Saturday, July 3, 2010

SA6 Refinish Complete--???

Been stuck refinishing this SA6 for way too long. This was supposed to be a quick respray, a few new o-rings and some spit and polish. A "fluff and buff" if you will.

The finish kept orange peeling on the second coat. I've been waiting too long between each coat and apparently, that's a no no. Blame it on my 10 hour days at work or whatever, the paint that has worked so well for me in the past has become my nemesis.

I buffed out the orange peeled areas and managed to not burn through all the finish. Rubbed out the remaining paint with some polishing compound until it looked passable. Great. Just what I was after--passable.

Since it was apart, thought I'd at least fix the finish on the trigger blade. The face of the blade was pockmarked and rough. I started on the wire wheel.

Followed with a small cratex wheel in the Dremel tool.

This left an acceptable surface.

At least the trigger blade looks good.

Blued the trigger and the hammer with Birchwood Casey Perma Blue Paste.

Think I mentioned previously that the accuracy of the SA6 was lackluster. Note the rough crown on the barrel. (In truth, there's actually no crown on the barrel.) A quick twist with a tapered reamer would be an improvement. It's so bad that banging it on a concrete block might even help. The rifling is also not uniform. The lands and grooves aren't spaced equidistant from each other. Ah, and the barrel rattles inside the gun. That's probably not good either. This is the single worst barrel I've ever seen--in anything. The inside of a toilet paper roll has a more uniform spiral.

Top soda straw is the stock SA6 barrel. Bottom is a remnant of a Crosman 2240 or 2250 barrel from the parts box.

Chucked the barrel into the Taig and set up a dead center.

Turned the OD down to 0.316"--about 0.003" larger than the stock barrel.

Needs cut to final length, a leade, and crowned.

Faced off one end of the barrel. Started with the leade as that was the easiest to screw up and the extra barrel length meant I'd get a second or even a third chance to get it right. The fired pellet from the SA6 jumps from the cylinder into the barrel. The leade acts as a funnel, easing the pellet into the rifling.

A cone shaped burr was used to remove some of the rifling and cut a taper.

Followed with another burr to chamfer the edge. A brass rod and some 600 grit emery cloth finished the leade.

Looked OK on the first try. Not shown: Cut the barrel to length and crowned the muzzle.

Almost forgot to cut the relief groove at the breach.

The relief is for the hole in the plate.

The barrel is secured in the hole--this fixes the breach end of the barrel at the cylinder. I went for a tight, no barrel rattle, press-fit.

While it was apart, I refinished all the screw heads. Cleaned up all the screwdriver slots, beveled the screw heads, and reblued. Reassembled as per Nick's blog post.

Reassembly note: I put the hammer spring in the third slot from the bottom of the grip. This would be the second highest tension location.

A few pics.

Here's the other accuracy issue. The rear sight is just a groove between the halves of the frame. Not sure if I should cut it deeper to make it easier to see, mount a red dot sight on a Picitinny rail, or live with it. Living with it is currently winning.

There should be a black plastic cover that wraps around and hides the CO2 cartridge. Um, maybe I'll just paint a case of cartridges. Wouldn't they work better in cold weather?

It looks pretty good, but...

after firing 30 only shots, the epoxy finish on the cylinder was coming off from the indexing lock-up. I'd had enough with flaking paint and stripped the cylinder down to bare metal.

An unseen bolt through the cylinder let me chuck it in the 3-jaw. I sanded the cylinder to 400 grit.

And it was put the gun back together again time.

I hate it...

I hate it a bit less...

I can sort of live with it for now. So, it must be growing on me. Actually, no more scratching the paint off the cylinder is growing on me. Most importantly, it shoots groups now. The sight picture is abysmal, but the trigger (being single action) is a winner. It breaks at just over a pound. I did exactly nothing to the trigger/sear interface as far as smoothing or adjusting. The SA6 has one of the very best triggers I've ever encountered outside of a purpose built target gun. This is really a fun gun to shoot, and the relative lack of mechanical complexity should keep it running trouble free for years.

After the newness of the SA6 wears off, I might try repraying it yet again (what? a fourth time?) and giving it a solid week of drying time. Looking back at a few of the projects that were successfully painted with the appliance epoxy, I see they all got substantially longer curing times before handling.

Friday, July 2, 2010

Another Sheridan Blue Streak, Part 1

Figured it was time to get this Sheridan Blue Streak working. The serial number, 243730, shows it was made in 1978. The stock is beat up and needs refinishing. The inlet valve is toast. It will hold one pump of pressure and that’s it. There’s some rust, etc.


The rifle.


You can see the buttstock is bleached and chipped. Not sure if I can work all the chips out…


Sheridans of that era had a big sticker on the buttstock, must have been removed after all the wear occurred.


Even before bleaching the stain was heavy and masked the grain.


Using my fancy roll pin extraction tool. Notice the rubber to prevent marring the forearm.


The forearm removed. The rubber bumper tube is in place.


Rubber bumper.


Since I’m going to sand the stock, I need to remove the trigger guard. Held by tubular split rivets. Some careful prying got them out.


The rivets are malleable and can be restored.


The pump cup was ok, but I have a new replacement.


Trigger spring with guide pin.


Using the antique wrench on the valve.


Worked well.


The antique puller in use. I like the brass cap that slips over the end of the tube.


Valve removed.


Rather than one washer there was a stack between the valve spring and the inlet spring. This also marks the first time the inlet valve was not stuck at the bottom of the valve. Small miracles.


Three washers? Was this a mistake at the factory or just one of many variations over the years?


Inlet valve was toast. I’ll make a teflon replacement as I have on so many other pumpers.

Now to get to the hard work…

Monday, June 28, 2010

Spinning the Wheels on the SA6

Progress report.

The second coat of epoxy paint orange peeled pretty badly. My fault. I second-coated about 10 hours after the first coat. Had I followed the directions on the can, I should have waited only about half an hour. Or maybe it was the 90% relative humidity. Either way, I'm stripping paint and waiting for the cold front to arrive. Today is almost 20 degrees cooler already than yesterday. I'm slowly getting there.

If you've not checked out the blog links, my uncle recently started writing a rather unique blog about knives. He's pretty articulate and thoughtful in his writing style. Maybe check it out.

I'll get back to the SA6 as soon as I have some dry paint that doesn't look cratered.