OT - problem soldering Dump Controller

[paulrogers6]

Hey Guys

Only indirectly related to renewables in that I was trying to assemble on of Ghurd's controllers.  I picked up the first soldering iron to hand (40W draper model I'd got for use on the car) along with some lead free solder.  After about half an hour (I'm a very slow solderer) the tip on the iron had "dissolved"!!  Why would this be?  Is the solder corrosive (presumably the flux is to clean the work)? Even so there must be something wrong with the iron surely? Are automotive irons different to electronics ones? or is the iron just cheap (and C**p)?

Sorry for such a weird question but there seem to be a lot of knowledgable folks here who probably know the answers.

Hope no one minds - otherwise apologies in advance.

regards

Paul

[Flux]

I risk upsetting the world with my comments but I will say it anyway.

There may be a case for concern about tons of electronic junk going into landfill so commercially lead free solder may make sense.

For one off home construction you are not going to pollute the world and you will be far better off using conventional eutectic lead /tin solder, it will make a far better job and will not need the high temperatures of the lead free crap. These materials need fairly accurate temperature control and it depends on the grade of solder. Your uncontrolled iron is not a precision device but it will work well enough with conventional solder.

There is always bit erosion problems and the better soldering iron bits are iron plated to reduce this as much as possible. Multicore and perhaps others produced a special solder with a trace of copper in it to reduce this bit corrosion, Multicore's version was called savbit but most of this is being phased out in favour of lead free for the large manufacturers who have to comply with regulations.

Unless pcbs are designed for lead free soldering you may also have trouble with tracks lifting but Ghurd's boards should stand it.

If you have this tip erosion problem then your tip is likely to be copper and you can just file it back flat and re-tin it just like we had to do in the days before iron plated tips but we didn't have the problem of lead free solder to contend with.

Flux

[luv2weld]

One more thing that should be added---
Make sure you are using solder and flux made for electronics!!
Never use plumbing flux on electronics. It is acid based.
A lifetime ago I was taught that the best lead/tin solder for electronics was a mixture that was 63/37.


Ralph

[tanner0441]

Hi

You can still get Tin/Lead solder I bought a 1Lb roll within the last six months, all it says on the roll is tin/lead 40/60 fluxcored super solder 1.2mm. As for soldering irons I always use an Antex Ceramic bit for fine electronic work, I would have thought 40W was being a bit adventurous. If you do like a challenge I have a 400W tinmans iron that was my fathers.....

Make sure you clean all the flux residue off though or it can eat into the tracks unless it has a good coating of solder mask.

Brian

[paulrogers6]

Hi Guys

I'd bought the lead free solder to have a go at soldering some DIY solar panels!! I assumed that aside from the lack of lead the the two solders be alike enough for me to just use the first thing that came to hand (see a theme developing here - alittle knowledge is a dangerous thing eh??).  I tried using my little 30w iron but it wouldn't melt the solder.  Having read Flux's response I now know why.  So I then tried the larger iron.

When Flux said just file the the tip back to a flat shape - there's not actually anything left of the tip.  I just managed to finish the soldering before the tip disintegrated completely!!

I see now I should have stuck with the lead solder.  From what everyone's saying the combination of the copper tip and the more corrosive non lead solder is causing the tip to "dissolve".  Is that correct?


Thanks for all the advice.

Regards

Paul

[DamonHD]

I had to "upgrade" immediately from a 25W to a 50W (temp controlled) iron to use the lead-free stuff at all.

I think I got entirely new tips speced-for-the-job with the new iron, so I haven't seen anything dissolve!

Rgds

Damon

[TomW]

I keep buying 60/40 by the # on feebay. Too old school to learn new ways. Would not even consider lead solder on plumbing of course but the tiny bit I use sticking things together will not likely leach into the environment in any worrisome amounts (unlike a certain Busted Pipe). I agree it is good they don't use it in bulk operations but my pidlin amount is no concern.

Just my opinion.

Tom

[ghurd]

I have no idea who can get what where.

Regarding the kit-

I tell people a 40W iron is too big.  Usually a 40W tip is the size of a pony.  It is too large.  And too hot.
I use a 15 or 20W.  A cheapie from RatShak.
My solder guy uses a temp controlled iron with a Long Thin tip.

We use 60/40 or 63/37 Rosin core.  Not silver bearing solder.

We use 0.030" to 0.032".  Could use 0.062" due to cost and availability, but in volume soldering of small stuff 0.031" is worth it to him, and we combine orders.

I think the tips (of typical irons) go bad from being to hot.
A typical 40W iron will get darn pretty hot if it sits a long time only melting a bit of solder on small connections.
I have to file my USED tip after about an hour, and that is a 15~20W doing quite a bit of soldering.  NEW tips last a lot longer until they are overheated, or have been filed down once.

The tips can Not be filed down too many times, or they seem to disappear faster, get too hot faster, and certainly do not work as well.

Keep the tip clean.
That black crud seems to be related to how fast the tip disappears.  However it could be related to how long the tip is sitting and heating up (overheating) without doing enough work.

The ghurd kits boards have 2oz CU, through hole plated, and double sided.
If the tracks lift, pretty sure the whole area was far too hot for far too long.  It was one of the issues I tried to avoid during the PCB design.

Lead is out there already, and always has been.  Especially for residents of California, according to the tags.
2.5oz of 60/40 that works is probably overall better than 8oz of PB-Free that does not work for the hobbyist.

My recent order of solder was canceled.  I hope that is not a bad sign.
G-

[paulrogers6]

Hi Guys

many thanks for all the replies - taught me a lot.  Think I'll stick to lead solder in future.  I did notice some of the tracks on the board had lifted but I assumed it was where I'd managed to clobber them some how.  Now I know better.

As I stated before I'd originally been advised to use the lead fee stuff for the solar cells and assumed it was some how better overall.  The environmental impact had never crossed my mind.  AS Flux says the amount of soldering I do it's not likely to have much impact.

Glen - thanks for the info on the boards manufacture.

All the best for now

Paul