Underrib Soldering

mooncoon

mooncoon

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I soldered an underrib on a fowler yesterday and thought people might be interested in the clamps that I used. Perhaps worth mentioning that I did not want to add solder from the outside edge because it is a pain to remove the excess later. Instead I tinned the inside of the underrib and the bottom of the barrel where the rib used to sit and left extra solder on the bottom of the barrel. First try, I secured the rib with wire which I twisted tighter when the solder was molten. That does not work because it usually does not put enough pressure on the rib during soldering.
I made 3 donut shaped C clamps and used those to push down on the rib as the solder softened and the rib was able to move down closer to the barrel. I used large washers on the redi rod screw portion to function as finger tabs. Although I only used the washers because it was convenient, they had the unintentional benefit that I could hold the body of the clamp with pliers and turn the screw with a large nail through the washer --- think no burned fingers. The clamps are crude and homely looking but they work. Essentially a variation of the home made C clamps that I have used on installing ribs on double barrels.
Almost forgot; despite my best efforts, the screws initially did not point exactly to the center of the opposite side of the clamp and by using a slightly open C I was able to bend the C a small amount to line things up

cheers mooncoon





 
The idea of a deliberately springy clamp for such things is a really good one. Filed away for if I need to do anything like this.

That same style of sprung clamp could also be made using slices of heavy wall tubing with a cut away section to open the pipe up to a "C" shape. I'd suggest it would be faster and easier than forming those C's from square bar like you've done. The spring movement would be more obvious at the sort of pressure levels needed for this sort of work as well.
 
To BC Rider; the clamps are not springy; the body of the clamp is 1/2" square stock. I suppose one could make up clamps with a coil spring on top of the clamp pushing a plunger down and if doing a lot of barrels it would probably justify the extra work. The coil spring would have to be above the clamp because the risk of overheating it if it was between the clamp and the barrel. In the photo of the double barrel clamps I think I will make a fourth and perhaps even a fifth clamp so that I don't have to move the clamps as I work down the rib. It is important to use a brass tip between the screw and the rib to avoid scratching the upper rib particularly. I think I will probably use fired 9mm shells as protective pads. Also I intend to upgrade the screws on the double barrel clamp to 1/4" redi rod. The washer screw "wings" turned out to be a pleasant surprise in how easy it made it to tighten the clamps.
In the past, seemingly knowledge able people have claimed (to me) to use various types of wedges under encircling wire loops and drive the wedges tighter as the solder melts. I tried a couple of variations of that and had trouble with the wire slipping and just being awkward to do. I have soldered 4 sets of double barrels now, the last two with the clamps and they definitely have been an improvement.

cheers mooncoon
 
The brass casings as pads is a slick idea!

I didn't figure that the square section would be all that springy. But it seems like some springiness for this application might be a nice idea so the solder line is pushed thinner as the tinning layers melt. The idea of making these from a thinner and therefore more springy metal is why I was thinking of the thinner pipe for the C's.

Or am I missing something in the process which would make a springier version less useful?
 
BCRider said:
am I missing something in the process which would make a springier version less useful?
Click to expand...

I think spring loaded would definitely be an advantage as long as the spring pushed straight down. Main reason that I chose 1/2" square stock was to have material thick enough for a 1/4" screw to go through. Based on having made a number of lock mainsprings, I think that a U shape made from drill rod and flattened to be maybe 3/8" wide and .070" thick would create about the right amount of spring. Alternately a U shaped bottom arm with wings to the side and a top bare with the screw through it and a tension spring on either side would work well but both would take a lot of work and be hard to justify unless a person was soldering quite a few under ribs every day

Just to put some perspective on a U shaped flat spring; most mainsprings are around .1" at the bend and taper to about .070" where they press on the tumbler. You would probably want something a bit weaker than a lock mainspring

cheers mooncoon
 
Mooncannon: That is a pretty innovative way to solder an underrib. Did you fabricate the rib as well or did you have to buy one? The reason I ask is that I have a Bobwhite CZ that needs a rib repair but the rib was ripped off halfway down and I don't have a rib or no where I can get a rib to solder on. I was going to use the wire/wedge technique to solder on the rib and just scrape off the excess solder with a file before re-bluing but your way may be better.
 
the one in the photo was one the gun but was loose. I have made one under rib and they are a tremendous amount of work even thought they look pretty simple and basic. I started with 5/16" square stock if memory is correct and am not completely sure how I started the concave surface closest to the ramrod. I made have milled a narrow cut first or perhaps ground it with a handheld angle grinder and then finished with a rat tail file. I did not have and / or chose not to make a round nose milling cutter at the time and am not sure if I had even bought my milling machine then. The sides of a under rib are tapered and not perpendicular and that was all filed to shape. I think I must have ground or milled a slot down the side closest to the barrel and then filed that concave with a rat tail file as well.

While on the subject, the biggest problem with tinning the surfaces to be soldered is that the metal of both barrel and under rib is almost always pitted and often the pits are too deep to completely remove. That leaves little gaps in the tinning and also forces me to wipe the solder on with fluxed steel wool in order to get as much as possible of the metal tinned.

I have not had much luck with resin type soldering flux so use the corrosive kind. On the rib in the photo, I left the ends open and then after soldering ran hot tap water down the channel to remove as much of the corrosive flux as possible, followed by drying with a heat gun. The barrel should not be attacked by the flux because in effect it is galvanized with lead as opposed to zinc. More or less the same thing applies to the inside of the under rib. When I am sure that the interior area is completely dry, I will fill the open ends with a small amount of solder. Strictly speaking I should solder in a small iron plug but I am lazy.

I use soft lead or tin solder and it seems to work well.

cheers mooncoon
 
Glock4ever said:
solder on the rib and just scrape off the excess solder with a file before re-bluing but your way may be better.
Click to expand...

I did make a sort of 45 degree pointed scraper using drill rod to scrape solder away from close to the rib / barrel seam. an L shaped tool with a sharp point for the spots where it is hard to file. Also have taken a triangular file and ground the sides and top to make in effect a short flat file with about 3/4" of cutting surface then bent the file into a stretched out Z shape for easier holding and obviously retempered the cutting area

cheers mooncoon
 
Thanks for the information. With so many commitments to work and the "honey-do" list, I am not certain when I will be able to do this project but if I do it soon I will put up some pics. As for scraping the excess, I will try using the needle files that I have - they are made for models so they should be able to reach into the rib/barrel but if I have to craft something, I will take your advice on the L-shaped tool. I was really hoping somebody knew where I could get a rib as I don't want to have to fabricate a rib...
 
these are some of the crude scrapers that I have made for various projects. The pointed one is similar to the barrel channel scrapers except that it comes to a roughly 45 degree point, The other tools picture are goose neck chisels which make working in barrel channels and lock recesses much easier. In both cases use old chain saw files or drill rod, heat red hot and forge to shape then harden in water and draw to about dark brown. The tools look very crude and homely but they take relatively little time to make and make a job much easier

cheers mooncoon



 
And not only will the scrapers not get loaded up by the solder but you can make them out of mild enough steel that they will scrape the solder away and not scratch the steel of the rib or barrel. Scrapers don't need to be file hard. The idea is to use what is appropriate to the job.
 
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