Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: PRNDL on November 20, 2008, 03:57:15 pm
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Someone gave me a very old Craftsman table saw that is built with lots of heavy steel.
Unfortunately, it's rusty - really rusty.
I have two questions
- What can I do to remove the rust?
- How can I prevent rust?
Thanks
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I had a similar situation. My wood shop had a leak over last winter and rusted up the table top. Such a shame.
Removing the rust is a real pain. I was unable to get it completely off. Here is what I did:
Use 100grit sandpaper and a large FLAT board. Glue the paper to the board and sand the top. You won't get it all off, but it will get the top half off.
If you are storing the saw, spray it with packing grease - that stuff will never come off. When ready to use, spray it with WD40 and wipe.
If you are not storing it and want to use it. You can purchase specific SAW lubricant, but I just use silicone spray. Works very well.
Good luck.
ToN
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There was a product we used to use on boats. I forget what it's called. It's a jelly and it gets the rust off really well.
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Boats? Naval Jelly? ;D
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And when you get the rust off, keep it off with wood paste wax. Routinely wax the entire table surface. This keeps the rust off and it makes your work pieces, miter gauge, fixtures, etc. move so much easier. It also will not stain your workpieces.
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I've actually used a grinder(90degree) with a stiff cup brush and oil it will remove the rust and not gouge in ...and as sluckey suggests I always have butchers wax around it works great on table saw tables ....I also use that paste wax to seal pine cabinets and such, I just like it . I have never had luck with the naval jelly.....but then again I never read the instructions :D
By the way I am talking about the table top .....
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Thanks Rafe
I tried a wire wheel brush on a drill.
It took off the some rust but left most of it, although it does look better.
Did you use the oil while grinding?
Or, to protect the steel after done?
I also have a 90˚ grinder and could get a cup brush - does that work better?
(I also have some butcher block oil).
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I do use the oil while grinding, wd-40 is good. A good stiff wire cup on the grinder because you can put some weight behind it (elbow grease) if you have to, clean it down with solvent afterwards and let it dry....
The paste wax is good comes in a can......if you are going to store it for a while coat it with oil or grease it's a lot easier to remove that than rust. No "Butchers Wax" is a brand name and would ruin the rib-eyes.
I've had good luck with that process
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try this stuff...
http://www.ospho.com/
we used to use it on drilling rigs. it dries into a gray-black hard coat, like paint but very thin. it paints on like water. it is used to prepare surfaces for painting without any other treatment. in your case you'd want to knock off the layer of ospho after drying. it will save you a lot of elbow grease. as stated already, use a wire wheel brush to remove the ospho. wax after it's spit shiny clean.
use goggles, gloves, apron, respirator, etc...
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I used a wire brush followed by 80 grit on a random orbital sander, and covered it with carnuba car wax. It's a bit dark, but looks great.
Thanks everyone!
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I've used Johnson paste wax and Turtle wax on mine. Heaviest grit I have used was 220 wet or dry lubed with WD40. Clean then wax. The wax last a suprisingly long time.
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I've used Johnson paste wax
That's what I use too.
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A COMPLETELY DIFFERENT THEORY (http://www.frets.com/HomeShopTech/QuickTricks/RustRemoval/rustremoval.html).
I've never actually tried this, but I've got a lot of respect for Frank.
Gabriel
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A COMPLETELY DIFFERENT THEORY (http://www.frets.com/HomeShopTech/QuickTricks/RustRemoval/rustremoval.html).
I've never actually tried this, but I've got a lot of respect for Frank.
Gabriel
The method works pretty well, I've used it in auto parts restoration. Those directions should give great results.
j.
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A COMPLETELY DIFFERENT THEORY (http://www.frets.com/HomeShopTech/QuickTricks/RustRemoval/rustremoval.html).
I've never actually tried this, but I've got a lot of respect for Frank.
Gabriel
The method works pretty well, I've used it in auto parts restoration. Those directions should give great results.
j.
Knowing Frank as I do, I would expect so. His real job is fixing guitars, and he is one of the best in the world, but he would have been great at any tool pushing he had set his mind to.
Gabriel
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I checked out some of his other tips ,,,,,extraordinary thanks for the lead .......
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I checked out some of his other tips ,,,,,extraordinary thanks for the lead .......
Frank's website is one of the true gems of the internet. HUGE amounts of really good information, presented with great photos, by one of the worlds real experts in guitars. He has some of the best hands in the business.
Gabriel
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> A COMPLETELY DIFFERENT THEORY.
Rust is iron oxide.
There's like 16 different iron oxides.
He shows conversion of Red (Fe2O3) to Black (FeO). The red oxide happens with ample oxygen, forms hard, coarse, and flaky. The black oxide happens when oxygen is available but limited, forms as microscopic balls which make a sticky "mud" which is easily crushed.
The scratch on my car fender gets an infinite supply of oxygen, is forming red oxide, our familiar "rust".
My steam boiler and radiators make lots of black oxide. There's liquid water to bring oxygen and iron together, but after the first firing there is not a lot of loose oxygen in the system. Each cycle, a bit of air gets in, all that damp iron sucks it up so fast there is not enough to go around. I tap the mud and it is pure black. I let splash dry in the drain and it brushes right off.
A radiator which has been abandoned, open to damp air, forms red rust inside. This may be black oxide converted to red oxide by ample oxygen and some damp to bring the O and Fe together. When I put a rusty radiator in service, I must drain a lot of black mud for the first month. I dunno if the red oxide goes back to black in the low-O system, or if the heat breaks red rust off and exposes raw iron which forms black oxide.
If you keep the system near-sealed, the black oxide covers the surface and oxidation nearly stops. If you leave the system open for a summer you get LOTS of black mud next fall.
So the oxide conversion makes sense. I never knew you could force it in minutes with soda and voltage.
The material of the counter-electrode is probably immaterial. Since we don't need great conductivity, and the process may attack the counter-electrode, and scrap steel is cheap, that's probably best.
There are rust treatments which do form black oxide with chemistry. The brush-on glop I have used (not Naval Jelly) was weak at forming black oxide, and was cut with other stuff to bind that black oxide to the surface. If it worked better it would be good for hidden areas of cars (and is widely used for that). The stuff I had was about as effective as a coat of good enamel, but messier.
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There is a product called Penetrol that is now advertised as a "paint conditioner" to oil based enamel paints.
HOWEVER, I first heard about Penetrol being used as a sealant to rusting problems on ships up in the Great Lakes area. I painted professionally for 17 yrs and used this product extensively to seal rust. AND it works great! They would take Penetrol and knock the big flakes of rust off these ships then spray the still rusted area with Penetrol and then paint over. I did the same thing with a bumper from a junk yard for a '66 GMC pickup I used to drive. It eliminated the rusting problem unless something scratched it deeper into new metal.
It is a remarkable product. I haven't seen it advertised in ages as a rust sealant but it sure worked great for me.
http://www.floodaustralia.net/treat_metal.htm
With respect, Tubenit
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Boats? Naval Jelly? ;D
There really is such a thing I used it
(http://i282.photobucket.com/albums/kk243/supro66/NAVYJELLY.jpg)
I have an old piece of thick canvas from a tent.
When I am not using the saw I spray oil on it and cover it with the canvas also my planer. Yes the oil will soak into the cloth that is a good thing
MY AMP SITE AND SAWMILL
http://www.geocities.com/insp/SUPRO6420.html
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I use Empire Manufacturing "Top Saver". It is a Rust Remover/Lubricant/Surface Sealer/Conditioner on
my joiner which has a cast iron surface. You just spray it on let it sit for a couple of minutes, then use
the enclosed scrubby and just like a ScothBrite on our dishes rub until it comes off. Then wipe with a
paper towel. I got it at a tool store. In my case WesternTool, but I don't know what you have where
you live. The site on the bottle is www.empiremfg.com. Good Luck.