or on curing it may not reach its full design spec as to strength. Naturally a commercial foundry has to shut down to reline the furnaces, and they will not chance using an out of date product, when an in date product costs the same. So it sure does not hurt to check and see if your distributor or dealer has any out of date refractory around that he has to get rid of. Most of the time it is dumped in a dumpster or landfill. A lot of the times they are more than happy to have you haul it off FREE! So how does it affect your back yard furnace....Well no matter how deficient in property it may be, if it hardens up when mixed with water, it should be fine, and better than any home made refractory using perlite and furnace cements etc. So don't be afraid to ask up front when buying refractory. Most times its fine to use outdated stuff, and it will work just fine. Do a test batch first and check to make sure it sets up. Odds are it will, and it will work just fine. One note on mixing factory castable and thats use as little water to just dampen it as necessary. More good factory fresh refractory is ruined by folks making it too watery. This makes it very weak and it continually creates a powdery residue.

So far I have made a few furnaces with "expired refractory" and the refractory is holding up just fine....best part is it was free for the hauling.

[FrankG]

Roy,

Sound advice... I read this earlier today and started sniffing around in a Boiler room on the 4th floor @ work, and what did I find but 2 bags or 1650 Degree Celsius refractory... Knowing that all bags were to have been disposed of, since moving to the wet "Volcano" refractory, I checked with the Plant Manager, and I'm now the proud owner of 100lbs of premo material... and any other bags that may be laying around...

Now I just have to haul them home.

Frank
http://www.theworkshop.ca

[Roy]

Good going. Make a small test batch before you commit yourself to it. BUT BE WARNED......it may not be in spec [img]/ubb/images/graemlins/smirk.gif"%20alt="[/img]

[Harold_V]

Yep!
What Roy said. [img]/ubb/images/graemlins/smile.gif"%20alt="[/img]

A few years ago I had a partial bag left after building a small furnace. Some time later when I tried a little to see if it was still good, it failed to harden at all. They're not joking when they say this stuff has a shelf life. In my case, it hadn't been wet, nor did we then live where there was much humidity. It was interesting to note that when the test piece had dried, it would crumble easily by hand. [img]/ubb/images/graemlins/frown.gif"%20alt="[/img]

Harold