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KS-4V Plus Castable Refractory (KS4V)

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KS-4V+ is a moderate-strength, medium-density, easy-to-use fireclay-based durable castable refractory to 2600° F.  Its versatility and cost make it an excellent choice for many applications.

Very popular for Ribbon Burners, as it fills moulds easier than some castables like Mizzou, and it has a fine grain structure making it suitable for burners and where detail is needed. 

A Finer & FASTER Setting 'GR' variant is available at a moderate savings.  

KS4V is our most popular PIZZA oven shell refractory.  It works very well stabilizing bricks instead of mortar on domes.  Most of the refractory is quite a fine powder, with occasional small aggregate particles to about 3mm.  It is versatile, allowing 'dome' stacking of bricks, with one brick edge held close, and a 'wedge' of KS4V+ filling in the 'gap' of the brick's outside dome edge.  It is also suitable for casting domes or a thick parging exterior coat.  We also have refractory pins & speed clipswhich can be embedded in the dome to secure wool, wire mesh, and casting layers.

KS4V 's strength and abrasion resistance make it popular in lining forge floors etc.

Note:  KS4V is a good option for pizza oven floor backings (if needed), but it is not rated for direct food contact.  Our Pre-Krete G8 is rated for food & potable water contact and is used for pizza ovens.  Tips are coming soon or contact us.

The lower iron content instills better flux resistance than castables higher in Fe (Iron).


  • 200 cubic inches per 1 gallon of dry castable.
  • The water mixing ratio is 12-13% water or 820 mls per gallon dry mix. 

Sizes Available:

  • 2.5 lb wide-mouth-jars
  • 12 lb one-gallon-pails 
  • 25 lb two-gallon-pails
  • 20 kg pails
  • 50 lb five-gallon-pails 
  • 55 lb Bags


50 lbs in a 5-gallon pail has enough room left to conveniently use the same pail for mixing the KS4V with water if you are going to mix near full bag batches. 

If you want to mix smaller batches, we also sell 25 lbs in a 5 gallon pail, for ease of mixing.  Of coure you can keep adding 1 or 2 gallons to this 5 gallon pail for mixing.

KS4V shipped in plastic pails minimizes damage in freight, and offers great versatility.  Scooping, re-sealing, dry storage, and transport is all easier and cleaner than product in bags.

Once cured, fireside KS 4V can be coated with ITC 100 HT to optimize heat retention & efficiency.

KS4V+ can be mixed with Reinforcing (304 SS) needles,  which behave like mini-rebar fibres in any castable.  1 lb per 50/55 lbs offers maximal strength reinforcing, but quantity can be used to suit.


Kast-o-lite 30 Li + (3000°F hand or form), Kaso-O-Lite 30 LiG+ (3000°F very fine, fast-set), and RescoCast 8 (2800°F hand or form) are castables ~50% lighter than KS-4V+. It's a popular option when optimizing insulation value and lowering weight is more important than strength. 

Note 2: 

VersaGun ABR+ (3000°F ),  GreenKleen 60+ (3000°F)and GreenCast 94+ (3100°F) are all denser (poorer insulators) but offer strengths of over 10,000 psi.  They all have different qualities, setting times, hand cast / moldable vs pourable/self-levelling characteristics.

Note 3:

KS4V+ is also available in a very finer & faster setting mix KS4V-G+ (online soon). 

Note:  Contact us about Retarder Additives that can slow the setting time and increase your working time.

Click here for the KS-4V SDS (Safety), and here for the KS-4V Technical Data Sheet. The application instructionsfor KS-4V are the same as the Mizzou+ refractory.


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