Can brass screw joints be soldered? Any tips?

[David in Normandy]

I had a pig of a job with some brass screw joints. Used PTFE tape and ensured the rubber seating washers were perfectly in place but found it damn near impossible to get a perfect join without a tiny leak somewhere.

Would it have been better to forget the rubber washer / PTFE and go straight to putting some flux on the threads, tightening up and soldering the joints? Is this "acceptable practice"?

It was very complex joint for some bath taps. For each supply (hot and cold) there was a brass fitting for connection to the tap. Attached to this was a small extension brass fitting to reach through the tiled wall. Attached to that was a brass fitting to take a flexible pipe. This meant there were three separate brass fittings between the tap and the flexible pipe the other side of the wall. The ensemble of three brass fittings taking two rubber washers. If you include the rubber washer on the flexible hose and at the tap join that is four rubber washers for the hot supply and another four for the cold supply. 8 bleedin rubber washers in all! I just couldn't get every damn joint tightened up properly without a leak somewhere.

So regarding the three brass fittings in the middle, would it have been better to simply solder those three together and forget the supplied rubber washers / PTFE tape?

[Newshound]

ABSOLUTELY. There's still a way of taking it out, presumably.

[David in Normandy]

Thank you for the feedback. It might just save my bacon! LOL

Yes, if the three pieces were soldered together to form a single piece it could still be easily mounted or unmounted. I think the problem is just having too many rubber washers in the assembly, so when fastening the back end of the tap on to it or the flexible pipe to the other end I think one or more of the other rubber washers in between is over-tightening and distorting.

[tony sayer]

If thats the case then something else must be wrong. Consider that these units are sold by the hundreds Thousands even and if all of them were like that they'd soon stop making them. If you've tightened it so much that its distorted then stop being so heavy handed is the answer to that!.

Still be interesting to see a few Pictures of this assembly..

[John Stumbles]

Back in the days of the 1976 drought, IIRC, Private Eye ran a spoof small add for "Instant Water - one packet makes up to 10 gallons"