You should also do your best to brush with the grain.
How to fix a lifting seal from hardwood floors.
Carefully vacuum up dust and grit from the sanding process and then wipe down the floor with a tack cloth to pick.
Use a rag or paint roller to apply a penetrating stain.
How to stain and seal hardwood floors.
To fix this problem you have to.
Clean the surface of the floor.
When the nails holding a hardwood floor pull loose as often happens when the subfloor is particleboard the boards lift and when you step on them they squeak.
Regardless of which method you use you will want to make sure that the floor is thoroughly coated with the sealant.
Use a brush or roller to apply a coat of polyurethane.
You can do this by using a paint brush or a roller.
Use a putty knife to apply the putty or filler and level it with the surrounding floor.