re-attach large solder pad - Page 1
Forum section: electronics / repair

author: Marsman1
author_rank: Newbie
timestamp: June 06, 2017, 11:38:36 am
content: I had a dpak over heat and melt itself loose from the pcb. In the process it lifted the solder mounting pad. What is the best high temp glue (locally available) to re attach the pad? So far the only epoxy I have found that has the heat rating is JB weld. Has anyone tried these puttys?

author: P90
author_rank: Frequent Contributor
timestamp: June 06, 2017, 03:11:55 pm
content: https://www.eevblog.com/forum/beginners/glue-for-lifted-trackspads/

author: screwbreaker
author_rank: Regular Contributor
timestamp: June 06, 2017, 04:12:33 pm
content: I'm using the Chemtronics CW2500 epoxy for this kind of works.https://www.digikey.com/products/en?keywords=cw2500It's rated up to 315°C/600°F.It works very well.

author: Marsman1
author_rank: Newbie
timestamp: June 07, 2017, 02:01:15 am
content: Thanks, I'll give it a try.

author: KL27x
author_rank: Super Contributor
timestamp: June 08, 2017, 04:29:37 am
content: Jb is the best stuff on earth for the price. Very tolerant of poor mixing and improper ratios. Just use a little more of the white half if in question. Has great stickum and viscosity. Warm it up a bit if u want it runnier.I never epoxied a trace to a board, with it, though. There are steel particles in jb weld. U can verify this with a magnet. I bet that reduces the coefficient of dieletricality, or some such.

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 04:33:05 am
content: Quote from: KL27x on June 08, 2017, 04:29:37 amJB weld is conductive. It's strong for general repairs, but I've found it's not that strong when applied in thin layers.

author: KL27x
author_rank: Super Contributor
timestamp: June 08, 2017, 06:22:12 am
content: QuoteThe problem may be the viscosity too high. If you want to make it run, hot air station. Very low heat, unless you don't mind bubbles. Not too far in the past I used it to hold a tiny blade to a piece of hex bar to make a 30AWG wire stripper. This was a very tiny bit of epoxy in a very thin layer. It's still solid.QuoteNo offense, but this smelled funny. It is very hard to make epoxy conductive. It would take a very high concentration of carbon or metal particles.So.. I just tested it, Mythbusters-style. Cut a large pad into some copper clad and smeared JB into the gap. There is no conductivity when wet, none when cured, per my DMM. My psu goes to 30V... and it was also nada. To be sure, I tested it with the magnet to make sure this is the same stuff from years ago... and yeah, it attracts.Because of the steel particles, I suppose it might have a lower dielectric strength. OTOH, maybe it has better thermal conduction properties?

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 06:39:29 am
content: Quote from: KL27x on June 08, 2017, 06:22:12 amVery interesting. I read somewhere that it was conductive. Perhaps I was wrong... wouldn't be the first time.I've used JB weld sort of as an adhesive in thin layer and it wasn't good. Perhaps next time I'll try your heat method...

author: KL27x
author_rank: Super Contributor
timestamp: June 08, 2017, 06:52:34 am
content: QuoteThe older I get, the more I am wrong and the less I am right. But it doesn't stop me from sharing my corrupted knowledge, lol.I still think you're wrong about Festool, btw. This one is for you:Damn thing is built like a laser printer.... but without the high volume of units needed to allow the overengineered throw-away ABS origami design to actually have any chance to meet the actual price point where it could actually make sense. Of course.... I am probably wrong, again!

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 07:20:41 am
content: Quote from: KL27x on June 08, 2017, 06:52:34 amI don't like to hate, but I hate that guy. He is so condensing and so utterly obnoxious, I can't stand watching his videos and listening to him talk...It's amazing how many of these pissant wannabe engineers armed with a camera and youtube, tinkering in their garage, think they know better than the German engineers and countless R&D hours involved in making these products. It's all about getting youtube views...

author: KL27x
author_rank: Super Contributor
timestamp: June 08, 2017, 08:48:50 am
content: I only ran across him a few days ago from a link someone posted on the forum. I'm not sure I'd call him condescending, but I have a tendency to give people the benefit of doubt. Obnoxious? Yeah, I give you that. Utterly obnoxious!I like the fact he tears down these tools to itty bitty parts. Which he does, here. I dunno if you watched any of it. I'll leave the mechanicals a wide berth. But would you at least agree that a proprietary power cord connector for a circular saw is at least somewhat undesirable? Do you see any drawbacks to that? And what do you think of the 6 cubic foot white plastic storage chest?Oh, yeah... it was his Juicero teardown what got me started down this rabbit hole. When he put the robot head on it and pressed the bottle of whiskey...

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 09:16:07 am
content: Quote from: KL27x on June 08, 2017, 08:48:50 amAgain, to someone who does not understand the engineering aspects of things, a "proprietary" plug might not make sense. Usually there is a reason they do what they do on a properly German engineered piece of equipment. That plug is used on all the Festool corded tools for interchageability, and ease of changing. I have my vacuum hose and power cord hanging from the ceiling above my work bench, and I can quickly connect and disconnect my TS55, and plug in my OF1400 with the same "proprietary" plug." 6 cubic foot white plastic storage chest"again, google " festool systainers" and you'll begin to appreciate how the entire "system" works, and what wonwrful engineering it is. Everything festool works as part of an efficient system, and makes tool use and organization easy. It's one of those things that people balk at the initial price, but once they they own it, they realize, you get what you pay for in life...

author: BMack
author_rank: Regular Contributor
timestamp: June 08, 2017, 02:45:35 pm
content: Quote from: P90 on June 08, 2017, 09:16:07 amFestool is out of my price range for hobby work...but this is EXACTLY what everyone that owns Festool or knows a lot about tools says about Festool. If one does some research into the Festool systems they are quite genius in design. Metabo and Hilti are built well too but they don't design shop systems made to work together, Festool is a stand out company because of their innovative ideas.

author: P90
author_rank: Frequent Contributor
timestamp: June 08, 2017, 02:54:25 pm
content: Quote from: BMack on June 08, 2017, 02:45:35 pmYes, I also have some Hilti tools, and metabo tools I bought in Germany, they make top quality tools, as does Mafell, in fact I feel Mafell is even nicer quality than Festool.If someone asks me for a recommendation for great tools at affordable price I always recommended Bosch.

author: KL27x
author_rank: Super Contributor
timestamp: June 08, 2017, 07:10:34 pm
content: I appreciate your viewpoint, P90.For me, there are obvious and less obnoxious way to make power cords that plug in/out, though. Pigtail cords have been around for a long time. IEC connectors are a thing. I even use figure 8 AC connectors on my power tools which are double-insulated and low amperage. My Bosch jigsaw and corded drill and my Dremels all have a generic AC socket in lieu of a cord, because I re-engineered them that way, and I am apparently not German. I can buy extra cords for $2.50."German engineering" dictates a proprietary plug, (but not a ball bearing on the end of the arbor shaft?)... which is not more compact at the connector... seems pretty much the opposite.. Huge plastic monstrosity of a connector, which if it has an improvement over a regular, say, extension cord, I don't see it. Other than for Festool, seeing as they can be the only ones to sell you a new one.Storage bins may be great. I dunno. Half of what I even do with my "woodworking" is organizing the workshop and tools to my unique space and needs... that's the big project after say a move. And i havent found any longterm use for tupperware, yet. I don't know how many Festool tools you need to own before the proprietary plug and integrated plastic bin german engineering system pays off, but that is a lot of tools.... that is all very iPhoney or Juicero-ey to me. I'm sure iPhone ecosystem is great, too, lol. No offense to iFolks.

author: P90
author_rank: Frequent Contributor
timestamp: June 09, 2017, 02:54:36 am
content: some people are happy using ryobi tools, what can I say... whatever floats your boat...

author: KL27x
author_rank: Super Contributor
timestamp: June 09, 2017, 09:35:14 am
content: You don't have to take it personally, P90. I was curious what you thought of the teardown. Instead your first instinct is to comment on the guy doing the teardown. And now me. Seems like German engineering floats yer boat right goot, ya?I thought you were going to comment on how the tool cuts straighter, easier to setup, cleaner, quieter. Something that might float my boat. But I get stackable Tupperware and a removable cord and some drool over German engineering.

author: P90
author_rank: Frequent Contributor
timestamp: June 09, 2017, 10:01:04 am
content: Quote from: KL27x on June 09, 2017, 09:35:14 amNot taking it personally... just stating that each person has certain needs and capabilities required from his tools... not everyone needs or wants to buy the best... thus, whatever floats your boat...