I'm painting a guitar using acrylic paints - Daler-Rowney system 3. I sanded off the old finish on the guitar, and have spray painted it white, before applying multiple coats of paint. I noticed, however, that the water from the paint has caused the grain to raise up, so I have applied a very watered down layer of filler and allowed it to dry fully, before sanding to level and smooth the body of the guitar, which was damaged by a previous owner.
I learned later that this is not the correct way to do things and filling and sealing/priming should have happened first. However, a lot of paint has gone onto the surface, and I don't particularly wish to sand the entire guitar down again (I don't own a sander). Is it ok if I simply continue applying coats of paint? Should I add some form of sealing or priming layer at this point? Or is my only option if I want this paint to adhere properly to start completely from scratch?
My intention is to paint the guitar with a design and then seal it with multiple coats glossy spray lacquer, buffing it to a shine.