ANTI-FLUX What Common Product?

[rhmc24]

I used to use some very common product around the shop for anti-flux but can't remember what it was. If you can remind me I would appreciate it very much. Thanks

[Oyeboten]

What is it used for?

[dfariswheel]

There are several anti-fluxes to prevent soft solder from adhering to areas you don't want it to stick.

One is to use a large #2 pencil to cover the area you DON'T want solder from sticking to. Just thoroughly rub the lead over the area to leave a uniform coat of pencil graphite on the metal.

The most common anti-flux is a stick of soldering talc which is some sort of soapstone material.

Probably the most effective anti-flux is Tix brand anti-flux. Tix also makes a good soft solder, but possibly not as good as the common soft solder that contains about 3% silver for added strength and tarnish resistance.

[rhmc24]

Flux is used in soldering to assure the flow and bond of the solder. It comes in several forms of paste, liquid, etc. Some is brushed on, some in the solder itself. Solder can also flow where it is not wanted. If you have an anti-flux and coat the areas you want to protect, the solder won't bond there. Anti-flux is available for purchase. Since I posted above I have learned of a couple DIY methods. I just trying to find what I used before, some common item that I can't remember yet. I'm talking here about soft soldering about 450 F.

Flux is also used in hi-temp silver soldering and brazing. Comments above apply in general but using different flux products.

EDIT
While I was writing this, dfariswheel stirred my memory. I used welding soapstone stick marker. Thanks for that and the pencil item. I'm using 3% silver attaching a front sight.

[rhmc24]

Thanks again to dfaris for jogging my memory. The soapstone marking stick worked great. I put my front sight on today -- one of the early steps on this project New Service.

[Oyeboten]

Ohhh! Okay...

Good to know!

I have usually just tried to be really careful and or to wipe off any unwanted Solder while it was still 'mush'.