Posted by Gary Dodge on April 26, 2003 at 01:15:58:
In Reply to: Brass lamp caps posted by andrew on April 23, 2003 at 14:44:15:
HI Andrew,
In all likelihood the culprit is not enough heat. Brass is an excellent conductor of heat and as soon as you lay an iron on it it begins to take the local heat you are applying and spread it around the cap. As a result it can be difficult to get enough heat to truly bond to the brass with a small iron typical of most hobby work.
If at all possible switch to an iron in the 150 to 200 watt range while soldering heavy brass. Another option is to use a torch when tinning the inside of the cap. Turn the flame directly on the brass and use a flux brush to spread the solder.
One last thing that might help is if you rough up the inside surface of the cap with sandpaper before soldering.
GaryD
: I normally use heavy brass caps (5 inch diameter) on stained glass lamps. I pre-tin the inside of the cap with solder, then line the cap up with the lamp and continue soldering the cap to the lamp. Usually, this works just fine but occasionally the cap begins to peel away from the lamp! The solder simply breaks away from the brass cap.
: I would be grateful for any advice!
: Many thanks, Andrew