A violin’s fingerboard is usually made of ebony, though on student instruments maybe be coloured timber of another make. As the neck itself is made of maple and quite thin, the fingerboard is important for the structural integrity of the violin. Because it’s thus a maple / ebony laminate you get differential expansion/contraction of the two from weather and over time my come loose and so can need to be reglued periodically of the lifetime of the instrument.
Violin fingerboards should be glued with hide glue, a reversible glue, in case the instrument needs repairing at some stage (for example repairing a violin or cello neck break). However some student instruments are glued with standard woodworking glue at the time of manufacture and can both be more difficult to remove, as well as move prone to lifting (would working glues tends to creep over time).
To repair, reattaching a fingerboard often means removing the old glue, resurfacing the neck/fingerboard if necessary and gluing with the correct alignment for bridge and playing. You may find adjustment of the bridge and nut is also required. Its also a good time to have the fingerboard dressed or planed if there are grooves from the strings on the top as well.
Once the fingerboard is reglued there is often a slight mis-match between the fingerboard and the neck that may require some scraping. This might be due to when it was made, though is more likely due to the ageing of the ebony and maple that will expand/ contract differently with age. This can be gently scrapped to ensure it matches flush for player comfort.
So if your fingerboard comes loose, worry not, loosen off your strings and get it to a reputable repairer. Its an over night job so not too time consuming or expensive.
