The weather has cooperated nicely the last few days, so I was able to spend a little time out in the shop. Two more of the legs have been de-rusted and the final leg is in the bath as I type adding it's rust to the soup. Three of the 4 legs have been primed with etching primer and I used some body filler to fill the grinding marks left from welding and grinding smooth the holes previous owners have drilled in the legs.
I was also able to work a little on my MBFFrankensaw project. By using the yoke and roller-head assembly from a model 925 I can use the frame 236 motor I am salvaging from a model 7770 on my little MBF. I will save the frame and column mount from the 7770 for another project, and will part out the rest of the saw. Today I separated the roller-head from the yoke. The difficult part of this piece is removing the set screw pin that locks the king bolt in place. The pin is hardened steel and the yoke is aluminum. Over the years the pin freezes to the aluminum due to galvanic corrosion. I have been soaking the threads in PB Blaster for about a week and was able to back the pin out with the application of a little heat from my propane torch. I really got lucky with this one. I have had problems with others where the head of the screw would snap off leaving me no choice but to pay a machinist to remove the pin. I also have several other project waiting for my attention: Gravely tractor repairs, replace the chipbreaker on my planer, finish my welding table and tune up my jointer. There are also several other projects in the queue, but I will save that for another time. I don't want to overwealm myself and shutdown. I also have an update on cost for some additional parts and supplies, but I think I will go over that tomorrow. I hope you all have a Merry Christmas. I am so thankful for my wonderful family as we gather to celebrate the holidays.
I had a chance to pull a couple of the legs from the soup and snap some photos. Once the parts are removed to dry they will flash over with a light coating of surface rust almost immediately. The rusted areas will be coated in a flakey black oxide. I allow the parts to air dry, knock off the surface rust and black oxide with a wire cup on my side grinder and then scrub the parts down thouroughly with a brown 3M finishing pad and some hot soapy water. I then towel them dry and set in a warm oven or in a closed warm car in the sunshine. This results in a part that is free from any rust and grime and is ready for primer. I will then fill any of the small defects left from welding closed the holes that were drilled in the piece. Sometimes I use the kitchen oven to process parts. SHHH! Don't tell Becky.
The Cayce end of the river walk along the Congaree is closed due to flooding, so we went upstream to the West Columbia entrance to get a little exercise and walk the dog. It was cool and breezy, but still a very pleasant outing. We stopped and admired a sturdy bayberry bush that was heavy with berries, and Becky spotted a black lizard trying very hard to go unnoticed as it warmed itself in the sun just off the trail. That's all for today as I need to do some studying.
Well, it's been a beautiful sunny day here in the Midlands of SC. I went up on the roof and patched a small area around the chimney that has started leaking. I found that some of the old caulking had dried and pulled away from the flashing, so I sealed it up with the last of some old roofing cement I bought many years ago. It's sort of ugly, but I have never had to re-do any repairs where I used the old roofing cement. It's basically a black tarry asphalt emulsion with some fibre content to give it some additional strength. I placed another of the DeWalt GR saw legs in the de-rusting bath and then did some shopping. I have purchased the finishing supplies I will need to re-paint this saw. I settled on a custom color that matches the old Oliver Machinery Teal that was used in the 1960's. I purchased the paint and the compatible primer from Sherwin-Williams. The smallest quantity available was in gallon cans, so I'm sure there will be additional machines painted Oliver teal from my shop. The paint is Sher-Kem High Gloss enamel and the primer is Kem-Flash primer. I also purchased a gallon of reducer, sandpapers, filler, and sanding primer fillers. Total for the paints and finishing supplies comes to $146.98. Now I know you can get a perfectly acceptable finish for much less with rattle cans, but I really want this machine to look like a professional restoration. The total is now $503.28. The cost starts to add up fast once you start counting every $5 to $35 dollar purchase. That's all for now.
This evening I picked up a brand new 5HP 3PH motor to use in the construction of a rotary phase converter. This will give me 3 Phase capability in the shop so I can run the big radial saw or any other 3 phase machines that may come my way... hehe hehe. I ran a wanted ad on craig's list and picked up this motor for only $40.00. Since I will use the phase converter on multiple machines, I will not be adding it to the restoration cost of the saw. I will add that I picked up a rattle can of etching primer and that will be added to the cost of the saw refurb. Etching primer from Advance Auto Parts, $6.30 including tax. My total saw investment thus far is $356.30. I also pulled the first saw frame legs from the electrolysis bath. It is paint and rust free, but coated with a black oxide residue. I need to clean it up with a green pad and water and check to see how bad the rust pitting is at the bottom of the leg. I will post some more pics once I get a chance. I may not get a chance to get back on this project for a few days due to a motherboard failure on my wifes desktop. This shouldn't be too bad since I have another MB on hand and her linux system will most likely handle it with little trouble.
Yesterday afternoon I set up my electrolysis rust removal system. The reversal of the plating process. This consist of a 12 amp 24 volt adjustable dc power supply, a plastic tub from the dollar store and some scrap iron to use as the sacrificial anode. I keep the workpiece slightly raised off the bottom of the tub with a couple of bricks. The electrolyte solution is simply tap water with sodium carbonate (washing soda). Hook the negative lead to the workpiece and the positive to the sacrificial anode. I like to keep the battery clips out of the solution as the negative lead will lose it's plating and the positive will rapidly erode if they are submerged in the solution. The electron flow is from negative to positive, and the electrons will scrub off the oxides, paint and anything else coating the workpiece. The byproduct is rusty water with old paint and hydrogen gas. Yes, this does produce some hydrogen gas, so only do this in a well ventilated area. Avoid any sources of sparks or flame while running this process, and of course, No Smoking. You shouldn't be smoking anyway unless you happen to be on fire. A day or two in the "soup" will usually result in a perfectly clean part ready for primer after a vigorous cleaning with a green pad and tap water. This process is only for ferrous metals and should not be used on yellow metals or aluminum as they will disolve away. Rusty water with sodium carbonate is not particularly nasty for the environment on its own, but since I don't know what may be in the paint, I like to let the water evaporate and then dispose of the rust and paint in a well sealed plastic bag for the trash. I also avoid using stainless steel for the sacrificial anode as it contains chromium which is toxic to the environment.
The helpful folks at Original Saw Company were able to decode the serial number on my GR and determined this machine was made in 1948. A well deserved thank you goes out to the helpful folks at Original Saw and Wolfe Machinery for making the parts that help keep these great old machines running.
Since I always enjoy sharing things from our life and my various projects, I have decided to start documenting these things in a blog. I am currently working on refurbishing a DeWalt model GR radial arm saw. I found this saw on Craigslist and went to have a look as it was identified as a model GP in the ad. A model GP is an older 12 inch saw that is a very nice size for a home shop. Heavy duty iron castings and plenty of power for most projects. Once I had a chance to look the saw over I discovered it to actually be a Model GR; a much larger industrial machine, with a 14 inch blade capacity and 3 phase, 3HP motor. I was not sure of the actual age of this machine, but it was clearly from the 1940's or early '50's at the latest. A deal was struck and I was the new owner for $225.00. One thing I would like to do is begin documenting the actual cost of my little projects and see just how deep in the hole I have to go to resurect some old iron. Disassembly revealed a broken miter index on the column and a poor fitting replacement elevation handle. A quick search of some of my favorite old woodworking machine sites secured an elevation handle $25.00 and column $100.00. Totals so far are $350.00. I spent most of yesterday welding closed all the extra holes in the saw frame that have been drilled over the years. Here are some pictures for your enjoyement.