KS-4 Plus mixing instructions

I was able to pick up 9 (55 lb) bags of KS-4 Plus from Harbison Walker in W. Haven, CT. The manager was kind enough to send me the data sheets by email. I just want to make sure I’m reading the sheet correctly:

55 lb KS-4 Plus requires 0.9 gallons of water (hand casting/pouring)? The only other info is for vibration casting at 0.8 gallons per bag. For those that have used KS-4 Plus does the 0.9 gallons of water per 55 lb bag sound right? Also, according to the data sheet the working time is 20 minutes. I plan on mixing 3 bags at a time (Cortile) in a cement mixer. Any thoughts?Thanks in advance!

I’m using KS-4 as my mortar. (Versatile stuff!) It’s a different application from casting, but yes, a little less than 1 gallon per bag sounds about right for pouring and casting. (Again for mortar) I had about a half hour of working time per batch, and could extend it just a bit with a light spray of water if necessary. It does dry rock-hard. So the data sheet information sounds right.

That’s the same HW branch where I’ve been getting my refractory supplies.

Good luck with your Cortile!

Thanks for confirming the amount of water per bag and the working time. It’s my weekend (Father’s Day) project.

.9 gallons or 7.4 pounds. I found it easier to weigh the water in a pitcher and mark the pitcher for refills. I had a very lengthy conversation with the HW rep who was awesome and explained everything in great detail. Whatever you do, resist the urge to add more water. After a minute of mixing it will look dry and crumbly. Keep mixing. After 5 minutes, you’ll find it has fully wet out and is the right consistency. They specifically make it with as little hydration as possible so you don’t get cracking (or explosions) when your fire the oven. The rep spent many years building kilns with this stuff and had actually seen one explode. He said they used to add water an once at a time if in very dry hot conditions. Maybe a little exaggeration there but still, you can’t take the water out once it goes in! Good luck

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Thanks Mike! I will follow the 0.9 gl recommendation and watch the consistency very closely.