Should the screed be vacuumed after priming or is it not necessary?

Hello everyone,
Maybe a silly question but we have just treated our cement screed with primer.
Now I have noticed that after priming there are still some "sand" particles on the surface, like individual grains of sand.
The question is, is it allowed or possible to vacuum again after priming, or would that rather damage the primed surface?

Unfortunately, I couldn’t find anything about this on Google.

The first coat should be applied in a few hours.

Best regards

Of course vacuum!

Thank you!

We vacuumed and then applied the first coat.
We used relatively little paint for the first coat, even less than the manufacturer states. However, after the first coat, you can still see the screed pattern through it.
I think we will apply the second coat a bit thicker than the first one. (In the hope that it will then adhere well.)

I have one more question:
As mentioned, we applied a very thin coat, but it immediately became noticeable that across the entire screed surface, there are fine "fibers" about 1-3 cm long sticking out.
You can easily pluck them out, but you would probably never finish doing that.
Do you think if I apply a thicker second coat, it could bind these fibers in the coating paint? Unfortunately, I couldn’t find any information about this online.

You have fiber reinforcement in the screed. You should sand it lightly. Vacuum, paint thickly again. You don't need to refresh the primer. It's called that because it penetrates deeper. You can't reach that deep. K.

Ok, thanks to you.
Best would be by hand with a fine grit (e.g. P120-P240?) or rather with a coarse grit (e.g. P40-P80)?
With little pressure, it is "only" about removing these protruding fibers.
I think that the random orbital sander or the delta sander would sand off too much, right?

No. Take a sanding block and a finer grit, about 120 or even finer, and then just go over it lightly. Just remove the little fibers.