Solder...

[Accord]

I have a bunch of different types of solder, however none of them really stick to my zap chassis very well.

what type of solder will stick very well?

[Larry Geddes]

1) Parts MUST be clean; use fine sandpaper or 3M Scotchbrite to remove all oxidation from the surface on steel or stainless steel chassis. If the chassis is nickel-plated aluminum DON'T DO THIS! You'll remove the plating! Instead, wash the chassis in hot water with dish detergent & dry thoroughly, or degrease it with a solvent like lacquer thinner or acetone. Once the soldering area is clean, don't touch it with your bare hands.
2) Use lots of heat.
3) Use liquid acid flux, like Stayclean or Lucky Bob's. This really helps the solder "wet" the metal. The solder will go wherever there's acid & heat.
4) Clean all joints with Comet scouring powder & a toothbrush. Use warm water, rinse & dry. If you don't get rid of the excess acid, it'll corrode the chassis.

It's not the solder so much, it's the preparation that makes good joints. Slick 7 silver solder is good, so is ordinary 60/40.

[Phil I.]

Like Larry says, HEAT....A GUN is not the way to go, a GOOD iron of atleast 40 watts,higher is better, and a control is the way to go.That way you can turn it down for electrical and back up for chasses and motor soldering!:)
PHIL I.

[Rotorranch]

I use acid flux for soldering on bare metal, but on pre tinned metal, I use liquid rosin flux. It does great for stuff that already has solder on it, and is non corrosive.

Rotor

[Mike Wyatt]

One thing a lot of guys don't understand- solder flows toward heat.

When you have a surface that doesn't give much adhesion for the solder (like steel, plated aluminum, or stainless), and then take a hot arn (iron), melt solder on the arn, and then attack a cold piece of steel- you often lose. You have also boiled away all the flux that is in the center of most solders when you put solder on the tip (not to mention corroding yer tip). So- don't put solder on the arn...

2. The proper technique:

- place the flux on the area to be soldered (after you rough it up)
- pre-heat the chassis with the arn;
- then once the chassis is up to temp- add the solder- if all is right, it will flow into and "wet" the area.

You will be so happy, you will wet yer area, too.

[zaprp]

Everybodies answers here are correct! The biggest problem I see with most new racers learning to solder on slot cars is, a dirty surface that is trying to be soldered, an iron that is not hot enough, too much solder, AND NOT ENOUGH SOLDERING FLUX!!! The flux will wash off. Many of you would be amazed at how much flux I use when building a chassis. When in doubt, seek the advice of an experianced local racer.

[Ramcatlarry]

A lot of soldering problems today revolve around different steels and other metals. Many pinions and many new chassis on the market are being made of STAINLESS STEEL> this material does not always solder well with standard HCL liquid flux. The same is true of aluminum. FLUX IS MADE FOR THESE MATERIALS!! JK has just added flux for SS to his line since ALL of his stamped cars will soon be only made of SS. Shop around at your local welding supply shop, you would be amazed what you find.....