Testing mortar

[jinxy]

I have bags of alsey flue set mortar (#100316) that have been setting for about two years in a dry shed. Is there a good test procedure for testing the mortar to assure that it is still "good to use." Temps here are in the 70's and it just seems that it is taking a long time for the mortar to set. Not sure as to whether there may be a problem or not.

Also should I spray the dome with water as I am building, or just leave the mortar set? Thanks for any help.

[david s]

Re: Testing mortar

I don't know that product, but it is probably a calcium aluminate based one which have shorter shelf life (usually 12. Months) if it were mine I'd ere on the safe side and ditch it, but you could try mixing a sample and see what happens.

[Tscarborough]

Re: Testing mortar

It is a Hygroscopic material, so unless it was kept in an airtight container, it has already fired off, although at a microscopic level. It may react a little with the addition of water, but it does have a shelf life and yours has probably exceeded it.

Mix some, make a 1x1x6 inch cube and let it cure for a week. If you can break it between your fingers, discard it.

[jinxy]

Re: Testing mortar

Thanks for the input. This stuff is 3 years old! I did mix a sample in a small plastic bottle and it set up pretty quickly. I will leave it for a week as suggested.
In the meanwhile, I contacted Alsey in St. Louis and spoke to their tech department. Was told that as long as the flue set hadn't hardened in the bags and was flowing smoothly, there should be no problems. According to the tech, flue set doesn't have a shelf life problem as long as it has not been exposed to wet conditions. The tech also said that the material takes a week to ten days to harden and cautioned against retempering the material with additional water.

Feel free to add additional comments and thank you for the help. I'm just getting started so expert help is appreciated.................Jinxy.

[Tscarborough]

Re: Testing mortar

He is technically correct, there is no shelf life if it is not exposed to moisture.

[Lburou]

Re: Testing mortar

...snip... Feel free to add additional comments and thank you for the help. I'm just getting started so expert help is appreciated.................Jinxy.

You are not going to get advice anywhere that is better than the advice you get from David s and Tscarborough.