Highland Park R-1 20″ Slab Saw Restoration Project

The club was donated a 50 year old HP R-1 slab saw back in October 2025 by a woman who had bought it from someone back in the 1990s and had it in her garage ever since. It was in relatively good condition when I went out to have a look at it to see if it would benefit us to accept it. It required five people and a trailer to pick it up and move it to my garage so I could work on it. Here is the progress and some of the issues in making it work properly.

The hardest work was removing the old blue paint which covered a lot of rust.

I copied the paint colors that The Cigar Box in Bend Oregon uses for their restorations, hammered silver and copper (they use gold, but I chose copper for the hood).

We had to order parts from HP Lapidary and they are being delivered gradually over a month; the motor, the switch box, blade splash guard, and a cutoff catch tray to protect the arbor. We also order things from Amazon; a ball valve for the tank drain, tap kits to make holes for the switch box, handle for the hood, a specific size pulley for the feed screw that would fit precisely between the drive pulley and the bearings on the arbor, that was a critical piece, and the belts.

The switch box: before and after repainting

I have to tap holes in the tank to mount the switch box and screw for the automatic shutoff chain.

The motor mounting plate did not have anything to support a motor. The newer models have a threaded rod that is screwed into a nut that is welded to the underside of the tank, but this particular model didn’t have that, so the threaded rod has to go from the mounting plate to the floor. Someone who knows how to weld could weld a nut to the tank and that would allow the saw to be moved without removing the motor.

I had to fabricate a gasket for the gear cover. This was a trial an error exercise because I didn’t know what the best material was for a gasket. Finally I used a 1/8″ thick piece of gasket rubber.

It would be ideal to mount metal plates to the legs so casters could be attached like the new models have. Anyone with welding experience could do that.

I replaced the wood blocks in the vice

I’m waiting on the blade splash guard which will have to be repainted and hopefully it will fit.

The pulley, arbor, and belt situation

More to come…