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Alright time to get rid of that flat black nonsense. Some folks employ a stripper, but I prefer to have all the fun and do the stripping myself. I plan on polishing the thing anyway, so I get started here with some 320 grit wet/dry paper. Cut it into roughly 1” strips. With a fancy bowl of water handy and some paper towels to catch the sludge I put my fingertip on the end of a strip, give it a dip and start scrubbing.
doesn’t take long at all to start seeing some shine. When the paper feels like it slips with no grit, it’s quit. Fold it over a bit and keep going. I get three folds out of each strip. Try your best to take it slow but firm and work in one direction. It will save time later. Keep some extra paper towels on hand and give it a wipe every so often. It removes the paint sludge allowing you to see what you’ve done, and also keeps the sand paper alive a little longer.
To get into the valleys where the tubes touch, take advantage of those folded bits. Push the edge into the channel and sand away. If you do it right, it will remove paint from the tubes on both sides of the channel.
and that’s a days work. At least for me today it is. Only took about an hour and I was distracted by a 6 year old a few times. If you have some wayward grit streaks in the brass don’t worry about it. We have quite a few step ups in grit left to do, they will disappear with future sanding.
So like a Zinc oxide that was used similar to galvanization of steel? I know that stuff is terrible if you heat and breathe it. Wet sanding and using gloves is probably the safest way to remove it. Polishing it off would put a lot of those particles in the air. Something you do not want in your lungs. Part of the reason I left the welding and fabrication field was due to all the toxic heavy metals and the lack of safety in the industry surrounding them.
Well, both of my torches refused to light today so I changed gears a bit. Decided to tackle the y2k bug. Not just a decades passed computer issue for those of us who brandish brass. The y2k pgps have a substantial design flaw.
the air transfer port lines up underneath the rear half of the ball. Pull the trigger and the ball shoots up before it shoots out. You can forget about using thin shelled paint. I’ve even had graffiti burst in barrel. To solve this in the past I glued a cutting board anti-skid dot to the bolt face as a little pusher. It’s held up to thousands of shots with just a dab of gorilla glue.
This time I wanted to try something a little different. I had this old cocker bolt kicking around, and it fits the barrel diameter perfect so a little mad science on the way.
After some measurements I rigged up a little cutting jig on a scrap 2x4 so I wouldn’t lose my fingers in the pursuit of science. I cut the two vertical red lines with a chop saw, and then sanded flat both sides and removed the horizontal bits on my belt sander, essentially turning that lower flat inshape with the round shank.
Measured that shank, drilled an appropriately sized hole in the bolt face, scuffed the shank and hole, added some gorilla glue and set them in a piece of old barrel for alignment while clamping.
after curing I slid the bolt into place and shined a flashlight down the barrel. We’ve got light coming through the transfer hole, success
just have to clean up a couple holes and a pgp Venturi bolt is born.
We’ll see how well the glue holds up. If need be I’ll drill and tap it into place.
another angle to better show how it all fits together.
I had a lot of fun making this. Took a few hours to get it done from planning to execution. Enough hours in fact, that my 6 year old kept asking me if I wanted to take a break from all that work for tea and cookies.
Got some hot work done today. Always takes longer with propane than you think it should. I clamp the thing to my saw stand so the tube can drop freely when it’s ready, but is still accessible to torch on all sides. Keep a big jar of water on hand to cool the lower tube as I don’t want that sucker dropping off the barrel as well. Then use the torch to make what feels like a thousand passes up and down the feed tube top and sides as well as the barrel top sides. When the solder starts to pop and run you’re almost there.
Next on the agenda this remaining solder can be gently heated and wiped away to a degree, then I’ll sand the rest.
After that I will have to make a sleeve from the old feed tube to place over the barrel, and cut a new feed hole further forward so the new Venturi bolt face is appropriately aligned.
Alright I wanted to test out the bolt functionality, so I temporarily reassembled the pgp and gassed it up.
the good
• valve rebuild works great
• Venturi bolt works great
the not as good
• I had a small oversight with my bolt design. I blame covid for keeping oxygen from my brain.
because I used an open exchange style bolt head instead of the transfer hole in the bottom variety, I am unable to cut the feed hole further forward, as the Venturi transfer won’t seal properly and will just blast the air out of the feed port. Luckily I caught this oversight before cutting the new feed hole. It pays to think ahead, reckon I’m just gonna have to think further from now on.
so I have a few options here.
• lose the Venturi and replace it with a pusher screw
• cock the bolt and muzzle load
• machine the bolt for a lug sled like the old general joes centerfire bolts
• cock the bolt, slightly push forward, then twist and pull to partially disengage enough to use the existing feedport.
lose the Venturi, ha that’s a good joke. This thing is cool.
muzzle loading is fun, but I’m planning to employ some anti rollout tech, so it’s a no go.
general joes bolt design is solid, but a bit advanced for what I’m willing to attempt with a dremel.
for now the twist method is easy enough to do. I’ve quickstripped these 2k’s so often from busted paint the motion is second nature.
maybe I’ll wind up having a custom bolt machined or having this one modified for the lug sled, but for now that’ll do.
This is what I was thinking when I asked about length....
What about taking a thin sheet of aluminum. Or even a very thin aluminum piece of tubing, and ripping a slot into it, and spanning the gaps on your bolt.
Then either tig weld the seams, or simply jb weld it? To seal it up?
That or, just re barrel it as a whole. I bet Wally has some .684 tubing he may be able to send you. Then make your new feed port further forward?
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