Strawing

I am working on a Luger project and need information on how the parts were originally strawed. Will be happy to post a picture of the project once it is finished. Kind of a different slant on a Luger. Ever see one that had the front strap checkered?

Thanks


neil Keller

[BILL]

[BILL]

hmmm..amazingly, he said, I accidentally hit the 'Post Message" button. (see previous post)

Certainly. Have done several. 30 Lpi. Vertical serrations work best. 40 Lpi.

Straw: Thought someone might address this for you. Well......there is the "scientific" method, the "simplistic" method, the "crude" method, and the "so-so" method. The "scientific" method involves the use of an expensive electric furnace, and the experience / knowledge of temperatures, and time to use in regards to the individual parts, and quanty (quantities) of parts. The "crude" method involves a propane torch. The "so-so" method uses nitre blue salts, as sold by Brownells. Let's go with the "simplistic" method, as most folks get good results on the first go-around.


You will need:


A kitchen stove.


An aluminum block with pre-drilled holes for the trigger pivot stud, safety-lever stud, take-down lever, and two grip screws. The ejector bar may be placed on edge. These are the usual strawed parts.


Hemostats or needle-nose pliars to handle hot parts.


Alcohol, or a similar de-greaser. Oakite is very good. It must not leave a "film".


A thin, light, good quality oil in a shallow container. There must be enough depth for the oil to cover the trigger completely.


Prep the parts with the appropriate level of polish you desire. De-grease each part. Do not handle with bare fingers beyond this point.


The parts are "cooked" individually except for the two grip screws; which are done at the same time.


Place a part on the block, and place the block on a stove burner. Apply a "medium" heat, and maintain a close visuual watch on the parts. You will see them start to turn color as they heat up. When the desired color is achieved; remove the part with the pliars, and drop into the oil to "set" the color. Do the two grip screws at the same time to get a color match.


This method is very forgiving, in that, if an error is made; simply re-polish, and start over.


Have Fun!

[Craig]

Thanks for sharing the srawing info Joe. The _simplistic_ method sounds good. What size is that aluminum block?

[BILL]

I guess I have never heard of strawed grip screws. Or maybe the 'stawing' that I am used to seeing on grip screws is just done at a much higher temperature for a longer period of time. Most grip screws on Lugers that I have seen are blued or fire blued. Am I missing part of the process?

[Ted]

Most are fire blued. I have strawed some, but I have never seen an original done this way. It was just for fun on oneof my reworks! Ted

GOTCH'a !! Reasonable critique! So.............How come we "forgot" the Magazine Catch ??

[Ted]

Some Krieghoff Lugers had the magazine catch fire blued like in this picture! Ted




http://boards.rennlist.com/upload/HughKrieg.jpg

[Hugh]

Beautiful kreighoff, Ted! Wish I still had it, now!

[Wolfgang Pfeifer]

Neil,


Strawing color indicates the Hardness/Temper ratio. After carbon steel parts are hardened they are brittle as a result of sudden cooling in oil or water baths. In short, tempering (re-heating, 300-750 F range) relieves the stresses and makes the parts serviceable for their designed use and less likely to break.


Colors go from:

â??Very pale yellow 430 Fâ?� to

â??Light yellow 440 Fâ?� to

â??Pale straw-yellow 450Fâ?� to

â??Straw-yellow 460 Fâ?� to

â??Deep straw-yellow 470 Fâ?� and all the way through brown, purple blue at 640 F.


Make note of the extreme narrow range, 10 F from shade to shade. Flame annealing is imprecise, difficult and frustrating. Gradual and uniform heating is critical to success while tempering/annealing. Electric Furnaces with process control including ramp and hold settings are ideal for this process, but are expensive.


I have done the following:


Use a steam iron, secure it bottom up in a fixture. Use a quality industrial thermometer with 1/8 inch probe and run trial heats to establish temp settings. Drill a 1/8 hole in a small block of aluminum, stick in the probe thermometer and place on the iron bottom. Under-shoot by 20 F and creep up to the desired range. Record all settings. This method has worked for me when I heat treat punching, shearing and forming dies.


Good Luck

I want to thank all of you for the information. I just wish I was back at GE with their tool room electric furnaces. I

was a little concerned to heat them the 2nd(?) time as I know that once thay have been hardened that reheating is in fact a hardness drawing methed to lower the hardness and there by reduce the brittleness. But, I guess that in this case that a reheat will not affect them adversely. I'll let you know the results.

Neil

Neil,


You do not need to heat the items selected for the straw more than once unless you are not happy with the color, and need to start over. Heat treatment is not a factor, as the parts are not exposed to much more than 300 degrees. The "quench" in light oil is intended to stop any color change the part might take on after removal from the heat source. The heat is "drawn" off rapidly, and the part will not take on any more color change. The oil is just a little slower than water, without worry of after-rust. In addition; you can improve the durability of the finish slightly by using a lower heat setting on the burner, allowing the part to reach color more slowly. Does take a little more patience tho. If you want any part "fire-blue"; increase the heat a little (around 600), and "cook" it longer. Don't do this to the take-down lever (locking bolt).