Pitted Unisaw top

[187 speed]

Hey guys, So after reading and watching Ryan's Unisaw post I decided I just had to have one. I scoured the internet for a few days and luckily saw one pop up on Facebook marketplace. It was completely disassembled and half restored, the cabinet is freshly painted along with all f the castings. It is missing the motor and motor cover but everything else is there and the guy was only asking $200 so of course I call my buddy up and told him we were going on a road trip in the morning. Of course I woke up to a downpour and drove through an absolute tsunami all the way there. The saw was exactly as he described, turns out he bought it from a friend who's dad passed away and they sold him everything in the guys garage. He was keeping the old tool box and a bandsaw but was selling everything else including this saw which he said is a 1947 Delta Unisaw. The former owner was in the middle of restoring it when he passed away.

So of course I snatched it up and proceeded to load it up in the downpour, covered it with a tarp and put all of parts in the interior of my buddies brand new king ranch f250....yeah he was like what the f#%^.

After getting it home I started to clean up the top which had some light rust on it and noticed it at one time had major rust on it and was severely pitted. It is way more than an orbital sander could take care of. I am wondering what my best course of action is, do I take it to a machine shop and see if they can resurface it or do I just fill the pits and paint it or something like that? Of course I am going to be sourcing a motor and motor cover in the next week or two so maybe I will find a better top for sale as well. The rest of the saw is really exceptional though, I already have the base and internals all assembled and everything functions smooth as new. I will upload some pics tomorrow morning to give you guys a better idea of what I'm working with.

 

[ZRX61]

I fix issues like that with JB Weld & a DA sander.

 

[Marctrees]

Pitting of the top is not a real world in use problem.

Sure... We would all like our Old Arn to look like freshly milled.. just consider it "Patina"

Clean the top up, wax, and enjoy your purchase.

I really can't see that the pitting would affect stock or sled sliding at all.

At least not on a Tablesaw where the flatness of anything sliding on it will bridge and glide

over pits.

If you over time have trouble, you can just as easily worry afix then as now.

Cleanup and use as is.

You have a better saw there than probably 98% of GJ'rs.

The epoxy idea sounds great.. as long as you KNOW there will not be adhesion problems.

I never had need to look into that.

I have a PM early 70's in use, and a Delta/Rockwell 12/14 from early 50's waiting to clean and setup.



Marc

 

[rlitman]

So long as the pits aren't big enough to catch on whatever you're sliding over it, they're purely cosmetic.

 

[jonshonda]

I'm sure a machine shop wouldn't charge too much to clean it up for you.

 

[OccupantRJ]

The pits should pose no issue in the normal use of the saw. Roll with it.

 

[matt_i]

I'm sure a machine shop wouldn't charge too much to clean it up for you.

Blanchard grind the top back to full cleanup is probably a $500 job unless you "know a friend".... and even then its going to be swirly.

 

[jonshonda]

Blanchard grind the top back to full cleanup is probably a $500 job unless you "know a friend".... and even then its going to be swirly.

I know a friend!

 

[Stuart in MN]

The main thing is if the table is flat, with nothing sticking up that will catch on the wood you're sawing. The pits are below the surface so they shouldn't affect its performance. As mentioned, a good coat of wax should be enough.

 

[6PTsocket]

I'd be more concerned with with finding the right motor. If yours uses the typical Delta /Rockwell type motor it is a special design with two metal plates welded to the side of the motor, that it pivots on. They come in different hp. Later Unisaws were 3hp /220 volts and new they are around $400. You might pay half that for a used one. I see lower hp. versions for correspondingly less. I have no idea what was standard in 1947. Just google "Unisaw motor" and a bunch of them will pop up.

Sent from my SM-G900V using Tapatalk

 

[gungatim]

does that take a RI bullet motor? good luck, I wouldn't put any effort into it until you price the proper motor for it. they aint cheap. and the covers are unobtainable. I think there was a guy on the ole arn site who was going to fab some but limited supply.

 

[Voi]

I have a 1947 Unisaw. I can take pictures of the motor if you need them.

I won't get to that this week, most likely.

 

[ez-duzit]

Pitting of the top is not a real world in use problem...

Yes, it is.

Wood needs to slide smoothly over the table top with little friction. Also the table needs to be kept clean so contaminates do not stain the wood.

 

[gungatim]

no it isn't.

more pits = less friction...

it is not a problem once the top is cleaned and flattened. it could have holes in it for all the wood cares, which is why many tables and extensions are webbed.

 

[rlitman]

Yes, it is.

Wood needs to slide smoothly over the table top with little friction. Also the table needs to be kept clean so contaminates do not stain the wood.

But the pitting itself isn't a problem. I'll agree that a rusty scaly top is. For rust, I'll just scrape down the top to remove anything sticking up. Then I'll go over it with steel wool to remove any flash rust. Then a good cleaning and waxing. By that point, there won't be any orange rust to stain the wood (the black oxide I like to leave under the wax, as it actually prevents rusting).

no it isn't.

more pits = less friction...

it is not a problem once the top is cleaned and flattened. it could have holes in it for all the wood cares, which is why many tables and extensions are webbed.

Exactly. Well, actually, there's one catch. You can't just drill "speed" holes in the top. You must countersink them. The holes aren't the issue, but the trailing edge needs a "ramp" that doesn't catch wood sliding over it.

But rust pits are naturally bowl shaped. So long as you scrape down any corrosion, you won't have anything that adds to the friction.

 

[187 speed]

Wow thanks for all of the advice guys!! So many things to take into consideration. I am aware of the motor that it take and have found quite a few actually, there is also several tutorials on youtube that show how to fab the brackets to adapt a standard motor base to it. I am a pretty capable fabricator/machinist since the used to be my profession. As far as the motor covers go they are available now through several places, I think i saw some on eBay for $99. I know it won't be a cast iron cover like the original but it will look the part and serve the same function. I know I can sand and polish the top to make it plenty slick and functional I am just one of those OCD types who needs everything perfect (so I think). Anyways I really appreciate all of your advice it has really helped, here are some snap shots of what I'm working with.

 

[rsanter]

I know a friend!

And you have to deepen the T slots and the recess for the blade insert the same amount you remove from the top

Bob

 

[rsanter]

Wow thanks for all of the advice guys!! So many things to take into consideration. I am aware of the motor that it take and have found quite a few actually, there is also several tutorials on youtube that show how to fab the brackets to adapt a standard motor base to it. I am a pretty capable fabricator/machinist since the used to be my profession. As far as the motor covers go they are available now through several places, I think i saw some on eBay for $99. I know it won't be a cast iron cover like the original but it will look the part and serve the same function. I know I can sand and polish the top to make it plenty slick and functional I am just one of those OCD types who needs everything perfect (so I think). Anyways I really appreciate all of your advice it has really helped, here are some snap shots of what I'm working with.

That is pitted very badly.
If that was mine I would either look for a replacement top from a saw that is being parted out or I would blast the top and skim it with epoxy and resurface down to the original level of the top so you don’t have to remachine the T slots and blade insert recess.
In the machine world they make an epoxy exactly for that. It is called MOGLICE , not sure of I spelled it correctly
It is machinable and resists wear just like the original metal

 

[toolmiser]

Have you tried to clean it up. My older eyes doesn't think it looks very bad. I used JB weld on some bolt holes that a previous owner put in my jointer. It worked well. It's been 15 years since I filled mine, but I suspect I filed and sanded after it was filled.

 

[seber]

no it isn't.

more pits = less friction...

it is not a problem once the top is cleaned and flattened. it could have holes in it for all the wood cares, which is why many tables and extensions are webbed.

As a machine design engineer I've had this conversation more times than I can count. Friction is defined by resistance = force (weight of wood) times coefficient of friction (Coefficient of wood on iron). Area of contact is irrelevant. By the way, this does not apply to tires which linterlock with the road surface.

 

[Zeke]

As a machine design engineer I've had this conversation more times than I can count. Friction is defined by resistance = force (weight of wood) times coefficient of friction (Coefficient of wood on iron). Area of contact is irrelevant. By the way, this does not apply to tires which linterlock with the road surface.

I believe you but I also think a nicely honed top will capture some surface air. I forget what they call the stagnant air on a surface when testing in a wind tunnel. But if you have a woodshop then you know a piece of large flat stock will glide over a smooth waxed and very flat surface.

IMHO, the Unisaw in question is pretty heavily damaged. Using a variation of surface scraping will help a lot. I've even gone so far as to use a good belt sander checking what I'm doing constantly with a straight edge and a feeler gauge.

 

[187 speed]

Have you tried to clean it up. My older eyes doesn't think it looks very bad. I used JB weld on some bolt holes that a previous owner put in my jointer. It worked well. It's been 15 years since I filled mine, but I suspect I filed and sanded after it was filled.

If you look at the close up you can see the discoloration on the right side, those are all pretty deep pits. I actually sanded the right side down with an orbital sander at 80 grit then went over with a finishing pad and an SCT tool. I am probably going to be filling the pits and sanding it all flat again.

 

[PittsburghTim]

While the pitted top will cause less friction, the pitting may cause any slightly warped, cupped, or twisted board to catch, which can lead to using more force to push the wood through, which is unsafe. Most wood, even from good hardwood suppliers, has some irregularity that could cause it to catch.

I would suggest trying some boards before you coat or wax the top. If you do not experience any catches, just use a wax meant for woodworking machines as it will not interfere with any stains or finishes. If you do have some catches, fill with an epoxy, sand smooth, and then wax.

I have a 1.5 HP (continuous duty) motor on my saw. If you plan on cutting thick 8/4 or 12/4 hardwood, you probably want to go with a 3 hp motor.

Good luck with it.

Tim