Quicksdraw MaGraw

My Feedback: (1)

I'm trying to build up some landing gear for a WWI scratch build.
Anyway I can't get solder to stick or flow on the wire.

I have sanded it clean.......
I have hit it with a grinder......
I have used flux paste......

The solder just rolls up into a ball and drops to the floor.
Any Ideas?
Thanks a bunch.

jaka

Hi!
It's so easy once you have the right equipment.
Great Planes sell a solder / flux called "Stay Brite". Use that and you'll will see how easy it is to solder piano wire.

Regards!
Jan K
Sweden

fledermaus

Sounds to me that you are not getting the music wire itself hot enough. If you heat the solder but not the metal it is supposed to bind together, you will get the result you describe.

Two possibilities I can think of:
1) your soldering tool (iron, gun whatever) is not powerful enough to do the job. Small soldering irons designed for electronics work are not suitable for working with heavy music wire. In this case, get a new tool.

2) you are applying the tool directly to the solder rather than to the metal workpiece. You should be heating the music wire and letting the music wire heat the solder.

There may be other causes but these are the ones that spring to mind...

Rodney

It is sometimes difficult to get piano wire completely clean. You may need to use some kind of degreaser solution, try acetone to scrub it after sanding it. Use a large enough iron, at least 60 watts (I prefer a 100-150 watt gun). As a last resort, try an acid flux, just be sure to thoughouly clean the joint of all acid residue afterward or it will quickly corrode (rust) away.

majortom-RCU

My Feedback: (40)

Great Planes Sta-Brite or silver solder from hardware store or Radio Shack will do the job nicely. These packages include acid flux. The usual advice is to flush the acid flux with running water after the job is done, but I've never done so and have joints that are several years old with no sign of corrosion. It only takes just enough flux to wet the surface. Watch where it drips though.

With silver solder and acid flux, the only other thing you need is plenty of heat--either a big (100 watt) soldering iron, or propane torch. Heat the wire, then touch the solder to the wire. It should melt and flow readily once the wire is hot enough.

tail strike

My Feedback: (1)

I agree heat the music wire let it melt the solder. Is there such a thing as drum wire

Edwin

My Feedback: (2)

To help hold things together and spread the heat a bit I use wire strand from striped power cord. Wrap it around the area to be soldered after doing all the prep work listed above. I use a 75w iron along with staybrite and some big solder. Takes about 15 seconds to come up with a good joint.
Edwin

ghost flyer

In soldering "Cleanlyness is next to godlyness" and Silver solder sticks to a lot more and holds better than regular solder. Always use fine emery cloth, clean with alcohol, and use flux. Something like copper wire to wrap the joints so there is a larger area to cling to.

ghost flyer

If everything is right and it is hot enough the soldier should flow into the joint

Quicksdraw MaGraw

My Feedback: (1)

Well so far those are great ideas. Is it possible to have too much heat? I have been trying to sweat the joint with a torch as a plumber does with copper pipe?

Gremlin Castle

My Feedback: (14)

Yes you can also have too much heat. if the wire is almost black or scaley after the soldering attempt then too much heat has been applied, If the wire has been sanded to a bright finish it should not turn more than a straw yellow color before the solder starts to flow if it goes blue into grey black it is way overheated and you need to resand and start over.
Only those that use a flame will stand a chance of getting the wire this hot. If it is beading and falling off with a soldering you either don't have a big enough iron for the job or you are not waiting long enough for the iron to heat the wire allowing the solder to flow properly.

bent

I do all my piano wire soldering with cheap (2%) silver solder and a small butane torch. The only way it works for me is if I NEVER let the flame touch the joint area. Try applying the heat a good 1/2" from both sides of the joint. The flame seams to contaminate my squeeky clean joints and the solder won't stick. I also clean the thin copper wire with alcohol before and after wrapping.

mscic-RCU

My Feedback: (6)

Be careful: If you get piano wire too hot, you will remove the temper and it will get soft.

dirtybird

My Feedback: (5)

I have never been able to get a good soldering job on piano wire using a torch. Its too hard to get it hot enough without burning the flux. I use a 100 watt iron.

Quicksdraw MaGraw

My Feedback: (1)

Thanks Guys! that was it.......... too much heat

bunsen

Couple of other suggestions.

I just finished the landing gear and cabanes for a 1/4 scale Albatros and suggest that to control the heat you can't beat one of the propane Micro/Mini torches. I have one from Bernzomatic. They are also available from Solder-it. Allows to get very fine control of the heat.

Solder-it: http://www.solderit.com/


For the Stay-Brite solder and flux check out "Knife and Gun finishing" supplies:
http://www.knifeandgun.com/index.htm

You can get both the solder and flux in larger amounts and it is cheap. As noted above you have to be careful not to overheat the joint.



Bunsen

krazycdn

you have to get the wires hot enough for the solder to flow if the wires are not hot enough the solder will just ball up and drop

susquach

My Feedback: (1)

You've gotten some good suggestions Quickdraw. Soldering well is probably one of the toughest aspects of the hobby!

Here's a thought...don't solder. Weld using one of those small propane/oxy rigs available at hardware stores. Brass welding if probably easier for most folks to learn than soldering....is faster, more durable and is great for fabricating small items on scale gear such as Cub and Fleet type gear. Overheating the temper can be avoided by heat sinking or simply staying away from bend areas on the legs. The outfit has a very small tip so it's pretty easy to control what gets heated to cherry red.

I started using brass welding to do a few items on a scale gear and it has gradually taken over all my soldering chores. Don't think I could get along without one of those little brazing outfits now.

redux

ddubya,

Could you elaborate a bit on your transition from soldering to brazing?

Like what equipment you use and a picture of what you have been able to accomplish.

I am looking at making a landing gear that I think is beyond soldering.

I keep thinking that if I could do 'some small scale welding', it would turn out better.

... but I don't know where to start.

Thanks,
--JJ--

mishal

Any one has tried J-B weld for welding music wires ?? is it strong enough ?

BarracudaHockey

My Feedback: (11)

I thought this topic rang a bell from the Magazine section.
http://www.rcuniverse.com/magazine/a...article_id=172

ptmac3

My Feedback: (3)

Is it possible that the flux is a non-corrosive rosin flux, rather than an acid flux? This is particularly true if the solder and flux are recommended for electrical use.

mishal

Thanks .. very nice topic, what type of flux should i use ? do you think silver solder will do the job too ?

j.duncker

My Feedback: (2)

IMHO you must use acid flux with piano wire. Do not know why but it is the only thing that works for me. The key after cleaning and fluxing is to get the heat right. I ALWAYS BIND PIANO WIRE JOINTS WITH FUSE WIRE. I use a very large non electric iron applied below the joint and apply the solder from above. When the joint is hot enough the solder flows in nicely.

Silver soldering is quite different. Silver solder requires temperatures of 600 o C up to 800 o C, or in some cases, even higher. The two usual heat sources are propane and oxy-acetalene, with propane being generally considered to be easiest for the less-experienced.