Is sandblasting the best method?
Recently I’ve purchased an old Unisaw and lathe, and I plan to restore them to their original glory. The paint is in okay condition, but it all has specks of rust I want to erradicate and repaint over (who doesn’t like their toys shiny?;). I’ve been suggested to have all of the parts sandblasted and repainted, but I was just wondering if there are other chemical ways that are just as effective and can be done efficiently at home instead of lugging all of this junk around. Heck, are sandblasters something you can rent and do at home? (I’m really new at this)
Also, with sandblasting, does that just strip the paint, or do I have to worry about it getting in certain areas where I don’t want metal missing like in the bearing mounts and pivot surfaces.
Thanks in advance!!
tony
Replies
Sandblasting would require that you totally disassemble the saw. Also, you would have to tape and protect all the surfaces you didn't want abraded. Seems a little radical for just dealing with a few rust marks.
I would just get out my rotary sander with some 80 grit sanding disks and sand down those spots that have rust. Feather the sanded spots into the painted areas. Now if you are after the best job, get some body sanding compound from an autobody supply store. Spread it on the spots and let it dry. Now sand the spots first with 220, then 320 then 400 W&D. Wipe down the rest of the surfaces with mineral spirits and sand with the 400. Then spray on a primer and then the top coat.
well, it's not so much distinct spots of rust, but the tiny ones all over... kinda hard to explain. the other problem i have then is that i would have to sand/grind the texture of the cast iron smooth which would look kinda bad (i'll admit, what i'm doing is for cosmetics, not functionality...). i'm going for the original brand new look, so i'd even like to get the truinions all pretty, too (i know, it's not everyone's cup of tea, but i enjoy it).
the bed on the lathe is more rust and discoloration than paint, so that one would really be a candidate for the sand bath.. (structurally, it's quite sound, though)
Sound like a labor of love. You might want to go over to the WOODNet board "Woodworking Tools" d-group. There are two Delta guys that hang out there and they may be able to tell you the type of finish you are dealing with and how they recommend you proceed. Look for "rock2car" or "delta007". http://www.forums.woodnet.net/
Howie's probably right about spot stripping, but you may find more and more little rust spots the more you look, and decide to do the whole thing on either the saw or the lathe. If you do, I recommend disassemling them. It will be a lot easier to see and reach what needs to be masked, and a lot of senstive parts, like spindle and bearings, will be out of the way.
You should be able to rent a sandblaster, but it will be the hopper type rather than the cabinet type and you will have to make your own arrangements to capture the used sand for reuse, or go through a lot of sand.
Regular household paint stripper might work. If it doesn't, oven cleaner almost certainly will. There is a way to remove rust electrolytically, but you may not want to buy a plastic tank big enough to submerge a table saw cabinet in. If you're interested, do a web search for
rust "washing soda"
However you end up stripping the rusty spots, make sure you prime with a rust conversion primer. If you paint over rust, even just a little bit in the bottom of a pit in the metal, it will eventually rust through again.
I'm not sure I would mess with it at all. There's no tool like an old tool.
For my first carpentry job (28 years ago), I went to the pawn shop and bought a beat-up set of leather nail bags so I wouldn't LOOK like a greenhorn.
If you just HAVE to repaint it, I would strip it down to the cast iron frame and get it dip-stripped. There are companies around that can put it in a vat of stripper. Most are listed in the yellow pages. Kinda radical but it probably won't damage the milled parts that you want to remain smooth. Sand blasting will eat everything.
I'd break it down and replace any working part that needs replacing and leave the rest the way it is. Consider it's history.
Ed. Williams
The old way to remove paint form wood was with a can of drano...dumped into a bucket of water....stir and slosh on with a stck with cloth on the end...keep on sloshing until paint washes off. With wood you had to use a vinigar and water mixture to stop the process. I wonder if that would work for you? cheap enough to try a portion...
Of course, this does nothing for the rust.
well, i went and took some pictures so you can all kinda see what i'm up against. while none of it's really that bad for 50+ years old, i'm not one to just put a band-aid on something and wait for it to reappear (hence i want to strip everything and give it a good coat of primer and paint).
thanks,
tony
...the dremel with a wire brush wheel just polishes the rust and paint, so that's out of the question...
I'm fifty and have rust in the very same spots...lol. I don't have a solution, but being cast iron I don't think you can expect a fine smooth surface like the tabel top. If you spot sand too hard your gonna have smooth spots. I'd sand lightly...or strip all...and hit with rustoleumn (sp)...spray light coats. Just one idea hopefully...
I once bought a Delta MultiPlex RAS that was rusted about like your saw. I sandpapered the rusty spots with coarse sandpaper and sprayed painted it with a engine paint that matched the Delta gray. That was 25 or 30 years ago and it's still fine.
BJGardening, cooking and woodworking in Southern Maryland
I understand were you are coming from. I have done the same thing to my drill press, many exterior c.i. house parts, and tons of c.i. car parts. Unless you plan to leave the tools outside or in a barn I think a wire brush is perfect for this situation. A hand wire brush will work but not very quickly. The easiest thing will be to step up from the Dremel and use a wire cup on an angle grinder. Make sure the wire cup or wheel is rated for the rpms of an angle grinder and you can't go without heavy gloves and eye protection. After you have brushed it to the extent you want use a good metal primer (rustoleum is one brand) then paint it. Sand paper will remove too much metal and can't get into the surface like a wire brush and in the end will drastically change the surface of the casting.
Good luck and have fun,
Chris
I have my Dad's old 1931 Craftsman table saw that I want to restore as well, just for the sentimental value.
I would consider complete disassembly, dip-strip or bead blasting, NOT sand-blasting, followed by powder coat paint. Many shops will do the dip-stripping, bead blasting, and powder coating at a resaonable cost (not the same shop for all three, of course), but the dissassebmly and reassembly is all yours! You might as well press in all new bearings while you're at it.
Mike
I know a lot of folks won't agree with me, but i would get Sear's small sandblaster and have at it. It sells for about $65. Go to Lowes and get some play sand and a tarp and when you're done, sift the sand and use it again. I had some really bad planes and we sandblasted them and they came out great. I wasn't really concerned with the japanning because they aren't going to be collectible. Like I said, I know very few would agree with me, but I was happy with the results.
The website below is all about restoring old woodworking machines. Do a search on their message board and I am sure you will find the info you are looking for.
Best of luck.
http://www.oldwwmachines.com/
quick update for anyone else interested in this topic...
i have just finished restoring my craftsman lathe using only wire brushes on an electric drill -the results were beyond my wildest dreams! it all went smooth, and the cast iron suffered no damage. the only thing that i did notice is on milled surfaces. if you hold the brush in one spot for too long and press good and hard on it, it will actually polish the surface making it stand out (nothing a little 220 grit paper and a scotch brite pad can't repair).
here's some pictures, and thanks again for everyone's input!
(now for that unisaw.... ;)
Looks great, it probably will never ever cause you a problem if you used the right paint. We have stuff here in Oz called Kill Rust, it does a pretty good job, sticks to just about anything and is supposed to inhibit further rusting (if its not deep).
If you want to do a really good job that will last for any extremely long time, that is unless you want to use your old iron on the beach, you really must blast that rust off or convert it somehow. Wire brushing has a tendency of causing some rust to be driven under the surface where it may reactivate if your finish is ever broken. We had seawater valves in the navy that had machined faces and they were blasted no problem. You just need to ensure all faces you don't want messed up have a good covering of blast tape. It would probably work out cheaper and easier to take the parts (disassembled of course) to someone who does this for a living, it would take them a few minutes to blast everthing and they would probably do a good deal on priming and painting everything as well.
I wouldn't worry too much about retaining patina, since how many vintage car enthusiasts proudly show off the rust they have carefully preserved on their 57 Chev or model T Ford. Different story with hand tools, but they are a bit different.
At the end of the day if you replace the bushes, bearings etc you will have a lovely old machine that works as well as or better than it ever did and give your workshop a groovy retro look to boot. This has got to be good......
I'll throw in my 2 cents. From the photos it appears the rust is not too bad. I restored a 1964 Delta/Rockwell Unisaw couple of years ago. For the rough casted areas such as the rip fence head and base, just use a wire brush mounted in a drill or on a bench grinder. After I did this I just primed with a good quality primer (2 coats) and 2 coats of whatever color you desire. This worked well for the base of my saw. For the inside of the machine, other than a good wipe-down, there should not be any need to paint or grind. You are asking for trouble if you sand blast the inside areas that are near any bearings. It is expected that old iron will have some character marks that show actual use. If it works as expected, do not sweat the small stuff.
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