Welding, soldering or brazing a bung to brass radiator tank

[FOMOGO]

On brass you would be fine using regular plumbing lead free solder and paste flux, though 50/50 would be a little easier if you could find any. Make your fit up as tight as you can get it, and clamp it in place so it can't move around on you. Don't forget surface prep, wire brush, or emery cloth/sandpaper. Put most of the heat to the fitting, and as soon as it freely takes the solder, let it flow in and around and get out. Just mapp gas should be more than adequate. if you are doing it on the bench, should be a piece of cake, and clamping it in place shouldn't really be neccessary. Mike

 

[r-mm]

Thanks guys. I go have a regular old Bernzomatic MAP torch. It has a reasonably fine point, nothing too precise but based on what I'm reading here it sounds like it should do?

I'm not familiar with the solders mentioned. What would make me pick 'plumbing lead free' vs '50/50' ?
I don't have anything on the shelf and can pick up either.

 

[Old Mud]

IMHO pure lead or 50/50 should be much better than Lead free. All old radiators were built with pure lead. Even the 50/50 means it's 50% tin. Tin is stronger but takes more heat. As far as your designed area for your fitting, you do know that would be the coolest part of a radiator ? Most heat would be at the top where the engine return is. A little practice and you will be fine.

 

[NortonDommi]

A pin-point flame is not what is needed. Soft solder with a large gentle neutral flame. I'm 100% with you as to location. Senders in the top of the head is insane as if coolant level drops the gauge reads low usually the last thing is the gauge pegging itself from superheated steam right before disaster.

 

[westerner]

In real estate there are three critical points-
Location, Location, and Location

In my experience with soldering, there are also three critical points-
Clean it, Clean it, and Clean it again.

Literally ANY contamination of nearly ANY kind in the joint will compromise the flow of solder, and thereby the integrity of the joint.

After that, any of the tips above will get you a good joint.

 

[Ulma Doctor]

have you considered a temperature sending unit in the block?
or was this purely radiator temp you were wishing to observe?

i cracked up when i read...

Ha I should have said... this is for a 10 year project where I am perpetually out of my league and like it. Did the welding, assembly, wiring, motor, rebuilt the transmission. I'd say a solid 85% of it I did right! Failures welcome/encouraged. Not a daily driver, a journey.

reminds me of my brother. no schoolin but has restored most of my dad's 84 F-250 6.9L Dino power Turbo,4X4. He's had a few setbacks but has seemed to take them well. i have had extensive training and real world working on a fleet of 6.9L engines, i was able to help with the beast when he didn't want the help- but the beast fired off about 6 months ago. not quite ready for daily driving, but in a few months that will likely occur.

as long as you keep up the good work, the hurdles will be surpassed one by one!
i think you'll do just fine

 

[markba633csi]

Biggest problem will be accidentally unsoldering nearby joints.
Use the wet rag method mentioned by Lo-Fi in post #7. Use some extra flux, either paste or liquid.
Electrical rosin-core solder would be ok to use.
-Mark

 

[tq60]

Lots of flux and "tin" it first.

Practice on loose part first.

Clean, then with paste flux on a paint brush heat the part then as it gets warm touch the flux to it and it will spread.

Grab solder and touch to item where flame is not.

When right temp it will flow easy and you want to get a coating of solder on the whole area.

Grab with pliers and shake off excess.

Stop in water to cool.

Repeat until you can get the heat just right to flow even without hearing just one spot.

Once comfortable tin the radiator and wipe off excess with dry rag.

When cool apply paste flux to surface then clamp the part in place.

Apply heat to the bung while touching solder to the joint.

The flux will transfer the heat and given both sides tinned they will bond with the heat and added solder.

When it melts apply all along the joint with heat removed and it should look like a Oreo when done.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[Alcap]

My Uncle and Grandfather used to solder gas tanks with an electric iron . I did one myself on a garden tractor gas tank that has a slice in it . JB Weld didn't hold up. Soldered a copper patch . I would think a large electric iron with the heat applied at the bung would get it hot enough to solder if using a torch might loosen up other joints .

 

[Old Mud]

R m, i just re read your post and saw the pic. you posted. I believe the pic. you posted is of an Aluminum radiator. Have you checked that yet ?