Just can't get the hang of tinning..

[Bearpig]

Howdy folks,

I have ONE brass fitting in my smaller still that I just can't seem to replace with copper. Copper fittings seem to be widely available in the US, and even lead-free brass, but they're not available locally and from Ebay with shipping would cost me a small fortune.

I don't trust pickling, so I'm left with tinning as a possible solution. I figure I can tin the inner surface that comes into contact with alcohol and make it much safer.

My problem is that I just can't get the hang of it. I have much more experience with welding than with soldering, my soldering experience is limited to just sweating elbows and tees onto copper plumbing.

Can anyone help me with this and give me some idiot-proof advice on how to tin the inner surface of a brass fitting like this? It's a standard brass 1/2" male NPT sweat fitting.

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Thanks in advance!

[Yummyrum]

First you need to clean the inside if the brass so it’s shiny . I use sandpaper or stainless steel scrubber .What ever but it must be shiny yellow brass .

Next you need to paint it with flux . I use a liquid flux .... pastes are a pain in the arse .
Most soft solder fluxes are Zinc Chloride based .
Apply the flux with a hog hair bristle brush .

Slowly heat the brass . As soon as the flux starts to hiss and bubble , remove the heat and paint on fresh flux with the hog hair brush .

At this stage the brass should be hot enough to melt the solder . (If its much hotter it will burn the flux and the solder won’t stick)
So grab the solder and touch it to the inside with a wiping motion . If its hot enough , the solder should melt and run all over the fluxed brass . If it won’t melt , apply a little bit more heat and try wiping on the solder again . You should find at this stage that the solder wants too melt real easy and “pools” at the bottom . So you may need to rotate it with a pair of pliers to ensure an even coating . You “paint “ the hot fluxed inside with the solder stick almost as if it was a paint brush .

Also apply more flux with the hog hair brush . You can use the flux brush to “paint “ the molten pool of solder to areas that have no solder yet .

You will probably end up with a lot of solder pooling in the bottom so just pick it up with pliers and flick the solder on the floor ...: a concrete floor is best .

[Bearpig]

Thanks.

It's currently soldered to the copper pipe, so should i desolder, clean both mating surfaces, tin the inside of the brass fitting, and then sweat the pipe on as usual?

Do I absolutely need liquid flux? The flux I have is not the rosin type paste flux but kind of halfway between that and a liquid. Looks like mayonnaise, it's for lead-free solder.

[Samyguy]

I agree with yummyrum, use a lower heat, turn down your torch, you may be over heating
your metal work. witch makes it hard to control your solder.

[Yummyrum]

I’ve had nothing but tears and frustration with that type of flux . Liquid is soo much easier to work with and clean up is just a quick spray with water whereas that muck in my experince bakes on and requires a pile of removing .

You could remove the socket and have another crack but if you can clean it well enough where it is just do that . Although youmay find if you flick the excess solder off it , it will drop off anyways .

[Bearpig]

Thanks guys, I'll go buy some liquid flux and give it a try next week when I'm up at the cottage.
Cheers!

[HDNB]

good idea. the right flux is paramount to a successful job.

[NineInchNails]

I've always used paste flux and never had a problem. Too much heat is the cause of most issues.

I've always used abrasives like sand paper to prep both surfaces, apply flux, apply heat and once it's hot enough to melt solder remove the heat. The solder should be drawn right into the joint. It helps to apply heat around the fitting, not just in one spot.

[Bearpig]

So as an update, I was able to tin the brass quite nicely.
I used a dremel with a 120 grit sanding drum to port the inside surfaces, cleaned it up with acetone, then applied the paste flux I had.
I heated it up with a torch from the outside, away from the flux, and when it got up to temp I touched it with some solder and spun it around until it coated. It was actually pretty easy.

The main drawback to the paste flux is I had to spend quite awhile removing every trace of it from inside the pipe, so I'm going to keep an eye out for some water based flux for next time.
So it looks like I have the only brass fitting on my small spirit still completely tinned on every surface that would come into contact with the vapor, which puts me a lot more at ease.

Is there any reason people choose pickling over tinning? This seems like a much more permanent solution to lead leeching from brass. I suppose you could even do both, tin and then pickle the rest in case any of the edges come into contact with the vapor.

[Yummyrum]

Thanks for the update . Well done .
One I did about 6 years ago still looks good today ..... no doubt its a pretty perminate solution

Is there any reason people choose pickling over tinning? This seems like a much more permanent solution to lead leeching from brass. I suppose you could even do both, tin and then pickle the rest in case any of the edges come into contact with the vapor.

tinned.jpg

Personally I have never had any faith in pickling . Its nothing more than a feelgood exercise as far as I’m concerned .