using the float is a definate no mate trowel it on as flat as you can use a spatula or a small rule to flatten it off quickly don't go back filling areas out after it's all on as that can cause you 'ghosting' problems where it will leave an unsightly ring around the area you have filled out , just make sure you get it on plenty thick enough let it set , then scrape it ...invest in a I section scraper (when you got one we'll explain how to use it , you can get them from lord and downing, encon , ccf , for about a tenner