So the problem is I don't have enough hobby's or projects so I took on building a deepsea waterproof tester. I have a 10 bar/145 psi tester that is ok for making me feel comfortable with washing hands and such without causing any damage. But I participate in many watersports including diving and have a couple gens (not rolex or omega) that are up to the task and want to make a couple of my reps equally capable. I found the litiz diver 125 bar/1813 psi tester but for over $4k USD that is not going to happen. I started with a solid cylinder of aluminum, 8" diameter by 12" tall, cut 3" off for the lid and machined a 3" diameter by 4" deep hole to insert watch. Machined a passage for the high pressure from pump, a port for the gauge in the lid, a weep hole to insure tester is full of water and 1/4" oring groove. I drilled and tapped 8 3/8" holes for hardened stainless studs to hold the lid down at extreme pressures. This all took months in my spare time between other projects, life and of course work. Finally put it all together today and tested outside with safety glasses on, 2k 3k 4k psi, yeah safety glasses sounds sufficient. Easily made and sustained 1k psi, 2k psi and 3k psi, however could not make 4k psi on first attempt. I noticed the gap between the lid and body of tester had increased by at least 1/8" or more. So I released the pressure and removed the lid, the oring had moved a little so I put it back and reinstalled the lid. On the first attempt the lid handles were hand tight, 8 of them so I thought that was good, on second attempt I tightened with a pipe wrench multiple times in a star pattern. On second attempt I achieved 4k psi but the gap grew between the lid and body again. I have come to the conclusion that the studs are being pulled out of the aluminum block. In the next few weeks I will drill out the stud holes in order to install stainless keenserts and try again. All in I have about $600 invested not including machine time, but we have mills and lathes at work and my home shop is well equipped, so I am still well under the litiz and even name brand 10 bar testers. Not really the point though, like most of us if I have less than 20 projects going at one time need to add one.