CHECKERING THE 1911 FRONTSTRAP
By Steve Locatelli
aka Slo cat
Many hobbyist gunsmiths consider doing their own checkering of the front straps of their pistols. To have this professionally done, which usually includes refinishing the frame, can be very expensive. The expense is understandable due to the needed skills and the time required to complete this task. Also, many pistol smiths dislike checkering because they consider the process to be too time consuming and, frankly, rather boring. This is high on their list of gunsmithing tasks they would rather not do.
Here is a layout of what I consider to be the tools, skills and a sequential process of checkering a 1911 front strap. My method has evolved over long-term use. I am sure there are other ways of doing this that also produce excellent results.
First check the thickness of the metal on the front strap of the frame. I lay a 1/2” steel rod in the inside of the frame, measure from the inside of the frame, on the steel rod to the front of the front strap. with calipers, and then subtract 0.50” from this measurement. You need at least 0.030” metal thickness for 25 lpi checkering. Measure in several places along the front strap.
Here are the tools I use:
Top right to low left:
60 degree bent needle file, Brownells 080-648-604AK
Hand Needle file, #1, ground safe on one edge, Brownells 249-211-212AK
Half Round file, #3, Brownells 249-215-231AK
6” Swiss Pattern Pillar file #0, Brownells 191-398-990AK
Checkering file, these come in 20 lpi, 25 lpi and 30 lpi, and even finer spacing,
Here I use a 25 lpi, Brownells 080-000-177AK
SDM 1911 Frame Holding Fixture, http://www.midwayusa.com/product/411823/sdm-1911-frame-holding-fixture-aluminum
Power Custom Universal Checkering Guide, http://www.midwayusa.com/product/233273/power-custom-universal-checkering-guide-1911 This is very inexpensive, but will produce excellent checkering when used properly. You can spend ten times as much for other checkering guides and not get better results.
Brush, for removing filings from work. I use a shaving brush.
The SDM frame holding fixture is not absolutely necessary, but it will save substantial time by using it. It allows you to change the angle of the frame in your vice as you file different areas of the front strap, letting you file at a comfortable position.
You probably will also need magnification in order to see your work. I use an OptiVISOR, Brownells 255-005-000AK
A strong light just above your bench vise also helps seeing small checkering details. I have a goose-neck light with a magnetic base sitting on my bench vise.
LET’S GET STARTED
Here is a 1911 frame with the frame fixture, clamped in a workbench vise. The checkering guide is being attached. This Power Custom checkering guide will allow you to file exactly vertical on the front strap, even as you rotate the frame and fixture in the vice:
Next you can see the guiding edge of the checkering guide in place to guide the first vertical file strokes:
Here is how you lay the checkering file next to the checkering guide. It is very important to keep this file in contact with the guide as you file. The entire edge of the guide must be in contact with the checkering file as shown in the next photo. This keeps the checkering file exactly vertical with respect to the front strap.
Here is what the first few cuts look like. Make these deep enough so that when the checkering guide is removed, the checkering file can easily follow these grooves. This is how all the remaining vertical cuts are guided, by having part of the file following the initial cuts.
In filing these first cuts, they will show that the front of many front straps is not perfectly level. This is because the finishing of front straps is done by hand at the factory.
Continue to file and deepen the grooves. As you progress, more rows of file teeth start biting the metal, cutting more parallel lines. When these first cuts are deep enough, remove the Power checkering guide.
It is crucial that your file follows these first cuts. A common error is that these next cuts are not parallel to the first cuts.
As you file, stop often and brush away the filing, then closely examine your progress. This also gives you a chance to rest. If you push yourself too hard and become fatigued, then you lose your feel for the checkering file and then mistakes occur more easily.
As you file, you should push down on the file with your left hand fingers. Doing this for more than a few minutes will chew up the skin on your fingertips. To prevent this, I wrap several layers of masking tape around the thumb and index finger of both hands.
Here is a filing technique that will speed up your filing. Hold the file to about a 30 degree angle to the front strap and just file with the teeth on the very end of the file. This creates metal filings much faster that when holding the file flat against the metal. But this only will work if the lines have been started. Don’t do this unless there are already some deep grooves for the file to follow.
Alternate this method with filing with the file flat against the metal. By doing this, the bottom of the filed grooves stay smooth and flat. Alternate from one technique to the other. The filing of the vertical lines will require that you place a lot of pressure on the file. Stop often to rest, brush off the filing, and then examine closely your progress. Get into the habit of doing this throughout the checkering process.
Eventually the file teeth at the end of the checkering file will dull. To correct this, just grind off the end row of file teeth to expose the next row of sharp file teeth.
The next photo shows how the initial filing spreads around the curve of the front strap.
Note how the frame fixture is rotated in the vise in the next photo. This illustrates how you can rotate the SDM frame holding fixture in the vise, keeping the part you are filing on top, making it much easier to file. This simple procedure makes the filing much more efficient and speeds up the whole process.
As the filing approaches the edge of the front strap curve, be very careful with your filing. Do not let the file touch any part of the flat on the side of the frame. This requires that you cut only with the very edge of the checkering file, so that the grooves do not extend past the rounded portion of the front strap.
This next photo shows how the file is guided with both hands, taking care to keep the filing lines exactly in the grooves, keeping them parallel. Being careful here will prevent filing that crosses existing rows.
The next photo shows the progression of the filed vertical grooves toward the other side of the front strap.
This shows how finger tips are chewed up by the file. Imagine your finger tips with no protection by the masking tape.
At this point, all of the vertical lines are cut. Make sure that the lines are cut to the full depth of the checkering file teeth. You can tell when the lines are at their full depth when it becomes easier to move the file. The grooves are then at their full depth and the file teeth are not cutting much, or any at all.
Now it is time to install the checkering guide, reversing it so that it guides horizontal cuts.
Again, lay the checkering file in close contact with the guide. It is important to make sure the edge of the file remains in contact with the entire flat surface of the guide as you file, to insure that the horizontal grooves are exactly 90 degrees to the vertical grooves. Rotate the SDM fixture in the vise as you continue to file more and more around the curve of the front strap. Keep your filing at a comfortable angle. Filing at an awkward angle greatly increases the likelihood of making a mistake.
Once the horizontal grooves have been cut all the way around the front strap curve, then take off the checkering guide. These first horizontal cuts should look like this.
Continue filing horizontal cuts, working toward the trigger guard, using the first horizontal cuts to guide the checkering file.
Continue filing horizontal cuts until you reach the point under the trigger guard where the front strap starts to curve toward the trigger guard. Stop here.
It is now time to start working on the contour of this curved portion of the front strap. Here metal will be removed, allowing the top row of checkering to stand proud, higher than the curved portion. A smooth relief cut under the trigger guard is made, leaving the top row of checkering protruding. To obtain a pleasing look, the original contour must be preserved, so that it looks like it was done at the gun factory.
First, take the small flat file with the ‘safe’ edge, placing the safe edge into the last horizontal groove, with the safe side resting against the top row of checkering. File to a depth equaling the bottom of the checkering grooves. File around the curve of the front strap like this:
This file cut should look like this:
Next get the half round file and remove all of the vertical scratches on the curve under the trigger guard. Keep removing metal until you get approximately to the depth of the top horizontal groove. The next photo shows the half way done, just on one side.
Then complete the other side to match.
Here are some supplies for completing this part of the job. Take some fabric backed sandpaper and cut off a narrow strip, about 1/8 to ¼ inch wide. I use 120 grit.
Next take this sanding strip, using a shoe-shine motion, sand down any irregularities left after filing with the half round file.
It should then look like this:
Next, take the 60 degree bent needle file and start sharpening all of the small pyramid points of the checkering. This will scratch up the trigger guard curve again, but this can be cleaned up with the half round file and sanding strips later. The area near the top will need the most attention and work.
The hand sharpening of each row of vertical and horizontal pyramids is very important. How well this step is done will determine whether your checkering job looks professional or not. I usually spend at least one hour doing this on each front strap. I then lightly follow up using the big checkering file to make sure the bottoms of all the grooves are at a uniform depth. Again, this adds to a professional finished look.
Doing the vertical sides of the pyramids. Start filing with the needle file exactly vertical with respect to the checkered surface. Then tilt the file slightly to the right while filing, then tilt the file slightly to the left while filing. Use a very light pressure on the file while doing this, as you don’t want to over-do the filing. After a few file strokes, stop, brush off the filings, and look at your progress. Then file some more, stopping often to assess progress. Do this with every vertical groove. The goal is for each pyramid to have a sharp point. The pyramid points may have slight knife-edges after all the vertical grooves are touched-up. These should be removed after horizontal grooves are touched-up.
Then finish filing the horizontal sides of the pyramids, filing lightly and stopping often to assess progress. Use the same filing process described above for filing the vertical pyramids.
Now closely examine the entire surface of the checkering. Look for any pyramids that don’t have perfect points, either pyramids with flat tops or with knife edges. Then touch up these areas with the needle file.
Lastly, the edges of the checkering area, specifically the right and left sides, as well as the bottom, which is at the magazine well, will need to be finished. There will be slight filing burrs, and these need to be smoothed. This adds to the overall attractiveness of the checkering job, and removes areas that may snag on clothing, and will give the checkering job a nice, finish feel.
Here the 6” Swiss Pattern Pillar file is used to touch up both sides of the front strap. File at approximately a 30 degree angle with respect to the flat on the side of the frame.
And the 60 degree curved needle file is used to touch up the bottom rows of the checkered area around the magazine well. Again, file at about a 30 degree angle.
Do a final examination of the checkered surface. Insure that the bottom of the filed grooves are all at a uniform depth. Use the big checkering file to do touch-ups for this. Inspect the tops of all pyramids to see that they have nice sharp points. Touch-up with the 60 degree bent needle file where needed.
The finished product:
An[IMG]http://i61.tinypic.com/10palad.jpg[/IMG] other view.
To prepare for refinishing the frame, the curved top above the checkering should be blasted to match the other curved surfaces of the 1911 frame. Many like to blast the checkering too. Tape off any area you do not want blasted. If the frame is stainless steel, after blasting the checkering job is completed, since refinishing is not necessary. If a carbon steel frame, then the front strap area must be finished to match the rest of the frame, bluing, Parkerizing or spray coating.
If checkering a front strap is now something you want to try, first practice on a piece of 1” iron pipe. Don’t file on an actual pistol frame until you have practiced enough to have confidence that you can do a good job.