Pinkie

[Jonathan McCullough]

Submitted for your possible entertainment and edification, a little saw restoration I’ve been doing in my journeyman sawyer’s odyssey.
http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky1.jpg
You may recall I picked up a $3 Disston D-95 “Masterpiece” with Disstonite handle. I’m thinking this saw shall be named Pinkie, because part of the plastic handle is a hideous pink fleshtone, born of that terrible mid-century kitsch you still see now and then. From afar, it kind of looks like a Barbie Doll that the dog dug up out of the garden.

I cleaned the plate up with a scraper, some mineral spirits, and some sandpaper, and it came out pretty well, considering. I like to sand some of the black corrosion off with fine, dry sandpaper. Though it may be considered heresy in some circles, I use a wire wheel to get the corrosion and wood tar/sap off of the tooth area. I’m just not going to be wrapping sandpaper on a wooden toothpick to finesse 260 teeth on one side, then 260 teeth the other.
http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky2.jpg
Now for a mini discussion on corrosion. As far as I can tell, there are three common types of corrosion on high carbon steel such as the spring steel used for saws. Black rust (Fe3O4) is a rust oxide much like anodizing is an oxide of aluminum. Though not as attractive as new shiny steel, it is protective and will not harm something like a saw. Red rust (Fe2O3) will put pits into the steel and ruin a saw. You see this type of rust on food cans that have been left out in the elements for years. Eventually the steel crumbles and breaks down. Another form of oxidation is brown rust, and you’ll see that kind of oxidation on things like man hole covers and some old guns. Apparently this is also a protective oxidation. At any rate, when cleaning a saw you want to get the red stuff out and clean any pitting out with a wire brush. You’ll never prevent oxygen or water vapor from touching the saw eventually, but I’ve been cleaning saws lately that were abused in my great grandfather’s lifetime that will probably outlive me and my son, so my advice is to just clean until the red and brown stuff is gone, and don’t sweat it if you can’t get the black stuff out. I like to finish the saw with 320 grit wet/dry sandpaper, without mineral spirits.

Now for the possibly more controversial part. After cleaning my saws as well as I can, I thoroughly rub paraffin into the surface, covering all, and I mean ALL of the surface with a fine thin haze of wax.
http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky3.jpg
I put an old sock on my hand, then I turn on the kitchen burner and slowly * s-l-o-w-l-y * warm the saw plate, about 18 to 24 inches above the flame, heel part first, until the wax starts to melt. Angle the plate so that the heat goes up, heats the plate, then goes away from your hand.
http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky4.jpg

Paraffin melts at about 150 degrees Fahrenheit, and after about twenty seconds, you can see it instantaneously change from a solid to a liquid state. When this happens, move the midsection of the saw over the flame, and the section of molten wax will spread.

http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky5.jpg

Move down to the toe until the whole thing is covered with glistening molten wax, then wipe it down with the sock on your hand. You want it to JUST get to the melting point of wax and no further. Don’t heat one end of the saw up and wait until all the wax is melted.

http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky6.jpg

It’s hot to the touch, a little too hot for comfort, as though the saw has been in the rear window of a car on a hot summer day. Ouch. But it cools rapidly. As it does, and you’re rubbing the hot wax with the sock, you’ll notice that the metal goes from an excited state to more of a spring steel state; as it cools, it starts to warble and sing.

I think that rust on a saw is like moss on a tuning fork. And this is rank speculation, but another thing that I think prevents a saw from singing after many years is the fact that if they’ve been out in the garage since 1953, or 1923, or 1873, they’ve been heated and cooled for decades. Twenty-degree-plus temperature swings, every day, for 120 years since the day it was tempered will (it is my conjecture) slowly but surely randomize the crystalline atomic structure of the metal. When you S-L-O-W-L-Y and CAREFULLY heat it up on the stove and it cools relatively rapidly in the presence of a cousin of mineral oil, the atoms realign.

Now this is not a procedure for thick-fingered bunglers, botchers, and clod-headed nincompoops. If you lay the saw on the range like a frying pan, fire it up and walk away, you’ll almost certainly draw out the temper and render the saw useless. Furthermore, I suppose the unwary and inept could catch the sock on fire and run around the house like Yosemite Sam with his ass on fire, looking for a hogshead of rainwater to sit in. So be careful.

Anyway, as it’s cooling, if your saw has a bow to it that you couldn’t flex out when it was cold, if you bend it in the opposite direction of the bend while it cools. Bend it about three quarters of the way, (all the way being from toe to heel) then sight down the teeth and the back to check alignment. If it’s perfectly straight, just let it cool. If it’s not there yet, keep bending it in the opposite direction until you’re there. You only have about 45 seconds to get this done. It will not take an “S” kink out; I'm working on a procedure for effecting that and will report later.

The wax has interesting optical qualities and gives the saw a sort of brilliantine finish. All of the little micropores are now clogged, so it prevents oxygen, water, and acidic wood sap from getting in there. And paraffin is something you should be rubbing on your saws anyway.

After sharpening, Pinkie turned out to be a pretty good saw. The taper grinding was a little more pronounced than a D-23, and with 10 tpi, Pinkie’s more of a fine finish saw. Pinkie has somewhat more refined sensibilities, you see.

http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky8.jpg
http://i575.photobucket.com/albums/ss199/Jonathryn/Pinkie/Pinky7.jpg

[Jim Koepke]

Very interesting write up.

Especially enjoyed the mental images of Yosemite Sam.

jim

[Kees Heiden]

I have no idea if your metalurgy holds up to any scientific types, but it sounds interesting :D

Your wax procedure reminds me of waxing my skis. I have an old smoothing iron for that purpose, and indeed the wax goes into liquid mode almost instantly. Maybe using such an iron is a safer method then using an open flame. It is very easy to locally overheat thin steelplate. Don't use your wifes iron! You never get the wax out of it.

[Lee Ludden]

I live in Phoenix where very hot days are pretty much the norm. Would this waxing process work just by letting the saw sit in the sun on a summer (114+) day for 15 or 20 min, then applying the wax?

[Jonathan McCullough]

Yeah, I think it would work. Temperatures in a closed vehicle can reach at least 130 degrees on a hot day. If it's hot to the touch, like a hot dinner plate, it'll probably melt the wax. But I'd apply the wax first and put the saw plate in the sun. Hot sun like that would probably be bad for the wood on a wooden handled saw. Put it this way, would you leave canning wax in the rear window area of your car and close up the windows on a hot day?

Or you could just use a burner on the range. It's pretty easy, you just have to keep the saw well above the flame or element, and be aware of what the wax looks like when it changes states. I just have to give lots of caveats because it's easy to imagine someone getting excited, thinking "Heat = melted wax. More heat = better quicker melted wax with fancy go-faster stripes!" and then ruining Grandpa's saw. Or catching on fire. I don't know how you could do that, but since it's technically, theoretically possible, someone somewhere will do it. But since they're smart and fix their own saws and read SMC Neanderthal posts titled "Pinkie" they won't do that, right?

Don't get me wrong, I have plenty of my own bonehead moments ("Whaaa? Safe-ty goggles? D' Ohhh! That solder sure smarts when it burns your cornea!")

[Marv Werner]

Hi Jonathan,

Very much enjoyed your pictorial.... I think I might try your method for sealing the nooks and crannies in an old saw blade. As an alternative to catching a sock on fire....I'm thinking "heat gun" "hair dryer". Seems that you want to heat the wax more than the saw blade.

Another thought is to slightly heat the blade without the handle attached in a cooking oven. Practice on an old junker saw until you know the safe temperature to use. Might take a pretty big oven though for a 28" big ripper. Controlled low heat just seems safer so as to not effect the molecular structure of the metal.

Marv

[David Weaver]

What...you don't want to seal it with mutton tallow?

[Steve Southwood]

What...you don't want to seal it with mutton tallow?

Ah, somebody read the same thing as I did.

[Jonathan McCullough]

Hi Jonathan,
Practice on an old junker saw until you know the safe temperature to use.

That's a good point. But we know the temperature because the wax melts at a temperature that's safe for the steel. Paraffin becomes pliable at about 95 - 100 ºF (at least in my garage it does) and goes from a solid to a liquid state at between 130 to 150 ºF. You can see the change in state from solid to liquid as it occurs--it's instantaneous--and then the area of warm, glistening wax slowly makes its way through the saw. So melting wax on a saw as demonstrated above is analogous to melting chocolate for making confections. Overheating will ruin the chocolate, but bringing it up to melting temperature and pulling it off the heat is okay. Natural gas burns at a very high temperature, but we're not putting the saw in the flame, we're putting it in the air above the flame, and not getting anywhere near hot enough to draw the temper. Here's a site with a temperature vs. hardness chart (http://www.diehlsteel.com/w1.aspx) for W-1 tool steel, which is pretty much the same as saw steel. (I have no affiliation with Diehl Steel--I just googled "W-1 tempering chart").

Yes, I tried an old junker that I subsequently sharpened. It cuts good! All my saws do, if I say so myself. I have a bunch of saws that got this treatment and they're shiny and nice as the day I cleaned them.

Of course the handles are off when I do this. I didn't think to mention that.

[Tony Zaffuto]

Does the application of wax do anything? I'm wondering if "soaking" the saw plate in an oven at 100 to 120 degrees for twenty minutes or so, may accomplish the same thing, in a safer manner than risking a hot spot by heating over an open flame!

As Phineas says to Ferb, "I know what I'm going to do tomorrow" (although I'm going to play around with a non-collectable saw).

Anyhow, I have several D95 saws with bakelite handles. Both are sharp, but I don't really use them. Nice looking & interestng, but I prefer the feel of wood.

Good, interesting thread!

T.Z.

[Jonathan McCullough]

Paraffin is technically flammable (actually a close relative of mineral oil), so I wouldn't put a pan of it or something like that in the oven. It could spill and hit a flame or an element. Of course grease from meat is the same so . . . .

Oven regulators can be 30-50 ºF out of whack. But I guess you could preheat an oven to 150 degrees, throw a paraffin-coated saw plate in, watch it like a hawk, and pull it out as soon as you see the wax melt. Remember, the wax is a .001" thick film, so it melts Bang just like that.

What the wax does is fill in the microscopic voids that could be occupied by acidic wood sap, moisture from wood or the air, and oxygen. In other words, everything that causes rust. Plus, when it turns solid again, the paraffin acts as a sort of dry lubricant or friction-reducer. If you've never tried doodling a zigzag of solid paraffin wax on plane soles or on the sides of a saw, you'll thank yourself when you do.

I wouldn't do this to a saw that hasn't been cleaned first; you'd sort of be sealing in all the dirt, grime, rust, sap.

[Marv Werner]

Jonathan,

I've always used a Minwax paste wax on my blades. A first coat to do a little more cleaning, then a second coat to give it some shine. How does your hot wax compare to paste wax and rubbing and polishing? I suppose a lot is determined by the condition of the blade before you wax it? Some people I know use bees wax. I'm kind of lazy and do what ever might be easiest and fastest and still get good results.

Thanks,
Marv

[Stanley Covington]

A customer for whom I built a factory in Ohio (THK) manufactures extremely high-precision ground rails in carbon steel using 24' long grinding machines. These rails are combined with ball bearing blocks and are used in turn as components in the machines that manufacture many precision parts, including computer chips. Anyway, their product is very expensive, and rust is a big concern for them, so they spent a lot of time and money researching the best methods to prevent rust in their products. This is what their top researcher told me they concluded. Clear lacquer or other durable paint works best on exposed steel. That is obvious. For machine tools, like their rails, where paint is not an option however, the metal should be warmed for a time to remove all pore water, and then treated with paraffin wax. A faster, safer method to apply paraffin wax than the one described in this thread is to use Boeshield, which is paraffin wax in a solvent. Much more expensive, but pore penetration is also better than straight paraffin wax.

I read that Boeing developed this product to prevent corrosion in their electrical components. It doesn't conduct electricity, won't attack insulators, is self healing, and lasts forever.

If you are serious about preventing rust, give Boeshield a try. Don't forget to get rid of the pore water first, though, if you are treating something recently wet such as a plane blade just off the waterstones.

Stan

[Jonathan McCullough]

Yes, Boeshield is really great stuff. I've been spraying my planes with it--polishes up the wood handles nicely too. Also been experimenting with it on a saw plate. Following the instructions, I sprayed it on liberally and put it in a saw vise in the garage for several weeks. The surface it created was tacky, sort of sticky, like thick grease, which though protective didn't seem suitable for use on wood. It subsequently cleaned up with mineral spirits. Is it clogging up the pores effectively so water doesn't get in? Kind of hard to tell. Ask again in twenty years! Boeshield has been around for a while now though; don't see why spring steel in a saw should act differently than spring steel in airplanes.

If we used Boeshield instead of a hot wax treatment, is there a non-oxidizing chemical we could use to displace the water first? Ethanol?

[Stanley Covington]

@font-face { font-family: "Times New Roman"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }table.MsoNormalTable { font-size: 10pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } I am not sure of the very best method to remove pore water quickly, but I can tell you what has worked best for me.

For those of you without an engineering background, nearly all materials, including steel, have small pockets and pits on the surface where water can collect. The more highly polished the surface of the metal, the fewer of these exist, but they are still there. These are called pores. If you put a material intended to prevent oxidation on top of the water in these pores, the material will seal the water inside, and rust will progress unseen, especially in the case of tap water that almost always has chlorine in it, a fierce oxidant. Most oils, whether natural or petroleum based, are lighter than water, and do not sick to metal as well as water does anyway, so it floats on top without displacing or separating the water from the metal. Warmth and time will cause pore water to evaporate. Of course, during the time the water is drying, corrosion is proceeding to some degree or another.

A good way to prevent the water you use to sharpen tools from corroding your tools is to use dionized water (called "DI water" in industries that use it). While still water, it won't cause rust because the electrical charge of the water has been changed (electrical action is what causes rust, of course). This is how modern industry does it. DI water is usually manufactured close to where it is used, and is not commonly available to the best of my knowledge. Bad for your health if you mistakenly drink it.

Another option is to dissolve common washing soda in water, store that water in a spray bottle, and use it for sharpening. This can still cause rust, but the effect is much slower, especially if you use distilled water instead of chlorinated tap water. I learned this trick from professional sword sharpeners in Japan.

I used to shoot flintlock black powder muzzle-loader rifles a lot. The barrels need to be cleaned with warm water, which penetrates the pores and nooks and crannies of a rifled barrel causing rust even after you think the barrel is dried and oiled. The routine I developed over a ten year period was to use the washing soda mix with Pinesol (pine-oil based liquid soap) for cleaning, rinse with straight washing soda water, and then treat the barrel with Corrosion Block, a product I learned about when using vacuum pumps to siphon seawater. This page also has some good explanations about pore water. http://www.nocorrosion.com/how-corrosion-control-works.htm

The Corrosion Block effectively removes pore water, but I learned through experience that it evaporates relatively quickly. It is good for a few weeks, but is not a long-term storage solution like Boeshield is.

After the Corrosion Block is removed, some of it still remains in the pores. For long-term storage, or in very humid conditions, a bit of Boeshield on top works very well.

Stan

[David Weaver]

Stanley - glad to see you're on here and posting, and presumably OK otherwise?

[Stanley Covington]

David:

I'm doing fine... some of my wife's relatives in Fukushima and Sendai may not be.

Stan

[Joe McMahon]

What a GREAT thread!