Recommended drill bits, pin vise, for thruhole solder cleanup? - Page 1
Forum section: electronics / general

author: lpc32
author_rank: Frequent Contributor
timestamp: November 17, 2014, 04:41:57 pm
content: Following another discussion on how to clean up stubborn thruholes, one of the ideas was micro drill bits.What range of sizes is good to have? Roughly measuring a needle and seeing how it fits in smaller holes, I think 0.5mm or even smaller could be handy. Is there a need for wider than 1mm?Any thoughts onthese 0.34-1mm bits, drill, pin vise?Aredouble-sided pin visesmore useful?

author: nanofrog
author_rank: Super Contributor
timestamp: November 17, 2014, 07:29:37 pm
content: You might want to consider8pcs Hollow stainless steel needles desoldering tool for electronic componentsinstead (not the least expensive set available, but selected for the pics).Tad harder to lose than those micro drill bits IMHO.

author: lpc32
author_rank: Frequent Contributor
timestamp: November 17, 2014, 10:11:09 pm
content: But surely not to drill with?

author: nanofrog
author_rank: Super Contributor
timestamp: November 17, 2014, 11:18:14 pm
content: Quote from: lpc32 on November 17, 2014, 10:11:09 pmSort of. You insert the needles when the solder is molten to clean out the holes, and it's not unheard of to use a twisting action.

author: lpc32
author_rank: Frequent Contributor
timestamp: November 18, 2014, 12:21:45 am
content: I'm after a real drill for cases where it doesn't melt all the way through.

author: nanofrog
author_rank: Super Contributor
timestamp: November 18, 2014, 12:50:14 am
content: Quote from: lpc32 on November 18, 2014, 12:21:45 amHow do you plan to solder if you can't get it hot enough to flow properly then?You might want to rethink your existing soldering iron (no idea what you're using), or perhaps supplementing it with a preheater. FWIW, even the best irons need a preheater if the PCB has enough layers sucking off the heat.As per drills, if you're set on them, just get a kit like what you're looking at and supplement as needed. But I'm thinking there are larger issues that need to be addressed first (insufficient thermal transfer).

author: lpc32
author_rank: Frequent Contributor
timestamp: November 18, 2014, 12:59:04 am
content: So what's the use case of drilling? I'm trying the simple options available. Some discussion on that already happened in the original™stubborn thruhole thread.

author: nanofrog
author_rank: Super Contributor
timestamp: November 18, 2014, 02:34:53 am
content: Quote from: lpc32 on November 18, 2014, 12:59:04 amDrilling the holes prior to plating them.Drilling is a last ditch effort at best, as you run a real risk of destroying the hole you're trying to clear. So it's best to try every other possible method first. The needles really do work, and work along the same lines you're after with drill bits (inexpensive too). Other methods were mentioned in the thread you linked, so re-reading those you've not been able to try would be worth it IMHO. Some scrap boards would also be helpful for practicing on before trying on something you really want to repair (regardless of the method).Really though, I'm under the strong impression you need additional thermal capacity (rather than higher temps) under certain conditions such as ground planes. Not horribly expensive either, and may only need to re-purpose something, such as an unused electric skillet (i.e. it's just gathering dust somewhere). Purpose built preheaters that are reasonably priced can be had as well, such as theTenma 21-10135(Hakko's equivalent is over $300). Hot air guns can also work, but are more clunky and cumbersome to handle IMHO.

author: AG6QR
author_rank: Frequent Contributor
timestamp: November 18, 2014, 05:22:01 am
content: Quote from: nanofrog on November 18, 2014, 02:34:53 amMaybe, but remember, he started this saga by desoldering a capacitor. When he melted the solder to get the capacitor out, he obviously had enough thermal capacity to melt the solder. My guess is that he probably still has enough thermal capacity to melt that same solder in the same hole again, but maybe it's not being conducted to the solder now. More thermal capacity rarely hurts, but careful use of what's there could probably do the trick, if a good thermal conduction path is established between the iron and the solder. That may mean applying a bit more solder above the hole, the way the solder was above the hole when the initial desoldering job was done.But preheating or using hot air won't hurt, and may help, too.

author: nanofrog
author_rank: Super Contributor
timestamp: November 18, 2014, 07:11:59 am
content: Quote from: AG6QR on November 18, 2014, 05:22:01 amThe following post from the OP is what led me to my line of thinking.Quote from: lpc32 on November 14, 2014, 10:21:54 pmIt's possible to remove a part if the solder reaches it's plastic range and sufficient mechanical force is applied IME (i.e. pull on part & heat 60/40 simultaneously until it comes out, yet not tear or remove any of the copper off the PCB or hole). Yet even after the part is removed, still can't get enough heat into the joint to fully melt the solder, so it won't clean off/out properly.

author: lpc32
author_rank: Frequent Contributor
timestamp: November 18, 2014, 10:27:39 pm
content: nanofrog, AG6QR: I'll reply in the other thread.If anyone has other drill/bits suggestions...

author: nukie
author_rank: Frequent Contributor
timestamp: November 25, 2014, 01:43:40 am
content: TAMIYA makes/sell very nice pin vise. I don't recommend drilling a via, it's worst solution I have ever heard. There are more than 4 layers sometimes drilling would break the connections.Get some low temperature solder or use a 200w ish iron with huge tips, these are cheap and easily available. Do it right, avoid all the monkey tricks.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 25, 2014, 05:09:42 am
content: Quote from: nukie on November 25, 2014, 01:43:40 amUnless you're Bill Bixby about to turn into the Hulk, there is no way you can hurt or damage a decent-sized through-hole via with a hand drill and a small wire bit.I do not understand the resistance to this method, nor the catastrophic scenarios people invoke.Don't use a 1/2 inch Forstner bit with a press and you'll be fine.But you're perfectly happy with a 200W iron, and tell people to mysteriously "do it right", as if they can't "do it right" with a small, harmless drill bit.Baffling.NOYESWhat is the difficulty?

author: SL4P
author_rank: Super Contributor
timestamp: November 25, 2014, 07:17:56 am
content: Quote from: Alex Eisenhut on November 25, 2014, 05:09:42 am

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 25, 2014, 01:19:14 pm
content: Quote from: SL4P on November 25, 2014, 07:17:56 amNow draw the actual FLEXIBLE drill bit, and the fact that copper is harder than solder, and how does a human hand keep laser-like positional accuracy like that!?Again, *where* do you people get these infinitely rigid drill bits? And hands capable of drilling at 100000RPM?Anyone, even me, can whip up catastrophic scenarios in the virtual world. What about reality? You've never seen the copper barrel come out of a via because of a heat-based approach? Really?

author: lpc32
author_rank: Frequent Contributor
timestamp: November 25, 2014, 11:13:52 pm
content: I kinda like the MAB 485 idea. It looks cooler. A bit on the expensive side, though.

author: nukie
author_rank: Frequent Contributor
timestamp: November 26, 2014, 12:23:02 am
content: Hi, over heating is a problem but with a high thermal capacity iron means you can work quickly instead of slow-cooking the board.

author: Kappes Buur
author_rank: Regular Contributor
timestamp: November 26, 2014, 12:47:47 am
content: Long time experience has taught me that trying to clean out a pesky bit of solder by applying the soldering iron usually will lift the pad. I have used the tiny drill bit method successfully for years. Nothing wrong with that at all.

author: pickle9000
author_rank: Super Contributor
timestamp: November 26, 2014, 01:34:06 am
content: Quote from: Kappes Buur on November 26, 2014, 12:47:47 amI agree, another tool to get the job done.

author: SeanB
author_rank: Super Contributor
timestamp: November 26, 2014, 05:52:44 pm
content: When the slow boat arrives with the cheap drill set and motor I will probably take another used Braun toothbrush and made a mini drill out of it. they are easy enough to open and cut the junky bits off the end and make up an epoxy mount that will allow me to make a bushing and shaft for the bits.

author: macboy
author_rank: Super Contributor
timestamp: November 26, 2014, 06:46:57 pm
content: Sometimes, after removing the component from the board, some solder is still left in the hole. I have tried adding fresh solder, adding flux, using braid, using suction, using compressed air... sometimes all efforts to remove the last 5% of the solder fails to make the hole clear enough to fit and tight fitting component lead into the hole. In this case, I use wire drill bitslike thesein an x-acto knife handle acting as a mandrel. The 40 RPM you get from finger-twisting the drill is just about the perfect speed. Copper is soft, but solder is much softer. I have never damaged a plated this way. I have, however, pulled the plating right out with the component when either too much or too little heat is being added (in combination with far too much force!). I would personally never attempt to drill out a completely solder-filled PTH.

author: lpc32
author_rank: Frequent Contributor
timestamp: November 27, 2014, 01:48:16 am
content: What drill diameters do you find useful?