You may find you have problems with needle dip, something I experienced for the first time earlier this year in Malaysia
As KIMBOKO pointed out:
"In the northern hemisphere the north end of the needle is pulled downwards, and the south end is counterweighted to balance the needle. When you use a northern hemisphere compass in, say, Australia, the south end of the magnet is pulled downwards by the magnetic field, and is also heavier than the north end - resulting in a needle that catches and drags on the bottom of the compass housing when the compass is held horizontal. "
This is a simplified example of what happens when a needle for zone 1 is taken to zone 4
Not all compasses are adversely effected by this the Silva type5 for example does not seem to be noticably effected.
Compasses that employ a disk type 'needle' seem to be more prone to needle dip and it is often noticed on prismatic sighting compasses where the needle dip causes the markings to appear out of focus when sighting.
If your compass is effected the needle may drag on the bottom of the housing and not rotate freely
As I am sure you are aware you will need to use different values to calculate magnetic variation in the Philippines the co-ordinates for manila are:
Lat 14° 35 N , Long 120°57 E
So the magnetic variation is currently 1.16 W
Whilst it is not relevant in this instance as the magnetic variation for the Philippines is to the west it is worth noting that the Mag to Grid Get rid, Grid To Mag Add Rhyme only works when the variation is to the west, it is reversed when the variation is to the east.