Author Topic: European style brass trigger guard tutorial.(pictures fixed)  (Read 13606 times)

Offline Rolf

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European style brass trigger guard tutorial.(pictures fixed)
« on: September 01, 2013, 10:11:44 PM »
Foreword.
I fell in love with the Swedish officer pistol made by Runar.
http://americanlongrifles.org/forum/index.php?topic=22826.0
He was kind enough to send me plans for the pistol and give tips and advice. It’s with his permission I’m writing this tutorial.The trigger guard is different from other guards I’ve made. This tutorial is written as an aid to help newbie’s like me who would like to make similar types of trigger guards. I’ve skipped some details in this tutorial. You can find most of them in this tutorial http://americanlongrifles.org/forum/index.php?topic=704.0

1. Material and basic tools.
 This trigger guard is made of five parts silver soldered together:
Front trigger guard extension, 3mm (1/8”) thick brass sheet
Tang, 3mm (1/8”) thick brass sheet
Bow, 3mm (1/8”) thick brass sheet
Two pillars, 15mm (0.6”) brass round stock

The parts are joined with Rio Grande brass color silver solder, flow temp 720oC (1328oF) and
Braze Tec flux paste h. All surfaces to be soldered were degreased with Brake clean spray and painted with flux paste. All the soldering was done with a heavy duty propane torch.  All shaping was done with a 6” and 8”nichcolson half round second cut file. Bevels were defined with a triangular needle file. Clean up was done with half round emery sticks 240 and 400 grain.

Warning!!! I just found out that brake cleaners and other degreasers can contain chlorine compounds that can react under heating to produce phosgene gas which is highly toxic. I recommend using pure alchol or aceton for degreasing.

2. Rear tang and front extension.
Mill/file pillar tendons. Cut the rear tang and front extension out of sheet brass and mill/file slots for
the pillar tendons.


NB!!! Do not cut out the final. Keep the front part of the extension square. This is so you can hold it in a vice when soldering the pillars on.  NB!! This joint has a large surface. “Drown” the joint in solder from all possible directions to avoid gaps. Be sure all the parts are heated sufficiently all the way through before adding solder.  I had to scrap the first four guards because voids appeared during the final shaping of the pillars. After the pillars are soldered on, file a shelf straight across the top of the pillars.


3.  Trigger bows and bending blocks.
I lack Runar’s skill at free forming parts, so I use bending blocks and jigs when ever possible. It also makes it easier to make identical pairs of trigger guards. Draw the inside curve of the guard.


Add the height of the pillars. This gives you the length of the bow blank.


Draw two lines, one parallel with the front extension and one parallel with rear tang. The distance between the lines is equal to the pillar height + brass thickness (10mm + 3mm). This is bending block pattern.


Make the bending block out of 1” thick hard wood. I used oak.  Draw the bow pattern, add a square (“ear”) at each end and cut it out of brass sheet. Screw the bow blank to an anchor block and screw the anchor block to the rear of the bending block.


Start bending, anneal often. The ears keep the bow level while bending. Stop bending when the brass starts springing away from the block.  I annealed 7 times to complete the bow.


Attach the second anchor block, cut of the excess part of the front ear and file flush to the bending block. What’s left of the ear keeps the bow level.


Remove the first anchor block and attach the third anchor block. Cut off the excess of the rear ear and file flush. I’ve epoxyed broken off Stanley blades to the two flat surfaces of the block to keep the file from cutting into the wood. The bow ends are now square to the guard’s long axis and have the correct angels.


4. Soldering the bow to the pillars
File away as much as possible of the inner portions of the pillars. Saw out the final. Hold the front extension and the tang in the vice by the pillar tendons. Place the bow on the shelves and angel the parts so the bow sits flush on the shelves. Solder everything together.


5. Shaping the guard.
Use the large half round file to shape the inner curve of the guard and the small half round to shape the outer curve. Notice that to get a smooth transition from the outer curve of pillar to the front extension, the curve has to continue down into about 0,5mm of the sheet metal. Same goes for the tang.


Next file the bevel on the tang. This is necessary to have room to file the profile on the sides of the pillar.


Next file the curving profile in the pillar sides with the small half round file.


Repeat the process with the front pillar and extension.


Next file the bevel on the bow.


The front and rear pillar are now square in cross section. The next step is to file them hexagonal in cross section and get the pillars to flow into the bevels on the bow, tang and front extension. This is done with the small half round file.


The front extension terminates in a low peak before the final begins. This peak is made by dishing out the front end with a round file. Don’t go deeper than 0,6mm.


Remember when establishing the outer curves of the pillars, we filed the curve 0.5mm down into the front extension. File the area between the pillar and the dish level and re-establish the bevels.
Do the same thing to get rid of the dip in the tang at the rear pillar.


6. Shaping the final.
Dish out the front leaves with the small half round file, but keep the berry tall.


Bevel the rear part of the final and round the berry.


7. Clean up.
Clean up and define all lines and bevels with a 240 grain half round emery stick. Polish with a 400 grain emery stick. When I start on the stock blanks, the tang will be bent to fit the grip curve and cut to length. 








Making two trigger guards that were reasonably identical was a lot of work. Next time I think I’ll make one master and have someone cast two copies for me. It takes me about three full days to make one trigger guard.

Best regards
Rolf







« Last Edit: September 17, 2017, 07:16:29 PM by Rolf »

Offline Rolf

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Re: European style brass trigger guard tutorial.
« Reply #1 on: September 25, 2013, 10:38:27 PM »
The brass I used was some scraps I got for free from a machine shop. I think any soft yellow brass will do. Whats important is that the round stock and flat stock are the same alloy, so all the parts have the same color.

Best regards

Rolf

Offline Rolf

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Re: European style brass trigger guard tutorial.
« Reply #2 on: September 26, 2013, 09:24:53 AM »
OK great. I was kind of thinking about the match on the braze too.


204 cartridge brass should be about the same color as the silver solder I used. But remember the brazing seams are less than 0.004" thick and hardly visible even if its not a close color match.

best regards
Rolf