Solder sticking issues.

[RLM]

I've had a blast at a few vmods over the last few months. pretty new to the soldering game.

First of I did the sensible thing and practiced on an old sound card, which went pretty well.

I then had a blast at my old IP35 Pro, and for the life of me couldn't get the solder to stick to the IC (Is that the right name?)

Recently I've modded my 8800 GTX, and that's gone pretty well. I've actually had to do it a few times, as I managed to pull the wires out, while re-mounting my waterblock. All good practice.lol

The solder to the IC for the volt mod, albeit a bit tricky, didn't present any major issues. However soldering to the ground point just above one of the six pin power sockets did.

Again the solder wouldn't stick. In the end I sanded it down a bit, and this seemed to help. I've also since dropped a couple of globs of super glue over that connection. not sure if that's a good idea or not.

So I'm just wondering now, is it my :banana::banana::banana::banana:e soldering skills, or do components sometimes come with a coating that can cause problems for soldering?

RLM

[zsamz_]

use flux it helps alot
put tiny amount on exact spot you want to solder "dont need much"
put some solder on end of wire n solder to spot
personnally i always but flux on wire end too wire suks solder up nice
i hate having solder on soldering iron in case i get a drop on board

[RLM]

zsamz_,

that's some great advice there, which i am going to try out on future mods.

I would like to know a bit more about the flux though.

How do you buy it, what form does it come in. From what I can see it's a liquid right? Would you apply it to the area with a small paintbrush maybe?

RLM

Edit. I see on radioshack it comes in a paste or as solder. Still none the wiser though.

[Sparky]

I use rosin flux core solder so it is already there. Works well and has satisfying smoke wisps rising from the work :devil:

Though I've never done any vmods but I do a lot of other board work (board repairs mostly).

[GMX]

to me it sounds like your solder is too hot and too much.

[RLM]

Possibly GMX, though I'm not convinced. I use a 20w iron for starters (shouldn't be too hot should it), secondly it's not a consistent problem I have, more a consistent problem with certain solders. Looking at the ground connection on the GTX for instance, there appears to be slight yellowish gunk over the connection, which is why I mentioned coating.

Could be wrong though. I know there's an art to it, and practice is probably key.

Still going to look in to flux though.

RLM

[ShootStraight]

Sounds like a cleaning issue. Might be some sort of lacquer or oil on the IC lead.

Perhaps try a pencil eraser and some elbow grease. Or a q-tip and a little acetone?

-SS

[harleybro]

The q-tip with acetone may work and if not scratch it with the tip of a knife if it's too small to sand. Sometimes you will come across a coating on parts that is really tough to make solder stick to.

[Fungus]

I've been building and repairing equipment for 15+ years. So here's my tips.

the q-tip + acetone is a good tip to pre clean the parts.
a pointy implement (like a retractable pen) and a bit of 600 grit sandpaper to rough up the connection point, or clean a part to prep it for soldering.
the same sandpaper to do the same thing to the end of the wire your going to attach. And yeah, "tin" the wire first with solder.

Using GOOD solder is the key, rosin core (never ever use acid core on electronics!) my favorite brand is Jacques Ebert (JE). Excellent whetting characteristics, get the .031 inch diameter stuff for surface mount. 60/40 lead/tin of course.

Always wear some kind of gloves while handling solder as it does contain lead, and if you do not, wash your hands thuroughly after using it, in a WELL ventilated area. Solder smoke is preety bad for you, not just the lead but the rosin too.

Your 20 watt iron should be ideal for this work if it is a weller iron. Rat Shack irons are crap. ;)

Heat the work and apply the solder to the work, not the iron. When the work can melt the solder, you will get a good connection. Be careful not to overheat parts. Overheating will cause traces to lift or the part to be destroyed. Don't blow on the connection afterwards, this will cause a bad solder joint, let it cool naturally. You can also hit the parts with some Freeze-It BEFORE soldering.

I'd suggest some pretty small stranded COPPER wire for this kind of work, 22 or 20 gauge, or even 24 if your soldering directly to chips.

Flux also continues to work, after you have done your soldering... so it's a good idea to clean it off afterwards with some acetone.

Cheers.
:up:

[RLM]

Some great info here. Thanks to all of you, much appreciated:up:

RLM

[yngndrw]

If you're failing to solder to the ground only. (Did I read that right ?) Then it's because your soldering iron can't heat up the larger volume of copper.

You need a more powerful iron, I use a 65Watt Weller for my Electronics and I have no problems. :o Weller even do 80Watt soldering irons.

[Ragnarok]

Also don't be afraid to apply heat, especially for contacts with large surface areas

roughing up the surface also help

[SPL15]

You need more heat!

A 20 Watt soldering iron is good for about nothing

I use temperature regulated HAKKO solding irons and I set them to 750F to 800F.

If you have lots of heat and your solder STILL wont stick, you need better solder. Flux is what chemically cleans the surface to be soldered. If your solder is old, poor quality, or the surface is oxidized your solder wont stick.

Super glue on a solder joint to keep it on is... well... umm... counter productive to put it VERY nicely.

Also, now that you have put super glue on the contact surface you must remove ALL of it every last bit or it will burn and stick to the surface to be soldered and and prevent the solder from sticking.

A good way to clean off regular oxidized contacts is with a nice fresh pink eraser from a pencil. It has to be nice fresh and CLEAN. If the rubber is hardened or has gunk on it, it will just smear on the contact making it worse. After you "erase" the oxidation, you gotta wipe off the residue or it will burn and prevent contact also.

My recommendations:

45Watt Fine tip Soldering Iron
Kester 77 Solder Fine stand

With this combination you wont need to rough up the surface or use flux or do any wierd things to get the solder to stick unless your surface is really oxidized and even then, a little more heat will do the trick.

Stay away from lead free (RoHS Compliant) solders if your less than 800F iron temp. They need more heat and I havent found them to stick as well as regular lead solder.

There is a BIG misunderstanding about soldering iron heat and damaging electronics.

It is MUCH MUCH better for the components being soldered if you use lots of heat and get the job done quick. It is more damaging to components if you have to keep the iron on the joint to heat it up and then have to hold the iron on the solder to melt it. You end up with a "Cold Joint" it may look OK, but it isnt nearly as strong as a good hot quick joint. Lots of times with cold solder joints the solder hasnt melted the surface of the copper well enough to bond with the lead and tin solder. The solder flows, may even look good, but give it time, heat and high current, the joint will fail.

Typical components are rated at 300C for 10 Seconds before damage may occur. If you use a really hot iron, you can quickly get the joint done in less than 1 second which doesnt heat up the component to 300C and the duration is a fraction of a second. If you use a warm iron you must heat up the part and reheat the part when solder hits it and it is enough to heat the actual component and for longer duration of time. If your iron is hot enough to melt solder, it is hot enough to damage components no matter how low the temp is. The quicker the job the better and the only way to do that is with a good hot iron thats at the minimum 700 degrees F.

Also, NEVER use super glue to secure a solder joint. If you wanna use it to electrically insulate a GOOD solder joint thats ok, but Super glue is not conductive and defeats the whole purpose of a solder joint. Super glue to fix a solder joint is like using Duct tape to fix a fiber optic cable (which I have seen before)

I get back LOTS of electronic PCB's in my job that have been poorly soldered and superglued... I usually send the customer back the board and dont even bother with it cause it's gonna cost them double the time for me to clean up the hack job.

Remember good Hot Iron, Kester 77 Lead Solder and you wont think twice about soldering a good vmod ever again, and you wont have to douche the contacts with flux or rub 600 grit sandpaper, or any other little tricks to get it to work. I gaurentee ya that 110% I promise.

Oh Ya, the yellowish gunk is flux from the solder. It's not laquer or special coating, just excess flux from the solder. Dont bother removing it, just use Kester 77 solder and you'll be fine

[RLM]

I'll have a good read through that advice, thanks a lot for taking the time.

Just from a quick scan, this quote stood out though


Super glue on a solder joint to keep it on is... well... umm... counter productive to put it VERY nicely.

LOL, okay point taken. I'll use something like a band aid next time(joke).

Right have now read through that. I didn't use super glue to stick the joint. The joint was already stuck and then I covered that with a few blobs of glue, just for good measure. So I think I'm okay there.

Very interesting and detailed advice though. I'm certainly looking forward to my next mod. Thanks again to all of you.

RLM

[hawtrawkr]

does the solder with flux in it still help even if youve already used flux on the contact points?

[Pacha]

You need more heat!

A 20 Watt soldering iron is good for about nothing

I use temperature regulated HAKKO solding irons and I set them to 750F to 800F.

If you have lots of heat and your solder STILL wont stick, you need better solder. Flux is what chemically cleans the surface to be soldered. If your solder is old, poor quality, or the surface is oxidized your solder wont stick.

Super glue on a solder joint to keep it on is... well... umm... counter productive to put it VERY nicely.

Also, now that you have put super glue on the contact surface you must remove ALL of it every last bit or it will burn and stick to the surface to be soldered and and prevent the solder from sticking.

A good way to clean off regular oxidized contacts is with a nice fresh pink eraser from a pencil. It has to be nice fresh and CLEAN. If the rubber is hardened or has gunk on it, it will just smear on the contact making it worse. After you "erase" the oxidation, you gotta wipe off the residue or it will burn and prevent contact also.

My recommendations:

45Watt Fine tip Soldering Iron
Kester 77 Solder Fine stand

With this combination you wont need to rough up the surface or use flux or do any wierd things to get the solder to stick unless your surface is really oxidized and even then, a little more heat will do the trick.

Stay away from lead free (RoHS Compliant) solders if your less than 800F iron temp. They need more heat and I havent found them to stick as well as regular lead solder.

There is a BIG misunderstanding about soldering iron heat and damaging electronics.

It is MUCH MUCH better for the components being soldered if you use lots of heat and get the job done quick. It is more damaging to components if you have to keep the iron on the joint to heat it up and then have to hold the iron on the solder to melt it. You end up with a "Cold Joint" it may look OK, but it isnt nearly as strong as a good hot quick joint. Lots of times with cold solder joints the solder hasnt melted the surface of the copper well enough to bond with the lead and tin solder. The solder flows, may even look good, but give it time, heat and high current, the joint will fail.

Typical components are rated at 300C for 10 Seconds before damage may occur. If you use a really hot iron, you can quickly get the joint done in less than 1 second which doesnt heat up the component to 300C and the duration is a fraction of a second. If you use a warm iron you must heat up the part and reheat the part when solder hits it and it is enough to heat the actual component and for longer duration of time. If your iron is hot enough to melt solder, it is hot enough to damage components no matter how low the temp is. The quicker the job the better and the only way to do that is with a good hot iron thats at the minimum 700 degrees F.

Also, NEVER use super glue to secure a solder joint. If you wanna use it to electrically insulate a GOOD solder joint thats ok, but Super glue is not conductive and defeats the whole purpose of a solder joint. Super glue to fix a solder joint is like using Duct tape to fix a fiber optic cable (which I have seen before)

I get back LOTS of electronic PCB's in my job that have been poorly soldered and superglued... I usually send the customer back the board and dont even bother with it cause it's gonna cost them double the time for me to clean up the hack job.

Remember good Hot Iron, Kester 77 Lead Solder and you wont think twice about soldering a good vmod ever again, and you wont have to douche the contacts with flux or rub 600 grit sandpaper, or any other little tricks to get it to work. I gaurentee ya that 110% I promise.

Oh Ya, the yellowish gunk is flux from the solder. It's not laquer or special coating, just excess flux from the solder. Dont bother removing it, just use Kester 77 solder and you'll be fine

thank you very much for these tips, I'm almost in the same situation a RLM

can you explain me a little further what Kester 77 is and where I can purchase it? I've been googling for it and searched on Kester website but I couldn't find something relevant.

I'm currently soldering with crappy tin and a 4$ 20W iron, sometimes I get good solder, but it looks awful and won't stick most of the time.
I'd really like to find some better equipment in order to have my solder stick better and vmod in a easier way.