Tinning Flux vs. Standard Paste Flux

[blueman]

I noticed at Home Depot that they sell an Oatey branded "No. 95 Tinning Flux" that supposedly "pre-tins" the pips and prevents the flux from burning out or the pipe from oxidizing ("turning green"). They say it is especially good on larger pipes.

Has anybody had any epxerience using such tinning fluxes vs. a standard flux like the Oatey #5 Past flux?

- Does it really work better on larger pipes?

- What about on smaller pipes?

- Any disadvantages (other than higher price) to using it all the time?

[EXT]

My experience with the #95, is that it doesn't really add enough "tin" to the pipe to be useful, and that it often leaves black burnt residue within the joint, that sometimes is continuous all the way through the joint causing a leak sometimes 6 or more weeks after completing the job. Personally, with either standard propane or MAPS gas, good old-fashioned solder paste still gives me the best joint when using either the easy to work with 50/50 lead/tin solder on non-drinking lines or with new difficult to work with lead-free solders.

[Paul Franklin]

I like it because it makes it easy to tell when the joint is up to temp. As you heat the joint, when it gets hot enough, the flux will "flash" silver as the fine solder particles in the flux melt. At that point, I stop heating after 1 or 2 more seconds and apply the solder. I've not had trouble with it burning or leaking using that technique.

I rarely work with anything bigger than 1" copper, so can't comment on how it works with larger pipe. The price of the flux is so tiny compared to pipe and fittings that I use it for everything.

HTH,

Paul F.

[skid]

blueman,

Since you did request personal opinions from other homeowners, I will not address any of the inaccurate statements made in the previous posts.

As it states on the Oatey web site:

Standard No.5 flux is intended for soldering copper joints using leaded or unleaded solder.

No.95 ?Tinning? flux is basically the same compound as No.5 flux, except that it contains small particles of silver solder. These particles help improve the flow of silver solder.

Since No.95 flux can be used for standard soldering as well as for silver soldering, Oatey markets it as a dual purpose product .

BTW: silver soldering requires higher temperatures than standard soldering and therefore tends to oxidize (aka ?turn green?)

[willshak]

skid wrote the following:

Original post dated June 23, 2008.

[Tony Miklos]

blueman, since you didn't represent yourself as knowing much about anything, I'll pretend you didn't reply to a post dated June 23, 2008,

12:08 pm. If you want to learn, get off that stupid web sight and look up "usenet". Study it well, then maybe post if you can find something interesting from this decade.

[Jon Danniken]

I've had good success using the 95 flux for pipes. Ended up putting some on a PC board I recently cooked up, and it tinned the copper traces with just a touch of the iron.

Jon

[Ralph Mowery]

Their product sheet says not for electrical parts. While it will do a good job of soldering, it leaves behind a residue that will in time draw moisture out of the air and corrode the electronics.

For electrical or electronics you should use the rosin core solder. With the extra metals in the 95 mix, it may not be compatible with the normal (not lead free) electrical solder. If soldering some of the newer lead free electronics, then it will probably be compatible, but there is still that long term corrosion effect.

[Andy]

replying to Tony Miklos, Andy wrote: Hi Tony,

Nothing wrong with replying to old posts, the internet keeps things for quite some time, and is searchable, so new information can be added at any point and still be useful. Also, blueman was the OP, so you're complaining to the wrong guy. Also, website.

Regards, Andy

[DIY Jake]

replying to Andy, DIY Jake wrote: Thank you. Most of the info I find useful is from years ago, just like this one.

[Branson]

replying to DIY Jake, Branson wrote: I agree. It is 2020, and I still found useful info. in this post.

[lvis1940]

There is no silver solder in tinning flux, only powdered solder. Check any mfr. site.

[DanHandy]

Since lead-free solder is at least 95% silver, it IS silver solder in powdered form, no?

[Clare Snyder]

Don't know where you get your info, but VERY FEW lead free solders have more than 4% silver - mostly tin (usually more than 90%) and antimony Copper, Bismuth, Cobalt, Nickel, Indium, Zinc, Germanium

[Ralph Mowery]

Probably he is confusing the Sn for silver instead of for Tin. Where Ag is the symble for silver.

The usual was about 60/40 Sn/Pb (tin/lead) for electronic solder before the lead free stuff came out.