Sal-Ammonic Block 4 oz.

Pound size is also available

The following is reprinted from the glassworking tips archive:

Sal ammoniac is a naturally occurring ammonia salt that is used for "tinning", which means coating with solder. Some metals like copper can be tinned quite easily using just flux, while other metals like the steel jackets on soldering tips take a bit more coercing. That's where the sal ammoniac comes in. The sal ammoniac tinning block has the ability to clean the tip better than flux can so that solder will easily adhere to it.
You need to use a fully heated iron tip, which will cause sal ammoniac to "sublime", which means to go straight from the solid white block and turn into a gas, in this case a choking white ammonia smoke. (So it is best to tin your iron with active ventilation.) Just add solder while rubbing all surfaces of the tip firmly on the block. When all surfaces are nice and shiny quickly turn the iron temperature down before you burn off the nice new tinning job!

Now here's something I learned from a real old timer I worked for twenty years ago. You can break off a chunk from a sal ammoniac block and dissolve it to make sal ammoniac water. (About two tablespoons full to a cup of water.)
As you work if you see the bright shine of your clean tip begin to dull a quick dip (actually more of a jab) into the sal ammoniac water cup will quickly restore the shine without causing the corrosive fumes that using flux would.
It is important to learn the correct technique for this. The iron tip must enter and exit the water as quickly as possible without getting the iron barrel into the water. If done properly you will hear a sharp "KISSing" noise as a thermal shock breaks all of the oxides off of your tip and they fall to the bottom of the cup. If you do it too slowly the junk will not break off and your iron will be over-cooled so you will have to wait to resume your work.
When the cup fills up with junk in a few months, throw it away and start over. Sometimes the salt tries to escape. If it starts to crawl out of the cup, just scrape it back in.

Sal-Ammonic Block 1 pound

The following is reprinted from the glassworking tips archive:

Sal ammoniac is a naturally occurring ammonia salt that is used for "tinning", which means coating with solder. Some metals like copper can be tinned quite easily using just flux, while other metals like the steel jackets on soldering tips take a bit more coercing. That's where the sal ammoniac comes in. The sal ammoniac tinning block has the ability to clean the tip better than flux can so that solder will easily adhere to it.
You need to use a fully heated iron tip, which will cause sal ammoniac to "sublime", which means to go straight from the solid white block and turn into a gas, in this case a choking white ammonia smoke. (So it is best to tin your iron with active ventilation.) Just add solder while rubbing all surfaces of the tip firmly on the block. When all surfaces are nice and shiny quickly turn the iron temperature down before you burn off the nice new tinning job!

Now here's something I learned from a real old timer I worked for twenty years ago. You can break off a chunk from a sal ammoniac block and dissolve it to make sal ammoniac water. (About two tablespoons full to a cup of water.)
As you work if you see the bright shine of your clean tip begin to dull a quick dip (actually more of a jab) into the sal ammoniac water cup will quickly restore the shine without causing the corrosive fumes that using flux would.
It is important to learn the correct technique for this. The iron tip must enter and exit the water as quickly as possible without getting the iron barrel into the water. If done properly you will hear a sharp "KISSing" noise as a thermal shock breaks all of the oxides off of your tip and they fall to the bottom of the cup. If you do it too slowly the junk will not break off and your iron will be over-cooled so you will have to wait to resume your work.
When the cup fills up with junk in a few months, throw it away and start over. Sometimes the salt tries to escape. If it starts to crawl out of the cup, just scrape it back in.