Should I use lead free solder?

[JohnForeman]

Hi all,
I'm starting my very first build (tonepad tube screamer) and I was wondering if I should use lead free solder?  I bought some from radio shack and used it to replace the switches in my digitech pds 1550 and it seemed to work just fine.  The solder joints didn't have a high shine like I expected but the joints looked good.  Suggestions?

Since this is my first build, I will be asking a lot of noob questions.. I will make each question a separate post so they can be more easily found by others..

[Mike Burgundy]

My immediate reaction is "No!"
Lead-free solder is a pain to work with - it won't flow nicely, requires temperatures dangerously close to overheating some components, and cools dull, so you can't see the difference between a good and cold joint. I think most people here dislike it.
The whole idea was to stop lead pollution in landfills and such, but for what we are doing that's not an issue. If you can still get 40/60 rosin core, do so. It's still available here (Netherlands) for electronics, although plumbers supplies seem to have switched.  I've stocked up just in case.

[J0K3RX]

NO, NO and NO.... Is there a reason why you would use lead free solder other than the fact that you bought a whole roll and don't want to go buy another roll of 63/37? I would use lead free only if I was going to be working on a child's toy and even then I would probably still use 63/37 rosin core.

[R.G.]

Learning to soldering is hard enough without handicapping yourself with lead free if you can avoid it.

[Earthscum]

Suggestions?

Go back to RS and just get yourself a roll of the Silver Bearing Solder.

That stuff has several advantages for a beginner, one is that it's easy to work with. The better part, for beginners, is that it's small diameter keeps your beads from getting too big. It melts nice and quick, so you can get in and out fast (larger diameter stuff can be a pain to get flowing, and easy to drop too much on a pad). It's easier to control.

[Mac Walker]

"The whole idea was to stop lead pollution in landfills and such, but for what we are doing that's not an issue."

Ironically the number of electronic failures due to manufacturing issues with lead free solder has led to an increase in landfill waste.  Go to ebay and search for Behringer pedals that aren't working if there is any doubt....

The other portions of the ROHS initiative make a lot of sense (such as eliminating cadmium or mercury for example) but this is one case where the Europeans have got it wrong....

Avoid lead free solder if at all possible....

[JohnForeman]

Sorry guys.  I should have said that I know how to solder.  Been doing it for years but have always used 60/40.  I picked up some of the lead free stuff while buying other supplies at the shack yesterday.  I didn't have any problem using it on a pedal repair so I'm not concerned about that.  My 30 watt soldering iron heated it up just fine.  The one reply that got my attention was the heat issue.  I always heat sink when feasible and use sockets on anything critical.  I guess my main concern is with metal interaction at the joint.  Is there any down side or do the components have to be designed to use lead free?  As I mentioned, the joint was dull and at first I was concerned that I didn't get a good joint.  But after close scrutiny under the magnifying glass the joint flowed very well.  If there is any real downside I'll use the 60/40.  Just thought I would ask around before I start building.
Thanks

I should also add, although I know how to solder, I don't have a lot of experience on pc boards other than some minor board repairs over the years.  Most of my skills center around auto/aircraft wiring..  

[R.G.]

We get a lot of questions about lead free solder from beginners. If you like it, have tools which can cope with the higher temps, and the skills to use it, it's fine. I've used it, I just don't like it.

There is no advantage to it other than the theoretical environmental ones. It doesn't make better joints. You don't have to specially prepare joints, use special materials, special parts etc. beyond using the right fluxes and keeping the joints clean, which are needed for tin-lead.

I don't use heat sinks, haven't for decades. This requires good technique; get in fast with high heat on a clean, well fluxed joint, make the solder flow. The "heat sink" is the time it takes the heat to flow down the connecting wires. I haven't heat killed a part in so long I can't remember, and largely don't use sockets. But I've been doing it for a long time.

The real bottom line is that lead free is higher temp, makes visual inspection of joints trickier. It can be done, and done well if you are skilled and persistent. But if you're not soldering enough to contaminate land fills, any advantages are largely moot. Why make it harder on yourself than you have to, unless you just like the challenge.

[JohnForeman]

Thanks for all the replies..  I won't be using the lead free based on heat and visual joint inspection.  As RG said, why make it harder than it has to be..

[StarGeezers]

There were some comments about the lead free solder growing "whiskers" over time , shorting out components ...  Not Sure !!!  But if you open up your pedal and the insides look like a guy from ZZ Top , then you may have a problem .... 

PS, I won't use it on any of my gear ... 

[slacker]

I don't have any problems soldering with it, never have had, if I can do it can't be that hard  

[amptramp]

There were some comments about the lead free solder growing "whiskers" over time , shorting out components ...  Not Sure !!!  But if you open up your pedal and the insides look like a guy from ZZ Top , then you may have a problem .... 

PS, I won't use it on any of my gear ... 

This has been implicated in sudden acceleration in cars where there is a throttle positioner to maintain idle speed regardless of air conditioner or lighting loads.  A whisker can cause the positioner to open the throttle fully.  Conformal coating is often used to prevent this, but lead will also stop whisker growth.

[R.G.]

Yep. Google "tin whiskers".

I think this is mainly from the pure tin coating that replaced tin-lead plating on parts leads. Tin with a voltage difference grows microscopic tin crystal whiskers. Lead inhibits this.