Need help. Strange problem with a table saw.

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Forum topic by deebee posted 01-06-2016 12:04 AM 1270 views 0 times favorited 13 replies Add to Favorites Watch
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20 posts in 1192 days

01-06-2016 12:04 AM

Topic tags/keywords: question

Hi everyone;
I have an odd problem, and am looking for some advice. After waiting for many years to switch out my Shopsmith, which I bought new in 1980, for a new cabinet saw, I finally made the plunge and bought a Grizzly G0690.
I love it, and have no complaints.

BUT. I liive in SE Missouri, and a couple of weeks ago we were drenched by torrential rains, and my shop leaked in one spot. Where? Yep. Right on my new table saw’s cast iron table.
No big deal, right? Except that I had left a piece of purpleheart, about 1/4” X 4” X 4” laying on the saw. The drip, sadly, was falling directly onto this piece of wood. The drip splattered all over the saw. Now, I do not know what sort of substance or chemical is in purpleheart, but it is not good for cast iron tables.

It left horrible blemishes and marks—almost but not quite to the point of pitting—all over the affected area of my new pristine cast iron tables. Subsequently, I have tried EVERY substance and chemical that I own—from Boeshield to acetone—to try to remove those horrible blemishes, to no avail. I did a little bit of good with WD-40 as the lubricant and a ScotchBrite pad and some vigorous rubbing, but I cannot seem to make any further headway. There are still very visible blemishes all over the saw. Does anyone here know of anything—or any sanding regimen—that might “cut through” this crud, and return my tabletop to its former (new, or close to it) appearance?

I would be very grateful for any help on this. Thanks in advance.

-- Dan B. , Missouri

13 replies so far

View MrUnix's profile (online now)


6586 posts in 2163 days

#1 posted 01-06-2016 12:12 AM

Try some Barkeepers friend (oxalic acid based).


PS: I wouldn’t worry too much about it – it will develop a patina all by itself over time that you can’t prevent. Just keep it waxed and make stuff. The wood doesn’t care what the table top looks like.

-- Brad in FL - In Dog I trust... everything else is questionable

View 716's profile


502 posts in 880 days

#2 posted 01-06-2016 12:18 AM

Leave it as is, it will fade out with time to the point of nonexistence, which is sad because right now you have a unique saw, that is about to turn into a one of many again.

-- It's nice!

View CharleyL's profile


222 posts in 3328 days

#3 posted 01-06-2016 12:58 AM

+1 on Barkeepers Friend. Mix it with WD-40 to make a thin paste and then spread it on the stained areas. Work it in some, then let it sit for a while. Use a ROS and your skotchbrite pad to work it in. Then wipe it off with more WD-40 on a rag. You may not get it all, but this mixture should make a huge difference. Of course you can repeat the procedure if you think it’s worth doing. Finish up with clean WD-40 wiped all over the affected areas. Let the WD-40 dry in overnight. Then wipe off any left and apply a wax. I like Johnsons Paste Wax. Rub it in well and let is dry. Add a second coat and let it dry. Then buff it with a clean dry rag.

Until you get that roof waterproof, it would be a good idea to keep the saw loosely covered with a plastic sheet any time you aren’t using it. Oh, and never leave any wood on the top of it. Even without a water leak some woods can cause rusting of cast iron when left against it. Treated lumber is well known for this.

The wax will make the wood glide across the saw, so using the waxed saw will be a pleasure, but using it will gradually remove some of the wax, so apply more wax whenever you think it needs more. My cast iron tools get waxed every week when I’m using them frequently. Keep the wax, Skotchbrite, WD-40, and Barkeepers Friend handy and attack any new rust quickly before it gets serious. It’s much easier to keep the cast iron free of rust than to wait until it gets serious.

Don’t ever use a wax that contains silicone. I have banned it from my shop. Anywhere that a drop of silicone touches wood, no finish will stick there, and you will discover fish eyes in any finish that you apply over it. It soaks into the wood very well, so completely removing it will be nearly impossible.i


View a1Jim's profile


117061 posts in 3541 days

#4 posted 01-06-2016 01:05 AM

Hi Dan
I would try some automotive rubbing compound ,Put a little rubbing compound on the spot and then your scottcbrite pad now place your pad sander on top and turn it on making sure the sander stays on top of the pad. Assuming this takes care of the stain ,wipe off the excess rubbing compound and then fold a rag and put your sander on top of it. you can also apply wax to your table saw by putting some wax(make sure it does no contan silicone) on a rag and using the pad sander to buff in the wax. This should do the job. Good luck.

-- wood crafting & woodworking classes

View BurlyBob's profile


5401 posts in 2229 days

#5 posted 01-06-2016 01:21 AM

I’m totally onboard with A1Jim. I’ve done the same with my saw a couple of times. Twice it was my fault, another was an unexpected water leak around a window frame. I frequently wax my shop tools not only for rust protection but for the improvement of their performance.

View realcowtown_eric's profile


608 posts in 1901 days

#6 posted 01-06-2016 02:20 AM

I once bought a whole hank of leather laces, walked into the shop and tossed them on top of the table saw.

No water involved.

Two days later I had dark lines in the form of an octopus on the top!!!

Little drops of PVA glue will also cause dark spots

From time to time I throw some 320 paper on the ROS and go over the whole top.

Chalk it up to “patination”

-- Real_cowtown_eric

View deebee's profile


20 posts in 1192 days

#7 posted 01-06-2016 03:17 AM

Wow, thanks for all the quick responses. I will certainly try the things you’ve mentioned. (I’m glad to know it is okay to use a ROS and some sandpaper, if worse comes to worse).

I realize that the damage is mostly cosmetic, it’s just that i waited SO long to own this tool and i hate it looking “beat up”already…

I had bought a can of (expensive) Boeshield T-9 just for this tablesaw, and had it coated down well with it, but it did not seem to provide much protection. May switch to the WD-40 or the paste wax, as you guys talked about.

Again, thank you all SO very much for pitching in here to give me some advice. I sure appreciate it.

-- Dan B. , Missouri

View knotscott's profile


7980 posts in 3339 days

#8 posted 01-06-2016 12:45 PM

I’ve used fine sandpaper on a ROS with some WD40 to remove stubborn stains before….it takes some time, but works well. For protection, I like to use the T-9, let it dry and buff it out real well, then add one or two coats of paste wax on top of that….that’s about the best protection I’ve managed to get for a saw in an unheated uninsulated garage in western NY.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

View clin's profile


827 posts in 960 days

#9 posted 01-06-2016 06:07 PM

I have a 6 month old saw, and in no time the top is showing some use. While I agree with putting effort to avoid rust and certainly to remove actual residues, I’ve come to realize if I want a saw top that looks brand new, I’d have to never use it.

A see the marks as a sign of a tool being used and developing a history.

Main thing is keep it smooth. I also wonder if repeatedly using polishing compounds or fine sand paper, could actually start to affect the flatness. Not in a single use, but if it were a regular thing, would it add up over years to actually wear out the top?

-- Clin

View SirIrb's profile


1239 posts in 1194 days

#10 posted 01-06-2016 06:50 PM

[Thinking about “patina-ing” my name on my saw table with leather]

That or Patina “Shop Rate is $100 per hour” on the saw.

I once bought a whole hank of leather laces, walked into the shop and tossed them on top of the table saw.

No water involved.

Two days later I had dark lines in the form of an octopus on the top!!!

Little drops of PVA glue will also cause dark spots

From time to time I throw some 320 paper on the ROS and go over the whole top.

Chalk it up to “patination”

- realcowtown_eric

-- Don't blame me, I voted for no one.

View Chubbz's profile


34 posts in 1207 days

#11 posted 01-06-2016 07:42 PM

To throw my 2 cents in… Not sure if this a decent way of handling rust but it seems to work really well for me. Eastwood makes a product called Fast Etch, which dissolves the iron oxide completely and leaves a zinc phosphate coating. I will use a paper towel to wipe on the Fast Etch and for the tougher spots I’ll use a very fine steel wool. Wipe down with WD-40 and apply a healthy amount of paste wax.

View HokieKen's profile


4736 posts in 1102 days

#12 posted 01-06-2016 09:13 PM

Phosphoric acid (Ospho, Jasco Prep & Prime) will convert the iron oxide (rust) to iron phosphate. The conversion will change the appearance somewhat but you can polish it back out to shiny. If the rust is only on the surface, you can remove it by scrubbing/sanding but if it’s penetrated below the surface, no amount of elbow grease will remove it unless you sand down to it. The Barkeepers Friend and Fast Etch mentioned by others do the same type of conversion with different acids. Just make sure that if you do have to do conversion that you neutralize the acids once the rust is gone otherwise it will continue to react with the metal. Water will neutralize most acids but whatever you use should have instructions on how to do it.

After either process, I like to put a coat of CRC 3-36 on and let it sit overnight then wipe it off and top it with a coat of paste wax. Your Boeshield should work just fine too, I’ve just never tried it.

-- Kenny, SW VA, Go Hokies!!!

View deebee's profile


20 posts in 1192 days

#13 posted 02-13-2016 05:43 PM

UPDATE: I got the Barkeepers Friend and used a round Scotchbrite type pad in a drill, and it did better than anything else i’d used to restore the top to a new appearance. I found the source of the roof leak and fixed it, so hopefully this never reoccurs.

thanks again to everyone who responded, and for all the info. (I’ll have to check out that “CRC 3-36”, i have never heard of it.)

-- Dan B. , Missouri

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