Filing welds

chris in va

Mar 4, 2005
Louisville KY
I finally had my CZ's slide crack fixed, it should be here in a few days. I have never had to file down welds before, as a beginner should I get a basic set or would careful Dremel work be better? The microwelding is in some tight spots around the extractor groove and slide rails.

If I go the file route, what set do you recommend?


Whatever you end up using, just go very slowly and take off a little bit of material at a time. Unless you have some kind of deadline, removing too little is not a problem--you can just take off a bit more. Removing too much, on the other hand... Where people get in trouble is they get impatient and/or tired and start trying to speed things up, then they take off more than they intend, or the tool slips.

If you file, take a stroke or two, look at everything to see if the file is touching/cutting something you didn't mean it to, make sure the removal is going to be level with the original surface, then repeat. You'll learn as you go--just go slowly enough and check frequently enough that you have a chance to learn before something gets messed up.

If you get tired or start feeling the need to go fast, put it away and come back another time.

Leaving a radius (even a small one) in the corners will make it stronger and less likely to fail in the future.
I would suggest putting a layer of painter's tape on each side of the weld before you start.
Replace the tape if it gets too scuffed up.
You can always remove the tape for the final cut.
I like to do final burnishing on outer surfaces using the hardest, smoothest piece of steel stock that I have at hand.
Whatever you try, stay away from a Dremel, unless you have been been using them in industry (highly unlikely).
The advice for "safe-sided" files is very helpful. Those are files which do not have teeth on their sides. Won't find them in most hardware stores.
Seems I keep talking about finding gunsmiths lately. Milling out the excess weld is easy with a mill and good machinists vice. Yep, you can sure do it yourself, but I’d suggest you at least look at the cost. Surely Louisville has some quality smiths.

A safe-sided file would do it nicely if you have room to use it. They are the best thing since sliced bread.

I’ve done a fair amount of Dremel work and think you might could do this job with sanding drums.
McMaster Carr has a nice selection of safe side files to chose from . I bought the finest grit they had , about 4 inches long . A joy to use .
Set of small safe sided riffler files. They're like Swiss files; should have a set of them too.
Some of the safe sided files around my bench.
The Boride Engineering and Eze-Laps are designed for hard metals. Nicholson has a few safe-sided choices.
Acquiring a variety of nice files is expen$ive. Especially getting into screw slot files.
Chalk is the gunsmith's file friend.

EZE-LAP Diamond files copy.jpg Screenshot 2024-01-28 at 7.51.12 AM.png IMG_5209 copy.jpg Screenshot 2024-01-28 at 7.48.47 AM.png IMG_9667 copy.jpg IMG_9668 copy.jpg IMG_9676 copy.jpg IMG_9679 copy.jpg IMG_9675 copy.jpg

Last edited:
Dremel NO, put it down and walk away.
Good suggestions but I missed the part about keeping the file lubed and use your file card every few strokes. Very important for file life and nice finish.
I'm fairly good with a file, but that just screams 'mill' to me. You've spent the $$ for the first part of the repair, having it completed correctly is probably smart money.

A little off topic but where does one find the safe sided file? I just did a Dawson front sight yesterday. Safe sided file would have been nice. OP you already good suggestions here...
Go slow and dip in water frequently, if it turns blue, you wasted your time.

Takes a little longer but if you “safe” a 3 sided file, you’ve got the best deburr knife there is.

Why isn't the gunsmith who did the weld filing it?
Or, it could be asked, why would you have a non gunsmithing welder do the work?
Good point but why ask why. I've welded milling machine and lath parts for restoration projects and I'm not a machinist. Picking up what I'm layin down.
You don't just grab any old rod (or load any old wire) when working on the type of weld the OP had done. Entirely different than when I had my son weld the buttplate back onto my AK.