Box-hinge fitting query

[Kalimna]

Greetings folks,
Having moved up a little from straight lift-off lids, with my third box I thought I would attempt to fit a pair of hinges to the lid. After constructing the box (fairly plain local sycamore that I left a little too thick) and finishing in a few coats of tru-oil, I set about bandsawing the lid off (a bit of a mare as the blade/my concentration wandered). All went relatively fine till I came to fitting the hinges.
Now, as this was my first attempt at fitting hinges, I didnt want to spend a fortune on Brusso, so opted for, erm, B&Q. Not the nicest, but I thought they would do.
Anyway, hinge mortise chiseled out and hinge screwed in place (using a couple of battens in attempt to keep the lid centred), but the damn thing wouldnt close. There was about a 5-10 mm gap at the front of the box. Oh, and there was a little rotational misalignment also.
So - any tips on fitting hinges? How to keep the lid aligned with the base? How to ensure that the hinge morrtise isnt too deep/shallow? How to remove screws that you have managed to torque the head off?

Any help greatly appreciated.
Cheers,
Adam

 

[andersonec]

The reason it wont close is because the mortices are too deep, pack the mortices with something like veneer or thin card, fill the holes with something like a matchstick, re-drill and realign the lid. I have never had to remove a screw so can't advise on that but I presume it is a brass screw, if so, next time insert a steel screw first then remove and fit the brass ones.

Andy

 

[Kalimna]

Thanks Andy - that does make sense. The screws are certainly not brass, far too magnetic...
With your 'use a steel screw first' idea - is that to cut a thread in the wood prior to using the softer brass?

Adam

 

[Ian]

Hi Adam

When mortising a hinge you have to measure the thickness or the barrel/knuckle, and then half of this thickness is the depth of each mortise. Best to not go full depth first time or there will be a gap at the front. You will then have a small gap at the back but that is much more acceptable then the front. As for alignment you should really cut the mortises on the router table using the fence and this will greatly improve the alignment. Another alignment issue is drilling for the screws, if you don't drill them dead centre the screw will pull the hinge forward or backward causing misalignment, best to have the hinge sit in a closed mortise rather than an open one this will help prevent the hinge being pulled forward. As for the screw just drill it out using a metal drill and as Andy says plug the hole and start again.

HTH

Ian

 

[AndyT]

Another possible reason for the box not closing could be if the screws are too big for the hinges and their heads stick up above the surface - when you close the lid, two sets of screw heads collide and keep the lid open. The solution is to use smaller screws, or else enlarge the countersinking in the hinges.

I much prefer to make hinge mortices by hand, which means that if you want to you can cut too shallow first, try it out and then sneak up on the right depth. Also, I find it really helps to make a specialist marking gauge to define the depth (ie half of the barrel diameter). This is simply a sharpened woodscrew in a block of wood:

More on chiselling techniques in this thread.

 

[Kalimna]

Thanks for your advice folks - I suspect that my main problem was cutting the mortice too deep (with chisels only, so quite chuffed at myself for that...), but that screw-heads too high was also an issue.
If a 'cut shallow and test-fit' approach is the best way forwards, then is it ok to re-use, in effect, the initial screw hole, or would you fill the hole with , for instance, matchsticks each time? I suppose using a 'dummy' screw for the testing and then a 'fresh' screw for the final is the way to go.
And (again) what is the best way to keep the lid aligned whilst marking out for the hinges? Unfortunately I dont have a router table, and anyway, I am trying to achieve all this with hand tools as a means to do things relatively quietly at night when small children in bed

Many thanks,
Adam