Pre Soldering DB9 Connectors for G540

[QSPSB]

Hey all... I don't have allot of experience soldering and have a question regarding the pre soldering of DB9 connectors... I'm awaiting my G540 and connectors and was wondering if anyone has any experience here soldering these types of connectors... Is it easier to pre solder them? or not?

I ran across a few videos on what I'm referring too here..
YouTube - Solder 3 - 03 Null modem cable, adding cover shells, cable test
Thanks in advance!!
Stoney

[doorknob]

What you are describing is usually called "tinning" the connector pins.

It can make soldering to the pins easier, especially if you also tin the ends of the cable wires prior to inserting each wire into the connector pin. However if the connector pins are clean, the wire ends are clean, and your soldering iron tip is clean and has the proper temperature control, it may not be necessary for you to tin the pins in order to make a good connection. It's best to use really thin solder for this (it will easily melt and flow into a thin film on the surface).

Some DB-9 connector pins may already be tinned right from the manufacturer (in which case there may be no advantage to tinning them by yourself, although you may still want to tin the wire ends). Other types of DB-9s may have a gold or other surface which is not tinned by the manufacturer.

If you do decide to tin the connector pins, you need to add solder sparingly, however - too much will fill up the "cup" portion of the pin, which will make it difficult for you to insert the tip of the wire into the cup before applying heat (inserting the tip of the wire into the cup makes soldering easier because it adds some mechanical rigidity to the joint so that the tip of the soldering iron does not push the tip of the wire out of contact with the pin).

You also want to avoid inadvertently leaving whiskers or blobs of solder on the pins, which can also make it difficult to insert the wires, or can lead to pin-to-pin shorts. Ditto for tinning the wire ends - if you end up with a blob of solder at the tip, just cut off the blob with your diagonal cutters. Also, avoid overheating the wire ends which can melt back the insulation, which could lead to a later short circuit within the connector.

Also, avoid leaving unburned flux on the surface of any pins or wire ends that you tin. You may be able to burn it off when you make the soldered connection, but it is also possible that you will not, which could lead to a bad joint. Swabbing with isopropyl alcohol should remove any left-over flux residue.

The whole process will be faster than it took for you to read this...

[QSPSB]

WOW... Thanks for the tips...

Aren't you the guy that just got a 44991 mini mill?

[doorknob]

Yes, I am one of them...

It's supposed to be delivered tomorrow... Can't wait.

(I've enjoyed reading some of your threads, BTW)

[QSPSB]

Thanks!

Hopefully you'll get a good one as well.. It sounds as that gopher guy got a lemon from the get go.. I haven't had a single issue with mine... these little mills are a good little hobby mill if i do say so myself...

If you haven't already... Pick up some WD-40 to remove that red china crap off your new mill... works great..

[QSPSB]

I picked up some .032'' '' light duty '' & some .062'' standard 60/40 rosin-core solder... Which would you suggest i use? either or neither..

I'm a rookie at this soldering stuff so bear with me

Anybody!!

[bobsch]

Originally Posted by QSPSB I picked up some .032'' '' light duty '' & some .062'' standard 60/40 rosin-core solder... Which would you suggest i use? either or neither.. I'm a rookie at this soldering stuff so bear with me Anybody!!

Either will work. Personally, I'd go with the .032 since it you don't want to use too much solder and take a chance on shorting between pins with a solder bridge. Neatness counts!

[Markwind]

I might also add, to your list,

Be as quick as possible when you apply the soldering iron heat to the pin and wire, just enough to flow, it's easy to heat the pin too hot which can melt the plastic, which can mis-align the pin.

[QSPSB]

.032 it is then... Thanks

Yeah i thought about them little pins getting distorted due to heat buildup.. I'll take your advice and solder them quickly..

Thanks again guys
Stoney

[Al_The_Man]

What kind of iron do you have?
If interchangeable tip it is better to have a long narrow point for doing these, this way you can fill the cup easily with solder first and then insert the tinned end after melting the solder in the cup.
To make a neat job I also but on a 7mm sleeve of heat shrink on the wire and slide it over after the connection is made.
Al.

[QSPSB]

It's a switchable 20/40w radio shack gun... It does have a screw on the side of it... Perhaps that's what secures the tip.. Do you know?

Other than the heat shrink insulating the joint is there another reason why one would do so? I do have a picture of one as you stated.. But the guy said he only did one like this once he found it wasn't necessary

I attached a few shots of my gun... as well as that DB9 connector with heat shrink on the leads..

Thanks
Stoney

[Al_The_Man]

Originally Posted by QSPSB Other than the heat shrink insulating the joint is there another reason why one would do so? I do have a picture of one as you stated.. But the guy said he only did one like this once he found it wasn't necessary

Probably force of habit and to stop moister migration and to make it neat etc.
The Weller series here show the PT-0 series I use for this work.
http://www.jameco.com/Jameco/Products/ProdDS/192170.pdf
I think the one you have probably has interchangeable tips but maybe check Radio Shack.
Al.