Author Topic: Safe way to clamp a round, tapered barrel?  (Read 4607 times)

Offline satwel

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Safe way to clamp a round, tapered barrel?
« on: September 08, 2012, 05:05:49 PM »
I recently had difficulty keeping a Long Land pattern musket barrel from turning while I finished the last bit of threads with a bottoming tap. Is there an easy technique for clamping a tapered, round barrel to resist the torque applied by the tap? I ended up wrapping a section of the barrel with 3/8" rubber tubing and clamping it in the padded jaws of my woodworking bench vise. Even though the barrel would still turn a little, I managed to cut enough thread to get the breech plug timed just right. The whole time I'm thinking there has got to be an easier way to hold a smooth, round barrel from turning without damaging it.

Offline Dave B

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Re: Safe way to clamp a round, tapered barrel?
« Reply #1 on: September 08, 2012, 05:22:10 PM »
The important part of this is to get the jaws to match the  shape of the barrel buy using vice jaw pads made from hard wood that match the barrel profile the more surface area you can grab the better your hold. I have seen the use of bondo on barrels to get the total contact needed to break loose a old breach plug. I would think you could improve your situation with just having a couple of tapered round notched blocks for your bench vice.
Dave Blaisdell

billd

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Re: Safe way to clamp a round, tapered barrel?
« Reply #2 on: September 08, 2012, 06:33:26 PM »
A split wood block that conforms to the OD of the barrel usually works.  If you need more traction wrap the barrel in fine sand paper or emery paper, like 320, grit to metal, before you clamp it.   Assuming it's an unfinished barrel.

You can also cast blocks out of lead, but the sand paper usually works and it's a lot easier.

Bill

wilkie

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Re: Safe way to clamp a round, tapered barrel?
« Reply #3 on: September 08, 2012, 08:19:35 PM »
Use split wood blocks with grooves for the major diameter of the barrel.  Then cast form fitting sleeves from epoxie glue with chopped up fiberglass insulation in it for strength.  A layer of saran wrap can be used to keep the epoxie from sticking to the barrel.  After it sets up you can use powdered resin to make a good grip on the barrel.

Offline kutter

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Re: Safe way to clamp a round, tapered barrel?
« Reply #4 on: September 08, 2012, 10:39:56 PM »
You need to be careful with bbls like that. It's like handling cartridge shotgun bbls and they will dent and crush easily in a vise.

Something as described already in form of a jaw that contours to the bbl shape is whats needed.

This may seem long, but it is a simple way of making a bench vise jaw for holding thin walled round barrels, mag tubes, straight or tapered and actually takes little time.

For use in a bench vise as opposed to a special bbl vise,,I'll take a piece of 4x4 and drill/bore a hole through it lengthwise just  big enough for the bbl to pass..
The piece of 4x4 only needs to be  3 inches long perhaps a bit longer. Don't over do it. A bit brace can cut a large diameter hole quite quickly or a spade bit with an electric drill or drill press.

Keep it centered as best you can.

Once it's cut, put the bbl in the vise verticle. Put paste wax, or other non stick stuff on the bbl and slide the block  down to the  spot you want it to set while you work on it. Make it even with the top of the vise for convenience. A stub peg in the bore held in the vise is convenient at this point. Leave an inch or so of bbl showing away from the breech to the block for working area when you're tapping the threads later on.

Plug the bottom with anything from clay to paper towel keeping the bbl centered in the drilled hole.
I often make a cardboard disc that slides down the bbl in front of the block and jams into position there to  seal it off.
Nothing fancy as long as it holds the block in the position you want and seals it off.

You can see that the need to cut the hole much bigger than necessary for the bbl to pass through isn't there. It just means more filler in the next step.

Mix up some epoxy. Stock bedding mtrl,, JB Weld, Bondo,,Anything that'll harden decently and pour it in the top opening (smaller end of the taper) around the bbl. Center the bbl in the hole again to make sure and let it harden up.

When it hardened,,knock the 4x4 block forward off the bbl. The taper and the non-stick coating will release it easily.

Mark the breech end of the block with some sort of mark so it covers both 'halves'

Now put the block back in the vise or on the band/table saw and cut it in two right down the middle lengthwise of the block. Making two halves. The saw kerf becomes the clearence for clamping.
The mark on the end makes for easy matching up the correct ends/taper.

Some 'smiths only cut one side of the block. Leaving the other solid. You don't have two separate pieces to manipulate (or get lost!) that way. I think the better clamping power is with the 2 separate pieces in my experience. Everyone to they're own way. If you've got bbl sights, bbl pin attachments, ect to deal with,,the 2 pieces is the only way.

Clean the bbl off squeeky clean,,dust with rosin if you have it. A bit of plain white confectionary suger works very well too if you want to go very old school. Maybe that's middle school,,,

Put the two halves of the block around the bbl in the right place and position. Place it in the bench vise and tighten it down and go to work.

Mark the blocks with the bbl style &type. As you accumulate others, you'll be able to keep them separated and matched up.

« Last Edit: September 09, 2012, 12:01:33 AM by kutter »