Erin, what do you mean by airtight joints? OK Erin you can solder so
this is not a newbie post to you. But newbies pay close attention.
Here are some tips that may be useful or not. But on this site we
post to try and help and eventually someone solves your problem. THIS
IS WHAT MAKES THIS SITE SO USEFUL, YOU CAN GET FIFTY POSTS THAT DON’T
QUITE SOLVE YOUR PROBLEM THEN ONE THAT DOES - REALLY MAGIC!
I use this to solder very heavily reticulated sterling silver rings,
so I am used to uneven metal thicknesses. Note I use one of those
"big" silver smith torches that run on LPG and air through a foot
bellows. WTF or LOL you say. But I have very little oxide build up,
by using this torch. Note oxide is not firescale. Oxide is removed
in pickle firescale is NOT. Now I don’t wont to start a million posts
on firescale here. But firescale is oxygen trapped under the fine
silver layer left after pickling. Firescale must be physically
removed by sanding etc.
NOTE I AM WRITING ABOUT A RING, MODIFY FOR OTHER APPLICATIONS.
1 File the ends to be soldered, to get them flat.
2 Put the ends together.
3 For a ring anneal the piece, lights out/dimmed so you can see the
subtle colour change, to deep cherry red. This is very important
because you may have work hardened the silver and if you solder at
this point you may “relax” the silver and it can move apart at the
join REMEMBER I AM TALKING ABOUT A RING. If you go beyond deep
cherry red welcome to excess firescale.
4 Cut vertically through the join with your jewellery saw. If not a
ring get joins as flat and smooth as possible by filing and sanding.
OK you seem to be doing this.
5 Hold up to the light, if you CAN’T see light through the join you
are ready to solder. Works with all solder joins not just rings. If
you can see light, work on the join till you can’t see light. Solder
DOES NOT FILL GAPS. IT FLOWS IN JOINS BY CAPILLARY ACTION. Maybe you
should use binding wire if possible.
6 Lots of flux.
7 Warm the whole piece with a big yellow/gentle flame.
8 Concentrate the flame on where you want the solder to flow to in
the join and heat till the solder flows.
9 Pull the flame away momentarily, then reheat till the solder
gleams/ shines. Pull the flame away as soon as it gleams.
10 For the first solder on a piece start with hard solder.
Subsequent solders go to medium then easy.
NOW BELIEVE IT OR NOT. Once soldered with hard the soldered joint
will flow at a slightly higher temperature than hard that has NOT
been balled up on a pick. You use a paillion/piece of solder on the
join for the second hard solder. Try this first time on a piece your
are prepared to have go wrong it probably will. This can be as much
fun as learning to bright cut bezels. So if you use this method you
get 6 solder temperatures not 3.
Hope this can be of some use, if not email me some more details.