The finish on my 30-year-old Beretta 92 is poop...

**Mike Irwin** · February 26, 2001, 01:30 AM

How about some suggestions for refinishing?

Anyone use the Brownell's baking lacquer?

How about their teflon spray?

It just might go to Scott & McDougal for their "Gnomekote" treatment.

George Stringer · February 26, 2001, 09:13 AM

Mike, the lacquer is ok. I use it sometimes as a cheap finish on low dollar used guns but you'll be much happier with the teflon. Both are applied the same way but the teflon gives a much nicer appearance. George

**Mike Irwin** · February 26, 2001, 11:34 AM

Is it the teflon or the lacquer that is available in different colors?

Are there any extra prep-steps for the teflon? I seem to remember needing to sand blast the gun?

Can I skip the sand blasting and instead use very fine emory cloth?

Romulus · February 26, 2001, 09:23 PM

Brownells Teflon finish has molybdenum disulfide in it...I don't know if it's safe in conjunction with Teflon, but alone moly disulfide will promote corrosion...

C.R.Sam · February 26, 2001, 10:38 PM

Please tell more about the corrosion promoting properties of molybdenum disulphide. I have heard quite the contrary.

Thanks, Sam

**Mike Irwin** · February 27, 2001, 12:08 AM

I'm pretty certain that molydi by itself is inert, isn't it?

Keith J · February 28, 2001, 01:13 AM

Moly promoting corrosion? I've never heard of such nonsense.

Besides, its in a Teflon coating which provides a good deal of protection from the elements.

As far as finishes go, the baked epoxys are great. Lacquer tends to chip and some solvents attack it. It also wears on the sharp edges and is only a temporary solution.

If the gun is steel, I recommend nickle, the electroless type. If you prep it, any plating shop can do it. Its just a matter of security on their part.

On the prep part, keep the flats sharp by using the right stuff and do them last. Use 400 grit for a brushed look and coat the bare metal with a preserving oil. The plating shop does a intensive degreasing so if you just oil it, all is fine.

I use a commercial rust stop known as Rust Ban, dilluting it with odorless paint thinner and dipping the whole fram in it. It dries to a tacky, wax coating.

Romulus · February 28, 2001, 02:32 AM

I've read a publication speaking to MoSO2 promoting corrosion...And while I can't back up the claim with my own knowledge of chemistry, I wouldn't be so doctrinaire in dismissing the claim as "nonsense"

Do any of you guys remember Arcographite, the miracle motor oil that was taken off the shelves?

C.R.Sam · February 28, 2001, 11:08 AM

Long paper on moly, worth readin the whole thing but I pasted applicable section below.

http://www.precisionshooting.com/aug98.html

I have heard that in a humid environment the sulfur in the moly will react with the water in the air to form sulfuric acid, and it will really eat up your barrel. Is this true?

A. No. Or at least, not under any conditions that you could live through.

Molybdenum disulfide is an extremely stable compound. However, any compound will decompose into its elemental components if you heat it to a high enough temperature. According to that technical bulletin, moly does not even melt before it undergoes thermal dissociation, which occurs at a temperature of 2910ºF, about 100 degrees above the melting point of steel! Now, that is what happens in a vacuum or an inert atmosphere. In the presence of oxygen, MoS2 oxidizes to MoO3 (Molybdenum trioxide), but only at temperatures above 300ºC (572ºF). Below this temperature the reaction proceeds so slowly, if at all, that the reaction rate is hard to measure.

At those elevated temperatures, it is true that the sulfur from the moly would react with the oxygen in the atmosphere to form sulfur oxides which would then react with water to form sulfurous and sulfuric acids. While this reaction can possibly take place, it does so only at high temperatures, and it is partially blocked by the surface formation of molybdenum trioxide and by any coatings of organic anti-oxidants on the moly such as oil, grease, or (carnauba) wax. At ordinary temperatures this just does not happen fast enough to be of concern. Maybe it might be a problem after a few million years.

Yes, the gas temperature inside your bore does go above 2000ºF—for less than one millisecond. However, for this purported chemical reaction to take place, there are two things that have to be present: water vapor and oxygen. There is some water vapor in powder gas formed by the burning of hydrogen that is present in the powder, but there is no free oxygen.

Even in the most highly nitrated versions of nitrocellulose, there is not enough oxygen for the powder to burn completely. There is always some carbon monoxide in the powder gases; and usually, there is some unburned carbon. Instead of the oxidizing atmosphere needed to cause sulfur to form sulfur oxides, the powder gas atmosphere is a reducing atmosphere that would tend to "suck" oxygen off any sulfur oxides rather than contributing to their formation.

Another rumor similar to this is that, at high temperatures, moly will decompose into molybdenum trioxide and elemental sulfur which are abrasives. The preceding paragraph should put the lie to that, simply because there is not any free oxygen hanging around from which molybdenum trioxide could be formed.

Even so, that technical bulletin is explicit in stating that molybdenum trioxide is not an abrasive! In fact, not only is MoO3 not an abrasive, the technical bulletin says it can be used as a high temperature lubricant for temperatures from 350ºC to 700ºC (that’s from 662ºF to 1324ºF). Note, this is below its melting point of 795ºC (1463ºF).

Elemental sulfur is not much of an abrasive either. It has a hardness of 2 on the Moh scale, the same as gypsum. This is softer than the minerals used in the abrasive bore cleaners!

So, don’t worry about this. This is just another one of those scurrilous rumors spread by ballistic Luddites who, for whatever reason, just don’t like moly-coated bullets. It seems that they don’t even like the idea of moly-coated bullets. This particular rumor makes no more sense than the rumor that moly in your bore will somehow suddenly grow into large crystals that are abrasive that will gouge great furrows in your bore. For a compound with the physical and chemical properties of moly, these things just do not happen.

Oh, just in case you are interested, that technical bulletin says that the lubrication qualities of moly are not affected by nuclear radiation. Moly will keep on doing its thing even if you and your rifle glow in the dark!

-----------------------------------------------------------

All we wanted to know and then some.......Sam

February 26, 2001, 01:30 AM	#1
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,390	How about some suggestions for refinishing? Anyone use the Brownell's baking lacquer? How about their teflon spray? It just might go to Scott & McDougal for their "Gnomekote" treatment. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

February 26, 2001, 11:34 AM	#3
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,390	Is it the teflon or the lacquer that is available in different colors? Are there any extra prep-steps for the teflon? I seem to remember needing to sand blast the gun? Can I skip the sand blasting and instead use very fine emory cloth? __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

February 27, 2001, 12:08 AM	#6
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,390	I'm pretty certain that molydi by itself is inert, isn't it? __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

February 28, 2001, 01:13 AM	#7
Keith J Senior Member Join Date: December 15, 2000 Posts: 469	What? Moly promoting corrosion? I've never heard of such nonsense. Besides, its in a Teflon coating which provides a good deal of protection from the elements. As far as finishes go, the baked epoxys are great. Lacquer tends to chip and some solvents attack it. It also wears on the sharp edges and is only a temporary solution. If the gun is steel, I recommend nickle, the electroless type. If you prep it, any plating shop can do it. Its just a matter of security on their part. On the prep part, keep the flats sharp by using the right stuff and do them last. Use 400 grit for a brushed look and coat the bare metal with a preserving oil. The plating shop does a intensive degreasing so if you just oil it, all is fine. I use a commercial rust stop known as Rust Ban, dilluting it with odorless paint thinner and dipping the whole fram in it. It dries to a tacky, wax coating.

February 26, 2001, 09:13 AM	#2
George Stringer Staff Alumnus Join Date: October 12, 1998 Location: Earlington KY Posts: 2,299	Mike, the lacquer is ok. I use it sometimes as a cheap finish on low dollar used guns but you'll be much happier with the teflon. Both are applied the same way but the teflon gives a much nicer appearance. George

February 26, 2001, 09:23 PM	#4
Romulus Senior Member Join Date: January 18, 2001 Location: Kettle Moraine country Posts: 897	Brownells Teflon finish has molybdenum disulfide in it...I don't know if it's safe in conjunction with Teflon, but alone moly disulfide will promote corrosion...

February 26, 2001, 10:38 PM	#5
C.R.Sam Senior Member Join Date: October 29, 1999 Location: Dewey, AZ Posts: 12,858	Please tell more about the corrosion promoting properties of molybdenum disulphide. I have heard quite the contrary. Thanks, Sam

February 28, 2001, 02:32 AM	#8
Romulus Senior Member Join Date: January 18, 2001 Location: Kettle Moraine country Posts: 897	I've read a publication speaking to MoSO2 promoting corrosion...And while I can't back up the claim with my own knowledge of chemistry, I wouldn't be so doctrinaire in dismissing the claim as "nonsense" Do any of you guys remember Arcographite, the miracle motor oil that was taken off the shelves?

February 28, 2001, 11:08 AM	#9
C.R.Sam Senior Member Join Date: October 29, 1999 Location: Dewey, AZ Posts: 12,858	Long paper on moly, worth readin the whole thing but I pasted applicable section below. http://www.precisionshooting.com/aug98.html I have heard that in a humid environment the sulfur in the moly will react with the water in the air to form sulfuric acid, and it will really eat up your barrel. Is this true? A. No. Or at least, not under any conditions that you could live through. Molybdenum disulfide is an extremely stable compound. However, any compound will decompose into its elemental components if you heat it to a high enough temperature. According to that technical bulletin, moly does not even melt before it undergoes thermal dissociation, which occurs at a temperature of 2910ºF, about 100 degrees above the melting point of steel! Now, that is what happens in a vacuum or an inert atmosphere. In the presence of oxygen, MoS2 oxidizes to MoO3 (Molybdenum trioxide), but only at temperatures above 300ºC (572ºF). Below this temperature the reaction proceeds so slowly, if at all, that the reaction rate is hard to measure. At those elevated temperatures, it is true that the sulfur from the moly would react with the oxygen in the atmosphere to form sulfur oxides which would then react with water to form sulfurous and sulfuric acids. While this reaction can possibly take place, it does so only at high temperatures, and it is partially blocked by the surface formation of molybdenum trioxide and by any coatings of organic anti-oxidants on the moly such as oil, grease, or (carnauba) wax. At ordinary temperatures this just does not happen fast enough to be of concern. Maybe it might be a problem after a few million years. Yes, the gas temperature inside your bore does go above 2000ºF—for less than one millisecond. However, for this purported chemical reaction to take place, there are two things that have to be present: water vapor and oxygen. There is some water vapor in powder gas formed by the burning of hydrogen that is present in the powder, but there is no free oxygen. Even in the most highly nitrated versions of nitrocellulose, there is not enough oxygen for the powder to burn completely. There is always some carbon monoxide in the powder gases; and usually, there is some unburned carbon. Instead of the oxidizing atmosphere needed to cause sulfur to form sulfur oxides, the powder gas atmosphere is a reducing atmosphere that would tend to "suck" oxygen off any sulfur oxides rather than contributing to their formation. Another rumor similar to this is that, at high temperatures, moly will decompose into molybdenum trioxide and elemental sulfur which are abrasives. The preceding paragraph should put the lie to that, simply because there is not any free oxygen hanging around from which molybdenum trioxide could be formed. Even so, that technical bulletin is explicit in stating that molybdenum trioxide is not an abrasive! In fact, not only is MoO3 not an abrasive, the technical bulletin says it can be used as a high temperature lubricant for temperatures from 350ºC to 700ºC (that’s from 662ºF to 1324ºF). Note, this is below its melting point of 795ºC (1463ºF). Elemental sulfur is not much of an abrasive either. It has a hardness of 2 on the Moh scale, the same as gypsum. This is softer than the minerals used in the abrasive bore cleaners! So, don’t worry about this. This is just another one of those scurrilous rumors spread by ballistic Luddites who, for whatever reason, just don’t like moly-coated bullets. It seems that they don’t even like the idea of moly-coated bullets. This particular rumor makes no more sense than the rumor that moly in your bore will somehow suddenly grow into large crystals that are abrasive that will gouge great furrows in your bore. For a compound with the physical and chemical properties of moly, these things just do not happen. Oh, just in case you are interested, that technical bulletin says that the lubrication qualities of moly are not affected by nuclear radiation. Moly will keep on doing its thing even if you and your rifle glow in the dark! ----------------------------------------------------------- All we wanted to know and then some.......Sam