Thin component leads not melting solder.

[frogman]

Pretty basic question here... I've recently finished my first pedal build on vero board. I had some 1/4 and 1/2 watt resistors from tayda electronics as well as some 1/2 watters from radioshack that I picked up last minute. By far, the biggest frustration of building was melting the solder joints around the resistors to the vero board. While each joint around the capacitors and pretty much everything else melted smoothly. The 1/4 watters had to be replaced with 1/2 watters because there was not enough heat transfer. Even the 1/2 watt resistors took a while. I'm talking minutes for each joint. Tried using flux, also tried to use a knife to skin the leads. However, when I grabbed the  the 1/2 watt resistors from Radioshack and applied solder to them, the solder melted much faster and normally. I realized it was only the 1/2 watt resistors I purchased from Tayda that were difficult to work with. I looked and saw that the leads were a bit wider. I am not sure if there is any difference in material... The soldering iron and solder I am using are both good quality and I am sure they are not the issue.

Is there some spec that refers to the size of the leads?

If anyone else has experienced this, do you know of one of the many electronics websites that sells resistors with leads like the ones at radioshack?

I suppose I could always buckle down and buy from radioshack, but if there are better prices out there for good quality, it would be cool to know.

Thanks,
Andy

[mth5044]

I've used both the resistors from Tayda and not had a problem. It should never take minutes to solder what we do. If it takes 5 seconds, it's still pretty long. What is the wattage of your soldering iron and what type of solder do you use?

[Seljer]

Are you by any chance using the new "environmentally-friendly" silver solder?

Go a find a spool of the old pre-restriction lead based stuff. It sticks to stuff way better and at a lower temperature

[merlinb]

If it's taking more than a couple of seconds to make a joint, YOU'RE doing it wrong. No doubt about it. Sounds like there's something wrong with your iron, or you've accidentally picked up a roll of tinned-copper wire instead of solder! (I've done that more than once   )

[R.G.]

Try soldering one resistor lead on a resistor that's not in the board, just lying on the bench. Will the soldering iron heat it enough for the lead to melt the solder?

The question about your soldering iron is pertinent: what is your soldering iron wattage (and what condition is its tip in, shiny and bright with molten solder or brownish gray with oxidation), and what solder and flux are you using.

Something is dramatically wrong here, and chance are it's not the resistors.

As merlin notes, a solder joint on little stuff like this that takes more than two seconds is evidence of bad prep or bad technique.

[KazooMan]

Soldering a resistor lead to vero should take just a few seconds.  I'll reiterate a few questions from above and add some more.

Tell us about your iron.  What wattage is it?  Tell us all you can about your solder.  Where did you get it, brand, metal composition, flux, etc.  

Curious what pedal you are building that requires 1/2 watt resistors.  

What technique are you using?  There are many good tutorials on the web.  Google "soldering electronics"  and check out several of the links.  In general, you need good clean leads, good solder with an appropriate flux or perhaps added flux from a "flux pen".  A HOT iron is very important.  Clean and tin the tip well.  Touch the tip to the lead and the vero and then apply solder at the joint.  This should all be over in two or three seconds for thin leads like resistors.  The minute you describe suggests something is really wrong.  You could never do this for sensitive components like transistors or ICs without destroying them.

You probably know this, so don't take offense.  You shouldn't  be applying solder to the iron and then try to transfer it to the connection.  Sometimes applying a tiny bit of solder to the iron helps it make a better thermal contact with the workpiece, but the solder for the joint should come after heating.

One of the best decisions I ever made was to invest in a good soldering station.  They heat up quickly to controlled high temperatures and can continue to generate heat for larger components where a lesser iron may cool off and not be able to do the job.

Tell us about your gear and we can try to help more.

[tommycataus]

Just to add to the above, I use Tayda resistors and have noticed the difference although never had a problem. 30 watts should be plenty of power to heat the leads. I agree that you need to check the composition of your solder. Use lead-tin with a flux core if you aren't already.

[vigilante397]

Corrosion on the solder tip can be a problem as well, especially on cheaper irons. The corrosion prevents the transfer of heat. Use some steel wool and gently clean the tip.

[frogman]

I'll try to respond to everything in one post. My iron is a hakko fx888 digital soldering station, I believe it is rated at 70w. I am using alpha rosin core 60/40 solder. The flux is radio shack brand. I usually have it around 700° f.

When making a solder joint on a lead going through vero board, I just touch the untinned tip to the lead about 1/4 inch from the joint-to-be and i flow the solder. I have a steel/copper whool pad that I clean the tip with. I always tin it after use and it is a nice shade of silver. The only reason I switched to 1/2 watt resistors is because their leads seem to be thicker. I have found that thicker leads heat up for me much quicker. 

I will try heating up and melting solder on one of the resistors, without the veroboard sometime tomorrow and report back.

[Buzz]

Maybe your problem results from trying to flow the solder down the component lead.



How I do it looks like this.

First holding the tinned tip of the iron at the joint, to heat the component and trace. About one second at 360 deg C.

Then touch the joint with the soldering wire, with the iron still in place. The solder flows almost instantaneously in a nice little cone.

60/40 rosin core seems to do the job.

[Jdansti]

Here's a great soldering video that should help. Even the old timers might learn something from it.

[KazooMan]

I agree with the others.  You need to have the iron touching the board and the lead. 

Very nice iron by the way. 

[allesz]

Hallo, have you tried to give a little "touch" of fine sandpaper at the resistors legs before soldering?

Never had this problem with resistors myself (I don't shop from tayda), but sometimes had to do this with pots or jack plugs.

[duck_arse]

and you need bright shiny clean copper traces on the veroboard, as well.

[pappasmurfsharem]

I just touch the untinned tip to the lead about 1/4 inch from the joint-to-be and i flow the solder. I have a steel/copper whool pad that I clean the tip with. I always tin it after

This is your problem you need to touch the soldering iron to ON the component and ON the board.

[Jdansti]

^ ...and have a little solder on the tip to allow the heat to flow to the lead and pad.

[frogman]

I just touch the untinned tip to the lead about 1/4 inch from the joint-to-be and i flow the solder. I have a steel/copper whool pad that I clean the tip with. I always tin it after

This is your problem you need to touch the soldering iron to ON the component and ON the board.

That was exactly the problem. Good reminder that I am still new to all of this.