Finding hydrated lime

[Amusinglisa]

Am I missing something? I cannot find hydrated lime (or calcium hydroxide) within 100 miles of me!

Is there a different name I should be seeking? Calcium hydroxide, right?

I got the impression somewhere that QUickrete is the same thing, but it clearly is not

Is there something else I could substitute?

P.S. I live a stone's throw from the lime mines in gold country! Sheesh!!

[deejayoh]

Masons lime @ home depot. Or better yet, find your local cement supplier - they usually have a mason-oriented retail outlet where you can buy lime, sand, and cement by the pound.

[Amusinglisa]

yeah. local HD (and for 100 miles) doesn't have it and can't get in-store delivery...

[UtahBeehiver]

I did a quick Google and there are several brick mason suppliers in Sacramento as well as a HC Muddox distribution store (they make fire clay). Type S lime is the preferred choice but it possible to use Type N with a small ratio change.Type N and S are standard masonry products. Do a forum search on Type N lime for discussion threads.on this subject.

[crisp]

Hi I'm new here and can't seem to post a topic of my build, can anyone help?

If you can get your hands on hydraulic lime http://www.limes.us/distributors/ , you don't necessarily need to add cement, and thus a cheaper alternative. Cement was first patented in 1824, so all ovens prior to this had no cement only clay mortars with perhaps lime added as a binder to assist hardening. A lime which is not hydraulic (common builders lime) will harden only by intake of co² (air) which can take some time to harden, whereas a hydraulic lime hardens both with co² intake and a chemical reaction with the water in the mix. A lime / clay / sand mix is more flexible than one with added cement (which becomes hard and brittle), and, a lime based mortar allows for thermal expansion and movement, which is arguably a better mix. Depending on the type of clay used, once the oven is in use and fired, the clay in the mortar will turn to ceramic and harden. An addition of either cement or hydraulic lime helps to harden the mortar whilst building. It is also feasible to use just a clay/sand mix without cement or lime but this mortar will only harden with firing. Using a mortar which doesn't harden to some degree overnight, can present difficulties under building because it remains wet, but not impossible.



Chris

[crisp]

Hi again,

I'm not from the USA but found this link to a supplier in Sacramento, not sure how far that is for you. They sell hydraulic lime and clays etc. http://www.sonsdevelopment.com/green-building/

Chris

[Alomran]

Chris: Thanks for the detailed information, always valuable.
What ration for a mortar mix would \you recommend using
A lime / clay / sand mix
In the UK, the fire clay bag is about £30 per 25kg bag, Lime £13 per bag and £2.5 for a sand bag. What viable yet economical mix do you recommend?
I am building a 67" dome oven.
Thanks

[jonv]

You should be able to get fireclay for around £8 - £10 per 25kg bag... plus delivery, of course. Worth seeing if you can find it locally and collect.

[Alomran]

I wish could, I live in surrey and I could'nt locate a cheap manufacturer here. Most manufacturers are up north. By the time I pay for delivery, the price is escalated to about £30.

[crisp]

Hi Alomran,

I've been out of town for a while.

There are three types of hydraulic lime available NHL2; NHL3.5 and NHL 5. The NHL5 is the strongest compressively and the NHL2 the weakest. I personally would be happy to use the weakest which is NHL2, but you can also use a NHL3.5 which sets quicker; the NHL5 i think is unnecessarily strong. The hydraulic lime most available in the UK is made in France by St Astier, you can read about it, and where to buy it here http://www.stastier.co.uk
What grade of sand you use really depends on the size of your joints. The largest grain in your sand should generally be no larger than one third of your intended joint size, so if you are intending on building with 3mm joints, your sand should have no larger particles than 1mm. If your joints are 10mm then you can increase the largest particle size to 3-4mm etc.. Sand is very important in any mortar and the correct graded sand combats shrinkage. When I built my dome I tapered all my bed joints which meant these were full joints of only 2-3mm. However, I did not taper all perpendicular joints which meant although the joints were tight on the inside of the dome they were large to the exterior. I used two mortar mixes for this, one with finer sand and the other with coarse sand. Both were the same ratio but differently graded sand. The coarser sand mix was used only on the exterior larger joints.
My mix ratio was by volume; 1 hydraulic lime, 1 clay, 3 sand

Another thought is that all solid walled masonry which is in compression is stable; it is only unstable where tensile forces are present. A drystone vaulted bridge without mortar is stable because all the masonry units are in compression, in theory, you should be able to build your dome without mortar as long as the dome is the correct shape and there are no tensile forces it will be stable. Likewise, mortar between solid masonry does not have to have tensile strength only compressive strength with is provided by the sand or aggregate. There are many who believe that it is the mortar that 'glues' everything together; mortar actually needs only spread the compressive load forces.

Chris

[jonv]

I'm in Hampshire. There are several places online selling it. I just had a bag for £9. Delivery was another £10.

How much do you need? I could have got it cheaper if I met the minimum order value for some places...

[david s]

It gets even more complicated because hydrated lime is not the same as hydraulic lime.
See here http://nmnikhilmishra.blogspot.com.a...-hydrated.html
Either will do depending on what's available to you. I's use hydraulic lime, but it's not available to me locally and it's way more expensive especially when you add the freight for a couple of thousand kilometres.

[Alomran]

I'm in Hampshire. There are several places online selling it. I just had a bag for £9. Delivery was another £10.

How much do you need? I could have got it cheaper if I met the minimum order value for some places...

Thank you Jon for your kind offer. I have just arranged for a delivery of 5 bags from Stoke for about £135.!!! I wish I had posted this earlier. Appreciate your chivilary.

[Alomran]

Chris: Thanks again for the detailed and informative answer.
Using lime and clay, under wet condition and moist environment, will that cause problems with curing? Do you think, given the wet weather. one should add cement as we are nearing October?

[crisp]

Perhaps build a shelter over your project (a cheap party tent?) which means you can work even if it's raining http://www.ebay.co.uk/itm/New-3-x-3m...-/121134907380 . Lime mortar will not carbonate under 5 degrees centigrade, so if you are intending a winter build you could add cement to enhance a faster set. However, South east England has a fairly mild winter, so you will be able to control the climate inside your party tent. It is well worth the investment, I built a shelter over my build, it means that i can work and mix mortar under cover.