Hi , i own and run a property maintnenace company,i trained as a plaster but in process of doing a eletricians course.
You have 2 options to get a plasterd finnish
1st option and best finnish is to apply boding coat to chased area.Leave a little short of desired finnish.
wash away all plaster around edges of chase immediatley from around the edges leave to firm up for approx 30 mins then lightly scratch the area to provide a key for final coat multi finnish plaster which should be done just as plaster is strting to turn dark brown in colour or very firm to touch BUT NOT DRY!!!!!.If the plaster is too dry the top coat plaster will suck all the moisture out of the top coat and an inexperienced plaster wil be in the s h i t as the plaster will be difficult to control.
Do not overtrowel this will create blisters!!
apply1st coat finnish coat plaster evenly to whole area ,then remove excess from around edges then wash edges immediately with CLEAN water,dirty water will make it go off really fast through a CHEMIACAL REACTION!!
leave for a further 10 mins then apply the final coat of finnish plaster 2nd coat apply this really thinly and evenly making sure not to over trowel SMOOTH LONG STROKES. then wash of edges immediael with clean water.leavce for 10 mins then apply significant pressure with the trowel at 15 degrees to wall up the chase from top to bottom and bottom to top, you have to use a lot of pressure!!
leave for 10 mins a little flick wth some water over area or light sray with spray bottle over area then trowel again as above applying pressure.do this twice with 5 min intervals making sure to remove all plaster from edges of chase and keep wash these edges wityh clean water making sure not to get on new plaster.
then its a final HARD dry polish after 10 mins.
other option is to use 1 coat plaster
to use this you need to mix and apply to area and apply a little proud of the whole area 1mm-2mm proud washing the overspuill from edges immediately leave for 30 mins untill starting to firm up.then apply firm pressure with the trowel to amke it all flat to wall wash edges and leave until quite firm but mot dry to touch.
Then you will need a tool called a spongue float .When wet this tool will bring the finer particles of the plaster to the surface when rubbed over the channeling do this a couple of times.then leave to almost dry then a really hard final polish.
Hopes these tips help you out..
