Sealing presealed polish porcelian? advase needed

[nasonovartem]

Hi everyone,
Does it need to be sealed Presealed polish porcelian?
In tile shop they gave me sealer and said it will be better to seal them(even it is presealed).
I went for advice to another tile shop and they said i only make worse for tiles.
So what do You think?

Thanks For Your Help.

 

[phill moulton]

Get a regular felt tip soluble marker pen (not permanent) & do a small test mark on the corner of one of the tiles that are assumed treated with the sealer, if the mark is cleanly & easilly removed with a tissue & water it is fair to assume that the preseal is doing its job it would though do no harm at all though to apply a second treatment...

IMPORTANT AFTER THE TREATMENT GIVE THE TILES A GOOD 5 HOURS + TO DRY THE TREATMENT IS ABSORBED INTO THE TILE & MAY APPEAR DRY ON THE SURFACE BUT IS NOT FULLY ABSORBED FOR A GOOD FEW HOURS.....

Good luck Phill

 

[oogabooga]

The polishing process on porcelain opens up minute pores on the tile surface, which can sometimes mark easily and be almost impossible to remove (don't ask me how I know this). Some polished porcelains mark easily and some don't - testing as suggested is certainly the less aggravating way of finding out