AmericanLongRifles Forums
General discussion => Gun Building => Topic started by: rickevans on September 25, 2013, 08:24:43 PM
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How do you fellows determine Top Dead Center of the round bbl in order to properly place the front sight for soldering? I have searched the thread and found lots of info on sight style, material and proper height, but none of how to acurately locate it!
Your advice and guidance will be appreciated.
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I clamp a 1X4 on the bench. I place the barrel upside down on the 1x4 and screw the tang down to the board so the tang is flat but the barrel can pivot. I place a piece of 150 grit sandpaper under the muzzle and move the barrel back and forth pivoting at the breech. This marks a nice line.
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I don't know if this is the correct way to do it but it works for me.
I set the barrel/stock (well padded!) in the mill/drill vise holding the butt end on an adjustable roller stand stand (also well padded). I square the gun up so the bore is sq with the vise/mill. Then with a end mill in the mill/drill I take a very light cut off the top of the barrel, just enough to see where the center is. This is where I put the sight. If the sight has a stake on the under side I use an end mill to cut the right size hole (blind) for the stake to fit into. Then I remove the barrel and soft solder the sight in place. Done right this insures the sight is sq with the breech/stock etc. Works for me!
Dennis
**Just read Kent's solution above and might try this next time. Probably much quicker and I am all for quicker!**
Dennis
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Brownells sells a little gizmo to locate top dead center but it might not be worth buying unless you plan on doing several.
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Kent's approach works for me!!
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Simple.........hold the barrel in a vise, pad the jaws if you want. Place a level across the top flat. Adjust it until the barrel
is level. Then place the level on a small file, 10" flat, then place the file on the muzzle end where the sight will go and
make sure the bubble is in the center, then merely drawfile a light line on the barrel........simple.........Don
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I like Kent's solution too, but will probably stick with what I've been doing. In an old book I read how Mauser mounted the sights on their rifles. Basically, they had a fixture that indexed off a constant point on the rifles (the bottom of the action). Looking over the mounted rifle, you saw a vertical line on the wall. Sights were tinned, put in approximate position, then aligned with this line on the wall and soldered.
I leveled the bed of my wood lathe, and made a little doohickey that clamps a barrel in place. On round barrels, I use a plumb line to center the breechplug tang. Then I drop a plumb bob at the muzzle, align the (tinned) sight with this, and solder it in place. The hardest part is remembering where I stored the barrel clamp doohickey the last time I used it.
A guy could use a similar approach with V-blocks on a known level bench.
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I use my Golden Mean caliper. Pace it off just the right amount from the muzzle, then walk it around the barrel until I find the sweet spot. That's where I solder it.
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Time to cut me off....
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No Thom..... It's time to get the stick and give you a wack.........
Dave
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Just a passing thought. I don't think I would SILVER SOLDER anything directly to the barrel. Requires to much heat...
Dave
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I use my Golden Mean caliper. Pace it off just the right amount from the muzzle, then walk it around the barrel until I find the sweet spot. That's where I solder it.
Tom you forgot that you do this at mid-night on Oct 31 ;D
Just a passing thought. I don't think I would SILVER SOLDER anything directly to the barrel. Requires to much heat...
Dave
I suspect he means soft silver bearing solder and not what I and others often call silver solder which I understand is properly called silver brazing and needs far higher temperatures than soft solder.
Dennis
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Acer needs a time out in the chair facing the back door of the classroom. ;D
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I now use Don's method with a small level. On a barrel with an octagonal section, I add a second step. I snap a chalkline down the middle of the barrel from the tang to my mark near the muzzle. The line should go right down the middle of the tang and octagonal section. I do this second step just to double check my work with the level.
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Flip the barrel up-side-down and place it on a flat surface (top flat on the tabletop). Place a file under the muzzle and move the barrel back & forth a few times. It will mark a centerline on the round muzzle in line with the top flat.
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I have a combination center punch-V block-level I bought from Frank Mittermeier in NYC years ago.
It wouldn't be hard to make one.
Bob Roller
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So, I like Dennis's idea. I'm trying that next. My question with the file or sand paper is after you mark the top dead center you have to tin over your mark. So now if I remark after I tin I cover that mark with the sight. So after all of that I still have to do it 3 times to get it straight. The mill is next. Bob
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Bob, would you send me a picture of that v-block jig? Thanks
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Long Ears,
I need an E mail address and I'll see if I can get a picture of this device.
It is an inverted "V" block with a level and a center punch thru the apex
of the "V". Not hard to make.
Bob
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Long Ears
That tool Bob has sound a lot like something I'm acquainted with as a tool for pipe fitters to find C/L of a pipe so they can apply fittings square (aligned) to each other. They should be available at any good welding supply house that also sells tools.
sweed ;)
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Plumber's 95-5 soft silver-bearing solder is perfect for this. Pick it up at any hardware store. You can't get lead solder anymore, but that would be fine, too.
Tin both sight and barrel separately as follows:
To 'tin' the barrel, first clean up the steel bright, then apply flux. Heat until solder just starts to melt. Take a small piece of steel wool with some flux in it, and rub the solder around to coat the steel evenly with solder. Apply heat sparingly, just to keep the solder melted.
Tin the bottom of the sight. Small part, watch your heat.
Then clean off both pieces, re-flux, clamp together and heat until solder melts.
You may bang some solder flat into ribbon, then clip some little pieces off and lay them in between sight and barrel. Then you will be able to have the perfect amount of solder without the great big globs to clean off.
Your enemy is too much heat, so heat just enough until the solder melts. More heat will just oxidize the steel, burn the flux, and prevent any flow from happening.
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To 'tin' the barrel, first clean up the steel bright, then apply flux. Heat until solder just starts to melt. Take a small piece of steel wool with some flux in it, and rub the solder around to coat the steel evenly with solder. Apply heat sparingly, just to keep the solder melted.
Tom any tips on keeping the solder from running onto the exposed area of the barrel? That's always been my problem, the cleanup is very time consuming! Especially if the the base of the sight has a lot of indentations.
Dennis
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Dennis, that's a good question.
You can tin the specific area that you want the solder to be. I've heard that rouge will prevent solder flowing.
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Thanks Gents, good ideas here and lots of industrious thinking. Not sure I will be doing this again, so buying a fixture is likely out. I like Kents idea, simple and effective for my needs.
Also...thanks for the helps on tinning the bbl and sight first, then joinging the two.
rick
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Silver Solder...
Nope, I am using the right stuff (from Log Cabin Shop) but wrong terminology!
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I think it is really important to get the underside of the sight to the same contour as the barrel. To do this I place my abrasive cloth or paper grit up over the end of the barrel, and rub the sight back and forth along it. This removes metal from the sight so that when finished, the two will be completely compatible. It is important to have a molecular joint of solder for maximum strength.
I also start with a polished barrel prior to sight and underlug attachment. I made several blocks of walnut with concave recesses that fit the barrel's shape(s), and polish lengthwise. After soldering sights and tenons, clean up is quick and easy, first with scrapers, and then repolish. Use cold blue on a q-tip to see if you've got all the solder off...you can't brown or blue over it.
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To 'tin' the barrel, first clean up the steel bright, then apply flux. Heat until solder just starts to melt. Take a small piece of steel wool with some flux in it, and rub the solder around to coat the steel evenly with solder. Apply heat sparingly, just to keep the solder melted.
Tom any tips on keeping the solder from running onto the exposed area of the barrel? That's always been my problem, the cleanup is very time consuming! Especially if the the base of the sight has a lot of indentations.
Dennis
I've read of others using graphite, i.e. defining the area for solder using a pencil. Apparently the solder won't stick to to the graphite-coated areas.
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Is there a tutorial on soldering? Duh, ask a moderator.
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Liquid Correction Fluid (White-out) works great for covering areas you do not want solder to stick to. It cleans up easily after your done soldering.
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Isn't the real question "where is top dead center of the bore at the muzzle" so that the round barrel may have the muzzle so marked for the front sight, then the mark transferred to the plug end so the plug may be fitted accordingly?
Lon
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A friend of mine uses a laser from the breech end, eye balls until it looks right. I haven't tried it yet but sounds okay.
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Find the top dead center using the upside down on a file method if the other end has a flat to work off of.
Make sure that top flat is really top center and square to the rifle. If not the front sight will be off as well using this method of plotting it out.
The bench/surface you're working off of must be flat and square also for the distance/length of the bbl. Any warpage and the sight will be off center. It only takes a few .000" to one side or the other to be noticable.
Much can be said for last minute eyeball lineup.
I contour the sight for a close fit to the bbl contour. A sweat (soft) soldered joint is very strong. But soft solder does't make a strong filler material as well. It's a weak joint if the fit of the parts is poor.
To make a clean job of it, tin the sight itself and let it cool. Then coat it with a minimum of flux material and clamp it into position onto the clean bbl. No tinning of the bbl is necessary.
When you're satisfied with the allaignment, wipe all around the sight & bbl to clean it of any flux that may have wandered onto the surfaces during the clampin. Then with a common pencil, softer the lead the easier to do,,scribble a coating of the graphite/lead pencil all over the sight and the surrounding bbl surfaces.
Now heat the assembly slowly till the solder melts and withdraw the heat.
Don't overheat it,,heat the bbl from the opposite side, Don't put the flame directly on the parts.
Go slow, you don't want or need to see any color change in the steel parts. If you do, you're burning the flux out and you might as well stop,,let it cool and start over by polishing the parts bright and re-tinning, ect.
Tweek the clamp a touch tighter if you dare just as the solder melts, but you're risking pushing the sight out of line in doing so.
A perfect fit of the parts and a wiped thin coating of tinning on the bottom side of the sight to start with will avoid any settling down of the sight once the solder melts, but you can be the judge.
I used to have a simple piece of flat stock with a sharp point cut on one end. The other was attached to a post so it could swivel. The post mounted on a base. The idea was to place the very point of the heavy bar on the top on the sight or other small object being soft soldered. It held it in position and it's weight also push it downward when the solder melted. The sharp point didn't draw any heat away from the parts during the operation. It's around here somewhere. I used it to mount an awful lot of sights, swivel, ect in years past.
Let the assembly cool on it's own.
Any solder that pushes out from the joint will not stick to the sight or bbl with the graphite coating.
It'll ball up and roll off.
There usually won't be any if the tinning process was done w/o excess.
With perfectly fitted parts and absolutely clean metal,,a perfect solder joint can be had w/o having to tin both surfaces. It saves clean-up and avoids loosing track of any center line point you've already established.
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Many thanks to Mr. Kutter for another very fine, easily understandable process description. SHould have the barrel ready to attach the sight to by the weekend.
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I was able to get the new brass front sight on as well as the underlug for the front swivel.
Went much easier that expected, thanks for the good ideas and instructions.
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Another example of the forum working!
Now that the problem is solved, I will ask another question. How often on originals is the front sight attached by soldering or brazing or any other method that involves it sitting atop the barrel? On some or many originals I have seen the front sight is like a raised inlay. Same as decorative bands at the breech etc, a slot is engraved then it is set into place. In other words even if the sight has a base in addition to a blade, all is flush with the barrel except the blade.
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While we are discussing soldered on front sights. I would like to know if any of you have done an inlayed spider front sight, like is seen on some chiefs grade trade guns, and even some high end dueling pistols?
Hungry Horse
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I used to have a simple piece of flat stock with a sharp point cut on one end. The other was attached to a post so it could swivel. The post mounted on a base. The idea was to place the very point of the heavy bar on the top on the sight or other small object being soft soldered. It held it in position and it's weight also push it downward when the solder melted. The sharp point didn't draw any heat away from the parts during the operation. It's around here somewhere. I used it to mount an awful lot of sights, swivel, ect in years past.
I have a piece of steel lumber strapping that I picked out of Lowe's trash barrel. Its maybe 18 inches long with a 90 degree bend in one end about an inch from the end. I cut a shallow vee notch on the bottom end of the 1 inch piece. I use a clamp to hold the other end of the strap to the barrel with the 90 degree bend/notch holding down fowler barrel tenons or sights that I am soft soldering to the barrel. The steel strap has enough spring to it to keep a downward force on the tenon/sight so that when the solder melts it will press the metal tenon/sight closer to the barrel. I have used it on Oct to round with the strap clamped to the oct flat and also have used it on a round barrel but put a piece of thin plastic under it to keep it from sliding around on the round barrel. Works for me.
Dennis
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This post is exactly what I've been looking for. I've been practicing soldering on scrap stuff and I definitely need to fine tune my technique.
But I'm still uncertain. With such a small amount of solder, I can't really see when it reaches its melting point. I must be using too much heat. I'm wrapping a piece of wire around the 2 parts to hold them together. So if it's not a good idea to put the flame directly on the joint, do you heat the barrel only, letting the heat run to the smaller part? And should I just let it cool on it's own, no wipedown with a wet rag to cool it?
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I heat the barrel some and apply flux. Then I continue to heat slowly. I swirl the flame at the area that needs the soldier. I check the heat on the barrel by removing the flame and applying the soldier directly to the barrel. If it melts and stays and doesn't slide off your at temp. Try to hold that heat while you spread a very thin coat of soldier in the area you need with a fine wire brush or steel wool. This will "tin" the area needed. Do the same to the sight. When both are tinned place flux back on the tinned spot of the barrel, clamp the sight in the desired location and heat slowly. Again checking heat by dabbing soldier at the base of the sight without flame. The second it melts stop. Let cool and hope its straight. This works great for me and I'm probably 50% on being straight on the first try. Bob
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I use an old roll of acid core solder that my dad had for years. He died in 1994 at the age of 85 and he had that roll for years prior to his death so you know about how old it is. It is the large diameter solder with the acid flux center. He also had a can of flux that look's like axle grease, brand has long sense worn off. I cut a small piece of the solder and flatten it on the anvil with a small ball peen hammer. I use a piece of 120 grit sand paper and sand the bottom of the tennon and the barrel where the base is to go. I then smear some of the flux on the barrel and some on the tennon base. You only need a small piece of solder, I cut mine so it just covers the mid part of the solder joint. I then sandwich the flatten solder between the barrel and the tenon and use my home made spring clamp to put pressure on the tennon. I then use my torch on the bottom/side of the barrel. I watch the tennon and as soon as I see the tennon drop down against the barrel I know the solder just melted and I take the torch away and let cool. I use a file to clean up the little bit (if any) surplus solder. I understand you can trace around the base with a lead pencil and this will keep the excess solder from sticking but I always forget to try it. I have never had a tenon solder this way to come lose, seems extremely strong.
Dennis
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I use my Golden Mean caliper. Pace it off just the right amount from the muzzle, then walk it around the barrel until I find the sweet spot. That's where I solder it.
Lol
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Dennis, To keep the solder from running down the barrel, I made a clamp out of about a foot of spring steel with a 90 degree angle on the end with a notch filed in it. I center the sight after tinning, place the notch over the sight, clamp the other end to the barrel, and turn the whole thing over to the bottom. If solder runs, it runs down the sight not the barrel. It shouldn't run unless you use too much solder.
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Just a passing thought. I don't think I would SILVER SOLDER anything directly to the barrel. Requires to much heat...
Dave
Lots and lots of modern guns have silver brazed front sights.
Dan
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Dennis, To keep the solder from running down the barrel, I made a clamp out of about a foot of spring steel with a 90 degree angle on the end with a notch filed in it. I center the sight after tinning, place the notch over the sight, clamp the other end to the barrel, and turn the whole thing over to the bottom. If solder runs, it runs down the sight not the barrel. It shouldn't run unless you use too much solder.
Nate,
I use a similiar spring clamp I made out of an piece of steel lumber banding. Never thought about turning it over, will have to try that. Thanks
Dennis