++++++++++++++++++++ See also Removing_Components +++++++++++++++++++++ Date: Wed, 15 Aug 2001 17:03:36 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] De-soldering tool Bob Baxter, AA7EQ, wrote: >For everyone who has had problems with de-soldering, check out the home >brewed tool in the new issue of QST page 63 Hints and Kinks. I removed >the bulb from the de-soldering tool in my GI Weller station (from Fair >Radio) and connected to my Soldapult with a piece of breathing oxygen >tubing. I removed a 20 pin IC from a scrap board in 5 minutes flat. >This thing really works. I must wholly agree... this is not only a neat idea. it's also VERY economical to boot. BE SURE to do a really good job of cleaning out BOTH the metal tube of the desoldering iron AND the air tube to the vacuum chamber as well. Finally, BE VERY CAREFUL about how long you allow the tip of the desoldering iron to remain on the joint being cleaned. Too much heat will lift the foil and this comes under the heading of "bad things will happen". Hakko, for their model 808 desoldering gun, recommends that the user hold the tip JUST ABOVE the board... IN the solder of the joint, but NOT actually touching the board. This helps to mitigate chances of lifting the lands. Unfontunately, in practice, this is bit more difficult to do (holding the tip 1/32" off the surface of the board), but regardless it hsould serve to make the user more mindful of the level of heat coming from the tip and the need to be rather 'brief' with its application. Tom Hammond N0SS +++++++++++++++++++ Date: Sun, 26 Aug 2001 14:22:05 -0700 From: "John Clifford" Subject: [Elecraft] Re: Damaged KSB2 trying to perform KI6WX PSK modification Sending this now is like closing the barn door after the horse gets out, but.... I, too, have had more experience with removing parts from my K2 than I would care to admit. However, I have learned a few things (about removing parts, at least). A lot of this is the result of reading hundreds of posts on this reflector, and some of it was discovered by trial and error (mostly error). I have two 'chisel' tips for my iron, a small 1/16" and a 3/16" wide tip. I use the former for small jobs and tight corners, and the latter for most soldering AND desoldering. Use a tip that will quickly apply enough heat (1 to 3 seconds, no more) so you don't have to sit there and 'cook' the pad. If you can't get the solder to melt in 3 seconds, pull the iron away from the pad. You may need to clean your iron, or put a little solder on the tip. 'Cooking' the pad is a sure-fire way to cause the pad, or a trace, to lift. First... remember that the board is always more important than the part. What does this mean? Use a set of cutters/nippers, etc., to remove as much of the component as you can without using a soldering iron, so that desoldering is very simple. For instance, I just replaced my PA transistors. To remove the old ones, I cut them off, then I cut the leads on the bottom of the RF board (the side that the PA transistors mounted on, as close as I could to the board. Those mangled parts look sad... but the board looks great. Second... I have found that pads pull when there is too LITTLE solder on the pad (your iron or the component sticks to the pad, but the heat from the iron destroys the pad-to-board bond). In the case of the PA transistors above, I then ADDED some solder to each pad on the bottom (side the transistor mounted on) side of the board. Next, having the K2 up on it's side (on a piece of paper so I don't scratch the side) on my bench, I took a pair of needle-nose pliers and grabbed the remaining transistor lead on the top of the board, and then heated up the solder on the opposite side. When the solder melted on the bottom, I pulled on the lead from the top, and it came right out. Note that this will drag solder inside the component hole... but that's okay. This prevents the pad from pulling. Third... (I do this for very small leads, like resistors, skipping the extraction via pliers of step #2 but I still add solder) I use a Soldapullt desoldering tool. It's best if you can heat the pad from one side, and suck the solder from the other. Again, the extra solder you added at Step #2 is very useful in that I find it 'replates' the hole as it is sucked through yet the hole is full-diameter and ready for you to install another part. Fourth... I use a flux pen that I bought at the local electronics store to add flux to each pad (both sides) after I remove a part. This makes soldering on another part easy, and I don't have to 'tin' the pad... it happens while I solder the new part on. I hope this helps. - jgc John Clifford KD7KGX Heathkit HW-9 WARC/HFT-9/HM-9 Elecraft K2 #1678 /KSB2/KIO2/KBT2/KAT2/KNB2 ...waiting for KPA2 & KAF2! Ten-Tec Omni VI/Opt1 email: kd7kgx at arrl.net ++++++++++++++++++++++ Date: Sun, 26 Aug 2001 22:27:38 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] re: David, et al: Be VERY careful with this procedure. ALL PC board holes in the K2 are PLATED THRU and you seriously risk 'drilling out' all of the internal plating in the hole itself. Thus, you will no longer have a top-to-bottom connection without taking specific steps to ensure that the connection is soldered BOTH on the top AND on the bottom of the board. Been there... done that... got the T-shirt... WON'T do it again if I can help it. Tom Hammond N0SS At 10:05 PM 8/26/01, you wrote: >Julian, > >When I have a problem like this at work (Engineering Lab) I >go for a drill bit. (This is when the Pace isn't available, when >a soldering iron on the top and the bottom of the hole doesn't >work or when I am in a hurry and I don't want to screw around >with this thing.) We have a selection of very small carbide bits >ranging from a #68 to #74 for these sorts of things. I pick a bit >that is smaller than the hole, select the side of the board that >I have started to suck out, I carefully twirl the bit back and forth >between my fingers (slowly not to breaking the carbide bit) and >I usually can clean out a stubborn hole. This sounds drastic >but solder is soft compared to a PCB feed threw hole. > >Good luck, > >Dave Garnier - WB9OWN +++++++++++++++++++++++ Date: Mon, 27 Aug 2001 09:44:14 -0700 From: Jeff Stai WK6I Subject: Re: [Elecraft] Drilling the thru-holes. At 09:14 AM 8/27/01, pqd wrote: >Please re-think your options before you take a drill bit to the board. I find a bit of heat and a poke with a dental tool makes quick work of it - the solder sticks to the dental tool just long enough to clear the hole. - jeff wk6i jeff stai radio stuff: WK6I in DM13 rocket stuff: NAR #21059 TRA #3356 Level 2 Cert. email: jstai at home.com or wk6i at arrl.net ROC web page: http://www.rocstock.org/ LDRS web page: http://www.ldrs20.org/ ++++++++++++++++++++++ Date: Mon, 27 Aug 2001 10:32:27 -0700 From: "Ron D' Eau Claire" Subject: RE: [Elecraft] Drilling the thru-holes. David, WA4PQD/6 wrote: > Drilling the thru-holes. > > Something is way wrong if you are doing that. These holes are plated > through which means the inside of the hole contains conductive "cylinder" > that allows the signal to pass from on PCB layer to the next. This is > probably destroyed during the act. > But more importantly, Why would this be necessary? > > Please re-think your options before you take a drill bit to the board. > > I admit that I have no experience w/ this deconstruction technique... I didn't make that post, but it is a process that I have used for many, many years when I found myself needing to fix a board with a stubborn lead stuck through the hole and without the proper desoldering equipment at hand. Working 'in the field' a lot this does come up. It is NOT necessary to destroy the feed through, nor does one "drill" out the hole. What one does is, as the post stated, use a tiny drill BIT by hand, between the thumb and finger, as a 'sharp probe' that opens up a partially cleaned out the hole. You use a drill bit substantially smaller than the hole diameter, and carefully 'twirl' it with your fingers to cut out the soft solder inside the hole. Your fingers cannot grip the bit strongly enough to 'drill' anything but soft solder. It is best to do this on the side that has a 'dimple' that goes down to the solder plug in the hole. It is better than repeated heatings of the hole with the improper equipment. Of course a good solder sucker is best, coupled with an iron that can put out plenty of heat quickly to melt the solder in the hole. One of the biggest problems with damaging boards, IMX, is to use too cool of an iron that makes you apply heat too long. That gets the board much too hot by the time the solder melts. Work with enough heat to melt the solder in less than a second and then work quickly. When using desoldering braids, etc., that means using a lot more heat than for normal soldering since you have to overcomes the calories of heat soaked up by the copper braid as well. Ron AC7AC K2 # 1289 ++++++++++++++++++++++++++ Date: Mon, 27 Aug 2001 15:47:29 -0400 From: "Alan J. Price" Subject: RE: [Elecraft] Drilling the thru-holes. Ask your dentist for an old "probe". They are stainless steel and are great for poking old solder out. 73 Alan W1HYV - -----Original Message----- From: owner-elecraft at qth.net [mailto:owner-elecraft at qth.net]On Behalf Of David A. Belsley Sent: Monday, August 27, 2001 2:41 PM To: pqd; Elecraft Subject: Re: [Elecraft] Drilling the thru-holes. I completely agree with those arguing against using drills to clear solder holes. Most of the time, if you have used good desoldering techniques, you can get the hole clean with the sucking device or the braid. If not, however, I can't see why you would ever need a drill. If you must poke the hole clean, use a stainless-steel pin for the job. Solder will not stick to stainless steel. Heat the hole to melt the solder (you might even need to add solder) and gently insert the pin, allowing it to "flow" in the hole. Don't force it and be sure to insert the pin vertically into the center of the hole. If you push it in at an angle, the tip could catch the pad on the opposite side and push it off the board. If you don't have stainless-steel pins, most safety pins are stainless and work just fine. best wishes, dave belsley, w1euy ++++++++++++++++++++ Date: Mon, 27 Aug 2001 15:47:46 -0400 From: "Bob Lewis \(AA4PB\)" Subject: Re: [Elecraft] Drilling the thru-holes. > (you might even need to add solder) The key in most cases - and not very intuitive. Add a little fresh solder and then suck it out with a solder sucker ($6.99 at Radio Shack). +++++++++++++++++++ Date: Fri, 28 Sep 2001 07:27:55 -0400 From: "John J. McDonough" Subject: Re: [Elecraft] Solder Paul I have to echo John's comments here. Silver solder looks nice, it makes for very shiny joints. A lot of people use it for that reason. I used it on my K1 - BIG MISTAKE. It borders on impossible to get the stuff out of the plated-through holes. I was very careful on the K1 not to make any mistakes, but installing the noise blanker and ATU both involve some desoldering. From time to time you are probably going to want to make some changes to your K2, certainly there are lots of options posted here. It is very hard to get silver solder out without damaging the board. Stick to a good quality 60/40 or better yet, 63/37, and get a nice, small diameter. I, too, use the .031 size and it seems to be about right. Personally, I haven't seen a big difference between Kester and other solders, but a pound of solder lasts a long time, so why not spend an extra buck and get the good stuff. 72/73 de WB8RCR http://members.home.com/wb8rcr/index.htm didileydadidah QRP-L #1446 Code Warriors #35 ++++++++++++++++++ Date: Mon, 29 Oct 2001 19:38:41 -0600 From: "Jack Scheinuk" Subject: [Elecraft] FYI - $35 Desoldering Iron - That Really Works I just converted my 40-20 K1 filter board to 80-17 and in the process had to remove all of the filter kit caps, toroids, xtals etc. About 15 years ago I bought a GC Electronics Heated De-Solder Pump. This is called: "The Solder Popper" One Hand Operation Melts & vacuums solder fast Easy Clean with tip cleaner 120 vac About 10.5 inches long, 1 inch diameter. The manufacturer's information reads: Combines the popular snap-vacuum solder removal tool with a 30 watt soldering iron for fast, one-hand operation and is an excellent tool for field repair or production work. Tightly sealed vacuum pump snaps-up all of the solder quickly. A removable reservoir stores solder and features a long l I was able to use this to remove all of the filter kit components very quickly, without damage to anything. I was not aware that the tip was grounded but have just tested it on my DMM, and it is at ground. The unit weight is about the same as a lightweight 30W soldering iron. Checking the web, I found these units available for $34.69 at http://www.action-electronics.com/desolder.htm 73 - Jack - W5WSF Jack Scheinuk, P.E. 7927 Maple St., New Orleans LA 70118 Tel: 504-866-1221 - Fax: 504-866-1258 +++++++++++++++++++++ Date: Fri, 15 Nov 2002 10:13:48 -0600 To: "Randy Moore" , elecraft at mailman.qth.net From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: [Elecraft] Re: Desoldering the xtals Hi randy: long time no see, pal... >I'm about to do the xtal mods. What kind of desoldering tool do you >recommend for this? I've managed to do a half-dozen or so mods with >nothing but solder wick, but I can never get the holes clean. I want to >do the xtal mod better. Can you point me to the right tool set? PERSONAL OPINION FOLLOWS... If you feel that you need a really great desoldering tool, and are willing to invest in one (and it IS in 'investment', but worth it), I'd certainly recommend the Hakko 808: http://www.tequipment.net/Hakko808.html This device is very easy to use... works like a champ(!), and with it I (literally) have been able to desolder all pins of an IC (or a K2 relay) and have the device FALL out onto the desk once the last pin was desoldered! This device sells for about $180 from the source shown above, The best price (by at least $10) I've found so far. There may be yet another contender though... I've not personally tried it (of even seen it, for that matter), but it looks promising: https://www.jameco.com/cgi-bin/ncommerce3/ProductDisplay?prmenbr=91&prrfnbr=3352&cgrfnbr=501&ctgys= If you can't get this link to work correctly, go to: www.jameco.com and do a Jameco # search for: 129066 This is the XYTRONICS desoldering gun. It sells for $100 from Jameco. Jameco offers a 4-page PDF of docs on this device: https://www.jameco.com/Jameco/Products/ProdDS/129066.pdf but note that the real FIRST page of the document actually appears as the 4th page in the set. This looks like it might work decently well... maybe as well as the Hakko 808... difficult to tell, having not used one. Maybe there's a K23 reflector reader who would care to comment here??? One thing to ask about though is whether Jameco can supply replacement parts (e.g. filters and nozzles). I saw no mention of them being available from Jameco in their ads. I once tried to look up XYTRONICS on the web, to see what they offered, and couldn't find usable info much at all. Hakko replacement parts are available from many sources. There's also the Weller SCD1000 desoldering gun. It appears to be in the same basic price range (c. $185) as the Hakko 808. See it at: http://www.elexp.com/sdr_d100.htm Tequipment.net also has the best prices on the Hakko 936-12 (ESD, $89) and 936-9 (non-ESD, $79) T/C soldering stations that I've found so far, too: http://www.tequipment.net/Hakko936.html I have NO interest in ANY of the companies mentioned here. There was a very good article on DEsoldering in the October 2000, issue of QST, page 54. It should be a 'must read' for all of us. Gives some very good info on HOW to use desoldering wick. I learned a lot from that part of the article alone. And the technique he recommends DOES work much better than the methods I'd previously used. If you can't find that issue of QST, I have scanned the article and committed it to a PDF. But the file is about 4.4Mb in size, and I don't want to be sending it out a bunch of times. That, and the fact that is IS copyrighted material. I guess I'd risk it once, but only ONCE. So if you (or others) want a copy, drop me a note and I'll send it out on Monday, Nov 18th, about 1500Z, to all who have requested it. Regarding other tools. I might suggest the following: A 'soldering aide'. This is a plastic-handled tool with metal ends which offer several options for tugging on and bending of component leads while you're soldering OR DEsoldering. SEVERAL widths of solder wick. There's not one width that works for all cases. A bulb-type solder sucker. Not that these devices are terribly goos, BUT there have been times where I found it much easier (and safer to the PCB) to remove the component lead first, place the tip of the bulb on the COMPONENT side of the joint, heat the joint, and the SQUEEZE the bulb to BLOW the melted solder out, rather than suck it in. this sometimes works better than sucking the solder out... READ WARNING BELOW...! WARNING - DO NOT PERFORM THE ABOVE-DESCRIBED TASK WITHOUT ADEQUATE EYE PROTECTION!!! The very LAST thing I'd want to happen is for you to risk damaging your eyes. It CAN happen... just ask me! A plunger-type desoldering tool. Edsyn probably makes the BEST! These can be very handy. A very long/thin/pointed tip for your iron. I have one which is about 1" long and goes down to almost nothing (.008" / 0.2mm) at the tip. This is sometimes great for helping to clean out a really difficult-to-clean PCB hole... esp. if I don't have my desoldering gun handy. A pair of medical hemostats. Long/slender nose, and a fairly 'light' closure pressure. Some close and lock much too hard, and can be rough on components and leads. And most of all... develop a good desoldering 'technique'. This may be most important of all, esp. if you don't have a desoldering gun. All too frequently we damage a PC board because we use excessive heat, or excessive force, when attempting to remove a component or clean out a hole. Learn how much heat to use and how long to apply it. If you apply heat for what you think is an adequate length of time, and you haven't gotten the result you expected. STOP and figure out why. Sometimes it's nothing more than the fact that you didn't clean (and re-tin) the tip of your iron before you started. Proper soldering AND desoldering boils down to several basic steps. The MOST important of which is effective application of heat. A clean iron tip is important. But even MORE important is a clean TINNED tip. One with just a small bit of solder on it, to make better thermal contact and thus a much quicker and more efficient transfer of heat to the joint. Learn to get in (and back out) with a minimum of component (and PC board) heating. Hope this helps a bit. 73, Tom Hammond N0SS ++++++++++++++++