I have used the compressed air trick more than once to drive glue deep into the joints or cracks. As I don't have an air compressor in my gun room I had to take the work to my farm shop to do it.

But, the most recent one was done with a little 18V Milwaukee compressor that I keep in my farm work truck for quick, small jobs. It comes with a needle and a nozzle that can be put on the hose, and was easy to take to the gun room. It worked perfectly for blowing the glue deep into the crack. Very controllable.

[Linked Image from jpgbox.com]

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