Soldered sight fell off

[lexington1]

I wasn't sure if this was the right forum, but here goes. I have an original that had a soldered sight. Out of the blue one day it fell off! I don't really want to take a chance on screwing up the finish or patina as the sight and barrel are both a brown color and I think it would be really difficult to match up if I soldered the sight back on. Any suggestions? I thought about just gluing it back on, as I have no plans of ever shooting it, but I guess I'm fishing for ideas, tips, and suggestions.

[Dave B]

I am assuming the sight is just a blade? Some are barley corn style and made from one piece. If its soldered right to the barrel it is possible to re-apply the sight much like re-soldering old shot gun barrels using the tinning of the loose part then using a slug of copper (soldering copper turned to bore size) to put into the barrel to heat the base metal having cleaned its surface and fluxed. It will re-bond the sight being held in position with a spring tension jig. Great care will need to be used not to over heat things and make a mess. soap stone rubbed around the bonding area will help contain the solder to where it needs to stay. I think JerryH uses white out painted around the area masking off where you dont need solder. I have not tried this yet but it seems simple enough.

[JTR]

I'd pin it back on.
If the sight blade is wide enough, I'd drill a couple small holes; 1/16" or smaller, in the bottom of the blade and corresponding holes in the barrel. Equally spaced of course. Leave the holes rough inside the sight blade and barrel, to give it some teeth.
For pins, soft silver wire would work nicely. Rough up the outside of the wire, to give it some teeth. Obviously the wire needs to be a snug fit on the holes.
To reconnect the sight back to the barrel, you can either cut the wire a bit longer than the depth of the holes, place the sight on the barrel with the wire entered into both sets of holes, then tap the sight blade down onto the barrel, expanding the wires into the holes to hold it in place.
Or, if your not comfortable tapping on the sight, put a bit of epoxy glue in all the holes with the wires, get the sight in place, and clamp it til the glue is hard. The teeth on the wire and in the holes will make it near impossible to come apart.
If you drill the holes a tiny bit off parallel, fore and aft, so you sort of have to wiggle the sight back onto the barrel, that'll guarantee it'll never come off!   
John

[lexington1]

That's a good idea John. I think it would work great for this application. I like your idea too Dave. Thanks for the tips!

[JCKelly]

Somewhere in basement I have some VERY low melting-temperature solder. Don't recall name just that it was very small wires. Amazon now sells some 55.5% Bismuth (Bi), 44.5% lead (Pb) solder which melts at 255F

https://www.amazon.com/gp/offer-listing/B07BBJFD7W/ref=dp_olp_0?ie=UTF8&condition=all&qid=1566166998&sr=8-11

My solder was made before we all became terrified of lead, probably contained bismuth & who knows what else.

Yeah, I gotta find and use it soon to put the front sight back on a rifle I made in the early 1970's.
Likewise do not wish to damage my fine old brown job, made with that nasty mercury containing brown solution Mr Cash used to sell. Did a great job if you didn't mind the health risk.
Gonna give this rifle to my quasi-stepson, with the (Douglas) barrel plugged so he can't remove any hand parts with it. Rifle does look pretty on the wall.

[Craig Wilcox]

JC, Brownell's has TIX solder, melts at 275 deg.  I have used a match to melt it.  #030-001-125WB.

I also use Hi Force 44, melting point of 475 deg.  VERY strong.  #080-649-250WB

If your front lug is soldered on, wrap some iron wire around it while you solder the sight.

[JCKelly]

Yes Craig, TIX is what I have used. I might use two different melting point solders if making subsequent joints to prevent melting the first one.

[WadePatton]

If you solder, and I don't think I would, it's the flux that'll ruin patina as it cleans when it gets up to temp. That's why the comments about containing the flux and solder.