What solder to use?

[Paul Taylor]

What type do you use on models?
I'm going to pickup that soldering iron I did not get for Christmas.

[George]

Stay Brite.

George

[Howard Rush]

That is rather a general question.  I have found that balsa doesn't solder worth a xxxx, but maybe I'm using the wrong solder. 

Stay Brite is good for tin-plated steel fuel tanks on IC-powered models. 

[Paul Taylor]

I know one type will turn green and not work well with LG and BCs

[Bob Reeves]

This subject comes up every once in a while.. In my opinion regular old 60-40 rosin core from Radio Shack will solder anything we need to solder. It's non corrosive and easy to use. If it needs more than that, braze it.

Be careful with that flux that comes with Stay Brite, I once used it to solder a stainless needle valve and it rusted everything I had on the bench withen 2 feet of where I was working. Really nasty stuff..

[Paul Taylor]

Thanks Bob.

[Brett Buck]

This subject comes up every once in a while.. In my opinion regular old 60-40 rosin core from Radio Shack will solder anything we need to solder. It's non corrosive and easy to use. If it needs more than that, braze it.

Be careful with that flux that comes with Stay Brite, I once used it to solder a stainless needle valve and it rusted everything I had on the bench withen 2 feet of where I was working. Really nasty stuff..

   Exactly. And there's nothing you can do to clean it off well enough to prevent it from eating away at the metal for literally years. If you have to use it, it works, but beware.

    If someone thinks they need the extra strength of silver-bearing solder, it comes in a rosin-core type as well, which will work fine for any of our purposes.
   
     Brett

[Bob Reeves]

   Exactly. And there's nothing you can do to clean it off well enough to prevent it from eating away at the metal for literally years. If you have to use it, it works, but beware.

    If someone thinks they need the extra strength of silver-bearing solder, it comes in a rosin-core type as well, which will work fine for any of our purposes.
   
     Brett

Am pretty sure Radio Shack also carries rosin core silver-bearing solder. Only need I ever had for it was replacing transistors in RF power amps. Motorola included a small amount with the transistors when ordered from parts.

[Jim Kraft]

I have been using Radio Shack 2% silver bearing solder for years. It works well for copper wire wound landing gear to fuel tanks. It makes a beautiful joint, and is strong enough for all of your soldering needs on models. It comes in a roll that is .022", and it has a rosin core that works well and won't corrode. Try it, you will like it.

[Joseph Lijoi]

Silver Solder is hard solder.  You can get this stuff up to 40% silver content.  Really it is meant to be used with a torch, not an iron.  The problem here is that you run the risk of annealing the metal that you are trying to bond  when using a torch.  40% silver solder is used for jewelery and brass musical instrument repair, using a propane torch.  I don't know what Sta Brites silver content is, but my experience is that you will need a 40 watt iron (not a soldering gun) and 100 watt even better.

Stay Brite flux is essentially dilluted acid so it is pretty corrosive.  Not only can it corrode your joints but it can also chew up your soldering tips.  The tips should be clean and use one of those soldering sponges to wipe the tip clean between applications.  The tips are coated so don't clean them with a wire brush  Flux helps to conduct heat and gets the solder to flow.  Given the proper temperature most of the flux gasses off and there is greater heat conductivity where the flux was applied and hopfully the solder will flow where you put the flux, giving you a better joint.

Acid based flux, when it gasses off, will get on the surrounding metal and corrode it.  You have to immediatley brush surrounding areas and the joint clean.  I use baking soda or baking soda toothpaste.  I have yet to see a properly done joint corrode under the solder.  Definetly have seen solder joints corrode around the joint.  Don't inhale this stuff.

60/40 is more user friendly but I still use seperate rosin flux, even if the solder has a rosin core.  I prefer solid solder because I use seperate flux.  When I do use silver solder it is wilth a torch or 100 watt iron.  I don't see the need for using silver solder on airplanes unless you are worried about the strength of control systems or landing gear, and there are better solder free solutions to these applications.  Silver solder for tanks isn't necessary.

Get a 40 watt Iron, stand and sponges.  A 40 watt iron works great wth 60/40 solder Good sources for these items are Radio Shack, Internet Slot car shops or Stained glass window supply houses via amazon.  A weller 40 watt Iron you can get at Home Depot.  You can get a Weller 40 watt temp controlled station fo 35 dollars.  The temp control isn't really necessary, mine is always set to high except for electrical.  Buy some 3/16 chisel tips from  Weller.  IMO soldering guns are worthless.
 

[Ryan Taylor]

Bit of an related note, but does anyone know what a bulb attached to the solder iron would be used for?
I've picked up 2 in the past few years and one of them has a bulb on it.
Here's a picture

[RogerGreene]

When you squeze the bulb where does the air come out? If by the tip the its for de-soldering. So you can heat the solder and blow it away with air from the bulb. Keep clothing and fingers away from the tip.

Roger

[Randy Cuberly]

When you squeze the bulb where does the air come out? If by the tip the its for de-soldering. So you can heat the solder and blow it away with air from the bulb. Keep clothing and fingers away from the tip.

Roger

Since the subject of de-soldering has come up (Roger is absolutely right about the bulb), a much better, and safer way to do it is with solder wick.  It comes in spools and is available from Mcmaster-Carr, and many others.  Heat the solder touch it with the wick and the solder flows up the stuff like magic.  It's actually tinned copper braid and works very well.  Most here probably know about this of course, but this info is for those who might not.

Randy Cuberly

[Brett Buck]

Since the subject of de-soldering has come up (Roger is absolutely right about the bulb), a much better, and safer way to do it is with solder wick.  It comes in spools and is available from Mcmaster-Carr, and many others.  Heat the solder touch it with the wick and the solder flows up the stuff like magic.  It's actually tinned copper braid and works very well.  Most here probably know about this of course, but this info is for those who might not.

     It depends on what you are doing, but I do A LOT of soldering and I prefer this type of desoldering tool shown below, the Edsyn "Soldapult". Its a spring-loaded piston thing, like a veterinary syringe with a spring to pull it out, and a latch to hold it in a cocked position. Heat the joint, put the tip over the solder, and push the button, and is springs back out and sucks in the solder.

   The only thing that I have found better is the Hakko desoldering tool, which is a heated iron with a suction pump attached but it's a lot more expensive and probably not worth it unless you do a lot of electrical work. It does work wonderfully well.

    Brett

[john e. holliday]

We used a lot of solder wick at the phone company when I first started on frame.   Time progressed to punch on tools and wire wrap.   Still have some of the solder wick somewhere in he shop.   But, we heated the wick while holding it to the solder joint.  Solder will follow the heat in my experience.

[Jim Kraft]

Back in another life when I was doing commercial two way radio work for a Motorola service shop, I used both braid and the Soldapult. Both seemed to work well except you had to clean out the Soldapult every so often or it would get clogged up from the solder. I would use it till it stuck, and then clean it out. That is where I found out about the 2% silver solder as that is all we used. To open holes in circuit boards I used toothpicks.