Background Surface Preparation
Conmix dressing plaster LC 11 is a pre mixed sand cement mortar for internal and external use. It is recommended as finishing coats/repairing coats on to Portland cement based background, or render surface. LC 11 is ideal material for dubbing out and leveling of backgrounds or as an thin coat plaster.
The density, smoothness and suction of the background, render etc. will vary.The work should not be started until the background has been properly prepared. The background should be thoroughly cleaned devoid of dust, loose particles, wood piece, mould oil or primer etc.
Primer can be removed by using grinder, scrabbler or any paint removing agents.The cracks appeared over the background without any hollow /de bonding should be rectified from the background itself.
Deboned area should be removed and re applied as per the method statement. Damage corner also should be rectified prior to the application of LC -11.
The suction in the background should be thoroughly neutralized by applying
Free water on the surface should be allowed to disperse before applying LC-11 .On
no account should LC -11 be applied over wet background as this will lead to debonding.
LC-11 supplied in 25kg bags must be mixed with potable water only, in a clean plastic bucket or a clean non-corrosive, uncontaminated metal tub.
To ensure a homogeneous and uniform mix and electric agitator or paddle mixer must be used.
The amount of water to be added is 6 liters per 25 kg bag (i.e. approximate 25% by
weight ) add LC-11 to water ,turn the contents of the bags carefully stir frequently.
Once mixed allow to stand for 5 minutes and mix again before applying.
No further water should be added to Mix. Hard and set plaster should not be
mixed or used
LC-11 mixed as above can be applied to prepared background in one coat thickness of 3-8 mm.
LC 11 can be applied to background with a trowel and leveled.
Wet the surface slightly and using a plastic float the surface can be rough finished. If necessary the surface can be closed with a steel trowel and finished and smoothed, however over working should be avoided.