Powermatic 300 Sander Rebuild

[Tim Livingston]

Over 2 years ago I bought a Powermatic 300 sander through E-bay from the Oriskany School district which is 100 miles or so from me, my wife was giving birth at the time I bought it so I was trying to arrange a time to go pick it up when the guy from the school said he was coming to my town the next weekend because that is where his father lived. Double score, my winning bid was $61 I think and the guy delivered it, I gave him $75 and said thanks. Unfortunantly I don't have any pictures of how it arrived but it was in pretty good shape for being 30-40 years old and coming from a school.

I just started to restore it, I am not worried about making it factory original, I just want to make it very usable. The only issues so far have been the two bearings that needed replacing, they cost $40 each from Kaman Bearing. Also I will have to rebuild the dust cover for the belt side and try to find some turn knobs or make some to replace the stripped out ones from the machine. Here are some pictures.

[Tim Livingston]

Here are a few more pictures, the picture of the Dewalt box is the color I am going to paint the sander and the rickety press is what I used to remove and install the bearings.

[Brian Lindenlaub]

Looks like a good project Tim. Keep us posted on your progress.

[Bob Aquino]

Nice sander, excellent price. I have a 30A that I redid last year. Good luck with the restore. For the life of me, I have never heard of a model "300" sander and if I didnt see the tag, I wouldn't believe it. They are normally a model 30A or 30B or 33, 33B, 35 or 35B. By the serial number, I would put it at a 1963 vintage. Take a looksee here for Powermatic serial numbers: http://wiki.owwm.com/PowermaticSerialNumbers.ashx#Sanders_8 and here if you want to see other examples of similar sanders: http://www.owwm.com/mfgindex/detail.aspx?id=655&tab=4

[Tim Livingston]

Thanks Bob I was wondering about the age and reading the other charts I have seen was very cryptic but I figured it was between 1961-63. There is one other sander on OWWM listed as a model 300, it was painted gray and looks as if it came from an industrial setting http://www.owwm.com/photoindex/detail.aspx?id=8903 but the base is different than mine, I wonder if they made optional bases during a model year. As near as I can tell it's a model 30 but got the 300 name for some reason, maybe that was some special school system number.

[Carroll Courtney]

Maybe they double stamp the zero by mistake,either way that is one nice sander.Dang the price not bad also,so with the cost of the good bearings your still way under.How about afew pics of your bearing press,it also looks good.Keep posting pics of your progress,love to follow along---Carroll

[Bob Aquino]

Thanks Bob I was wondering about the age and reading the other charts I have seen was very cryptic but I figured it was between 1961-63. There is one other sander on OWWM listed as a model 300, it was painted gray and looks as if it came from an industrial setting http://www.owwm.com/photoindex/detail.aspx?id=8903 but the base is different than mine, I wonder if they made optional bases during a model year. As near as I can tell it's a model 30 but got the 300 name for some reason, maybe that was some special school system number.

I saw that too, so it couldn't be just a fluke of stamping one machine. That funky serial number with the extra -3 on the end is also on that other machine listed on the "mothership".

Here is the machine I finished up with. The only thing I would do over again would be to shoot the base with something other than a rattle can. You just cant get real good coverage on a large area with one. It was missing some original parts, I keep my eyes open for them and have already gotten the end casting for the belt side.

http://lh5.ggpht.com/_nh7rpc89jO0/ST8HXXok-HI/AAAAAAAAExA/3jy5p_BZkOs/s800/P1030508.JPG

[Tim Livingston]

Mine came with two tables and is very complete, it's just a little beat! The one thing it doesn't have is the fence for the belt sander like yours. If you come across one of those let me know, I think it would come in handy. By the way yours look nice Bob

[Chip Lindley]

A worthy Project, Tim! I enjoy seeing any good old machine be brought back to life again. Keep after it.

Years ago I found a Rockwell 6" belt/12" disc sander in VGC, for less than $200. But, it was missing the CI table for the belt. This was wayy before eBay or CL. Several years later I lucked into the complete table on a pallet-full of odds and ends at a business auction--$10!

Perservere!

[Carroll Courtney]

Having the table is a big plus,wish mine had the fence also.Bob,nice job and can't tell rattle from other---Carroll

[Tim Livingston]

The arm that holds the belt had some pretty big grooves in it from 40 years of high school kids not caring how the belt was tracking. Let me next say I consider myself a jack of many trades but a master of none, that being said I tried a new process today, I do a little welding on the side just as another hobby and only for personal use, I have TIG, MIG and stick welders and figured I could fill in those grooves on the side so I started researching about fixing the grooves, in the past I have used nickle rod to fix cracks in cast but have had limited success because the extreme heat causes more cracks. Well today I read about TIG brazing which uses a silicon bronze rod and a TIG torch to braze the grooves closed. It's a bit different that oxy-acetylene brazing but also similar. Here are some pictures of the before and after.

[Bruce Page]

That is going to be nice when you're finished!
I refurbed an older Delta a few years ago but it ain't half the machine those old PM's are.
I'm looking forward to the finish pics.

[Tim Livingston]

How about afew pics of your bearing press,it also looks good.Keep posting pics of your progress,love to follow along---Carroll

The press is nothing special, I borrowed it from a friend but I can see I need to build one similar but a little more heavy duty. It is basically some channel iron welded together and teh bottle jack is not a permanent installment. Here are some pics of it, as you can see the bottom rails are adjustable and the top got reinforced after the fact.

[Tim Livingston]

Just a small update of pictures, haven't worked on it all weekend because I am working nights.

Anyone have a source for the original adjustment knobs? If not I will probably make some new one but that is going to mean I am going to have to get off my butt and get my South Bend lathe up and running too which is going to require me to build a new stand for it because the tired old wood table is.....well tired.

[Rob Calkins]

keep the pictures coming...that is going to be one nice machine.

[Tim Livingston]

When I bought the sander the guy gave me a stack of 12 inch sanding disks, hundreds of them and I got to thinking I wonder if there was anything else in that pile so I looked and the manual was there. Even though the sander is marked Model 300 the manual is for a Model 30/33. Whoever was the woodshop teacher? at the school wrote on the front of the manual, "purchased June 1963" so it looks like Bob was exactly right on the age.

[Tim Livingston]

A little more painting and a little more assembly. You can see in the pictures that I need to get my platen re-ground. I scraped off some of the glue from the disk portion and then used alcohol to get the other 40 years worth off, it really came off pretty easy. Also the tables aren't perfect but I'll do a little work with the 4 1/2 inch grinder and even them up a little. As you can see it's not the original snot green, I went a little off track, not quite snot green and not quite the newer green, it's actually some of that textured paint and seems to look pretty good.

[M Toupin]

You can see in the pictures that I need to get my platen re-ground.

Having rebuilt several PM30s, all had worn plattens. I had one platten machined, though I would not do it again. The problem is the platten is only about 1/4" - 3/16" thick. The webs and sides give a false impression of the thickness. The one I fly cut was only dished about 1/8", but by the time I get done cleaning it up some areas were less than 1/8" thick!. On the others I've restored I used lab metal to fill in the depressions. Clean the platten well and wipe it down with MEK or acetone and put the lab metal on with a putty knife in the low spots. Heating the casting and lab metal a bit helps to work it. After you get the lab metal on cover it with saran wrap or sheet of plastic and clamp it flat on a peice of MDF or the like. I used the wing of a TS. Don't go overboard with the lab metal, the idea is to just fill the depressions. After the lab metal hardens sand it flat like you would a plane iron with sandpaper attached to a flat surface. Get carried away with filler and you'll make the job a lot longer than needed.

To eliminate damage in the future attach graphite cloth to the platten. Places like supergrit sell it by the foot for about $2.50 a foot. The graphite cloth also makes the belt slide by easier, as a plus there's more power available to sand!

Tables and fences are hard to come by. PM only shipped them with one table making spares rare and expensive. The table is supposed to be switched between the belt and disk, it's a pain. The fences also got damaged easy or just misplaced making them rare too. I made a fence and a couple of tables out of corian for machines that were missing them. Nothing fancy, just 90deg, but they work very well and the price is right.
137662 137663
Mike

[Tim Livingston]

Well I used Mike's recommendation and used some liquid metal type stuff for flatening the platen. I need to get a graphite cover but it turned out really good so far. I've got a question though, which way should this thing turn? I expected the belt to turn down but it is going up. I rewired it to 110 volts because I don't have a 220 outlet down stairs but on 220 it can be made to rotate the opposite way by changing around the wires according to the name plate.

[M Toupin]

Tim,
The belt should run down so it keeps the work planted on the table. Not sure what motor you have, and I'm no motoer expert, but I would think if it is reversable in 220v it should be reversable in 110v too. Post a picture of the data plate and maybe we can figure it out.

Mike

[Tim Livingston]

The motor was reversable, here is a picture of the wiring diagram, I just had to switch the 5 and the 8 wires. Now I need to find new adjusting screws and knobs. What I really need to do is get my lathe going and make some myself.

[Kirk Poore]

Thanks Bob I was wondering about the age and reading the other charts I have seen was very cryptic but I figured it was between 1961-63. There is one other sander on OWWM listed as a model 300, it was painted gray and looks as if it came from an industrial setting http://www.owwm.com/photoindex/detail.aspx?id=8903 but the base is different than mine, I wonder if they made optional bases during a model year. As near as I can tell it's a model 30 but got the 300 name for some reason, maybe that was some special school system number.

Dear Tim:

My sander is the one shown in the link above. Sorry I didn't see this thread back in January, I would have chimed in then. Here is a link to my restoration effort:
http://owwm.org/viewtopic.php?f=1&t=53936

I think the "300" model was one with an integral dust collector. Mine was mostly missing by the time I got it--just a few pipes left. I had someone offer one of the little vacuums to me, but I declined. Also, I think the "-3" is a version number which has something to do with the original motor size. Mine was 3/4 hp (since upgraded to 1 hp). I don't know why the cabinet is different--PM seems to have made several versions of the cabinet.

Looks like somebody gave your belt cover a bigger dust port--a better job and less mangling than mine underwent, but also more permanent.

Be sure to check that your belt pulleys are crowned. They often developed wallowed out spots, giving kind of a "W" profile that keeps the belt from tracking well. This usually requires a metal lathe, though I've heard of somebody sanding it back into shape too.

Good luck with yours. So far, it looks really nice.

Kirk

[Bob Aquino]

Its looking good Tim. I like the repair job you did on the castings that were cut by the belt. I'm only just getting into welding and I know I wouldn't be that neat. How is the platen? On mine it was dished so I filled it in with some lab metal and then put on a graphite cloth with contact cement which helps quite a bit. When you get it back together, then you will see how well it tracks. If it doesn't track well (and I'm guessing it won't because the drums are worn) then you will have a couple of options. One way is to turn them so you can regain a crown. Several methods for this that range from Hillbilly to high tech. Another alternative that I used on mine was to build up a crown with tape. So far it has worked very well and the sander has been in use for over a year. If you want to actually turn the drums, you can do it on a metal lathe or there are other methods mentioned over on owwm.org.

No crown left on the drums:
http://lh5.ggpht.com/_nh7rpc89jO0/SSh9vDnYoWI/AAAAAAAAEjo/SUvXMipsFKI/s800/P1030454.JPG

Graphite cloth on the platen:
http://lh3.ggpht.com/_nh7rpc89jO0/SSh9t7pvs5I/AAAAAAAAEkc/_n2EU6cOQPU/s800/P1030448.JPG

[Tim Livingston]

Thanks Kirk, I have looked at that thread before. Mine has a 1 hp motor but it's probably not original, mine doesn't have the integral dust collection, no internal pipes and no extra ports. Mine came from a school and then I saw your has the tage from the Municipal Tool Company so I was thinking the 300 was some type of government agency model for schools or state systems etc. My pulleys seem fine so far the tracking is good.

[Anthony Diodati]

W205PP Bearings, what do they fit?
Upper Idler drum, or drive drum?

[Anthony Diodati]

I think it is the lower drum, is that correct?
Is the upper drum bearings
a W205PPG?

[Anthony Diodati]

don't blow up my computer with all the replies now.

[Don Studhalter]

I have a Powermatic 300 sander SN 4-3912-3. Was wondering if anyone out there had a source for a manual?

[Dimitrios Fradelakis]

I have a Powermatic 300 sander SN 4-3912-3. Was wondering if anyone out there had a source for a manual?

Try vintage machinery. Run a Google search and it will come up. Great site!