Sponge floats are for levelling and smoothing plaster before the final set. They can be used with a water brush to bring back the plaster. They take a bit of stickiness out of the plaster

Customer comments 

“Sponging the plaster allows use of the Superflex skimming spatula again; wait till plaster has firmed up a little bit; mist and sponge the walls or ceilings”

“I prefer apply two coats and to sponge even over skim work as the finish looks a lot better i.e. no water marks and one uniform colour. Allow 3-5mins until sponge lines are not so wet   and have started to firm up again; don’t flatten it in while still really wet as you will just take it off”

“I get a good laugh at reading some of the comments on the old trowel finish verses sponge finish. I find it hard to believe there are still some plasterers out there that don’t like the sponge. I know plenty of very good spreads that won’t use it; the sponge wins almost every time for me and the only time it doesn't work for me is when its used on Knauf skimming, or in very small areas, pipes plugs where you cannot get the sponge in”

“For people that want to get into using a sponge don’t forget there are generally two kinds of sponges, one rough and one smooth. I use them in different ways. When working alone I would knock one bag to one and half bag mix of multi on a re skim, this for me is usually comfortable. I would apply two coats and use the smooth sponge. The difference is the smooth or finishing sponge, tightens the skimming in better, but it takes longer to rub up and this sets it faster, so I can get away with one less towelling if I wanted to. Now for the rough sponge, I use this when putting a bigger batch on, that is one and a half to a two bag mix of multi. This is my maximum as I still like to two coat and get two thirds on as quick as possible. I rough sponge then get the other third on, It can be sponged very quickly using the rough sponge, and this seems to hold the skimming back giving me plenty of time to get over the bigger batch”

“If you are a good plasterer there should be no difference between trowel finishing or sponge finishing, one coat or two makes no difference. The one or two coats in my case is only down to setting times and its just I prefer to two coat; really its just one coat and a lay in 80% of the time to make life a little easier nowadays. As for the better job, for me it comes down to the sponge can knock one hour off a six hour room, with less stress on the elbow; it just makes skimming that little bit easier”