The Recapping FAQ

[Elitist]

crkhed:
The scribed marks in the top of caps are deliberate stress-relief markings so that when they explode they do so with less ferocity and in a semi-controlled manner. This is a standard technique in engineering. In hydrogen plant engineering the roofs are generally hinged! Upwards, that is....

[willawake]

i am updating with some pics as requested.

[Elitist]

Beautiful!
You didn't include an hairdryer/electric paint stripper to warm the board before attacking it with a soldering iron. Also a useful implement for removing smc ics and memory chips!

[Elitist]

PS. Sometimes I use a fine drill bit in a hand chuck to clear the hole. Essential to use an undersize drill bit!

mod comment : this is not recommended. probably you will screw it up.

[parttimebill]

...some very good information... thanks... parttimebill

[solarvolt]

Have found it useful over the years to ALWAYS photo document boards as well as diagram; just often enough being able to refer to a series of clear BEFORE pics from various angles will reveal some element that hadn't been covered in a diagram. Thanks to all for these excellent articles! (doing Abit VL6 project prep)

[bgavin]

Many thanks to Willawake for the sticky FAQ. I followed it verbatim, and my first recap job was a complete success.

Notable points in the FAQ are the temperature points for removal and replacement. I found the pin method for clearing the board holes worked best for me. I used some of my wife's dress making pins with a ball end for easy pushing.

Key point: be sure to clear the holes using the 450C temp setting. Lower than this doesn't work well at all.

Key point: flow new solder on to every lead you are going to remove. The FAQ is dead-on with this one. Worked great.

I used a Hakko 936 12/P with the standard small chisel tip. Solder was Kester 60/40.

[ftaduffy]

I have been in electronics for over 40 years and the best way I found to clean out holes after removing a part is to use compressed air set at about 10 to 15 pounds. USE ONLY A LOW AIR PREASURE!!! THIS MUST BE DONE CAREFULLY!!. I hold the board vertically in a vice by putting some padding one the edge so I do not damage the board. I put a cut down box about a foot in back of the board. Wearing a glove on the hand with the soldering iron I heat the hole while at the same time I hold a blowgun one the other side of the hole. As soon as the solder is melted I press the button on the blowgun and quickly remove the iron. This blows all the solder out. The box collects the solder splatter and the glove protects my hand. CAUTION SHOULD BE USED AND SAFTEY GLASSES SHOULD BE WORN!!.

[Paul S]

I wanted a recaping How-To that I could just print out, so I created a PDF document of The Recapping FAQ. But, it is too larg (1.7MB) for me to attach it to a post. I made the original on Linux using the OpenOffice Office Suite, but the OpenOffice document format of .odt is not an allowed file format.

So, OO will also save it as a MS Word document, so I attached that file here. It altered it a little, so I had to re-edit it.

Is there any way to get the PDF version added to the forum or badcaps web site? That is assuming you want to add it.

[Paul S]

I see that the images weren't saved with the Word file. That is why a PDF file is better. I can't edit the last post anymore to remove the bad file.

[Paul S]

I corrected the problem with the images in the Word version of this How-To. But now the file is 8.6MB and way too huge to upload. The PDF version is still 1.7 MB

Moderator: If a file (PDF) version of this thread is something that you would like to add, please contact me. Also, you can remove my last two posts, as they are no longer relevant.

[Scenic]

upload the .pdf version at http://upload.wozzap.de (10MB Filesize limit ; not allowed file extensions are listed there) and post the link here. i will then upload it to my private webspace and post the link here.

edit: my private webspace is paid webspace... not some free hoster crap that could disappear without a warning

[Paul S]

Originally Posted by Scenic

upload the .pdf version at http://xxx.xxx.x.xxx(10MB Filesize limit ; not allowed file extensions are listed there) and post the link here. i will then upload it to my private webspace and post the link here.

edit: my private webspace is paid webspace... not some free hoster crap that could disappear without a warning

Done.

Thanks, I hope that I did it correctly. My Deutsch is a little rusty. Just because my last name is Schmidt doesn't mean I know the language.

[Paul S]

I don't know if you needed me to give you the url for the uploaded file, but here it is;
http://upload.wozzap.de/up/The%20Recapping%20FAQ.pdf

[zandrax]

Originally Posted by Paul S

I don't know if you needed me to give you the url for the uploaded file, but here it is;
http://upload.wozzap.de/up/The%20Recapping%20FAQ.pdf

Nice collection, Paul
I noticed only a minor error: Asus brand is spelled As us in page 15, below the picture.

Zandrax

[Paul S]

Originally Posted by zandrax

Nice collection, Paul

Willa did all of the work, I just copied and pasted.

Originally Posted by zandrax

I noticed only a minor error: Asus brand is spelled As us in page 15, below the picture.

Zandrax

Dam spell check got me! There was one time when I accidently double-clicked and accepted something that I didn't check. I guess that was it.

[Scenic]

http://bambooz.pytalhost.net/badcaps...apping_FAQ.pdf



BTW: all files uploaded to upload.wozzap.de will be deleted automatically after 1 month.

[zandrax]

Originally Posted by Scenic

http://bambooz.pytalhost.net/badcaps...apping_FAQ.pdf



BTW: all files uploaded to upload.wozzap.de will be deleted automatically after 1 month.

Like Rapidshare. So thank you Scenic, your link should last.

Zandrax

[ratdude747]

Originally Posted by willawake

6.2. Mechanical Solder Pumps

It is NOT recommended to use a mechanical pneumatic solder pump in order to clean the hole, they really have far too much power. There is a possibility to damage the lead port by sucking it out at the same time as the solder. This would mean that you would have to carefully solder in the new cap, making sure that solder flowed all the way through the hole in order to meet the right traces in the layers of the board. It will be quite difficult so forget about mechanical solder pumps. Additionally the recoil can impact the board and damage a trace or the pump can spray solder debris on the board that can cause a short when you power up the board.

i beg to differ. first, if you spray wd40 in the barrel form both ends, then you have virtually zero recoil. the debris issue is taken care of by pumping the sucker a few times after desoldering a joint. after every job take 5 min to diassemble and clean it out and relube it every other time. i have never had it suck out a lead port. if you are decent with your thumb, then a mechanical sucker will do fine.

i don't like the bulb. looks like it would be a pain to clean out. and it would be HEAVIER action than the mechanical sucker- a button press vs. squeezing a bulb... the button iq quicker and lighter than squeezing the bulb.

desoldering irons would be nice if they were cheaper... sounds like a waste of money to me

ps, helps if you use silver bearing solder. melts faster and helps desoldering (softens solder to the point where you don't have to worry about sucking out lead ports. costs a little more but is totally worth it.

[ratdude747]

oh, and beyond the solder and sucker, i use a xytronic 30w grounded temp-controlled corded iron with small chisel tip. on max temp, with the addition of some silver solder, seems to melt joints really well (maybe it is capable of more than 30w... same model that the irons at my high school's robotics team uses for custom circuit boards)

for iron accessories i use a weighted tin can for iron holder (works great as long as you keep the cord on the table) and a yellow wetted sponge from a multipack from the supermarket. cheap and effective.

i use a tiny set of diagonal springed pliers to cut leads. keep it lubed with wd40 and it does really well.

on my choice of tools from the this post and the one before: