Tuning It's just a flesh wound😆

[Crank]

Just got my 1936-1939 BSA Light pattern. I knew it was in need of some major help when I bought it.

That'll buff out won't it? 

I will admit that I made the failed repair more ghastly looking by annealing the area to reduce stresses, but that really is someone's handiwork from days gone by. 

BSA in true fashion, made sure the thread in the tube is somewhere between metric 1.25 pitch and 21 TPI. 

They didn't harm the tube etching, but gouged the rear area while prepping for the brazing. I'll have to see what I can come up with to try cutting some internal threads that will work, if so I'll thread a piece of tubing, part off the damaged section and TIG on a new section of tube.

If the threads get the best of me, I could make a collar to encase the damaged section, but it would certainly be an obvious repair. 

I'm going to work on removing the brazing and see what I have, I may just do the entire repair by welding and hope I can keep the threads clean. I've got some heat sink that may do the job.

Mark

 

[KWK]

They didn't use metric threads. The pitches BSA used are Imperial. It's just that they used random diameters. And pitches not ordinarily used! They obviously wanted the guns to come back to them for repairs. They did the same thing when they made bicycles, Enfields, and Martinis. This link might help. https://www.rifleman.org.uk/EnfieldThread-table.html. 

 

[Crank]

KWK,

Well, I have no idea what it is exactly, I used my thread pitch gages and there wasn't anything that was an exact fit. 20TPI only matched up when I angled the gage at about a 30 degree angle +/-. 1.25 metric was darn close also, but it's something goofy. BSA was notorious for proprietary threads and diameters. 

I'm slowly using some Swiss files to remove the brazing and get down to bare steel. The more I look at it, the possibility of welding the tube seems more viable by the moment. My buddy has a quick TIG job he asked me to do this weekend, so I'll use that excuse to set the welder up and play with trying some repairs on the tube.

I'll add some pictures of the tube after I get the brazing removed.

Mark

 

[Crank]

Okay, for the most part, I'm as done as I can be at the moment. I'll need to use a cut off wheel to chase the cracks and get the last of the bronze out. Then I'll make up an arbor to clamp everything in. I'm going to make sure that the existing threads stay in alignment, but I won't be too worried about weld intruding into the thread area, a fine wheel or cutter can clean them up.

I'll probably cut the area that distorted, but didn't crack all the way through so I can get it lined up. As basic as it sounds, a simple band clamp will do wonders to hold it in place while I get my tack welds done, then I'll do some passes. Some areas are thinner than I care for and I'll likely build them up so I can machine them afterwards. 

Mark

 

[KWK]

The end can't be saved. Cut it off. Weld on another 1 1/2" or so of tube . Chuck it in the lathe. Support it with a steady. Clean up the weld inside with a short boring bar. Chase the internal threads. I bet it's 21tpi. Trim the outside close as you can on the lathe and finish with a file then polish it out..

You can do 21 tpi on a lathe with change gears. You might be able to use a lathe with a Quick change if you can calculate what gears to put on for your end gears. Change the ratio of the end gears. I have a whole stack of gears to swap on my QC gearbox lathe so I can use metric transposing gears.

I've never seen a thread pitch gage with 21 on it but that's a pitch BSA was known to use. Cut a trial thread first. 

Mark, I hope you don't mind my suggestions. 

My 2 cents ain't worth a dime

 

[Crank]

Karl, 

Challenge accepted !

I promise I'm not trying to be a jerk, I'm laughing as I type this. Your suggestion would make complete sense to most of the people faced with this and had a shred of sanity. To steal a quote from Gomez Addams "I am that fool!" R.I.P. Raul Julia.

I spent some time after work chasing the cracked section with a cut off wheel so I could get my joints prepped. I also gently shaped most of the distorted sections so that the laid almost ideally without any clamping. I will still use one since my intention is to let the weld joint shrink slightly as it will normally do and snug the threads just a bit more. 

I've welded parts even more delicate than this successfully, so I'm feeling reasonably confident that this will be fine. After 35 years of gunsmithing, I have always rallied when people give up on stuff. I was notorious for dragging home road-kill guns that were destined for parts and bringing them back to life. 

Here are some pictures after nibbling and some tweaking.

I can completely understand that it still looks horrible to most people, but to me, this is a far better outcome than I had hoped for. Bear in mind, what I'm planning at the moment is to utilize the trigger block instead, as a mandrel to do my initial tack welds. Those will be shallow and not going to bond to the trigger block. Then I will remove it for full penetration welds at the forward edge of the damaged section. I will have to work slowly with chasing the section with the threads, but low amperage and a minimal heat affected zone should keep from distorting the too much. I will apply a series of beads to the rear portion to build it up for turning and boring to final dimension. I'll add some weld to the gouged spots to build them up also and keep the tube thickness uniform. 

All of this is theoretical until I light off the first time and see how the steel reacts. It has a nice ring of quality steel, but it could be crap with major impurities. I will keep the idea of cutting it off as plan B.

Mark

 

[KWK]

You ain't no fool. Keep going . Looking good. 

 

[Crank]

I also spent some time cleaning the stock up. There were discolorations in the finish and strange "lines" in the wood. They looked very much like scratches, but had almost no depth. I used a stripper that doesn't raise the grain to clean off whatever kind of varnish it had. I don't have any finished pictures yet, but I did take some before ones for reference.

 

I have one pressure dent on the top of the stock that I'm on the fence if I want to steam it out, or leave it as a bit of honest wear and tear.

Mark

 

[Crank]

Here are some pictures after some gentle attention. I need to keep applying boiled linseed oil and build up a good finish. Hopefully I can build up a nice old school finish that will look period correct. Luckily stripping didn't raise the grain and the pores stayed filled, so no major work was needed.

I'm happy how it's coming along, but time will tell if the final product will be a good shooter. The bore has some corrosion for the first few inches, but the rest of the bore is squeaky clean. I'm guessing moisture built up by the tap and damaged it. I may try lapping that area to at least get the pellet off to a good start.

Mark

 

[d3vnull]

@crank please keep this thread updated. I'm really enjoying watching the craftsman discussions and progress.

 

[Crank]

d3vnull,

It's funny, this thread has had a ton of views and yet I was thinking only Karl and I had any interest. I was chalking it up to morbid curiosity hoping to see a mutilated appendage. LOL

I appreciate the compliment. I'm notorious for not documenting my work since I take it for granted that I don't need a photo record for myself. I forget that others enjoy following along. I promise that I will do my best to accommodate your wishes so everyone can see the progression.

Mark

 

[AndyKunz]

What is the "14 1/4" a reference to? Trigger pull?

I like how the stock is coming out. That's really nice. It'll be a looker at the very least once you finish.

Andy

 

[Crank]

Andy, 

Good question to ask, the stocks were marked with their length of pull. Strange how much discoloration there was, most of what looked like scratches I wet sanded with 320grit and boiled linseed oil. It was more like polishing out the markings, almost no material removal occurred. I'll move on to 400, 600, etc...continuing to wet sand, to get where I feel it will look right. Thanks for the compliment.

Mark

 

[AndyKunz]

I'm really impressed with how you preserved the black in the checkering while cleaning up the rest of the stock. Which stripper are you using?

Andy

 

[Crank]

Andy,

I use Jasco, very nasty stuff, but the solvents wick away quickly and don't change the underlying wood, The checkering was allowed to soak and a tooth brush was used to keep the pressed checkering from being clogged with debris. As walnut goes, this is an unspectacular example with a significant shift in colors between the sides, so it'll never be classed as exhibition grade, but makes sense for an air rifle. The sandpaper never touched the checkering itself, I worked right up to the edges.

As a rule, I don't usually consider wood my happy place, but it's nice when a stock responds well to some basic attention. I just stripped and refinished my Beeman R1 stock, it looked hideous and I expected all sorts of physical damage to the wood, but it turned out that the finish coat lifted from the wood wherever it got hit and made it look like significant damage.

Mark

 

[Windmill01]

Mark I to am throughly enjoying the transformation of your “flesh wound”. Please keep up the reporting. 

Gary

 

[Crank]

Murphy is a D**k!

Busted my butt to clear my work area so I could move freely. Great, now I feel pretty good, the job on my buddie's lathe part went flawless. 

Last minute cleaning to make sure the area is degreased and a final check that the joints are settled in the desired position. 

Start my arc and gently increase amperage, so far, so good. Get a tack that joins three points and then shift the clamp to get a tack at another point. Now is when Murphy begins to lurk. As I start welding the weld starts getting contamination floating to the top. A quick check with a file would appear that it's glass. 

Great , now I have some kind of silicate in the metal. I won't bore you with details, but I spent quite a while carefully heating areas to float the contamination to the top, manually removing it and then adding filler. The simple fact was that the threaded area was paper thin and wound up with fine radial cracks following the threads. 

Okay, I'll concede defeat, but I gave it a solid try. Plan B, I'll make a new threaded end and weld it on to the tube. After some quick work, I have an unthreaded portion ready to graft on. 

Time to trim the back of the tube. I set it up in the lathe, bring my tool in for a scratch pass to establish a start point for my cut and all of a sudden.... Thunk! I'm staring at my 5hp lathe actually stopped???? I hangfire for about a second in complete bewilderment before I kill the power. By some astronomical chance, the tool bit had caught a hairline crack and peeled the metal over the tool bit and proceed to mangle the tube into something resembling a cruller, but without the tastiness or a honey glaze.

Let it suffice to say, that I couldn't help but give it a try to get it a bit straightened out. I'd have better luck unscrambling an egg.

Okay, obviously I was done for the night, so I start dragging all of my crap back into the garage and go to lock my truck and it only partially locks. Like it has no power??? My brand new battery is drained. Crap! I go get the charger off the shelf and in the process, my heavy old soldering gun falls, the cord wraps around my pinky but at the point it has about four feet of free fall before it cinches my finger. I almost cut loose at that point, but fearing the harm that could cause to the psyche of any mortal within earshot, I just put the charger down and removed my finger from the cat's cradle of electrical cord. 

This, as a day, has gone south in ways I can't fathom and will try to erase it from memory. Sorry, no pictures, because the good ones are of no help since it wasn't going to work an I didn't want to take photos of the carnage.

Plan?X3.27d, is to buy myself a piece of 4130 tubing and make my own. Unless of course, anyone just happens to have an 80+ year old spare laying around.

Mark

 

[Pneumatic-Addict]

Combination of Halloween and full moon?  

 

[AndyKunz]

After a day like that I can't blame you for not taking pictures!

Andy

 

[Crank]

Andy, 

I'm a pretty laid back and usually unflappable type, but I was having a major WHAT THE ***** experience last night.

I'm back to being pretty unwound and taking it in stride this morning, but I'm still floored how that lathe bit caught just by a couple thousandths and everything went off the rails. Let me emphasize the amount of force a 3 phase, 5hp motor generates and what it did to that tube wasn't pretty. I pride myself on being able to fix most things, but it ain't happening on this one

Oh well, it's not the end of it and I'll keep everyone posted as I get to the next phase of the recovery process. Maybe I could sneak in a carbon fiber tube and no one would notice

Mark