Months ago, I inherited a coal hammer. I know it's a coal hammer, partly because of the shape, but mostly because the words "Coal Hammer" are cast into either side of the head.
It's been kicking around on my bench for a while and found much use as a weight when I'm sticking things. What I couldn't do is use it as a heavy hammer because the head was lose. Lose hammer heads make using the tool difficult and more importantly dangerous. You don't want the metal bit coming off and flying in the direction of your (non-metal) head.
Glue, anti-freeze and old oil are all suggested as a fix but I was always taught that hammer heads should be wedged in place. Of course I didn't have the wedge, which is why it took so long to fix the thing.
Anyway, in my favourite hardware shop (Torry's, Warwick) the other day, I remembered to ask for some metal wedges. The first question was "How big?" and of course I'd assumed they were all the same. "Is it for a pin hammer?", I was asked and then sold a couple of quarter inch wedges for pennies.
I want to call these brads for some reason but I'm not sure that's right.
Anyway, all that is required is to make sure the head is well on the handle and then hammer (assuming you own more than one, but who doesn't?) the wedge in. There was one in there already so I cut the new wedge in half with a junior hacksaw, then belted it in.
The hammer head is now secure. Sadly, this has exposed a crack in the metal which means no thwacking coal or rocks with it. Light taps for model making and use as a weight is still on though. And I have a spare wedge if I can find it on the garage floor.