How to clean a saw plate
When sharpening a saw you need to ensure that your saw plate is clean and free of crud, rust and other goop that might have accumulated over the last several decades of use and storage. If you want me to sharpen your saw you can either pay me to clean it or you can save some money and do it yourself (I wont object, I promise). The reason that a saw must be cleaned before sharpening is that a dirty or rusty saw can increase the resistance that is experienced during sawing and can cause the saw to cut slowly or pull during a cut. If a plate is clean and polished and there is an issue with saw tracking, you can more easily troubleshoot the issue and eliminate potential problems more quickly.
The items that I use to clean a saw plate are sandpaper grits 220, 320, 400 and 600. I use simple green as a cleaner and use paste wax to coat the plate upon completion. If a saw plate is heavily rusted I use Evapo-rust prior to cleaning with sand paper and simple green. Evapo-rust can be a huge labor savor and reduces the chances that you'll accidently remove the etch while sanding off heavy rust. I wouldn't use it for light rust covering but if your saw is the color orange, it could be worth it.
I lay down a piece of craft paper to collect the dirt and grime that comes off of the saw plate and replace it after I clean one side. To decide on whether to do a handle off or handle on cleaning I will look at the condition of the handle and nuts and decide if it is worth removing the handle. Use caution if you're contemplating the removal of split nut screws. Due to their age and their thinner shafts than newer saw plate screws, removing split nut screws can cause the shafts to break or the threads on the shafts to shear off on the saw plate during the saw plate if not done carefully.
The first step is to look at a saw and see what type of cleaning you might need to do to get your saw back to good working condition. This saw has staining, rust and some staining. If you follow a couple of steps the majority of this plate can be cleaned, permitting the plate and etching to be seen once again.
To remove a saw handle the first step is to clean in the middle of the screws and around the outside the exterior of each screw. To do this I use a dental pick, which can easily get in and around each saw nut. Allowing the dirt to remain in the screw slot prior to its removal might not allow the screwdriver to seat properly in each screw which will increase the possibility of stripping a screw.
Once the screw slots are cleaned, clean around each screw. A screw remaining in the handle untouched for the last fifty plus years can cause the nuts to stick to the surrounding wood. If the nut is removed without first cleaning around it, the wood can break or chip away with the screw. There might still be a small break or chip in the wood when cleaning is done but it will be greatly reduced if this step is done first.
Once you carefully remove each of the screws put them back together so you know which nut goes with each screw. This can be especially important with split nut screws which can be a bit more picky on which screw they belong to. Also, not all screw nuts are the same size. Some Disston D8 top left screws, for example, are smaller than the other screws. Trying to screw a larger screw into a smaller hole during installation can cause the screw hole to be damaged.
Prior to removing the handle from the saw plate look at the top of the handle. Certain types of handles are covered while others are not. If you try to wiggle a stuck saw handle off of a plate and put pressure on the handle cover, you can crack or break the handle cover.
Once the handle is removed a gunk line becomes quickly apparent. This can be cleaned away with either a razor blade or with sandpaper used while cleaning the rest of the saw plate. If you use a razor blade it is important to be careful not to scratch or cut into the blade.
When the saw plate is ready to be cleaned, start off with 220 grit sandpaper. I don't recommend using anything more aggressive because it can quickly remove the etch. Power sanders should be avoided for the same reason. With the plate on top of craft paper, spray the plate with simple green. When you use the sand paper, scrub in long strokes along the length of the plate. Do not scrub using vertical strokes or the sanding marks will be easily seen. This sanding is done by hand. When cleaning by hand, avoid the areas that the etch might be. Ensure that you pay particular attention to the teeth and not just the plate. This saw was first cleaned with Evapo-rust due to the high amount of rust that was on the blade. The Evapo-rust puts a black coating on the plate but will come off during cleaning. I would only recommend Evapo-rust when the saw is coated in rust. If there is 80 years worth of gunk or lite rust, I would only use sandpaper and simple green.
Once the outer edges and the teeth are cleaned with the 220 grit sandpaper by hand, you can concentrate on the etches. In the picture below you can see that I specifically avoided the center of the plate which I will go over using a sanding block (the darker spot in the middle is the color left over from the Evapo-rust. This is why I don't recommend using this product for a light cleaning). A sanding block permits more even pressure over the etch while sanding and will reduce the possibility of removing the etch if done properly. This plate also has some pitting on the teeth. This area can be cleaned but the darkened color will remain due to small pin sized holes containing the discoloration. (Be careful while setting teeth in a pitted area. The metal has been reduced, the teeth have been weakened and the teeth could break).
When dealing with the center of the plate where the etches will exist, use a sanding block to keep even pressure over the etches. The key to not removing the etch is to take your time and use light pressure. I put enough pressure to move the block and sandpaper. I keep a rag close by and continually clean the area to monitor the etch. If at any point you see that the sandpaper is removing the etch, stop sanding.
Once you have completed the cleaning with the 220 grit, move up the grits until you get to 600. You don't have to get the plate completely clean off of 220 grit, the higher grits will increase the shine of the plate. When I complete one grit I clean the dirty simple green swirl off of the plate. Once one side is complete, I flip to the other side and put a clean piece of craft paper down so I don't put the clean plate down on a dirty piece of craft paper. This side is usually quicker since you don't have to worry about any etches. Once both sides are cleaned, I clean the left over dirt off, dry off the plate with a clean towel and then coat the plate with a paste wax so rust doesn't form on the new metal that has been exposed by the sanding.
Here is a side by side of a before and after. The goal of a cleaning isn't to make a saw new or fool someone into thinking that it was recently manufactured. The goal is to provide a clean plate to assist sharp teeth in cutting through lumber. If you're lucky, you might have a nice plate that you only need to touch up with 400 or 600 grit sandpaper. More examples of the saw I restored can be seen under the "my work" page and also in the "restored saws for sale" page.
Here is a product that works great for cleaning the handle of a saw. Kramer's Best Antique Improver is a BLO mix that when used with some light scrubbing from a scotch-brite pad creates excellent results and brings a luster back to the handle which it probably hasn't had for decades. The paste wax next to it is what I use to coat a clean plate. With a little time, a pair of rubber gloves and some patience you can get a saw ready for another century of use.