LugerForum Discussion Forums - View Single Post - Guide to Re-Strawing your parts?

DaveinTN · 12-13-2007, 12:37 AM

Zamo,

Here's a reprint of an article that was posted by John Sabato on 10/5/2006. I'm sorry I didn't give him due credit when I re-posted it here.

Good Luck Zamo! Post some pictures of your results.

Dave in TN.

A process for creating straw color finish on steel gun parts

Strawing or coloring small steel gun parts with heat is a fast and simple process. Do not try to make it complicated. If the process does not go smoothly just stop, and take a break, and then start over again. You can not mess up the outcome, but you may have to start over, especially if you have achieved a color darker than you wish. You will just have to re-polish and then re-heat treat the parts again until you get the color you are trying to achieve.

Buffing can take a toll on proof marks and serial numbers so you want to be cautious. I learned this process. This process originated from Harry Jones, author of the book Luger Variations,as used by him in his California shop some 35 years ago. This process has been used successfully to straw color the small parts on at least 400 plus Luger pistols all over the world since then.

On the checkered areas, such as the magazine release and take down lever, it may be sufficient to properly prepare these surfaces by just using a heavy wire brush. A fine wire wheel on a buffing machine is a good method to do this. Another method would be to use a small wire wheel on a Dremel tool to achieve the same degree of cleaning. The small parts should then be polished with 240 grit polish on a buffing wheel. You do not want to bring the surface to a bright mirror finish, as that would exceed the finish applied by factory work, and you should try to come close too what was done at the time of original manufacture. Tight and hard to get into places can be polished with approx 360 grit sandpaper.

The surfaces that do not show when the gun is assembled do not need to be polished, even if the part is already blue or patina. It makes for a more professional job if you do, but in areas behind the trigger, this may prove tough to get to. Also, if your ejector is pitted, you should polish it on the area that shows when the gun is assembled. You can also polish the underside of the ejector, but if removing pits on the under side of the ejector is going to make it too thin, then stop polishing after outside surface is done. Un-seen and un-polished parts will not affect the out come of the new straw finish on the polished areas.

Once polished, use something like gunscrubber to degrease the entire part! Also degrease the tools you are going too use for handling the parts during the strawing process. Heavy tweezers should be used to handle the parts once they are cleaned, and again as they come out of the oven. Degrease at least the part of the tool that will come into contact with the part. Even clean washed hands will leave some oils on the parts and this may cause the finish to be other than your objective so be careful. Oil of any type will mess up the finish during the strawing process.

Heat your oven to approx 450* (degrees Fahrenheit). The hotter the oven the darker the color result will be. But a hotter oven will also color faster, so watch carefully for the color you want and immediately remove the parts from the oven once you achieve that color.

Use 530* for a darker Krieghoff-type look. Use 510* for 1940-43 ejector temper blue. If you just stick with 450* you will very likely be fine.

Place parts in a small de-greased pie tin in the center of oven and stand back and watch the parts through the oven window. Right before your eyes the part or parts will start turning that magical straw color. Smaller thinner parts will color faster. Take the parts out of the oven individually once they achieve the color shade you want.

If the color is darker than you desired, you have waited too long so you have to cool the parts and re-polish. Then degrease and start over. Heavy thicker parts will take longer.

It is recommended that once you get the color you are looking for, immediately take the parts out of the oven and start cooling the parts with a light oil. 3-in-1 brand oil is recommended, but any sewing machine or light gun oil will work. Use several light drops, don't be cheap on the oil, but there is no need too have the part swimming in it. When the parts have cooled down to room temperature, wipe the excess oil with a soft cloth and install the parts. You will be very pleased with the results.

Strawing small parts is just that easy!

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

Yes, the strawing does occur simply by means of the heat applied. It really is a controlled oxidation process. To say it occurs "simply" is perhaps an over simplification. A lot has to do with the preparation of the metal surface and the control of the temperature. As John's instructions indicate, thin portions of the metal tend to heat up faster than the thicker parts so the heating process needs to be applied uniformly, monitored carefully and the parts cooled/quenched relatively quickly when the correct color is attained.

An old trick is rather than place the parts on a pan and heat them up, fill the pan with clean (emphasis on clean) fine sand. When the sand has attained the approximate 450 degrees, push the part to be strawed into the sand (needle nose pliers or surgical hemostat are handy tools). The sand bath provides a uniform heating medium. Remove the part after a few seconds, check the color, and repeat as necessary to achieve the proper color. Quench immediately to stop the process. Like many things, color hardening is as much an art as a science.

12-13-2007, 12:37 AM	#2
DaveinTN User Join Date: Nov 2006 Location: Tennessee Posts: 186 Thanks: 3 Thanked 15 Times in 11 Posts	Zamo, Here's a reprint of an article that was posted by John Sabato on 10/5/2006. I'm sorry I didn't give him due credit when I re-posted it here. Good Luck Zamo! Post some pictures of your results. Dave in TN. A process for creating straw color finish on steel gun parts Strawing or coloring small steel gun parts with heat is a fast and simple process. Do not try to make it complicated. If the process does not go smoothly just stop, and take a break, and then start over again. You can not mess up the outcome, but you may have to start over, especially if you have achieved a color darker than you wish. You will just have to re-polish and then re-heat treat the parts again until you get the color you are trying to achieve. Buffing can take a toll on proof marks and serial numbers so you want to be cautious. I learned this process. This process originated from Harry Jones, author of the book Luger Variations,as used by him in his California shop some 35 years ago. This process has been used successfully to straw color the small parts on at least 400 plus Luger pistols all over the world since then. On the checkered areas, such as the magazine release and take down lever, it may be sufficient to properly prepare these surfaces by just using a heavy wire brush. A fine wire wheel on a buffing machine is a good method to do this. Another method would be to use a small wire wheel on a Dremel tool to achieve the same degree of cleaning. The small parts should then be polished with 240 grit polish on a buffing wheel. You do not want to bring the surface to a bright mirror finish, as that would exceed the finish applied by factory work, and you should try to come close too what was done at the time of original manufacture. Tight and hard to get into places can be polished with approx 360 grit sandpaper. The surfaces that do not show when the gun is assembled do not need to be polished, even if the part is already blue or patina. It makes for a more professional job if you do, but in areas behind the trigger, this may prove tough to get to. Also, if your ejector is pitted, you should polish it on the area that shows when the gun is assembled. You can also polish the underside of the ejector, but if removing pits on the under side of the ejector is going to make it too thin, then stop polishing after outside surface is done. Un-seen and un-polished parts will not affect the out come of the new straw finish on the polished areas. Once polished, use something like gunscrubber to degrease the entire part! Also degrease the tools you are going too use for handling the parts during the strawing process. Heavy tweezers should be used to handle the parts once they are cleaned, and again as they come out of the oven. Degrease at least the part of the tool that will come into contact with the part. Even clean washed hands will leave some oils on the parts and this may cause the finish to be other than your objective so be careful. Oil of any type will mess up the finish during the strawing process. Heat your oven to approx 450* (degrees Fahrenheit). The hotter the oven the darker the color result will be. But a hotter oven will also color faster, so watch carefully for the color you want and immediately remove the parts from the oven once you achieve that color. Use 530* for a darker Krieghoff-type look. Use 510* for 1940-43 ejector temper blue. If you just stick with 450* you will very likely be fine. Place parts in a small de-greased pie tin in the center of oven and stand back and watch the parts through the oven window. Right before your eyes the part or parts will start turning that magical straw color. Smaller thinner parts will color faster. Take the parts out of the oven individually once they achieve the color shade you want. If the color is darker than you desired, you have waited too long so you have to cool the parts and re-polish. Then degrease and start over. Heavy thicker parts will take longer. It is recommended that once you get the color you are looking for, immediately take the parts out of the oven and start cooling the parts with a light oil. 3-in-1 brand oil is recommended, but any sewing machine or light gun oil will work. Use several light drops, don't be cheap on the oil, but there is no need too have the part swimming in it. When the parts have cooled down to room temperature, wipe the excess oil with a soft cloth and install the parts. You will be very pleased with the results. Strawing small parts is just that easy! --------------------------------------------------------------------------------------------- Yes, the strawing does occur simply by means of the heat applied. It really is a controlled oxidation process. To say it occurs "simply" is perhaps an over simplification. A lot has to do with the preparation of the metal surface and the control of the temperature. As John's instructions indicate, thin portions of the metal tend to heat up faster than the thicker parts so the heating process needs to be applied uniformly, monitored carefully and the parts cooled/quenched relatively quickly when the correct color is attained. An old trick is rather than place the parts on a pan and heat them up, fill the pan with clean (emphasis on clean) fine sand. When the sand has attained the approximate 450 degrees, push the part to be strawed into the sand (needle nose pliers or surgical hemostat are handy tools). The sand bath provides a uniform heating medium. Remove the part after a few seconds, check the color, and repeat as necessary to achieve the proper color. Quench immediately to stop the process. Like many things, color hardening is as much an art as a science.