Steam clean router bits or blades?

[chris dub]

I got my wife a steam cleaner for her jewlery and was wondering if it does such a good job on jewlery can it be used for Router bits or even blades? Would the steam do any damage to the carbide? because it does a really good job on jewlery.

[Mike Hess]

Tungsten carbide has a coefficient of thermal expansion that's about 1/3 to 1/2 that of steel. If you end up heating the bit/blade significantly with the steam, you may cause cracking where the carbide is brazed onto the steel.

I'd make sure to go slow, and not heat the blade/bit much - and probably start with one that you could stand to lose until you see how it works out.

Then again, it would be pretty awful to clean one, and cause a crack or weakness in the braze that only becomes apparent when the bit/blade is spinning and flies apart.

[chris dub]

So pretty much no.

Thanks!

[Mike Hess]

Originally Posted by chris dub

So pretty much no.

Thanks!

I guess it all depends on how much you heat the bit/blade. I mean, I've had some router bits get plenty warm after being used, so I'm sure they're desinged for some amount of heat. Maybe take the temperature of one after a few long cuts and see how that compares to the temperature of the steam coming out of the cleaner.

[Bill White]

Don't think the steam would damage the carbide, but it would play the dickens with any bit bearings. I use Arm & Hammer washing soda. Biodegradeable, quick, and a great all-purpose shop cleaner.
Bill

[scott spencer]

Originally Posted by Mike Hess

I guess it all depends on how much you heat the bit/blade. I mean, I've had some router bits get plenty warm after being used, so I'm sure they're desinged for some amount of heat. Maybe take the temperature of one after a few long cuts and see how that compares to the temperature of the steam coming out of the cleaner.

I was thinking the same thing. I can't imagine steam creating any more heat than a good routing session, but it sure could create a lot more moisture. I bet it'd work well, but you'll have to be sure to dry them out well after.

[Bob Wingard]

When you are cutting wood, and you pause the feed, the result is usually a "burned" spot. This means the bit/blade cutting surfaces have attained a temperature of at least 451 degrees. I don't think steam-cleaning will come anywhere near this temperature.

[Tom Esh]

Originally Posted by chris dub

I got my wife a steam cleaner for her jewlery and was wondering if it does such a good job on jewlery can it be used for Router bits or even blades? Would the steam do any damage to the carbide? because it does a really good job on jewlery.

Unless the steam cleaner has a pressure vessel, it's output will be 100 C or less, and heat damage won't be an issue. (Basically they're hot water cleaners.) However since heat accelerates any chemical reaction, and water contains plenty of oxygen, corrosion might be a concern. Dry the bit immediately, re-lube, and inspect. Obviously, you'll want to test the method with something other than your favorite bit.

[Tom Walz]

Carbide gets brazed on at about 1100 - 1300 F. The steel transformation temperature is just above that. So steam probably won't hurt it.

Modern tungsten carbide is designed to suffer a huge amount of abuse and keep working. Sometime try breaking it by hitting it with hammer.

The thermal expansion figures given above are pretty generally recognized as being accurate except for some really special materials. However proper braze joint design and brazing materials (sandwich alloy, manganese additions, etc.) compensate for this and actually create a composite structure that makes it more impact resistant than just the plain, unmounted carbide.

The carbide you use is essentially the same used in saw mills where a 30” saw may run at 10,000 rpm (47” circumference = 28,200,000 inches per minute or 445 mph.) and have to cut through 12 penny nails and similar without losing its edge.

It has to run underwater in many applications where the saw are flood cooled. It has to cut though a lot of really strong acids as in green Western Red Cedar. It has to survive the saw being bent as in curve sawing where they move the saw carriage to follow the twists of the log.

Attached are a couple pages I use in speeches. You might find them interesting.

Tom

[chris dub]

So Tom, it sounds like the bits should survive my little Sharper image steam cleaner and probably the the ultrasonic cleaner as well.

Well I will have to give it a whirl on one of my older bits.

I must admit I was surprised at how well the worked on my wife's rings.

[Bob Genovesi]

Originally Posted by chris dub

So Tom, it sounds like the bits should survive my little Sharper image steam cleaner and probably the the ultrasonic cleaner as well.

Well I will have to give it a whirl on one of my older bits.

I must admit I was surprised at how well the worked on my wife's rings.

I brazed carbide to steel more times that I can remember and have no idea why someone would think really, really hot water would cause the carbide to crack......

Steam away, you'll be fine but there's no guarantee how effective a jewelery steam cleaner will be at cleaning a router bit,,,,

[Larry Nall]

Let us know how that works.

[Mike Hess]

Originally Posted by Bob Genovesi

I brazed carbide to steel more times that I can remember and have no idea why someone would think really, really hot water would cause the carbide to crack......

Steam away, you'll be fine but there's no guarantee how effective a jewelery steam cleaner will be at cleaning a router bit,,,,

I'm not suggesting that it would crack the carbide. I'm saying that if you heat it enough, the steel expands faster than the carbide, and the differential expansion (one side gets bigger faster than the other side) may cause the braze to fail.

As for whether or not the steamer is sufficient to cause this, I can't say, but I'd at least want to know that the steam temperature is somewhere within the bit's working temperature range.

[Tom Walz]

Carbide tools can be very tough and very corrosion resistant which doesn’t mean that all of them are. There are some truly horrible $100 10” blades and some really great $10 10” blades.

I have been doing failure analysis on saws and tools for over twenty years. In my experience Mr. Hess is absolutely correct. The difference in expansion can crack a piece of carbide at any time if it is not brazed properly.

As soon as the braze alloy starts to cool (call it 1,100 F conservatively) the parts are locked together. As they cool to room temperature the steel shrinks more than the carbide and wants to bow the carbide. Assume the carbide is rigid and won’t bend (which is pretty true in these circumstances) then the force is locked in the carbide.

The carbide tips will sometimes break by themselves just from the cooling. They will sometimes stay together until they start to run. Sometimes they run until they hit something.

However a pre-stressed tip can crack under the most unusual circumstances. Water shouldn’t hurt the tool and neither should that kind of steam. However it is possible that a poor quality carbide tip which has been poorly brazed could survive this far and then break although I would think the possibility to be more theoretical than practical.

Personally, whether the caution is applicable in this instance or not I find it hard to fault someone who goes out of their way to mention a possible problem before it arises.

[Ed Costello]

Steam is 212 degrees. I may be over thinking here, but I think you are over thinking.

Good luck
Ed