Author Topic: Soldering problem (Read 4050 times)

LynnC · « **on:** January 27, 2020, 01:59:40 AM »

Im trying to solder a brass sight onto a Wrought Iron fowler barrel. Everything filed bright and absolutely clean. Thin film of paste flux applied to mating surfaces and a tiny thin sliver of solder placed between sight and barrel. I hold sight down with a thin blade and apply heat from underside of barrel. When solder flows and bead shows I remove heat and let cool.

Solder covers bottom of sight. None sticks to barrel.....

This works for me on thin steel barrels for sights and lugs. What am i doing wrong?

Clark Badgett · « **Reply #1 on:** January 27, 2020, 02:45:23 AM »

Welcome to the Club de Solder Woes. I'm running about 25% success rate on my solder attempts.

longcruise · « **Reply #2 on:** January 27, 2020, 03:55:48 AM »

I don't know much about the science and technology of soldering, but I have my best success using the paste solder with no flux other than what's in the paste.

smallpatch · « **Reply #3 on:** January 27, 2020, 04:11:56 AM »

I second what longcruise said.

LynnC · « **Reply #4 on:** January 27, 2020, 04:24:56 AM »

thanks for the commiseration.....I will say when I filed the barrel it looked like cast iron. The carbon inclusions.

In 30 years Ive bored, reamed, rifled, fitted plugs, cut dovetails in Wrought Iron barrels. But this is the first time i ever tried to solder a sight to it!

Im stumped.....

Clark Badgett · « **Reply #5 on:** January 27, 2020, 04:26:54 AM »

I used that solder paste on my trade gun build. The sight held tight but both pin lugs popped loos after a year. I experiment a bit trying to get the knack of soldering and so far it's frustration.

Goo · « **Reply #6 on:** January 27, 2020, 04:48:30 AM »

Some words to remember if you want to solder on steel. Zinc Chloride & 50/50 lead tin mix solder. Tin first and don't over heat it. You will have success

LynnC · « **Reply #7 on:** January 27, 2020, 05:16:48 AM »

Thanks guys but this is a wrought iron barrel. I reckon its the first time i ever tried to solder something to one.

Im sure the antique gun restorers have run into this many a time.....

Stophel · « **Reply #8 on:** January 27, 2020, 05:23:15 AM »

You only got the sight hot enough to melt the solder. The barrel wasn't hot enough.

Tin both surfaces individually, then put them together.

LynnC · « **Reply #9 on:** January 27, 2020, 05:32:15 AM »

I heated from under the barrel holding the sight down on top till the solder flowed. Tried twice. Filed all clean. It just didn't stick to the bbl. It did stick to the eight base fine

I can try tinning barrel and see if that works. Thanks

Stophel · « **Reply #10 on:** January 27, 2020, 05:51:23 AM »

If the surface of the metal gets any oxide/blueing, the solder will NEVER stick. You have to be pretty careful, keep the flux on it, and keep the color off, and get the solder to flow and stick.

LynnC · « **Reply #11 on:** January 27, 2020, 06:30:17 AM »

Perhaps i overheated...

Stophel · « **Reply #12 on:** January 27, 2020, 06:47:40 AM »

It's VERY easy to overheat. I am not the neatest solderer, but I can get a good bond, after a fashion. I will often have to brush it off with a wire brush and work with it to get it to flow and stick good.

Wingshot · « **Reply #13 on:** January 27, 2020, 08:07:52 AM »

Quote from: Stophel on January 27, 2020, 05:23:15 AM

You only got the sight hot enough to melt the solder. The barrel wasn't hot enough.

Tin both surfaces individually, then put them together.

I’m a plumber and I’ve often soldered dis-similar metals and the above advice is correct.

Clark Badgett · « **Reply #14 on:** January 27, 2020, 08:12:46 AM »

If I'm soldering, it probably on a round surface. I can manage to get the sight or lug tinned, but every time I've tried to tin the barrel it has rolled right off onto the garage floor. What is the trick to tinning the round surface?

Stophel · « **Reply #15 on:** January 27, 2020, 08:28:23 AM »

No trick. If it doesn't stick, it's because it's not hot enough, or oxidized/blued, or not enough flux. Keep the metal clean, keep it fluxed, keep if from turning color, and keep touching your solder to it, and when it gets hot enough, the solder will melt and stick right to it. Avoid letting your torch blow around the barrel, as that will melt the solder, often even before it touches the barrel. That's what makes it roll off.

There is a solder-stop material that you can paint on around the area that you don't want solder to stick, though I've never used it, though it would be a good idea. I've just always cleaned/filed/sanded off the excess.

LynnC · « **Reply #16 on:** January 27, 2020, 08:59:42 AM »

I appreciate all the advise. Im likely out of practice as i rarely have need to solder anything.

I’ll regroup and try again in the am. Thanks.....Lynn

577SXS · « **Reply #17 on:** January 27, 2020, 03:07:29 PM »

Use a good acid flux and tin both parts first.

Metalshaper · « **Reply #18 on:** January 27, 2020, 07:24:05 PM »

for all the more experienced guys??? would a 'pickle' of 10% hydrochloric acid help to break the surface of the wrought?

asking cuz an old welder/brazing guy once told me to pickle an iron part if I encountered difficulty in soldering!
Just wondering what you guys would say??

trying to learn and learn!

Respect Always
Metalshaper/Jonathan

smokepole45cal · « **Reply #19 on:** January 27, 2020, 08:15:38 PM »

Exact same problem 2 months ago with underlugs! I was using Brownells low temp silver solder and tinning on practice scrap barrel pieces...not the same as a 42 inch barrel.

Mass (a lot of steel to preheat in your barrel) vs. a tiny piece of front sight and thermodynamics are fighting against you. Next time I do it I am sanding clean my mating surfaces, slowly pre-heating my barrel on coals or hot plates then torching slowly under my targeted area just before tinning and melting the solder in place.

Good luck.

Craig Wilcox · « **Reply #20 on:** January 27, 2020, 08:39:38 PM »

You can use the graphite from a "lead" pencil to keep solder from sticking where you don't want it to. Also, while it is still hot, wipe it with a cloth rag to remove over flow solder.

The guys above are right - the barrel isn't hot enough at the spot being tinned or soldered. When you use the flame on the bottom of the barrel, it - the flame - will wrap around and melt the solder - but the barrel is not yet hot enough for solder to adhere. Takes a lot of patience, for sure, but tinning both sides of the joint will help a bunch.

D. Taylor Sapergia · « **Reply #21 on:** January 27, 2020, 08:41:53 PM »

For non-ferrous metals, paste flux works well, but for steel and iron, you need an acid flux. I don't know what acid it is though. sorry.

LynnC · « **Reply #22 on:** January 27, 2020, 08:53:08 PM »

You guys recommending acid flux are right. Ive been reading all i can find on the net and for wrought iron, acid flux is called for.

The barrel wall is about .080” out at the muzzle

All have given good advise. I’ll change my flux and try tinning the bbl.

Thanks.....Lynn

msellers · « **Reply #23 on:** January 27, 2020, 10:29:17 PM »

Rosin flux is for non ferrous metals, and electrical almost exclusively. Even copper plumbing is usually an acid flux from my limited experience also.
Mike

JCKelly · « **Reply #24 on:** January 27, 2020, 11:32:56 PM »

Yep, listen to Goo, Stophel &c
Acid flux. No I don't know which "acid" is used, but just fer I have soldered 18% chromium -nickel-silicon-aluminum high temperature alloy with acid flux & common lead-tin solder.
I am not a genius in the workshop but as an engineer/metallurgist I know something about soldering & brazing. Been messin' with this stuff over half century now.
It really is easy. In truly Ancient Times when everything did not come in a pretty plastic container (Ike was President) we used ammonium chloride. In our small town truly antiquated (we didn' think so) school shop. Yeah, we actually went out & bought plain ol' ammonium chloride.
Strength. Well, its My Nickel right now so you get a free lecture. Yeah, different grades of solder or braze metal have different strengths. Remember, though, what you care about is strength of the joint. Huh? Ain't it the same thing? Nope. Lead-tin solder is pretty soft stuff but the joint itself can be stronger. No I no longer remember how to explain it. But the joint needs to be thin, the two pieces of steel/brass/silver/whatever need to fit closely together. The thinner that layer of solder the stronger the joint (within reason, I guess)
As to my front sight to barrel joints, yeah they tend to break in the solder when, ahh . . . abused. Doubt that I made the joint thin enough.

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Author Topic: Soldering problem (Read 4050 times)

smokepole45cal