Using old components stored in a damp cold shed for decades?

Question

I have tons of never used electrical components like resistors, capacitors, coils, transistors from 10 years back and tons more of my fathers stuff (made in the Soviet Union) from 20..30+ years back.

They've never had anything rain on them, but they've spent only 4 years of that total time in a heated house and then went back into a shed.

Most of the resistors, capacitors and coils are in matchboxes or bigger cardboard boxes and most of the transistors are luckily packed in waterproof (and airproof?) plastic. All of the smaller boxes have been packed tightly into larger non-weatherproof cardboard boxes.

Answer 1

For unknown moisture ratings, parts can be baked at 85'C for 2hrs to avoid solder moisture evaporation stresses.

For old electrolytic caps measure leakage R with a large series R divider at rated V or less and compare to spec, on a few samples before after baking they may be excellent or not. Russia is a prime source of good tantalum. Alum caps may need conditioning , or observe large drop after a few minutes with current meter or series R , V drop.

The epoxy coated parts are still good, their ceramic disks may have some moisture absorption.

The leaded wire oxidation can be improved with dip flux before soldering.

All good parts most likely with attention to above .

Answer 2

Some of the components may have suffered simply from age. And some of the components may not have been all that great when they were new. Likely most of the components have oxidized lead wires which may require cleaning before you can solder to them properly.

Highly recommend one of those $15 "Digital Combo Component Tester Transistor Diode Inductor LCR Capacitor ESR Meter" that are available from many vendors on Ebay. It will identify what kind of component, measure the value, give you secondary measurements (like capacitor ESR, etc.) That will help you evaluate which components are still viable and which have expired.