Soldering questions.

[Rt5403]

So I have a Jim Chambers New England Fowler kit. The barrel is supposed to arrive in a few weeks. It's an octagon to round barrel. I have some questions about the lugs and sight. So first of all Mapp gas or propane or does it matter on torches? And what would be the best solder to use for this application? Any help would be appreciated. Thank you folks.

[jm190]

Hi Rt5403,
   If you enter "solder" into the search function and then choose only the "Gun Building" forum  to search you'll find everything you need. I dare say you'll find so much info your head will spin after awhile. Lots of good recommendations and lots of varying opinions.

John

[fahnenschmied]

Mapp or Propane, either will work fine.  Its best to tin your lug and the spot on the barrel first.  A lead blend solder will flow better than lead free.  Position your tinned lug or sight on your tinned spot, and heat the barrel from underneath till it settles down. Prod it into place, maybe add a bit of solder if you feel like it.

[flehto]

I've used low temp  solder paste w/ excellent results...used it for bbl lugs and attaching hinge plates to the lids. For RR pipes I use high temp silver solder to fill the  inside groove so the tab is only 1/2" long......Fred

[BJH]

Maybe I like to do things the hard way. I use common plumbing solder, rosin core. With rosin flux. Either lead base or tin/ silver base. Never had any problem that weren’t prep related. Cleanliness is imperative, freshly sanded or filed surfaces an no fingerprints. Really can’t be hard if I can do it. BJH

[Daryl]

Maybe I like to do things the hard way. I use common plumbing solder, rosin core. With rosin flux. Either lead base or tin/ silver base. Never had any problem that weren’t prep related. Cleanliness is imperative, freshly sanded or filed surfaces an no fingerprints. Really can’t be hard if I can do it. BJH

You hit the nail on the head!!!

[Joe Stein]

First place your parts where you want them and mark their edges all around, then with a pencil rub the area outside where you are going to solder to coat it with pencil lead. This will prevent any solder that runs out from between the parts from sticking to the barrel. You can also paint that area with correction fluid as an alternative.

[Bob Roller]

I was on a forum that had a man that claimed if it was reaaaaly clean, that an ice cube could,according to his father be soldered to Teflon .It' been over 40 years since I soldered anything so this silly joke is all I have,
Bob Roller

[smylee grouch]

Some people will use a higher heat solder for the lugs then use a lower heat solder for the front sight.

[Rt5403]

That was going to be my next question. What's the best way to keep lug solder joints from coming loose when I heat to put on the sight?

[smylee grouch]

Wire wrap or clamp works for some.

[smart dog]

Wire wrap or clamp works for some.

Hi,
They won't come loose unless your front sight is directly over a lug.  If you are heating a barrel sufficiently hot to loosen previously soldered lugs, you are really heating it too much.

dave

[Rt5403]

Thank you.

[bama]

Really clean surfaces are a must. A good flux is a must. A good fit between the two surfaces is a must. Not overheating is a must. The solder joint will not join together properly if all the above are not done correctly.

Things to remember: solder is not a gap filler, the tighter the fit the stronger the joint.

You only need to tin one surface, be it the lug or the barrel, I usually just tin the lug.

Flux the joint surfaces very well.

I use soft iron wire to hold the lug to the barrel.

Heat the barrel slowly from underneath the the lug position until you see the solder joint start to melt, immediately take the heat source away. Over heating the joint causes most failures in soldering.

Remove wire and clean up as required.

When I am soldering two joints that are close together I will wire both pieces to hold them in place or wrap the completed joint with a damp paper towel, this will keep the completed joint from getting hot enough to keep it from coming apart.

[Daryl]

Dad always told us that the strongest bond was a 1 mil bond. That 1 mil. bond is a .001" fit.

[J. Talbert]

My choice for lug of a sight is Paste Solder (or as I call it -soldering for dummies).  Flux is already in it and there’s no tinning.
Clean the surfaces,  apply small amount to lug or sight, clamp or wire in place, apply heat to barrel until solder flows.

I use Swif 95.  I don’t know if it’s still available, but there are other similar products.

Jeff

[Ric Carter]

That was going to be my next question. What's the best way to keep lug solder joints from coming loose when I heat to put on the sight?

I use a dripping wet sponge wired loosely around the bottom lug.

[P.W.Berkuta]

I will use 50/50 plumbers solder with an acid flux or Stay-Brite with Stay-Brite flux. The things to keep in mind is have the parts clean, flux and tin the parts, flux the surfaces of the parts, wire or clamp in place and don't over heat and burn the flux or you will have to start over. I will start to warm up the barrel/parts all over the area then I will move the torch to either side of the joint and play the flame around the area until the solder starts to flow then there should be enough heat in the parts to complete the joining of the two - again don't over heat the joint and burn the flux out.

[tlallijr]

I like the “solder it” paste its the easiest method.

https://www.tractorsupply.com/tsc/product/solder-it-silver-bearing-solder-paste-with-flux-sp-7-1710628?cm_mmc=feed-_-GoogleShopping-_-Product-_-1710628&gclid=CjwKCAiAqIKNBhAIEiwAu_ZLDlZ4lLiUhb3jZUU6ufqTvrED-gWdjuhgpnqzmob39TnPVVFDGX1-DRoCEbgQAvD_BwE