First make sure the threads in the base and in the screw are clean, of all grit, dust, rust, wood or metal chips etc. Use a wire brush and a rag, and a light spraying of kerosene or WD40, or to be "greener" use some orange citrus cleaner (no pumice). Wear rubber gloves or throw-away latex gloves, plus put newspaper down under all to make cleanup/recovery fast and easy. Make sure the load bearing head-plate (I don't know its proper name) on top of the screw shaft spins freely, i.e. stays unmoving as the screw is turned. Wipe away all your cleaner, then squirt or brush oil into the threads. Vegetable, mineral or petroleum oil all work, or work in some light grease. Coat the threads, don't pack them. They need to be clean, protected from rust, and be slippery. If the action starts getting a little stiff you may need to spray flush out some hardened grease or grit with WD40, or just slippery them up with some squirts from your oil can. Summer and winter temps effect the lubricant and the screw action as you would expect.
Set 'em up on a heavy wood block or a steel plate, Keep 'em out of the dirt. That's how I use a screw jack, Jack. Just like with clamps, you hardly ever have too many jacks. Good luck lifting your barn Mike.
Steve
If I knew how to load a picture I'd put some recent pics of lifting a small carriage barn.....
Last edited by Waccabuc; 05/02/08 09:35 AM. Reason: remembered the newspapers...
