Important information on Blade Cleaners

[Michael Schwartz]

Whe have had a lengthy thread down on the EZ Smart Forum discussing simple green as a blade cleaner, as it has been recommended by servile official sources and its use has also beeen warned aginst as well.

Here is a link to the thread on the EZ Smart Forum, it has sources of some of the info I present in this post, as well as comments on the matter by other SMC members.

http://www.sawmillcreek.org/showthread.php?t=62469

In general any Caustic, Chemical with a High PH, or Ammonia, can and will probably have damaging effects to the blade. The caustics to the cobalt binder, and the Amonia to the Copper Brazing.

To try to clear things up I sent an email dirrectly to Frued Here is what I got.

In this email Freud recommends Kerosene, warns aginst the use of commercial blade cleaners, and didn't comment on simple green as they hadn't tested it.

When he referes to the product, he is referring to Simple Green.



All of the commercially sold blade cleaners that we have tested or have seen test results for all have negative effects on the carbide. Oven cleaner, which many people have used in the past, is even worst than those. While I can not comment on if the cleaner in question has negative effects because we have not tested it, we would not recommend either. The way we recommend cleaning of blades is by soaking them overnight in a sealed container of kerosene and then brushing off the teeth with a soft brush like a tooth brush. This is also the most economical as the off the shelf cleaners cost $4 to $5 for a few ounces while kerosene is under $2 for a gallon.

There is a post from Charles, the freud fep, from another forum saying pretty much the above information and then reccomneding simple green, and saying he usees it himself

There is supposedy a post on another forum somewhere that Charles does not reccomend "Simple Green Extreme Clean" but that regular simple grean is ok.

I have read two contradicting responces from the manufacturer of Simple Green one stating Simple Green is OK, the other warning not to use it.

So as it stands don't use the following

Oven Cleaner
Caustics
Ammonia
Acids

It seems to be ok to use

Kerosene

Looking for a definitive awnser on

Simple Green

Don't Know

Solvents
Dish Soaps (For a Dishwasher)
Hand Washing Dish Soaps
Hand Sopas
Mild Detergents

Anyway, I have been using Simple Green myself, and I know many many people who use it to clean blades, so I think it needs to be settled weather it is ok or not. We need a definitive list on what is safe and what is not safe to use. No sense in damaging a 100+ dollar blade and risking safty using it. Even if a cleaner just shortens the life of a blade a bit.

[Jerry Allen]

I've tried a lot of cleaners including Rocklers cleaning kit, bug and tar removers for cars, and Krud Cleaner from HD. The bed of my laser gets gummed up a lot faster than my saw blades so I usually try something new on it first.
I tried LA's Awesome Original Cleaner and Degreaser (undiluted) and was impressed with how well it loosened pitch and tar on my laser's cutting table. The pitch starts running of instantly whereas most other stuff took some time and a little scrubbing to get it to start breaking loose. So I tried it on my saw blades and was equally impressed. Pitch just runs off and needs little if any scrubbing. I even used it on a blade I use to cut PVC pipe and although it didn't run off like the blades with pitch, it loosened it enough to get off with a plastic scrubber.
It is ethanol based, so it shouldn't harm the blade. I can see no evidence of degradation after a few months of use.
And it only costs $1 at dollar stores. Awesome!

[scott spencer]

Glad to see someone has tried LA's Totally Awesome....my impression is the same as yours. I've tried several methods with good results, but none that I liked better than Totally Awesome.

[Brian Penning]

Some folks swear by Baking soda. Never used it myself.(use simple green)

[Cliff Rohrabacher]

I bought a jug of that stuff for an out of doors cleaning project. I got in really close to the work and realized that the stuff is anything but simple or green. It's metasylicates or something about as harsh.

I wouldn't let it near my steel or iron.
I use mineral spirits, but will use Naptha, Acetone, Toluene or gasoline if that's all I have.

I'll also use a wire brush if I got lots and lots of goo on my blades.

[Kyle Kraft]

I've heard that 409 is ok. What about the water based goof-off stuff in the orange spray bottle? It smells like 409 on steroids, so it probably is just a stronger solution.

[Art Mann]

The OP quotes some guy from Freud as saying he can buy kerosene at $2 a gallon. I sure would like to know where he is buying his kerosene!

[Cody Colston]

I'd like to know if there has ever been a documented case of carbide flying off a saw blade because of the cleaning solution used. My guess is no.

While simple green and other cleaners may "damage' the cobalt or brazing on saw blades, how severe is that damage? Is it bad enough to shorten the life of the blade?

I'll bet Crest toothpaste damages our teeth, too but not enough to worry about.

I don't like unsupported or incomplete claims and Freud is the only mfg I've heard make this claim.

[Greg Funk]

It will be very difficult to get any blade manufacturer to endorse any type of caustic cleaner as there is too much variability in how individuals use the cleaner. For example, soaking a blade for 24 hrs in Simple Green will have quite different effects than spraying it on for 30 seconds and rinsing it off right away. Conducting a scientific test of the effects seems like it would be quite expensive and of little value to any particular blade manufacturer.

I'd certainly be interested in seeing some actual test data but I won't hold my breath.

Greg

[Michael Schwartz]

Also with cleaners any cleaner is going to be either a bit caustic, or a bit acidic. I guess it is strong acids and strong cuastics to avoide, because otherwise we would jsut be stuck with water.

My opinion not based on any scientific basis whatsoever about Simple Green that for a short 5 minuite soak every now and then it won't cause dammage. Mabey if you soaked it in a concentrate for a few weeks, but water would eventuly dammage it as well. Cutting wood wears away at the carbide :rolleyes:

Then Again, I have heard so many contradicting things from manufacturers that I don't know what to belive.

It would be nice if somebody could come up with the simple answer of is that Simple Green Safe to use on a carbide blade?

[Andrew Williams]

I beg to differ... comparing Simple Green to oven cleaner is analagous to comparing lemon juice with boat hull cleaner. I am perfectly willing to accept scientific data concerning it's specific unsuitability to this task, but not as a matter of comparison to oven cleaners which have a much higher pH. Speculation is not going to change my policy on it.

http://consumer.simplegreen.com/cons_faqs.php

note the pH of Simple Green, 9.3-9.5, much lower than ordinary alkaline cleaners. I'll stick to using it unless I hear specific test data using it with negative results.

[Michael Schwartz]

It also does not contain Ammonia

[Bill Huber]

I ask Forest about how to clean my blade and this is the reply.


Dear Bill,

You can clean your blade with an ammonia based product such as 409 or Fantastic or any other saw blade cleaner. There are several on the market to choose from. Soak it and then scrub it with a plastic or brass bristle brush. Do not use steel! Allow blade to dry completely before storing away because any amount of moisture can pit or rust the surface.

If that does not help there is a possibility that your blade may be dull and needs sharpening.

If you have any other questions please don't hesitate to contact us.

Sincerely,
Janet

[Steven Triggs]

I don't like unsupported or incomplete claims and Freud is the only mfg I've heard make this claim.

At least in this case, they have no horse in this race. I'd be much more skeptical if instead of endorsing kerosene, a rather cheap solution, they were endorsing some product that they made.

I'm with you though. I'd rather see some really meaningful data. And I'm thinking that if Freud did a bunch of testing, as the OP's Freud contact's quoted email seems to imply, perhaps they have the data.

Michael, can you email your Freud rep back as a follow-up and ask him for the data?

[Mack Cameron]

[quote]Some folks swear by Baking soda. Bri; I'm sure you meant "Washing Soda"!!! Check out CHW.

[Rick Christopherson]

I'd like to know if there has ever been a documented case of carbide flying off a saw blade because of the cleaning solution used. My guess is no.

While simple green and other cleaners may "damage' the cobalt or brazing on saw blades, how severe is that damage? Is it bad enough to shorten the life of the blade?

I'll bet Crest toothpaste damages our teeth, too but not enough to worry about.

I don't like unsupported or incomplete claims and Freud is the only mfg I've heard make this claim.I've taken a few black-eyes by asking the same myself. The biggest question is why is it that Freud is the only manufacturer that is claiming that caustics are a problem? What I find more disturbing is that Freud has actually recommended using cleaners with a pH that is below 7.0 (acidic) for cleaning. Acids attack metals and bases attack organics, so why would anyone suggest using a cleaner with a pH below 7.0?

I've followed this information for years, and I feel that this is a case of an over zealous engineer in Germany presenting slanted information. If you soak a blade in any material long enough and it will impact the metal, and this includes even water. The point is that acids will degrade metal much worse than bases.

Back when I was in the product review industry, I personally spoke with the CEO of another blade manufacturer, who back then was considered superior to Freud, and specifically asked about this. He stated that there was no truth to the myth.

If you soak your blade for any length of time, it doesn’t matter if it is caustic, acidic, or neutral, it can damage the blade. However, the fear mongering that moderately high pH cleaners are going to cause the carbide to fly off the blade is horsehockey. Now I am seeing that Freud is taking this to the extreme and claiming that even near neutral-bases will degrade the brazing.

[James Suzda]

Just FYI Simple Green was used by aircraft owners for years to clean their airplanes until it was found that it corroded aluminum. (This is not a good thing on airplane fuselages!!!)
Anyway, the manufacturer’s of Simple Green have come out with a new product several years ago that is lemon based that is not supposed to corrode any metals. At the EAA’s AirVenture last week, they were giving away tons of samples and I picked up a couple of these samples, but, I’ve not tried it on my saw blades.
Jim

[Cliff Rohrabacher]

Acids attack metals and bases attack organics,


Both attack metals. Leave any metal in a bleach soak and you'll see. Straight bleach can strip the Chrome oxide from stainless and start a rust problem.

Which reminds me I have to start a thread on SST and passivation

[Charles McCracken]

why is it that Freud is the only manufacturer that is claiming that caustics are a problem?[/b]

Rick,

Perhaps the reason that Freud is the only one "claiming" this is because the others don't manufacture their own carbide and do not know what damages it (BTW, we manufacture our carbide in Italy, not Germany, for those that are interested).

Do caustic cleaners attack the cobalt in carbide? Absolutely.
Does this affect the life of the cutting tool. Most certainly.
Do caustic cleaners create huge craters in carbide? No.
If I can't see the damage with my naked eyes does it really matter? Only if you want to extend the time between sharpenings.
Will the tips come off the blade if ammonia is used? Probably not.

Does Freud have some sinister motive for offering this information?

We have produced our own carbide for many years and have always said that kerosene is the best and least damaging solvent. At one time we tried Simple Green in our US Tech Department and found that it is effective on pitch but have since found that it, too, is damaging so we no longer recommend it (there have been multiple posts in the past with quotes that were purported to be from SG saying that they also found it damaging to carbide). At one time we looked at nearly every cleaner available with the potential of marketing one under the Freud name. Our factory did not find any that were suitable. So we do not offer a product that we point to and say "Use our brand of cleaner or you'll damage your blade". Freud is not an OPEC member nor an oil refinery and we don't reap financial benefit from your purchase of kerosene. The motive is that we want our customers to enjoy a longer tool life.

[Greg Funk]

At one time we tried Simple Green in our US Tech Department and found that it is effective on pitch but have since found that it, too, is damaging so we no longer recommend it (there have been multiple posts in the past with quotes that were purported to be from SG saying that they also found it damaging to carbide).
Charles,

So am I correct in understanding that you don't consider the use of Simple Green to be a safety issue, but that it that effectively dulls the edge of the carbide tips? Any chance you'd have any test data lying around?

thanks,

Greg

[Charles McCracken]

Greg,

Yes, that is correct. I do not have the test data although I have seen some of the SEM photos of the affects. If the posts I've read in the past about SG are accurate you can contact them for verification. Purportedly, they have a new product that they claim will not negatively affect carbide but we have not tested it so I can not verify that.

[Tim Lynch]

I also wonder about the time element...

I've been using a spray-can foaming type of pitch remover and it removes the buildup in less than a minute. I usually spray, wipe the blade with a rag, and then wash it in the sink w/ dish detergent and water.

It's obviously an aggressive product, but I wonder what kind of damage can be done in only a minute.

[Rick Christopherson]

I do not have the test data although I have seen some of the SEM photos of the affects.And therein lies the issue. When you need a Scanning Electron Microscope (SEM) to see the effects, they are down on the atomic level. However, the discussions regarding this phenomenon make it seem as though the effects are large-scale and will cause the teeth to fall off or cause major damage to the blade in one fashion or another.

If you used the same SEM to examine a blade with 50 hours on it, you would probably see similar damage (or worse) just from the acids and oils in the wood that was being cut. If that were not the case, then you would have a sawblade that would never require sharpening. The problem with this story is that the specific details are not provided, and that it appears to be taken out of its natural perspective.

Are these test results real-life, or was the blade left to soak for extended periods? Soaking a metal part in just about any cleaner will eventually cause damage. I read about one demonstration of this effect where the engineer used laboratory grade Sodium Hydroxide with a pH approaching 14.0 to show the effects. That’s 100 times stronger than drain cleaner, and 1000 to 10,000 times stronger than oven cleaners (which BTW do not contain NaOH, contrary to other reports).

So the real question to answer is whether this is a real threat to a blade, or is it the inflation of a perceived threat? (I am not advocating using strong chemicals to clean a blade, I just want to understand the basis for this information.)

[Andrew Williams]

also it would be good to indicate the amount of dilution of the simple green.

[Charles McCracken]

Rick,

You have got to be kidding me. Are you looking for "how long can I get by with it before the damage is more than I am willing to accept?" How about "I only smoke a couple of cigarettes a day so that must be okay". Deleterious effects are just that - deleterious. It's a free country and you are entitled to use whatever cleaner you can buy legally. I admit to being a natural born cynic and skeptic but the need to challenge this information and use terms like "fear mongering" is truly puzzling to me.

[Gary Curtis]

The local saw-sharpening company sells blades and sharpens for three sawmills up here in timber country. I just got off the phone telling Bud Ryland, the owner, about this topic. He's been in the business for 42 years, taking over from his dad.

He said, years ago we used lye. Then OSHA outlawed it. Now, I used garage floor degreaser from Costco. $8 a gallon. Just don't leave the blade in it for more than an overnight bath. He reminded me, for the umpteenth time, that us woodworkers are not building Swiss Watches.

Gary Curtis:o

[Gary Keedwell]

I also wonder about the time element...

I've been using a spray-can foaming type of pitch remover and it removes the buildup in less than a minute. I usually spray, wipe the blade with a rag, and then wash it in the sink w/ dish detergent and water.

It's obviously an aggressive product, but I wonder what kind of damage can be done in only a minute.
Exactly. My unscientific opinion is that if you only leave it on to penetrate the pitch and resins and immediately rinse it off, I think damage to the blade is minute.
I don't see the reason people let it soak for hours. Is it the lazy housewife syndrome...who lets the dishes soak over-nite?:rolleyes:
Gary K.

[Garry Stockton]

As a former specialist in making punches and dies from carbide, using a process known as wire EDM (electrical discharge machining), what Charles from Freud says is absolutely true.

Carbide is a matrix material; tungsten carbide particles in a-usually, but not always-cobalt binder. It's the cobalt, primarily, that is the problem for most cleaners-and even simple tapwater; deionized water is better, but not perfect.

The cobalt binder is easily leached out in water, and many other cleaning solutions; not particularly quickly-it's not going to turn the carbide to mush overnight-but then, it doesn't have to in order to deteriorate the carbide to the point where it dulls more rapidly, and becomes more likely to suffer fatigue microcracking leading to insert failure.

I know, because it was a major problem with carbide punches-so much so that many companies specified that EDM could not be used to make their punches; they found they had a shortened time between regrinds/sharpening, and when the punch costs 2-3K, and there are upwards of 70-100 in a single die station, well, you become very conservative.

The problem is that with the cobalt binder leached out by the cleaner-or by simple water-the tungsten particles embedded in the cobalt matrix are standing proud of the surface, with little or no support. On impact-and blade tooth impact is considerable-theses particles are sheared off, creating a dull edge, requiring sharpening prematurely.

I helped develop manufacturing processes that virtually eliminated the problem-but they aren't particularly applicable here; Charles' suggestion to use kerosene is sound; we found, doing the research, that it didn't cause leaching or any other problems-but in a manufacturing scenario, it was not suitable.

I hope this helps clarify the problem, and Charles' reply; he ain't BS'ing, guys, just making a very sound suggestion; in fact, if he said nothing, Freud would likely sell blades faster-but acquire a reputation for dulling quickly. BTW-under an SEM of a leached surface, you can see the carbide particles standing free of the matrix-kinda like a bunch of hairs waiting to be cut by a razor.

[Basil Rathbone]

So, a question for the chemists, is Washing Soda caustic, acidic or neutral?

I know it works well on my blades and it's cheap because I just steal a bit from the laundry room.

[Steve Clardy]

Ineresting thread.

I've never bought/used anything for blade cleaning.
If it gets that bad, say from pine pitch, I just soak the overnight in a pan of water then scrub with a soft bristle brush.

I have used WD-40 on the insides of my table saw, when pine pitch builds up inside, from the blade throwing it on the arbor parts.

[Rick Christopherson]

Are you looking for "how long can I get by with it before the damage is more than I am willing to accept?" No, I am looking for how long before the damage is even apparent. I too have seen the images presented by Freud, but they are images from nearly the atomic level. Have you ever seen how rough the surface of a razorblade looks like under a scanning electron microscope? Under these magnifications, a surface that by its own function is smooth and sharp, looks like the Rocky Mountains.

You keep repeating this story, but in all this time you have not presented the supporting information that frames the magnitude of the effects. Aside from examining the extremes, what are the effects of Simple Green or other cleaners when properly applied and removed in a timely fashion? How deep is the penetration--10 angstroms, 100 angstroms? How does this compare with the etching present just from using the blade to cut average wood? These are all important things that have never been presented. The information has not been framed or put into perspective.

Using the same methods, I could assure everybody that exposure to the atmosphere would have deleterious effects on the surface of the metals, but that doesn't mean that storing your blade in anything short of a vacuum will cause it to disintegrate. It needs to be framed by a reference of some sort. Yes, oxygen will degrade metal, but most people already understand that it is on a very small scale.

[Steven Triggs]

You keep repeating this story, but in all this time you have not presented the supporting information that frames the magnitude of the effects.

The topic is interesting, and I too would be curiuos to see some scientific data. However, in fairness to Charles, is it the case that if you post something on this forum you have to be able to prove yourself using emperical scientific data? I'm not trying to be funny here, I think this thread is getting a bit out of hand. For example, in a recent post I asked for people's opinions of Bosch router bits. I got several responses, and I will weigh those responses how I see fit. But I certainly will not demand the "proof" from the people who responded. It would be inappropriate to ask them their opinion and then try to prove them wrong.

Anyway, not trying to ruffle anyone's feathers, I just feel like this has kind of turned into an "attack Charles" thread.

[Gary Keedwell]

I agree...Some people's "tone" could use a little refinement. Thank-you, again, Charles for the info and the patience.;)

Gary K.

[Greg Funk]

Greg,

Yes, that is correct. I do not have the test data although I have seen some of the SEM photos of the affects. If the posts I've read in the past about SG are accurate you can contact them for verification. Purportedly, they have a new product that they claim will not negatively affect carbide but we have not tested it so I can not verify that.
Thanks Charles,

I had a look at their site and it sounds like they don't see any problems as long as the blade is not subjected to 'long-term' soaking. They recommend strong coffee for long term soaking. Here is an exerpt from their site:

Simple Green has been successfully used by many woodworkers over many years as a good “spray – wipe – rinse” cleaner for saw blades. When pitch is fairly fresh (typically within a 12-hr period since deposit) it is fairly easily removed with Simple Green. Older, dried-out pitch is much more difficult to remove. We do not recommend long-term soaking of Carbide blades in Simple Green. Long-term exposure like this can possibly cause cobalt leaching that will, in turn, affect the integrity or carbide. Shorter term “spray/wipe/rinse” applications do not create that kind of problem.It has been reported to us that long-term soaking of carbide blades covered with older, tougher buildup of pitch in strong, black coffee does a great job of removing pitch without harming the blade.

Greg

[Rick Christopherson]

Steven, I am not suggesting that Charles needs to prove anything. If that is how you read my post, then you misread it. I was saying that the information of this discussion has never been put into context. It's a legitimate assertion.

[Gary Keedwell]

I used oven cleaner for years...used to hate to clean my blades. :( Then about 3 years ago I switched to Formula 409. I spray it on....wait a couple of minutes....brush with tooth-brush...wipe it clean with paper towel. The whole process takes 5 minutes.
I think that if you only leave a product on for a short time, as compared to soaking it for hours, you should be fine. I have blades that are 17 years old and never lost a tooth.
The only time I lost a tooth was on a brand new Forrest WW11. Must of been a factory defect.
Gary K.

[Chris Barnett]

Just today tried kerosene, gasoline, alcohol, paint thinner, acetone and rubber covered wire bristles on brush; and I had just chucked up my 8 inch polishing wheel to clean my old hollow ground blade. Reading above suggestion of 409 led me to Black Streak Remover; has been a long day and was too lazy go walk upstairs for the 409. Worked like a charm; hard pitch, tar whatever on blades not cleaned for 20 years, literally ran off. Cannot comment on effect on stainless or carbide tips, but it is noted as BEST, better environmental solutions on the bottle. Might just mean its slightly less hazardous than C4....:D . MSDS lists sodium metasliicate; resistance high for stainless 304 and 316. No info yet on carbide etc.

[Tom Walz]

First, there are thousands of grades of carbide so discussing the properties of carbide is like discussing the properties of wood. Therefore, I suppose, everybody is right.

Freud is an excellent organization with a fine reputation. If they say that caustic solutions damage their blades then I believe them. However that is not what my research has shown on other grades of carbide. It is not what my research has shown of Freud blades either. I think there may be a bit of an effect but too small to be of practical concern. See the SEM argument above.

I think maybe this whole caustic thing started with my research. I have two patents (5,624,626 and 6,322,871) where we use a caustic solution to change etch the surface of tungsten carbide and related materials so we can braze them. This gets changed on the Internet over and over.

However the caustic has little or no effect on the carbide by itself. When you run an electric current through the material, as in EDM or in electro etching, the caustic solution serves as a medium to carry the current and the current acts on the difference in electrical susceptibility of the tungsten carbide and the cobalt to remove material. In order to make any practical difference in the surface of the carbide you need an extremely strong caustic solution and a lot of current for a long time.

The whole point of our research was to develop saw tips that stayed sharper much longer than carbide. To do this we wanted materials that resisted chemical attack of any kind. (See Forintek ((University of British Columbia)) report) Our saw blades cut green cedar, MDF, OSB and everything else you can think of.

Chemical attack is one of twelve factors we assess in building superior saw blades. Email me for a complete list. We are working on getting it on the web. It is in my book Building Superior Brazed Tools.

The handbook of Physics and Chemistry shows Cobalt as being soluble only in acid only. Even then an acid attack will create an inert surface on the cobalt that will slow or prevent any further attack.

I do not know what braze alloy Freud uses. Common braze alloys are about half silver and about a quarter copper and zinc with maybe a little nickel or tin or manganese. (AWS Bag-3, 7, 22, 24, etc.) Chemical attack on copper or cobalt as a pure metal is different than a chemical attack on a metal alloy. Iron corrodes differently than steel which corrodes differently than stainless steel.

Much of this argument is similar to arguing about whether you can lose weight by getting your hair cut. You can but it is not practically important.

Again I do not know about Freud blades but most blades are not significantly affected by any commercial chemical cleaner. In our test we found that BBG grill cleaner from a janitorial supply store was cheapest and worked best. Simple Green was good.

Anyway, that’s what my research shows. If you are interested I have primary sources for this.

Tom

[glenn bradley]

Glad to see someone has tried LA's Totally Awesome....my impression is the same as yours. I've tried several methods with good results, but none that I liked better than Totally Awesome.
Another LA user. I used to use Simple Green and it did quite well. LA Awsome is quicker and cheaper (not that I would launch a carbide tooth just to save a buck).

[Garry Stockton]

Tom, I'd be interested in seeing some of your test data; it sounds interesting.

I suspect, however, that you may be ignoring a couple of things here; mostly regarding pH and solution types.

You note-correctly-that cobalt is soluble in an acidic solution. And you state that you are using a caustic solution and electrical current to etch surface of tungsten carbide to prep it for brazing-and acquired a patent to do so; congratulations-it sounds like a useful technique for brazing prep.

Do you know if the etchant action is removing the cobalt or the tungsten?

I ask because you say "When you run an electric current through the material, as in EDM or in electro etching, the caustic solution serves as a medium to carry the current and the current acts on the difference in electrical susceptibility of the tungsten carbide and the cobalt to remove material. In order to make any practical difference in the surface of the carbide you need an extremely strong caustic solution and a lot of current for a long time."

In EDM, however, you are not using a caustic solution-alkaline, with pH higher than 7; you are using deionized water, whether you are cutting in a submerged tank or open air with a flush; and, while deionized water has a theoretical pH of 7.0-neutral-carbon dioxide, present in the atmosphere, will dissolve in the water, introducing ions and giving an acidic pH of around 5.0.

So you have an ideal state-an acidic solution-for damaging/dissolving the cobalt binder while doing EDM; and if you were using water, or any even slightly acidic solution to clean the carbide, you would have to effectively neutralize that acid after cleaning, or the action will continue to dissolve the cobalt, removing the 'shock absorber' support for the tungsten carbide particles.

You are, or were, researching ways to develop saw tips that would stay sharper, longer, than carbide; may I suggest that what I described is part of the problem with the carbide becoming dull quickly?

The acid solution-water or any acidic cleaner-dissolves very minute amounts of the cobalt matrix. The cobalt matrix is what protects the very hard, but very brittle, tungsten particles from being fractured on impact with the material being cut-or, in my application, punched.

The forces generated by the impact of a saw tip on wood-or a router bit, or a punch on metal-are pretty high; and when the tungsten particles are fractured-and, if the cobalt binder is etched away by an acidic solution, they will fracture easily-they will dull much more rapidly; they basically break flush with the unevenly etched surface.

Which seems to me a likely mechanism behind your need to research saw tips that remain sharp longer than carbide. May I ask what kind of solution you were using to clean the tips prior to your research?

I may be misunderstanding your process-but I fully understand that water becomes acidic rapidly on exposure to the carbon dioxide in air, even when deionized; and even running sophisticated deionizing systems doesn't fully return it to a neutral-pH 7-state.

So, if you could comment on this, I'd appreciate it; it's been a few years since I did my research, and you may be using an approach I missed; but it does seem to me that the basic chemistry hasn't changed.

[Richard Niemiec]

Gee, I dunno, but there seems to be a whole bunch of energy around this and I don't get it. I just put my blade in the bottom of a 5 gallon bucket and cover it with an inch of dilute Lestoil and warm water for no more than 15 minutes or so and then brush with a brass brush for 5 minutes and all the crud comes off real easy. Works fine, hell, you could soak my head in Lestoil for 15 minutes and I'd still be fine - maybe it might grow back some hair to boot! Last go-round my bride ran out of Lestoil, so I used regular dishwashing detergent, Dawn I think it was, and did the same thing, worked great as well. Kerosene sounds like a good idea too, never tried that before, maybe next time.

Never honestly understood why folks spend good money on specialized blade cleaners.

Always intuitively understood that oven cleaning sprays and caustics just can't be any good at all for the brazed carbide teeth.

I might be all wrong on this, so your mileage may vary.... RN

[Gary Keedwell]

I'm with you Richard...seems alot to do about nothin.:rolleyes:
Gary K.

[Tom Walz]

Excuse me, I may not have made myself completely clear before. My company is small with limited research funds.

What we wanted to do was to figure out how to successfully braze materials such as TiCN with a Ni/Cr matrix and similar. We have a process that works on cermets and ceramics as long as there is a conductive component in the materials. That is, we can successfully with Alumina that has a TiC additive but not straight alumina.

We did not have the funds to completely analyze the process.

The original program was to license the process to a big company and do further research. However no one wants to make saw blades that last several times as long as it will cut their sales and especially the sharpening. We know this last is true because we have been told it over and over.

Anyway, the original purpose was to provide a clean, etched, rough, activated surface for brazing. Acid makes a surface that interferes with wetting so we used a strong caustic simple to carry the current.

We are removing oils and grease, oxides and free carbon from the surface as the cleaning. The electric current serves to separate the two materials.

We had some WYKO analysis done and we do create deep cratering. I believe that we remove the cobalt because SEM and BSE (elemental analysis) show protuberant grains after the process as well as Cobalt depletion. However there also appears to be formation of a tungsten based or tungsten containing polymer.

You are absolutely correct about the medium changing with use. We achieved the goal of a repeatable process and left the rest of the research hanging. See results at http://www.carbideprocessors.com/Brazing/book/38.htm

Out initial process we call ECP for Electro Chemical Process. You can see the SEM and BSE photos at http://www.carbideprocessors.com/Brazing/book/06.htm (http://www.carbideprocessors.com/Brazing/book/06.htm) This process is the first patent and you can see that we use the carbide as both an anode and a cathode.

The next process
We clean in the strong caustic, then etch in acid then we plate in an acidic solution.

You may be absolutely correct. I should have made it clearer that in my experience, the use of an electric current flowing into or through the carbide greatly accelerates the breakdown of the material.

There are so many kinds of carbide and so many testing methodologies that almost any answer can be correct.

One theory has it that carbide is extremely strong in compression but not in tension so that the release of force as carbide leaves the cut can be more damaging than the forces on carbide as it enters the cut. However this is only one of the many forces involved.

What follows is from a recent speech. It seems to be pretty valid in that it helps solve problems. However I would sincerely appreciate any comments you cared to make.

Typically people think that carbide is worn away. There are other considerations that are often much more important.

Tungsten carbide is actually tungsten carbide grains cemented with a metal, usually cobalt.
A. You can have individual grains breaking or pulling out.
B. You can generate an electrical potential through rubbing that will accelerate this.
C. You can get a chemical leaching that will dissolve the binder and let the grains fall out.
D. As with any chemical reaction of this sort the acids create a salt that protects underlying binder until the salt is abraded away so grain size and binder chemistry are also important.
E. You can get welding between the carbide and the material being cut depending on the carbide grade and the material.
F. Heat from rubbing can affect carbide so a slicker grade can increase life. G. You can get macro-fracturing (breaks large enough to see) and micro-fracturing. With some grades a good hit can start a fracture (fracture propagation) that will sometimes run and sometimes not (fracture propagation). H. The binder is a metal so it can flex and fatigue.
I. If there is too much binder the part can deform.

Theoretical considerations
1. Macrofracture – big chunks break off or the whole part breaks
2. Microfracture – edge chipping
3. Crack Initiation – How hard it is to start a crack
4. Crack propagation =- how fast and how far the crack runs once started
5. Erosion – the binder leaches away and the carbide grains fall out
6. Electrochemical effect – erosion compounded by the differences in electrical resistivity between carbide and cobalt
7. Wear – the grains and the binder just plain wear down
8. Physical Adhesion – the grains get physically pulled out. Think of sharp edges of the grains getting pulled by wood fibers.
9. Chemical adhesion – think of the grains as getting glued to the material being cut such as MDF, fibreboard, etc.
10. Metal fatigue – The metal binder gets bent and fatigues like bending a piece of steel or other metal
11. Heat – adds to the whole thing especially as a saw goes in and out of a cut. The outside gets hotter faster than the inside. As the outside grows rapidly with the heat the inside doesn’t grow as fast and this creates stress that tends to cause flaking (spalling) on the outside.
12. Tribology – as the tip moves though the material it is an acid environment and the heat and friction of the cutting create a combination of forces.

Actual Practice
1. Straight wear – almost never found alone and typically not the most important reason.
2. Fracture of individual grains
3. Grains being torn out
4. An electrical effect through rubbing that will accelerating grain fall out.
5. Chemical leaching that will dissolve the binder and let the grains fall out.
6. Chemical leaching is affected by grain size
7. and binder chemistry
8. You can get welding between the carbide and the material being cut depending on the carbide grade and the material.
9. Heat from rubbing can affect carbide so a slicker grade can increase life.
10. You can get macro-fracturing (breaks large enough to see) and
11. micro-fracturing.
12. With some grades a good hit can start a fracture (fracture propagation) that will
13. sometimes run and
14. sometimes not (fracture propagation).
15. The binder is a metal so it can flex and
16. fatigue.
17. If there is too much binder the part can deform.

[Ted Illi]

You guys are making mountains out of nothing. Washing Soda is the best and Cheapest!

Baking Soda is Bicarbonate of Soda. A pinch in your cookie dough will make them rise. Washing Soda is Carbonate of Soda. It's almost the same but a little more caustic. Your mother and grandmother probably used it to wash your dippers! A couple of tablespoons in the bottom of your stationary tubes and H2o to cover the blades. Place two or three blades and a dozen router blades in and wait five to ten minutes! Take a soft brush to them if required then rinse. You wont believe how well it cleans. When your done open your wifes washer and dump it in.

Where do you find it? In the grocery store in the detergent section. Arm and Hammer Washing Soda. Cost five bucks and will probably last you for the next twenty years!

[Bruce Benjamin]

A couple of tablespoons in the bottom of your stationary tubes and H2o to cover the blades. Place two or three blades and a dozen router blades in and wait five to ten minutes! Take a soft brush to them if required then rinse. You wont believe how well it cleans. When your done open your wifes washer and dump it in.


Won't dumping the blades and bits into the washer possibly damage the cutting edges? And what am I supposed to do with the diapers?;) :D

Bruce

[Ted Illi]

Won't dumping the blades and bits into the washer possibly damage the cutting edges? And what am I supposed to do with the diapers?;) :D

Bruce

Well I gave it some thought........ I suggest you wrap them in the dippers put them on the gentle cycle and stand back when it goes into spin!

[Bruce Benjamin]

I'm all over it, Ted. I'm on my way out to my garage/shop right now to give it a, "Whirl". :rolleyes: ;)

Bruce

[Dave MacArthur]

Charles Mc-- Thank you very much for taking the time to respond to this thread. I salute your considerate participation.

[Gary Keedwell]

I'm all over it, Ted. I'm on my way out to my garage/shop right now to give it a, "Whirl". :rolleyes: ;)

Brucehttp://sitelife.woodmagazine.com/ver1.0/Content/images/store/0/2/809b3466-60eb-4c60-b29b-2d5e8ddc9a92.Medium.gif Gary K.

[Ken Glass]

After reading Jerry Allen's reply I called my wife who just happen to be going to the Dollar store with her mother. She picked up a bottle of the Awesome Cleaner and Degreaser and am I amazed. It cut a very heavy amount of pitch from my Forrest 10x40 WWII blade as quick as any cleaner I have ever used, including Simple Green and 3 or 4 other expensive brands I have on hand. All for only a buck. Thanks, Jerry

[Michael Schwartz]

I'm all over it, Ted. I'm on my way out to my garage/shop right now to give it a, "Whirl". :rolleyes: ;)

Bruce

Just make sure that you use a washer with a plastic drum, not mettal and only wash one blade at at time so that you never have any carbide to carbide or carbide to metal contact :p :p :p

Mabey I will email Freud and ask how much fabric softner to use :D :D :D :D

[Gary Keedwell]

Just make sure that you use a washer with a plastic drum, not mettal and only wash one blade at at time so that you never have any carbide to carbide or carbide to metal contact :p :p :p

Mabey I will email Freud and ask how much fabric softner to use :D :D :D :D
http://sitelife.woodmagazine.com/ver1.0/Content/images/store/0/2/809b3466-60eb-4c60-b29b-2d5e8ddc9a92.Medium.gifGK

[Bruce Benjamin]

http://sitelife.woodmagazine.com/ver1.0/Content/images/store/0/2/809b3466-60eb-4c60-b29b-2d5e8ddc9a92.Medium.gifGK

Uh, Gary?...http://sitelife.woodmagazine.com/ver1.0/Content/images/store/0/2/809b3466-60eb-4c60-b29b-2d5e8ddc9a92.Medium.gif Right back at ya!:rolleyes: :p

Bruce

[Bob Moyer]

Saturday, I went to my local Woodcraft store to view a Forrest Demo, the individual there recommended this for blade cleaning.

http://www.amazon.com/Empire-Blade-Saver-Spray-Bottle/dp/B000R5I7JY

[Bruce Benjamin]

Saturday, I went to my local Woodcraft store to view a Forrest Demo, the individual there recommended this for blade cleaning.

http://www.amazon.com/Empire-Blade-Saver-Spray-Bottle/dp/B000R5I7JY


Wow! At $21.50 plus shipping for 16 ounces that stuff better also remove the blade, sharpen it and then reinstall it too. :rolleyes: I wonder if there's any affiliation between Empire and Forrest.

Bruce

[Ted Illi]

Bruce:

I agree! At that price you can send the blade out and have someone else clean and sharpen it!