Instructables

Step 4:

i punched along the marking in a straight(ish) line with the widest chisel I have to the approximate depth of the glass 6mm in this case, i then chiselled up the remaining wood roughly to accomadate the glass, im sure there's probably an easier more efficient way of doing this but I quite like the uneven finish as it matches the rotten wood. also be careful not to catch or 'nic' your straps as this will weaken them for future use, you dont want your suitcases flying off the top of your car because you were careless with your chisel. with hind sight you could probably do the next step first to avoid damaging the straps.