Hi all:

I restored a Powermatic 66, back about 25 years ago that I bought at a school auction.

I took the top off and took it to a large grinding shop in Philadelphia.

It needed some machine work to get it back flat.

I bought another one recently that had a pretty badly rusted top, not pitted just heavy rust.

I don't want to go to Phila. this time, just want to get the top in decent shape myself at home.

Anyone have any suggestions or pointers in getting it looking good again?

Thanks,

Charlie

Charlie,

I have restored a lot of table saws over the years and as a matter of fact I have 5 Unisaws taken apart in my shop now. Some are just parts saws that I will switch a few parts out on the saws I am keeping, but I plan to restore 2 Unisaws that were made the first year of the Unisaw production which was 1939 and keep one in each of my shops. I posted a method of patching panels over here http://www.theamericanwoodworker.com/forum/topics/its-friday-what-a... 

 

Anyhoos back to the table saw tops ......there are several ways to get rid of the rust from chemicals, razor blade scrapers, steel wool, scotch brite products, and the list goes on, but I taught machine shop years ago and you are not dealing with critical dimensions like if you were working on "scraping" in the ways on a metal lathe so I would't worry about any metal loss due to the following advice. What I use if the rust isn't too deep is a begin with about 120 grit aluminum oxide paper on a random orbital sander and take a look at the results after about 30 second test run. Then you can evaluate if you need to go up or down a bit on grit. Be sure to wear a dust mask and I like to do this job outside if possible and have a small fan blowing the "dust cloud" away from you and the work area. If you want to hold the dust down you can pre-spray some light penetrating oil on the top, but you will use a lot more sanding discs. Some people use a razor blade scraper, but I find the sandpaper to be much quicker and produces better results. After getting most of the rust off  I would make a last pass with something like 320 grit and then clean off the surface and place whatever metal protectant / rust preventative on the table you choose. 

 

Good Luck ~ Dan

I am one of the guys that like to go at it with a razor blade. If you get it at just the right angle it will scrap all the rust off down the the bare metal. If there are any machining marks on the table like ya can see in the pic below then a blade will not remove them.

Get ya a good holder for the blade. Something like this one and a lot of blades. You can buy a package of 100 blades from the Borg stores for about 5 bucks. Make a couple dozen swipes with the blade and throw in a new one.

Here's a shot of a rusty table on a Newman planer that I am working on. This was shot just after scraping half of it with a blade.

I Scrap all the rust dust into a pile and then suck it up with a shop vac or brush it off into the garbage pan.

Finish it off with a couple of different grit scotch brite pads mounted on a random orbital sander followed by some 0000 steel wool and you'll be good to go.

Thanks Shane:

I will give this a try, I had never thought of using razor blades to clean it up.

About what angle works best for you?  Something like the angle in a hand plane?

 

About what angle works best for you?  Something like the angle in a hand plane?

Yeah, somewhere around there. Start out low and increase the angle till it starts scrapping it off, you'll get the feel for it.

Shane,

 

To quote myself.....Dan said: "there are several ways to get rid of the rust from chemicals, razor blade scrapers, steel wool, scotch brite products, and the list goes on, but I taught machine shop years ago and you are not dealing with critical dimensions like if you were working on "scraping" in the ways on a metal lathe so I would't worry about any metal loss due to the following advice."

 

I agree with you about razor blade rust removal on "some surfaces", but if you read my advice it was directed toward table saw tops which are cast iron. Typically these tops have no remaining Blanchard grinding pattern, are not "scraped" from the factory to be accurate to ten-thousandths of an inch, do not have a "milling pattern" on the surface, or have metal planer marks, or other "figured metal finishing" that you would perhaps be slightly de-face with sandpaper. Since working in a body shop while in college back in 60s I have worked on the preparation of hundreds of rusty metal surfaces (machine and otherwise) and probably dozens and dozens of the aforementioned "figured" cast iron surfaces and I use a combination of processes depending on the "pattern" on the metal, and how hard it is, etc, but for cast iron tops with out any "figure" to damage I lean toward a random orbital sander with the appropriate sandpaper because it is not nearly as labor intensive as most other methods including razor blade scraping plus you usually have to do other surface work after you razor blade scrape. I have also used and discussed numerous processes for surface rust removal with many people on several forums and razor blade rust removal is a fairly straight forward process, but some skill is required and here is why....... When using a razor blade one can very easily "dig" the cast iron or machined steel surface with the edge of a razor blade and produce a scratch that is a few thousandths deep and a few inches long that is almost irreversible and looks bad. When I do choose the scraping method I much prefer the Unger scraper system (please see picture below) for "most applications" for several reasons as it has a much more rigid and therefore accurate scraping blade than the common razor blade plus the blade is wider and a lot more stable than the narrower razor blades. The Unger blades are more expensive, but I have several diamond impregnated lapping stones / steels of various sizes and grits and it is about a 30 second job to touch up the edge on a dull Unger blade and have it back to new specs.

 

Unger Scraper

Again I suggest that rust removal depends on the surface and conditions. EG: I have a 1945 Delta 14" DP 220 bench top drill press that was in almost brand new condition "wear wise" when I found it, but that had set is a basement and surface rust on it and the Blanchard grinding marks were still very pronounced that I chose to carefully razor scrape then I used a very fine wire wheel with oil and light pressure. Somewhat labor intensive, but it turned out well. 

 

Another example is a drill press table surface on one of my Delta 17" first generation drill presses that was originally Blanchard ground from the factory, but the figure has long since been worn off so I "carefully" used a random orbital sander on with 120 then 220 then 320 on that you can almost comb your hair in the reflection and I would venture to say that I did not remove more than .002 or so from the surface. Given that a human hair is .003 I am not concerned about that minuscule amount of metal removal. This method is far less labor intensive as razor scraping and then using other processes to get this type of surface finish. Here are a couple pictures of it and I also used sandpaper on the column etc. 

 

  

 

In closing and coming back full circle .......... again there are several ways to remove rust on a table saw surface, but I still maintain that on the specific Powermatic table saw that I was addressing in my first post concerning the removal of light table top rust....... I would use the sandpaper / random orbital sander method and if you don't have too much surface rust you are looking about a 10-15 minute job to get it "presentable" or obviously more time if you want a mirror finish. 

 

Here are some other examples of sanding metal surfaces like the chuck, lead screw, handwheels, etc. that I cleaned up on the old South Bend metal lathe that I restored that is used sandpaper on some, Scotchbite on others, buffing wheels on some, etc. On some surfaces I used 2000 grit.

 

 

Over and Out ~ Dan

 

 

 

Dan you truly are a master at the restorations and the pics ya posted above prove it. You have been huge inspiration to me over the years and whenever I restore a machine I push myself to go the extra mile to make them as nice as yours ... especially that South Bend

 

I wasn't disagreeing with what ya said, it's great advice, was just offering up how I do it. I've done a few table saw tops with the blade, including my Oliver
below, and have had great results.

 

Oliver 270 with minor surface rust when I got it ...

looking all purdy.

Wow, what a transformation. That is almost beyond words. You definitely went the extra mile and if you got inspired by Dan to do that he needs a BIG KUDO. 

 

Very fine restoration!


Shane Whitlock said:

Dan you truly are a master at the restorations and the pics ya posted above prove it. You have been huge inspiration to me over the years and whenever I restore a machine I push myself to go the extra mile to make them as nice as yours ... especially that South Bend

 

I wasn't disagreeing with what ya said, it's great advice, was just offering up how I do it. I've done a few table saw tops with the blade, including my Oliver below, and have had great results.

 

Oliver 270 with minor surface rust when I got it ...

looking all purdy.

Hi Shane,

 

Thanks for the compliments and I think that we probably go the extra mile to make an old machine not only as functional as it was when new, but perhaps a bit better. 

 

Also thanks John.............Shane and I have been friends for quite a while now and I sure wished he lived closer so we could hang out in each other's shops..........then he could teach me how to take pictures. Our son has a degree in Graphic Design and also a degree in Photography, but he lives in Portland, OR and that is still further than Shane who is in Utah. I will keep tryin I suppose.......thanks again guys.

 

Dan ~ thinkin i might trade my little Brownie camera in for one of them fancy ones .......... ho ho! 

Well I just learned every thing I need to know here to restore machinery, what a wonderful post  and thread guys, the detail, the tutorial, great job guys, this is the way to spread your wealth of knowledge, thanks for the pics, the information, and the discussion.

Great job!

John Morris said:

Well I just learned every thing I need to know here to restore machinery, what a wonderful post  and thread guys, the detail, the tutorial, great job guys, this is the way to spread your wealth of knowledge, thanks for the pics, the information, and the discussion.

Great job!

 

 

Well, there's a few things that these guys know that they didn't say, like a few volumes worth! Now seriously they are both quick to share and I am a big fan of both Dan and Shane's work. They push the envelope of an already fine art. Their machines look way better than new. And then they use 'em! My machines don't usually want their pictures taken but I have sure learned lot from Dan and Shane...

 

Bob

 give me that old arn every time

Thanks for the kind words Bob ... Glad to see ya here.

 

and I agree with your sig 100%
BobHall said:

Bob

give me that old arn every time