practice.. practice.. practice..

[ThreeSheds]

Going to make my own Megajolt from the Autosport Labs kit so I thought I would practice on something cheap before I start. I bought a 4.99 self assembly thermostat from Maplins. So far I have stuffed the first three components that I tried to solder onto the circuit board

Need a solder-sucker now

I watched 'how to solder' videos on the net and it looked so easy! I have been soldering for years with no problems but this circuit-board stuff is a whole new ball-game...

And that's what I LOVE about my hobby (the RRC) - I am constantly learning!

This week I have learned about variable reluctance sensors, zenner diodes, wasted spark HV polarity and a thousand other snippets.

You know I really don't care if this car ever gets on the road again - I just love messing with it

TwoSheds

[FridgeFreezer]

Did you know that Ford are so tight that on the V6 with wasted spark they specify three platinum plugs (for the side that erodes quicker) and three normal ones for the other side

Solder suckers are handy, also solder wick works surprisingly well. How did you manage to stuff it up exactly?

[ThreeSheds]

Did you know that Ford are so tight that on the V6 with wasted spark they specify three platinum plugs (for the side that erodes quicker) and three normal ones for the other side

Solder suckers are handy, also solder wick works surprisingly well. How did you manage to stuff it up exactly?

Yes, I read about the plugs - one might in a more generous mood, refer to it as efficient design?

I also read (only in one place - and now I can't find it) that the EDIS system reverses the polarity of the HT side depending on which plug is on the firing stroke...

How did I stuff them up? Well first I put the screw-down external power connectors on the wrong way round - not noticing that they had a blind side. (lesson learned - be more careful)

Next I tried a relay - this went on at an angle to the board (lesson learned - use a clip to hold components in place while soldering)

Next I tried the pot - this time I used a bulldog clip to hold it in place - and during the soldering, one of the legs collapsed. (lesson learned - use a lighter clip, like a clothes peg for example)

I have also decided that I really need some way of holding the board while I work - thinking perhaps of resting it on some Kevlar gloves that I have... I probably also need some of those squeeze-to-open clamp things (like tweezers) and a decent set of mini side cutters. Oh and a small fan to take the fumes away... By 'eck it soon mounts up! Another thing I have done (after a bit more research) is to order some 60/40 Sn/Pb resin cored solder, and today I will be nicking an eraser from the office for joint preparation.

Phew! I think that covers it for now

TwoSheds

p.s. Which is best bang for buck - considering that this will probably be a one-shot electronics project - a solder-sucker or this solder-wick that you mention? (I haven't noticed solder-wick, but I can imagine what it's like)

[edwardatherton]

p.s. Which is best bang for buck - considering that this will probably be a one-shot electronics project - a solder-sucker or this solder-wick that you mention? (I haven't noticed solder-wick, but I can imagine what it's like)

I have never tried a solder-sucker, but the wick is very good. I had to use it when I built my megajolt board!

[red90 driver]

Solder suckers can easily stuff up the pads that you need to solder on to. If you get too much heat onto the PCB, then the track and solder pad can lift.

For a beginner, I would reccomend the solder wick. You just melt the solder joint to be removed, and then put the wick onto the solder along with the soldering iron to wick away the liquid solder, and hey presto, there should now be a clean joint.

Solder braid available from:

http://www.maplin.co.uk/Search.aspx?criter...rce=15&SD=Y

I take it you are using a nice small tip on your iron, and you are using a damp sponge to clean it before every set of joints?

TIP: Check twice, check again. If youre not sure about values or orientation, then dont do it.

[Astro_Al]

I'm no soldering expert, but I did have a job making pcbs and then soldering the components onto it for a year or two.

I also suggest using braded solder wick - it really works well, I never needed a sucker.

For supporting your components, I used to chuck a few in the right holes, turn it over (so its soldering side up) and put it down on a large soft foam pad which held the components against the board no matter what their shape. Works well. I would avoid the clip if you can, just sounds like a bit of a handful, and not very effective.

You don't need a fan (isn't all solder supposed to be lead free nowadays - even if it is carp?). Especially if its a one off. Hold your reath if its that bad!

Use a flux if you want to prepare the joints. then make sure you've got heat flowing into both the leg and the board's track/contact, and feed in the solder. It should flow nicely and evenly onto both. Make sure it does and you haven't got it sitting 'next to' one but not actually 'soldered'. You'll see this easily by inspection - look all round each joint, cos one side can be good while the other side has not 'taken'.

Use a nice clean tip, wipe it clean on a moistened sponge pad. you might find 'tinning' the tip with solder helps too (just melting a small amount onto the tip before you use it, so its 'wet').

Careful not to put more heat in than you need. You can destroy components and lift tracks etc.

Hope it helps a bit. Like I say, I'm not exactly proficient, so some of the above may be wrong, but its what I found useful.

Al.

[FridgeFreezer]

I tend to use solder suckers but as has been said, leaving the iron on the PCB too long whilst prodding it with things can lift tracks and pads off the board. I am fortunate enough to own a desoldering iron, which is the bling way of doing it B)

A few tips / common practices:

• Use a fine pointed solder tip and 50W iron, it may seem counter-intuitive but a low-powered iron can leave you heating a component for longer before the solder melts, rather than a quick stab and done.
  
• Use 0.4mm solder - gives better control and also seems to contain more flux per length than the thick stuff
  
• Place components through holes and then bend the legs out slightly to keep them in the holes before turning over & soldering
  
• Get some decent side-cutters, the ones with the little extra bit that stops the off-cuts pinging off everywhere
  
• Keep your tip clean, use a damp sponge, and for worse use a tip cleaner tinner from Maplins.
  
• Those little "helping hands" stands that are adjustable arms with a pair of croc clips are useful for PCB and connector soldering, they often crop up in £1 shops - buy a couple.
  

[Bull Bar Cowboy]

Sounds like you may be using too much heat ............. a 15 watt iron with a 0.5 or 1mm tip is all that is required for PCB's.

When it comes to removing components I guess you will find that those of use who do it on a daily basis (like fridge & me) will always use a PTFE tipped solder sucker............. just enough heat to melt the solder then suck it off remove it with the sucker. Then gently heat the componet wire / chip pin and you will hear it click free form the PCB pad.

Solder wick is for plumbers

Ian

[ThreeSheds]

Thanks all!

As always on this forum - lots of superb advice - I will certainly take on board all I can from what you have said.

I have a 30 year old electric iron and a nice spanker Portasol with a 2.5x1 tip and have just been out an bought some self-gripping tweezers a sponge and a sucker. I'll let you know how I get on...

Cheers

TwoSheds

[FridgeFreezer]

I have a 30 year old electric iron and a nice spanker Portasol with a 2.5x1 tip and have just been out an bought some self-gripping tweezers a sponge and a sucker. I'll let you know how I get on...

Just to be a PITA I would hesitate to use either of those near a PCB, the old iron is likely to be more suited for plumbing and the portasol could get too hot and lead to damage, especially while you're learning the ropes (Portasols are great bits of kit to have about though). You have to watch where the exhaust of the portasol is pointing too

I would recommend this from Maplins, I bought two last time I was in there, they're great for the money.

I realise I've contradicted Ian's advice with the 50W iron, but I reckon being temperature controlled helps prevent it getting too warm and being 50W it will get to temperature quicker. Certainly mine has done sterling service and built about 10 megasquirts and counting.

[ThreeSheds]

I would recommend this from Maplins, I bought two last time I was in there, they're great for the money.

wow! How do they do it for £10? Well I guess if I want to do this properly then another trip to Maplins isn't out of the question. Sorry Sam (my dog) - that's another hungry night coming up...

[FridgeFreezer]

wow! How do they do it for £10?

I don't know either - I bought one when they were £20 and thought it was great then, unfortunately I left it turned on in the loft for about a month without realising and it burned out so I went to replace it and ended up buying two just to have a spare. While you're in maplins buy the tip cleaner tinner thing too, it's a tiny metal tin (about the diameter of a 10p) containing a sort of solder/flux/mild abrasive paste and does exactly what it says on the tin

[ThreeSheds]

I don't know either - I bought one when they were £20 and thought it was great then, unfortunately I left it turned on in the loft for about a month without realising and it burned out so I went to replace it and ended up buying two just to have a spare. While you're in maplins buy the tip cleaner tinner thing too, it's a tiny metal tin (about the diameter of a 10p) containing a sort of solder/flux/mild abrasive paste and does exactly what it says on the tin

Well neither of my nearest Maplins have any in stock so I ordered one and a tin of tinner too from the net - also got some heatshrink which means tha tI got free postage However it does mean that I won't have it for a couple of days so I'm going to put my soldering practice on hold until it arrives.

Thanks again for all the advice

TwoSheds

(p.s. FridgeFreezer - TEN Megasquirts? Phew! That's got to be some kind of a record?)

[HoSS]

Did you know that Ford are so tight that on the V6 with wasted spark they specify three platinum plugs (for the side that erodes quicker) and three normal ones for the other side

3 x 5 quid x 1 million cars = 15 million quid.

I wouldnt be giving that away unless i had to. Is that tight? B)

Just to add my 2p....

I think 15W is a bit too small for anything. I do very delicate surface mount work with a 80W iron. FF is correct, not getting enough heat in quickly is more likely to make a bad joint than vice versa.

But, my 80W is temperature controlled... and thats the problem with the cheaper irons. Buy the cheapest temperature controlled that you can. The one the FF linked to looks fine.

The other complication that has been introduced in the last couple of years is lead-free solder. It has now become mandatory. there are a number of different solders, some containing silver or other metals. None of these solder as well as 60/40 lead/tin, and most except the extotic require a higer temperature. the ubquitous wiki link http://en.wikipedia.org/wiki/Solder

If i had to give you a soldering lesson in 20 words:

- Clean & tin the iron tip before each operation.

- put the tip in contact with the pcb & component lead

- a split second later introduce the solder, it will flow in. get just the right amunt to make a nice concave joint.

- remove the iron asap after the solder flows.

[101nut]

Lead free solder is now mandatory for commercial use but is still ok for personal ... I use lead based all the time as lead free is generally utter c**p. If you must use lead free make sure it's got silver in it, don't use the cheapest you can find and for your application use 22swg and a 1-2mm tip (you may find a bigger tip a little easier to handle as it holds the heat better). Temperature should be set so that you touch the iron firmly on the joint, dab the end of the solder wire onto the joint and it should almost instantly melt and flow cleanly. You shouldn't have to hold the iron on the joint for more than a second perhaps (though you will until you get used to it). If the solder doesn't melt make sure the iron is hot enough, it's clean and tinned and if the solder doesn't flow well make sure the board and component legs are clean.

Oh, and it you do support the components using foam make sure it's not a low melting point type stuff because that gets very sticky if you use a bit too much heat ...

AndyG

[missingsid]

My two penneth.

Definitely use a Temperature Controlled Iron

Keep the tip clean – old solder will oxidise on the tip Wipe the tip on damp cloth, flicking the iron is not a good idea!

Only use multi core solder

Even when at work we ditched the low temp solder as it was carp and (illegally?) used lead solder (this was awhile ago).

Don’t leave the heat on too long or you will loose the copper pad from the PCB or destroy the component.

Power Transistors will need a heat sink and heat conductive compound and insulators once installed.

Even after bending the component legs out to hold them in place some still fall out so I don’t place too many at one time but fit some and solder then fit some more.

Personally I use a good solder sucker

Even after removing the solder some will/may still stay inside the component hole as surface tension will keep it between the component leg and the plated hole. To remove the item you will need to break the solder by GENTLY rocking the leg back and forth or round in a circle.

If you are not sure of soldering chips into the PCB then buy chip holders and solder them in first (if you have the space).

Chips do not like static electricity you must ground yourself before touching a chip or a PCB with a chip on it. It won’t stop working straight away but it does seriously reduce it’s life expectancy (Military grade chips have each leg protected better than commercial chips or so I was told at work).

Take your time like most things rushing is a bad idea.

Hope this was useful and not just me spouting off?

Good luck with the build and I for one would be interested in how it goes when you get to the final project as I hope to build my own Megasquirt in the future.

[ThreeSheds]

Thanks for all the advice

Yesterday I received my spanky new (£10) variable heat soldering station from Maplins, but the tip cleaner - that the web-side said was in stock - is not, and so I will be waiting for that so that I can do some more practice before I start on the MJ kit that also arrived yesterday Man those pads are small! I reckon around half the size of the ones on my practice project. No way could I have done this with the Portasol!

Got the SWMBO staying at the moment so not much happening on this front, but will post some pics soon

Thanks again guys - I know that I would have made a real mess of this if it wasn't for all your help.

Roger TwoSheds