I use mineral oil if the handle looks very dry. I figure that will soak in and "moisten" the wood deeply plus repel some water.
Then, after the mineral oil has soaked in, I rub the surface with paraffin (because that's the cheapest wax, and leaves a somewhat slippery surface). Then I leave it in the sun, if it's warm out. Otherwise I just re-apply paraffin occasionally and rub it in hard.
I also prefer fiberglass handles over wood: they are lighter and I expect them to outlast me without any care at all.
Some tools, like a straight-handled shovel or hoe, I want to slip so I don't raise extra blisters. Hence, paraffin. In other cases, I want as much "grab" to the wood as possible. Then, I rub beeswax on top of the paraffin.
If I wanted the
wax to soak in deeply, I would melt the wax with mineral spirits and some mineral oil first, store it in a tightly sealed can, and then rub it in as a paste.
Instead, I'll sometimes "splurge" on Johnson's Wax - that is already a paste of some hard, slippery waxes and some volatile solvent. Or "bowling alley wax" would be a classy, pricey substitute for paraffin.
(Paraffin can sometimes be found at supermarkets or as a canning/jelly supply. I think that candle-making paraffin is likely to be more expensive.)
And sometimes i just use a commercial "orange wax" goop that has some wax and some oil in a slurry. I tend to use that on knife handles, not shovel handles.
I don't like vegetable oils (usually) or turpentine because i think they can oxidize.
If I wanted to go crazy and spend money, I would put a layer of polyurethane on top, to seal it. But I like the feel of wood better than plastic!
Check out some fancy product$ to protect and $trengthen wood for marine application$: Doctor Rot.
http://www.rotdoctor.com/poly/...
P.S. Mineral oil also protects metal from rusting.
If you have a metal surface that won't be scratched or rubbed by grit, a light layer of wax will protect it even better (melt it after rubbing, or apply with a solvent). I've heard that woodworkers will apply Johnson's Wax or bowling alley wax to a machine tool to prevent rust.
