I believe you mentioned, before, that you did thru hole soldering at your work. Extra flux is not needed. You need to feed so much solder wire into the joint, the flux will be there, anyway. With SMD soldering, fluxing the joint and then adding solder is commonplace in industry. Google "wave soldering."
And sometimes you simply need flux. Try installing a BGA without flux.
QuoteAnd sometimes you simply need flux. Try installing a BGA without flux.
As far as I know, that's not a hand-soldering procedure. That's an oven procedure.
Hot air station. I consider anything soldered with hands, not fully automated, hand soldering, no matter direct or convection heat transfer.
To solder an SMD in place, I put a small amount of solder on one of the pads, placed the SMD with tweezers and tacked one of its legs to the pad with my iron, soldered the other legs one at a time (feeding solder wire to each one, usually 0.015" diameter), then reflowed the tacked joint.
Or maybe they just need something to keep you guys busy in downtime for when they really need you?
In practice, if you used the same flux that is in the wire. And you preloaded the tip with solder. And you let the flux IN that solder drop off and/or burn off onto the edge of tip where chrome plating starts. Then you touch the crusty solder to the pads which are fluxed with the appropriate amount of flux and drag solder it.... the end result is same as point to point soldering with solder-wire, alone.
I've watched NASA soldering video where not only tip of the iron must be cleaned before each and every joint, but also the solder wire must be cleaned with a GD Kimwipe before making each joint. Am I going to do that for all my soldering?
Question then for people who prefer wool; do you work on production of new boards/circuits, rework, or a mix of both, and how do you keep the wool from trapping debris?
I've used the wet sponge for a long time and never had any issues with tips becoming bad early because of this. A few years ago I've moved to brass wool, and I like the convenience of not having to wet the sponge each time. The solder which is removed from the tip while cleaning simply falls down into the wool's container. And no corroded sponge holders anymore.
I'm not a fan of brass wool because it seems to abbrasive to me.
Brass: 3 mohs
Steel: 4-4.5 mohs
Harddened steel: 7-8 mohs
http://www.jewelrynotes.com/the-mohs-scale-of-hardness-for-metals-why-it-is-important/
Question then for people who prefer wool; do you work on production of new boards/circuits, rework, or a mix of both, and how do you keep the wool from trapping debris?Mix of both but like you but mainly rework.
I never bothered with brass wool and use stainless wool in a short stout ceramic tumbler, easy to clean.
If you've ever tried to solder to stainless you'll know why I use it.
I'm not a fan of brass wool because it seems to abbrasive to me. I only use it if a tip is so crusty it cannot be cleaned with a sponge. IMHO the biggest disadvantage of a sponge is that it needs to be wet (I have a squeeze bottle with water for that purpose) and many people use it upside down so it falls apart quickly.
Question then for people who prefer wool; do you work on production of new boards/circuits, rework, or a mix of both, and how do you keep the wool from trapping debris?
FWIW, tips will wear out faster with lead-free alloys IME. Not only due to the higher temps cracking the iron plating when using a sponge vs. brass wool (greater temp differential), but lead-free alloys also have a greater affinity for iron than lead based alloys.
FWIW, tips will wear out faster with lead-free alloys IME. Not only due to the higher temps cracking the iron plating when using a sponge vs. brass wool (greater temp differential), but lead-free alloys also have a greater affinity for iron than lead based alloys.
but lead free solder usually has less agressive flux in it than older solder formulations.
i have not used a lead-free solder that leaves burned flux residue on my iron yet, but most 60/40 formulations always did that.
IMO the biggest threat to the iron tip is large amounts of rosin in the flux.
before lead-free i used to go through tips every few months (production level use),
now tips last years with lead-free solder with no-clean fluxes.
There's the difference^^^ production where comparatively little flux is required as most everything is clean. Rework is an entirely different proposition where aggressive fluxes are often required.
Horses for courses.
There's the difference^^^ production where comparatively little flux is required as most everything is clean. Rework is an entirely different proposition where aggressive fluxes are often required.
Horses for courses.
I use the same 1.1% (P1) no-clean flux-core solder wire at home for rework (mostly on arcade PCBs from the 1980s, some of which are pretty nasty, especially CRT monitor chassis) that we used at work on brand new boards. I've never run into a situation where I needed a lot of and/or more aggressive flux. To replace a part or resolder a joint, I first desolder it (I don't use any flux to do that) and then the pads are inherently clean and lightly tinned after that, because they've been protected by solder fillets since they were manufactured; they accept new solder just as easily as brand new pads do.
I am curious though, about what sort of situations you encounter that require a lot of and/or aggressive flux.
FWIW, tips will wear out faster with lead-free alloys IME. Not only due to the higher temps cracking the iron plating when using a sponge vs. brass wool (greater temp differential), but lead-free alloys also have a greater affinity for iron than lead based alloys.
but lead free solder usually has less aggressive flux in it than older solder formulations.
i have not used a lead-free solder that leaves burned flux residue on my iron yet, but most 60/40 formulations always did that.
IMO the biggest threat to the iron tip is large amounts of rosin in the flux.
before lead-free i used to go through tips every few months (production level use),
now tips last years with lead-free solder with no-clean fluxes.
As per the burnt/crispered flux, that tends to have to do with the operating temperature IME. FWIW, I've dealt with that as well as a clean tip, depending on operating temp (iron's recovery v. set temp has had a HUGE impact on this IME).
Yes you can soft solder cast iron. The best advise I can give you is keep everyting clean. A fresh ground surface works better than one that has sat for several days. Use a high tin alloy and the best flux you can get. Even heat with a propane torch kept moving works better than anything I have found. Tin the parts well and use a clean, steel bristle brush to rub the solder into the area.
Question then for people who prefer wool; do you work on production of new boards/circuits, rework, or a mix of both, and how do you keep the wool from trapping debris?
I believe that the tips cracking is more prevalent on lead free systems due to the composition of the tip.
lol - BS
the tips are the same, they never changed.
some people will blame anything on lead-free!!
So, regular iron is highly susceptible to oxidation. It is a very reactive metal. And it's not particularly hard. Copper tip plus relatively soft plating = soft tip. Soldering iron tips are not particularly malleable. Unless they're by Radio Shack.
Cast iron is hard and resists oxidation and scratching. But unlike stainless steel, it has a high thermal conductivity.... and it will hold solder. Unless you leave it bare for a few days.... Hmmm..? Maybe at some point pure iron was commonly plated onto a copper tip...
A tip typically consists of a solid copper core, a plated layer of iron, a plated layer of nickel behind the
working surface, and a plated chrome layer. Copper is used for the core primarily to ensure good heat
transfer. The nickel layer is a non-wetting layer designed to keep the solder from wicking away from the
tip's working surface. Without this layer, the solder would travel preferentially up the tip toward the heat
source, making it impossible to apply solder to the solder joint. The chrome layer is applied as an
additional protective layer.
Must Be Wettable
The working surface of the tip must wet to transfer molten solder to the joint and to aid heat transfer. Iron
wets. Molybdenum doesn't.
Dewetting is the most common form of plating failure and is preventable, for the most part, with good
daily tip care. Thermal dewetting is caused by oxidation of the iron plating to iron oxide. Iron oxide is
non-wetting.
We know that can't be technically accurate, because they can't simply be using iron, because it effectively doesn't exist;
^If you look at the cross section, the chrome plating is only over the shaft part of the tip. It stops where the solder bead begins. The chrome plating is there to prevent solder from adhering. If you look closely at a tip, you will see where the tip doesn't wet, it's thicker. It's a chrome plating OVER the wettable "iron" plating. This is how is appears on my Hakko tips, anyway. On a cheaper station I used before, the base of the tips were covered with some thicker/crustier stuff that almost looked like ceramic.
I wonder if early irons were plated with pure iron. I am not sure you can electroplate an alloy?
So unless case hardened, after, perhaps some tips used to be made with pure iron plating. Radio Shack copper tips actually come with a thin plating that lasts about 3 days... perhaps this might be example of electroplated "pure" iron?
The chrome plating is there to prevent solder from adhering. If you look closely at a tip, you will see where the tip doesn't wet, it's thicker. It's a chrome plating OVER the wettable "iron" plating.