What is the reason of plastering mortar base cracking?

A

Ankur

Member
Hey guys, I would like to ask one thing about the interior wall scrapes and wall putty-if it is lime based, what is the minimum amount of quick lime should I put in? How about this formulation-

Quick lime- 40kg
Calcium/Magnesium powder -960kg
Starch ether- 0.7kg
Cellulose ether- 3.5kg?

Just want to ask if it is okay to do this; will there be too less quick lime?
Plus, what causes the putty powder sinks to the bottom during plastering? Is it because it dries too fast and the cellulose is less?
 
You have put 3.5kg cellulose, I think it is enough. If putty powder sinks again, you should consider replacing cellulose. Besides, you only put 40 kg quick lime for this putty- I personally think it is really less, at least should be 140kg.
 
There is no quality required for top scrapping. I tried a small sample and found it to be no problem. But the workers didn’t give feedback yet. I don’t know how the adhesion strength of this type. 140kg of quick lime should be enough for waterproof putty- as far as I know, 160kg quick lime is enough for inspection, but I don't know if it's true.
 
That will be dependent on quality of quick lime. It is not as much as you want or no powder off the wall after scraping or pouring water on it. That is too less requirement on the product. We tested our garage wall if it can be rubbed off by hand after drying, with adding amount to 20%. You should test the calcium content of your quick lime.
 
You should see the hydration of the lime- if it causes powder sink, and then decide if it is problem of cellulose ether. But 40kg of quick lime is definitely too less. Even if it is the best quick lime- I have used at least 3packs.
 
You must log in or register to reply here.
Back
Top