What am I doing wrong? (soldering question)

[kryptobs2000]

I use this solder http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F009%5F007%5F001&product%5Fid=64%2D005 and a 15/30w iron (usually use 15w). Problem is I always have trouble getting the solder to flow. I have tried putting flux on w/e I am trying to solder to, but it still dosn't help too much. I've been soldering for almost a year if not more, I've done all the nf7-s mods, 9700 pro vddr and vcore, modded all my psu rails. yet I still havn't gotten it down. I always have this problem. It just dosn't seem to flow, it will melt, yet just sit there, it dosn't flow onto the component as I imagine it should :(

edit: if ur too lazy to click the link, it's 60/40 rosin core solder .032 diameter

[Tatewaki]

are you trying to solder to a ground pad? when soldering to large ground area, you'll need to supply more heat. Solder will not flow to cold surfaces.

[kryptobs2000]

Thats probably my problem, so if I just let the solder heat up the surface I am attaching it to it will eventually flow to it? Right now I'm trying to do the 6800 GT 2nd molex mod, and it's pretty easy, no small spaces or anything like that, it's just bothering me, since I always have this problem. Particular thing I'm trying to do right now, is solder some caps to some smd caps on the 6800. Should I just use 30w, or what? I would think it should work with 15w.

[Tatewaki]

if 15w can make the solder flow fine, stick with 15w. One tip for soldering is to use only the amount of heat require to have good wetting. If you are soldering to ground, try raising the tip temp (just a bit), then have the tip sit on the ground pad for a while so the heat can conduct to the entire pad (just place the tip there, don't rough it in) Once it's hot enough, you can then apply the solder. If there are solder already on that pad, when hot enough you'll see that solder slowly flowing.

[kryptobs2000]

Still isn't working for me, I can't get these caps on. This is easier than all the other mods I've done (besides psu) and I can't do it :( been trying for almost an hour. All I've managed to do is melt the smd cap on the 6800 a little bit. I don't know what I'm doing wrong. The solder just won't connect or flow onto the solder points on the smd caps.

[Tatewaki]

hm...is this 6800 fairly new? I don't suppose nvidia changed to lead-free solder already...?

[kryptobs2000]

I dunno, would that make it alot harder to bond the two? I still have this problem with everything else, so... more likely my fault/inexperience

edit: I just rememberd though that I used to use lead free solder. I think I did for all my mods except maybe the psu mod, so that could have contributed to my problems before. I know lead free solder is harder to melt, would it also make it harder to flow/bond?

[Tatewaki]

yes it would. lead-free solder melting point is 217, traditional 63/37 solder melts at 183. lead-free solders are known to have less wetting

[kryptobs2000]

I don't think it's lead free, just my fault, but I got it on. I just tinned the smd cap, and it went on right away. I normally don't tin what I'm soldering to, either because it's too small, or I don't want to get it too hot.

http://img159.exs.cx/img159/358/dscf07360jy.th.jpg (http://img159.exs.cx/my.php?loc=img159&image=dscf07360jy.jpg)

[SPL15]

Some people say use only the amount of heat needed, but I've found personally that this doesnt work well. Use as much heat as you can (Within reason). The best way to solder is to get in and get out. if you gotta hold a luke warm iron to a surface to heat it up first then your doin it wrong and risk damaging whatever your soldering. 15 watts is way too low of power. For unregulated cheap irons I recommend 30 to 45 watts.

Think of it this way, does it hurt more to wave your finger fast across a blowtorch flame or slowly across the flame of a bic lighter? Electronic components are the same way. They are safer with short duration of high heat than long duration of slightly lower heat.

When welding, if your heat isnt high enough, you'll get a cold joint which is weak, the same is true for soldering electronic components.

Also, I've used Radio Shack solder and it is absolute crap.

My irons I use are regulated to 700 Degrees fahrenheit which is about perfect for my particular iron because it is a regulated expensive set.

But no matter how good your iron is, if your solder is cheap crap then you'll never get good joints. I use solder for no clean environments and these seam to flow the best and resist vibration damage the best. In my experiances, No clean solder products work far better than normal stuff. I really hate rosin core solder, makes a mess doesnt flow as nice as no clean.

Also small tubes of silver solder with thin diameters work great for what you want to do.

[Iggk]

it's allso verry important to keep the tips clean and allways tin the iron before storing it for any length of time if the solder isnt sticking to the tip or balling up in 1 spot you need to clean the tip. to clean it just skuff it up a bit with a fine (220 grit or finer) sandpaper or emery cloth. then dip it in some flux and tin it, if you dont have flux rosin core solder allso work's

[phobos]

Before you solder, clean the tip (when it's on temperature) on a wettish (not wet!!) sponge and put some fresh solder on the tip each time you start to solder. The solder helps to transfer the heat to the soldering pad and it has to be fresh because you need flux in it for proper soldering. When the tip turn's darker, the flux is burned away and it's time to clean it again. You should do it each time you solder an new component or after soldering a few pins.
When you solder that way you don't have to clean it with sandpaper. I never cleaned a soldering tip with sandpaper.

And I totally agree to SPL15: I never use weak soldering irons. I soldered every part with a 50W or 80W soldering station at 370°C-400°C and a big soldering tip. With a powerful iron and a thick tip you are able to solder things in a few seconds. I tried lower power irons but I always needed a long time to get the soldering pad at temperature with them. And I love thick tips. It much easier to transfer the temperature with them. I also solder 100-pin TQFP SMD compontens with it when I have no hot-air. No problem. You just have to use enough flux :)

[kryptobs2000]

Well this thread is pretty old now, but I'm tons better than when this started. Havn't had any trouble with any mods I've done for awhile. And I was just out of the loop when I had made this anyways (hadn't done anything for a couple months). But i use a 15w iron, and never have any problems heating things up. I don't use flux normally, and I hate big tips. How do you get things on such small components with huge tips?

[Malves]

You can make soldering as hard or as easy as you want. Soldering is so easy that even if you have only one hand, you can do it. Seriously...take a look at this very basic simple guide (http://www.extremeoverclocking.com/articles/guides/Soldering_Guide_1.html). That's all you need to know to do vmods on your board.

[phobos]

How do you get things on such small components with huge tips?

Just hold the big tip on the small component ;). No Problem. Place the small component, hold it with tweezers if it's really small and solder it.

[SPL15]

Just hold the big tip on the small component ;). No Problem. Place the small component, hold it with tweezers if it's really small and solder it.


I use a medium sized tip for must stuff, The fine point tips lose heat way to quick for my tastes, but they are useful if your not too good with an iron. Technique is something you develop after soldering thousands upon thousands upon thousands of joints.

I have an Infrared reflow station and a hot air system so SMT is a piece of cake.

When i was a technician, I would get PCB's to repair that were "Fixed" by the customer. I dont see how people can possibly solder so incredibly horrible and expect the board to magically work after they halfway glob 10 pounds waterpipe solder onto a part that they replaced with one that looked almost the same physically. I had one guy irrate after i told him he destroyed the PCB and it was unfixable because he ripped out all the via's on the PCB where he replaced a halfwave rectifier with a Tip120 transistor and soldered all the legs togethor with one large cold solder joint with plumbing solder and a whole tin of acid based flux.... Claimed he didnt do it and that's how he got it from me :banana: .

The right tools/supplies and most of all experiance will make soldering a walk in the park. I recommend experimenting with different solders and irons. I use kester silver solder and expensive Hakko spl;dering systems. A Soldering/desoldering station can make soldering a joy or a chore so it's worth gettin something worth gettin.

[phobos]

[QUOTE=SPL15]I had one guy irrate after i told him he destroyed the PCB and it was unfixable because he ripped out all the via's on the PCB where he replaced a halfwave rectifier with a Tip120 transistor and soldered all the legs togethor with one large cold solder joint with plumbing solder and a whole tin of acid based flux.... Claimed he didnt do it and that's how he got it from me[QUOTE]

Nice story...lol.

I use weller soldering systems btw.