Interesting, from your link;

“Laser etching markers work by focusing energy directly on the surface to be marked. The heat generated by the beam actually alters the surface of the part or vaporizes surface material… in other metals (than steel), the surface is etched when material is removed by high temperature vaporization… it modifies the metal alloying and etches the surface in a way that degrades the part’s strength and can lead to fatigue or stress corrosion crack failure.”

One thing's for sure, if I were you I'd make double damn sure followed all idiotic and arcane NFA laws in fixing this because hey, "it's the law". No matter that I'd have to pay another unconstitutional tax and go through that whole rigmarole again for no sensible reason.

Of course, if I was to contemplate such a dastardly deed as violating NFA laws, I would first refrain from spilling the beans and posting pics of the failed tube on the web.

What cones and spacers were used in the can?

As I said earlier in the post, my millennial son posted on the interweb first for the world and the NSA to see so I figured I might as well share my misery here.

this x 1000

One thing to be aware of is to insure that you DO NOT use a Magic Marker (tm) on titanium.  The solvent in them is known to instigate cracks in titanium.  Sharpies are good to go.

I wonder if drilling through the cracks between the words, etc and TIG at those spots, then blend on the inside as/if needed (or use a clean backer during the process) would suffice to keep it from getting worse. There could be some fatigue (not seen with the naked eye) slightly beyond the ends of the cracks, so those holes might be drilled slightly beyond the crack ends. At this point, you don't have much to lose with trying a repair since the tube is close to lost already.

As I understand it, in some cases (this is key, do your own research, it has been a long time since I researched this), a serial number can be restored as long as it was never completely obliterated or defaced. However, I would call the local ATF field office and see when I might catch someone there who specializes in the technical side of things, let them see the can or at least a good pic of it, and see what they might recommend. If it seems to you that the local guy might not quite be an expert about the matter, get a second opinion from elsewhere, maybe even at the NFA Branch (I hate cold-calling them about things of a technical nature, sometimes it starts of being a very rough road). Do bear in mind, the local guys are the ones that are most likely who you need to keep happy as if you ever have contact during a matter it will likely be with them. This is how I view the way I do business, local IOIs are who I need to please. If what they want is above and beyond, that is exactly what they will get from me. As far as interacting with the ATF goes, from what I have seen, they do not want the guy who is trying his best to do things right, they generally want the guy who thinks he can get away with doing as he pleases with blatant disregard for the law and regulations.

As far as this engraving goes, now I understand why it is uncommon to see a commercial can with all of the engraving in one line. I have also noticed that many are circumferentially engraved in a well spaced stack or with details spaced around the can. Gotta keep 'em separated...

As far as I'm aware, welding would be a mfg process and outside the bounds of a form 1'rs, legal, repair abilities.
It would most likely need to be sent to a licensed shop.
After the time and $$ spent, you'd still have a repaired tube, and another possible failure.
Best to file a new form 1 and buy a new tube.
Serialize one of the old end caps, w/ the original serial and put the new serial on the new tube.

I would disagree about filing a new form.

I think the correct action in this case would be to sleeve a tube inside  of the suppressor and have new baffles installed or have your baffles turned to reflect the new internal diameter.  .

Again, this would require an SOT. The new sleeve and spacers would be silencer parts.
By the time you pay a SOT, you could have a new tube instead of one that's already failed.
Not to mention the internal volume you've lost and weight added.

To each his own, I guess.

Fixed! Now to make a cover.
Attached File

My Murphy's Law desk calendar had an entry "There is nothing as temporary as a permanent solution, and nothing as permanent as a temporary solution".  Keep your expectations light and that will likely last a long time.

Clear Tygon tubing might also be useful.

On the outside of the tube?  I’m sure someone at ATF would get all bent out of shape and consider that a tube and therefore a silencer part.

FWIW, I had asked years ago when I first got a 3d printer if a plastic suppressor for a paintball gun would be considered a firearm suppressor. Lost the letter, but the gist of it was yes. It didn’t matter what it was made of if it was not integral (permanent) to the marker.

Don't use it as a tube reinforcement, just as a heat shield - aka Bowers/Griptastic high temp silicone silencer cover (which they do make for rimfire cans).

What about tempering previously built and laser engraved suppressors ?

Nevermind.