The tube ran about $7 shipped from Hong Kong, and 4 weeks for delivery. The IZH 61 barrel has a nominal OD of 13mm. Not needing this for structural support, I opted for a 13mm/15mm (ID/OD) carbon tube. That equates to a wall thickness of 1mm.
The tube arrived and as I suspected, didn't quite fit over the barrel. I stripped the barrel down to bare steel, then changed course and sanded out the ID of the carbon with 150 grit emery cloth on a long mandrel.
Got a snug slip fit. Not shown: re-blued the barrel.
Eyeballed the length and cut it 1/8" long with a hacksaw. Wrapped the tube before the cut with masking tape to help prevent splintering. It can be helpful to treat carbon fiber like wood or fiberglass.
Faced it closer on the lathe then finish sanded the edge.
This isn't necessary, but I opted for a semi-permanent installation. Pretty sure I can break the epoxy bond with either a heat gun or a torch if I ever change my mind.
Thin coat on the barrel and slid the sleeve home.
Used a gray scotchbrite pad to knock back the gloss finish to a matte. Ran out of time about here. Still need to make a new barrel support for the larger tube size. Despite my recent misadventures with plastic, there's a piece of acetal on the bench.
Hopefully I can get to it tomorrow.
3 comments:
Looking forward to seeing the finished product. I've contemplated playing with carbon fiber tubing myself, maybe this will push me over the edge. :-D
Paul, you know what they say, "Fortis Fortuna Adiuvat".
Who you calling Fortis? :-D But I have been scouring AliExpress for a deal on tube... 11mm ID would be too tight for a standard Crosman barrel and 12 mm would be quite loose, but there's plenty of clearance between the barrel and the main tube on the 2240 it looks like. With the long steel breech the barrel brace is optional with only a 10 inch barrel. Hmmm...
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