Commercial Castable Refractory question

[BenKeith]

This looked like about the best place to ask this topic, didn't see any other place that might be better suited.

I know it has a life span and expiration date. That's how I got mine, it had excided it's expiration date by a couple of months and the commercial guys can't/won't use it. Friend of mine worked for one the major contractors that does repair and installation of huge boilers, kilns etc and he had over a half a pallet he was going to pitch. He said it would be fine for my oven and it was. That was two years ago and I had 15 bags left. Even though I put them in additional plastic bags and stored them and a dry area, they still have gotten hard.
I bounced and rolled one bag around to loosen it up, dumped it out into a large plastic trough, and using a hand packer, it broke up and returned back to it's original texture fairly easily. I have 22" vibrating plate packer I can use to easily break up the other 14 bags.

The question I have, would it do me any good to do that.

I have 15 bags, and it's going to take all 15 to build another oven like mine and I don't have any to waste to do a sample to see if it still holds together after mixing. If it wasn't for a couple pieces I have where I change my mind on building mine, 15 bags wouldn't be enough. My friend and his company packed up and moved out a while back so can't go to him for the answer. This stuff was almost $75 a bag when it was new, and If I can even begin to salvage it, I would like to try, kinda bites to throw that much money in the trash. Basically, it boils down to whether my granddaughter will get an oven or not.

[UtahBeehiver]

This is a good question for David S our casting expert. But my take, is you need to use some of the material and do a test sample regardless of only having enough. Having flashed in the bag is a concern that the chemical reactions of the material has already begun. If the material does turn out not to be good, many builders on the forum have gone the home brew route with good success. Look at Nick JC from the UK build.

[fox]

Obviously not an ideal situation.....the aggregate will be good but the cement won’t so you need to sieve it through a fine mesh and add fondue cement back at 4-1 ratio.
whether that is worth the effort only you can say and whether it will ever be as good as the original is doubtful!
You could take it one step further and add fibres and SS needles.

[BenKeith]

Thanks for the responses. Yea, I got to thinking my best bet is cast one of the floor sections for a test. I only takes one bag to do one section so it wouldn't be wasted if it did hold together.

[AgentG]

Two years later, but for clarity, do not store your bags of material in plastic. You're trapping in moisture which will begin setting the castable.

[Gulf]

Two years later, but for clarity, do not store your bags of material in plastic. You're trapping in moisture which will begin setting the castable.

I beg to differ slightly on this advice. If someone lives in a high humidity area, the material will not be used immediately, and/or will go outside of the shelf life recommendation, do seal it as soon as possible. All masonry cements have an affinity for water. Sealing it may trap a very small amount in the container. But, leaving it in porous bags will just allow it to take on more moisture from the atmosphere That will further accelerate the amount of spent. Sealing will buy you some time. I like sealable plastic buckets for doing this. Usually, the amount of spent will be only the top 1/4" of the bucket if it used in a reasonable amount of time.

[david s]

General advice regarding castable refractory is not to use it if it’s more than 6 months old. However, in practice the material should be fine as long as it hasn’t gone lumpy. After using a bad batch and having to sieve out lumps, I had a few failures which caused warranty issues, extra labour and expense. The supplier replaced that batch with new produc free of charget, but now no longer have the manufacture date printed on the bags. Their advice was that if it’s not lumpy the product is ok. I’ve found this to be correct, but the stuff should not be stored on a concrete floor and bags, once opened should not be left open. We store the stuff elevated on a timber pallet and kept well covered once opened.