Okay, I think I have read all the links here for soldering clevises and am still having problems. I have been trying to solder my clevises on a Great Planes Pitts using 4-40 rods and supplies hardware. I have tried several different silver solders (the suggested type) and flux stuff and NONE seem to work! They never flow correctly and just glob up or drip right off! I have tried a soldering gun as well as a LP torch. I have gotten it really hot and not so hot. If I use standard Tin/Rosin core solder (standard electrical type) they look perfect every time. Question: Will the ‘electrical’ solder I used hold up? Has anyone else used it. I got $100 bucks in different solder, guns, and torches, PLEASE HELP

Sheldon

One important factor, is to clean the rod, and apply a flux paste. otherwise, teh solder jsut won't bite onto the rod.

I usually sand / polish the area inteded with a fine grit paper, like 300 - 600, so the metal rod has a sheen to it. then I coat it (stick teh rod end into) with flux. The flux is regular plumber's flux, for copepr pipes, should be avaliable in any 'home improvement' store

slip on the clevis, twirl it a bit, to ensure there's flux everywhere!! then I heat them up with the pyro pen / mini torch. Once the flux bubbles and crackles, remove the heat, and feed in the solder. It should wick in nicely. maybe a little more heat, but you'll get the hang of it after a while!

remember to clean the solder joint afterwards, as the flux is considered corrosive (it is an acid afterall!!). Use a bit of Acetone on a cloth or tooth brush., and it' should shine!

From what I've read, silver solder is stronger than regular 'electrical solder, but so far, I have had no probs with regular 63/37 solder on my links.

Well, it does not sound like we are doing things that differently. First I used emery cloth (sand paper) and scratched it up good and shiny, next paper towel with rubbing alchol to clean it. Tried plumbers flux first. (paste I dipped the rod end and clevis into.) Next tried the liquid flux. (clear liquid fluid) heated up with the 140 watt soldering gun. I thought I must not be getting enough heat so got a new tip and finally a propane torch. Maybe it's the size of the solder???? the electrical stuff is super thin and flexable where the silver stuff is 3/16" dia and stiff. ??? maybe the solder is so big it disapates the heat the smaller 4-40 rod can hold ????

The 63/37 is that the normal rosin core electrical solder? Is that what you have been having no problems with?

Thanks

I'm using electrical solder and it has held up. I share your frustration and have had similar problems with the solder not sticking. Maybe your torch is making it too hot. If the silver solder is 3/16" dia, you probably have to heat it up before it will flow into such a small clevis. I know people use the Great Planes silver solder with good luck. It is a smaller diameter.

Tom

Goldwing- The numbers 63/37 represent the alloy component percentage. In your case 63% tin, 37% lead. You mentioned a new tip. I presume that you 'tinned' it before hand. You may also need to clean your solder, I fold a small piece of sandpaper over the solder and pull it through a few times. If all else fails, you might try acid core solder. Jim

I haven't had great success with silver solder, but the acid core stuff works very well for me. Never had a joint pull free either.
Dennis-

Yep, slowly heat it with the torch. make sure you have the flame about 1"-3" 'under / away' from the parts. this gives maximum heat to the parts. the thicker rod may require extra 'heat up time' so be patient. You'll know when it's hot enough, as you'll see teh solder just wick right in. You'll probably have to 'touch' it with the flame, to ensure you're still at tempurature. it all happens pretty quickly.

Soldering Irons I find take time to heat up the parts, and only heat a small area. hence why I prefer a torch, as you can move it around teh parts...

Also, let the parts cool natually. don't speed up the process, otherwise you'll get a 'cold solder joint' and that can lead to failure. At least it does in the electronics world...

Hey GoldWing! LTNS!!

I have always used regular solder (not silver) and have never had a connection fail.

3/16 diameter sounds like way too big for solder to use on a clevis. It sounds like your solder is a rod used for large work. There is a wide variety of silver solder available but the most common for our use is mostly tin with 2-4%silver. It requires a fairly active flux usually containing ammonium and zinc chlorides. I normally use 60/40 electrical solder which I find tins and flows better, but it is getting harder to obtain since lead has been declared bad stuff by the EPA.

I'll go along with MinniFlyer, I use electical solder with no problems. silver solder is overkill. I do not use acid core solder or acid flux as, unless you really clean the joint and neautralize the acid, you joint will corrode and weaken in time. For normal 4-40 or 2-56 cvlevises, a good soldering iron works better than a torch, just use at least a 60 to 100 watt iron.

What the others said about clean... It needs to be clean. I've used a tourch and iron. I prefere the iron. Been using plumbers solder. HAs some silver in it, and it's as cheap as rosincore solder, and just as easy to use.
What are you guys using to nutalize the acid flux? I clean it really well after wards with Denatured Alcohol, but sometimes still get soem rust.

Also if you choose to use a soldering gun...(and nothing wrrong with it), just make sure your servos and any other electric motor are no where near the gun. With the gun you are shorting a winding in a transformer ( basically), and this generates enough of an alternating magnetic field to, and can (and will) demagnatize the magnets in a motor.

I've never had this happen, but it did to a buddy. A known good servo no longer worked after using near a soldering gun.

If you do them right, you shouldn't be anywhere near teh aircraft. In other words, doing each rod separately, in it's own work space. Then threadding them in / through the airframe.

The acid is water soluble so just needs to be sloshed around in a styrofoam cup and dried off.

Just to add my two cents worth.....

When I started soldering, I was running into the same problems - cold solder joints, no solder joints, etc. All the tips above are pretty good. I won't debate any of them.

I just wanted to add that I use a silver solder called Stay-Brite that I got from my LHS, It comes with solder and liquid flux. I only need to use a 140-Watt soldering gun and get very good solder joints. I haven't had one break yet.

As everyone here has pointed out, cleanliness is the key here. Mechanically clean the pieces with steel wool, sandpaper, etc., and then use the flux.

I hope this helps somewhat.

Bob

Clean the parts well as others have mentioned and get the heat right - thats the secret. Stay-Brite is agood silver solder and is easy to use-I have used it on a lot of control systems with the gold Sullivan links. No failures with Stay Brite but have had one failure using electrical solder-the rudder joint failed after many flights on a Kaos but igot away with it! Bob Violet recommends Stay Brite for the linkages on his line of jet models-thats agood testament.
Al Watson