We have several ways here in the shop to tighten actions. In the past I put up a pictorial of replacing the hinge pin. In a search for additional methods of invisible repair we have developed the following process which is applicable to most barrel types, though not chopper lump barrels. We begin the process by carefully measuring both the gun and the barrels using both micrometers and an optical comparator. Once we know the location of the hook and how much material needs to be added we have the hook welded shut. While I can TIG weld moderately well, I contract this part out to an expert welder. We then cut the hook in it's new location and hand fit the final couple of thousandths of an inch using the traditional smoke and fit method. The result is a completely invisible repair and one that gives excellent contact between the hook and the hinge pin.
Steve, I'm a little confused. How does your method differ from the common repair of tig welding the hook and refitting it?
we use a cnc machine to re-cut the hook and match the proper radius. I do not believe anyone else is doing this. Most are using just smoke and fit to get the hook fit.
I've been doing this for several years now on a regular vertical mill equipped with a DRO, and I posted a pic collage on the Fox site as well as here a while back. It is an excellent method. Your holding fixture is similar to mine although I can use a shorter end mill, and mine doesn't use a jack screw that can mar the side of the hook. My fixture sits on parallels in the machine vice same as yours but is longer to help support the weight of the barrels. More info for readers... I don't do it commercially. Frank Silvers
I just searched the Fox Collectors website for you collage of photos on the method you developed to weld a hook, but did not find it. Would you be so kind as to post a link to it?
the jack screw does not mar the surface when a thin strip of copper is placed between it and the lug. I have done it on a regular mill as well, but you can not match the radius of the hook with a standard mill unless the pin just so happens to be the same size as one of your endmills.
Steve, Dennis Potter teaches a similar method in his NRA summer class at Trinidad State JR collage. Dennis uses a mill with a boring bar to get close to the correct diameter. Then smoke fit the final fitting.
Does anyone refit the circle joint?
It's easy to match the radius of the hinge pin when recutting the welded hook, through use of an end mill ground to size. I've done quite a few Foxes using this technique along with Ithacas and even a SAC which was challenging because it had a tapered hinge pin.
Bushveld, most of my 'smithing posts on the Fox site are on the private Members Forum and they won't come up using the search function for anyone who isn't an annual/life member and has access enabled. The latest post I did on this is dated 2/7/12 and it's there in the Fox Members Forum along with descriptive text but the pics are missing due a problem with Photobucket.
Here are two salvaged pics showing a Fox hook after welding, and after the hook was recut to within 1-2 thou overlength, and before the spot & fit to the frame. Weld was done by a welding tech and is 100% with no dark spots/voids showing after the machining. Also, note how little "heat" propagated onto the hook. Frank Silvers
more than one way to skin a cat.....
Interesting stuff, guys. Thanks.
Krieghoff at Ottsville does that procedure on the trunnion recesses of the K-32 and the K--80. I have seen the setup. I have no idea why they don't just use oversize trunnions, but I guess they want to return the gun to its original dimensions.
Steve & Frank, thanks for sharing. Interesting method. I have a question, what advantage does your method have over a method such as precision laser welding the hook? It seems to me that as much tig welding that is going on in your method you are running the risk of excessive heat transfer from that lump to the braze or solder, possibly causing something to come loose. You're right, theres more than one way to skin a cat, both of your methods seem to be overkill. Does it take you the same amount of time doing this method compared to how you used to do it? Are the results that much better? Thanks.
When answering LeFusil, could you also address the advantage of this method over replacing the hingepin?
If I may,
It decreases the amount of file time.
It accommodates less than parallel file strokes.
Welding up the hook can be outsourced.
No reason to make reamers or engrave a replacement pin.
Time is after all, money.
Rejointing costs 2x as much here as in Britain, where it's done all the time.
Replacing a pin is not even in my vocabulary. With a Parker it is impossible, there is no "pin". With guns with flush mounted pins, it is a nightmare. Working on the hook is the only way.
I find this to be the most seemless, evidence free method of repair that I have used to date. I get excellent contact and the mill cuts straighter than I can file. It does not get near hot enough to compromise a silver solder joint. This method takes more time to layout and set up and less file time. Overall it is more costly, it does take a bit longer and I have increased costs for the welding and shipping, but I feel the final product is worth it.
this method vs replacing the pin is dependent upon the gun. I will usually build a new pin given that option. Just my opinion, but I feel if it is a good gun and it was designed to have a replaceable pin, that is the way to go. Others will disagree.
Parkers.....I'm getting to that. Soon I will be making new knuckles just the way the Brothers P went about tighten up one of their guns.
Well, Steve, if you can build a good replacement Parker knuckle you'll find yourself with too much business to do any other gunsmithing.
Like everything else, it is hard to get the time to work out the process. We are building a new cocking hooking for a 2 barrel set DHE now. The clients needs forced me to take on the job. The engineering aspect of it usually takes as long or longer than the actual building of the part. Were some one to need a new knuckle....I'll build it.
You need a lazer wielder like we use in jewelry to keep from heating up the barrel.I have asked around and ours are not big enough to wield that big a spot.
So far from what I have seen, a laser welder is the wrong tool for the job. This requires penetration and if you are going to machine the surface again I really do not see any advantage at all to a laser. Tig is the way to go.
No disrespect meant Steve, but Ken Eversull who uses a laser weld, and Abe Chaber who says replacing the hinge pin is the only proper way to go, would disagree with you on the best way to put a gun back on face. Frankly, I'm confused as to the BEST way to do this as there are so many different opinions regarding this matter. I think the cheapest way to do it would be to tig weld and most expensive would be to replace hinge pin, but I'm not even sure about that.
as I understand it Ken uses a spray welding technique and has excellent results with it. Spray welding is not laser welding. I have stated that this is one way to do the job, not the only or the best way. I also replace pins and would usually choose to do so before welding the hook. Lots of ways to get it done. Which one is best? That remains to be seen, but I feel very confident in offering this as one of the methods we use in this shop to get the job done properly.
The best way is the way that is both most efficient and economic . It will also depend on the gun and how much work will be needed to do the job correctly and permanently .
There is no best way just that some methods better than others and some merely bodge jobs temporary to say the least.
I do not know how many guns I have rejointed but it must run into hundreds ,it sometimes seems that you spend longer deciding which way to do the job than you take doing it .
Thanks for sharing Steve. The jig is impressive. What about soldering on a steel shim? Is there a downside? I've never done it, but it seems like it would work fine with high force solder. Just curious.
Eversull uses a very expensive laser welder. No spray welding in his shop. Alot of high end gunmakers, here and overseas have bought into the laser welding method. I had a Brit gun put back on the face last year using this method, even under a jewelers loup you cannot tell there was any work done at all. There is a gentleman in Michigan that laser welds for the trade. Next to Eversull, he's the best in the business. Extremely precise work.
interesting, but I have had issues with laser welded filler bonding to the parent metal the one time I contracted out the work. Lots of ways to do things. I'm happy with my methods and I have heard nothing but good things about Kens method. The final result and a happy customer is all that counts.
This is an interesting subject Steve, and your procedure looks great to me. I am confused and I hope you can explain why your procedure is unsatisfactory for chopper lump barrels? I know the laser procedure is used on chopper lump barrels because Ken Eversull rejointed a gun with choppers for me by that procedure.
chopper lump barrels are joined using high temp silver solder. The silver solder will act as a contaminant when the TIG welder goes add his filler rod and it usually results in porosity in the weld
Funny how snarky comments to others' posts kills interest in posting here.
I didn't see any bragging in this thread. But in Texas they say if it is true it ain't bragging.
Neat! Thanks for sharing.
Yes, the "story" is out there and heard by many of the spray welded hook where the piece of weld "just fell off" I don't remember where I heard it a long time ago. Just a "good story" about bad technique.
I have TIG welded hooks on chopper lunp barrels that are silver brazed with no problem. I won't say all, but some. Now not all chopper barrels are silver brazed, those that have brazed ribs probably are not silver brazed, but either copper or brass brazed to allow the heat req'd for silver soldering the ribs. That is a nice and informative thread you posted. Keep in touch.
Why not cut a dovetail in the hook and silver solder in a new bearing surface? I think that English gunsmiths have been doing so for 160 years. But, what do I know?
Dovetailing also known a piecing the hook works but it makes a weak spot at the bottom corner of the dovetail. I have seen cracks at this point. If they had TIG 160 years ago they would have never dovetailed.
Just my opinion