solder ingress resist - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 09:43:03 pm
content: What chemical can I use to "mask" a section of something like braid, that can prevent solder from going past a certain point during tinning. Sometimes its difficult to tin something so the solder does not get sucked down too farif you do your own braids you might notice for a short bit, it becomes totally stuffed with solder and there is no flexibility left. (acts like solder wick), making flexible short jumpers rather hard to make.And it should be easy to remove later, with solvents or something.On a solid its easy enough to use bascially anything and then sand it off. But for something like braid, sponge, etc.. I don't know how. And it should not wick alot, i.e. if you dip it, it stays up to where you dipped it, does not go past that point because of capilary action.Some kind of paint maybe? I don't know what won't get disgusting from the soldering heat and remove nicely after its been heated substantially. Or some kind of silt/ceramic/clay/etc suspension?

author: wraper
author_rank: Unknown
timestamp: May 25, 2025, 09:52:28 pm
content: It will not work for simple reason. If it's not liquid enough, it won't penetrate the wire and thus won't protect it from flux/solder wicking internally. If it's liquid enough, then it will wick along the wire in the same way as liquid flux and compromise the solder joint. Therefore you will replace one problem with another. Much easier to get the flux application/soldering process right.

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 09:54:15 pm
content: But what if its a gel like thing that wicks alot less. I don't think it will work with something simple.I.e. flowable silicone.. you can get it in alot of different viscosities. If you heat cure it then it should behave OK (hot air gun after dipping) before it goes nuts. But its difficult to remove.I wonder what honey would do. I wonder if it reacts to wire or if you can get burned stuff off.Another option I thought is getting spray paint (from the can) and doing a quick dip. It like cures pretty quickly, and you can kinda thicken it up, but it would be tricky to try it. Its different then normal paint when it comes out of can because once the stuff dissolved in it quickly evaporates it becomes really gel/syrup like.. I think its like 'condensed soup' version of soup.Or just mask it and use spray paint. I wonder if VHT paint would work. And then dissolve it in goof off. The VHT paint is high temperature (3000F)Hmm or those UV resins. But that will definately smell mad bad.And I think the hot solder wicks faster then liquids do, on copper, but I am not sure. I think its like chemically attracted

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 10:01:38 pm
content: Hmm actually I wonder if it still wicks if you compress it strong with a parallel jaw clamp that is also a heat sink.Will it go past a goot heat sink clip (aluminum).

author: coppercone2
author_rank: Super Contributor
timestamp: May 25, 2025, 10:45:14 pm
content: Hmm I wonder about cable pull lubricant too. I will do some smelly experiments

author: Gregg
author_rank: Super Contributor
timestamp: May 27, 2025, 08:30:51 pm
content: Yellow ocher pigment is the traditional anti-flux; try making a slurry of the pure powdered pigment with IPA.

author: coppercone2
author_rank: Super Contributor
timestamp: May 27, 2025, 08:34:36 pm
content: I knew it some kind of clay.But the thing is, this stuff is fine to suck in between braid that is high strand count? Is there different grades ?I am not expert on clay but I believe it makes a suspension instead of dissolving.I can get it on next amazon orderoh wow they sell it as suchhttps://www.etsy.com/listing/520941334/yellow-ochre-pigment-25-inch-tube-solderThat gives me another idea, graphite slurry.My plan would be to clean it in the ultrasonic when its doneMm the nice thing about braid though is that you can like.. separate it by playing with the braid so the strands are more exposed. With wire you can't do that because its compressed by the sleeve.This should be nice, I wonder how many people had the idea to make a flex jumper and then they are left with a solder soaked 'wire' that does not work at all.#1 place It bugs me is on battery cavities. You can get nice battery cavities but you need to jumper them. Some of them like the metal ones for AA basically flex ALOT when you put a battery in. When I did it up with normal wire I thought for sure that is gonna have a problem for the short jumpers.

author: coppercone2
author_rank: Super Contributor
timestamp: June 02, 2025, 04:37:32 am
content: bit of a nauseating purchase to buy rusty clay but I got some Yellow Ochre

author: coppercone2
author_rank: Super Contributor
timestamp: June 16, 2025, 07:31:39 pm
content: its fluke case yellow when mixed with water and paints OK

author: tooki
author_rank: Super Contributor
timestamp: June 16, 2025, 07:49:23 pm
content: For military electronics, they make special heatsink clamps that encircle the wire. But they’re very expensive and each one is specific to a single gauge of wire.I saw a video of a Japanese camping stove maker who uses plain old-fashioned liquid White-Out (correction fluid) to keep solder from flowing to unwanted places when brazing brass.

author: coppercone2
author_rank: Super Contributor
timestamp: June 16, 2025, 09:18:57 pm
content: yes its been on my mind for a long time to perhaps modify a knipex parallel pliers or make some other contraption perhaps with O rings and pieces of aluminum or nickel plated copper to make various solder clamp heat sink kitTheoretically it would just look like a bunch of small gauge blocks you can o-ring together over different conductors. I think the most practical way to do it really is to cut up a bunch of mating aluminum parts out of a flat bar and use small files to fit it. Much harder if it needs to clamp on a curve (then you need the micro mill)the yellow orche is much like wite out when mixed upI think silicone o-rings is a reliable way to 'rubberband' heat sinks IMOAnother idea is to get ALUMINUM braid and use it for wrapping. Like 0.5mm aluminum braid (like solder wick) that you can wrap around stuff heavy to make a 'heat sink' . I see they sell nickel plated braid, and stainless braid, etc that might work too and infact be copper based. But its usually big gauge for things like EMI in nasty enviroments like furnace or for putting it as a physical shield around stuff (and possibly mag shield too)The big problem with all of this advanced fixturing is that when I do things they are hardly worth doing even if you have everything set up, let alone doingmorethings.But that got me thinking : what if you just use high temp magnet wire and just wrap the hell out of it. Perhaps a few drops of water or glycol. I even have that right now. Its wasteful but usually there is a kilometer of it laying around........A generic idea is to make a large amount of aluminum half circles that have a o-ring brand cut around the outerside so you can turn it into a circle with 1 o-ring. Then have a clamp that holds it together in circle form, so machining could be done on it. So you would just load 2 blanks in the fixture, machine the shape you want in it, then o-ring it around the structure. If its aluminum it might route OK with micro end mills. Someone with tools and inclination should be able to make that pretty easily.I wish they had a tool that is like a big mechanical arm for a dremel that mimics exactly what you do with a dremel on a duplicate or mirror imaged part. ! so it can duplicate your hand made mold as you work lol

author: coppercone2
author_rank: Super Contributor
timestamp: June 16, 2025, 09:45:31 pm
content: I am also wondering what would happen if you mixed in a whole bunch of copper powder into a piece of rodico . I noticed rodico does absorb water too, if you wet it, it becomes much softer

author: coppercone2
author_rank: Super Contributor
timestamp: June 16, 2025, 09:49:29 pm
content: Maybe I should get this, I only have welding craphttps://www.solder.net/products/heatshieldgel-tm/

author: David Hess
author_rank: Super Contributor
timestamp: June 16, 2025, 10:58:00 pm
content: Quote from: coppercone2 on May 25, 2025, 10:01:38 pmThat is what I would do. It will work fine.

author: coppercone2
author_rank: Super Contributor
timestamp: July 16, 2025, 05:16:27 am
content: it looks like people use graphite to make a solder resist for sheet metal work lol. you can just draw a fat line

author: Berni
author_rank: Super Contributor
timestamp: July 16, 2025, 06:00:48 am
content: Heatsink is the way to go.Solder will only wick up a wire that is hot enough to actually keep the solder molten. So all you have to do is tightly clamp two chunks of aluminium around your braid using vice grips or similar. Since solder does not stick to aluminium means you can clamp right up to the solder joint without worrying about it soldering itself to the heatsink.Sure it will still wick a little bit under the heatsinked part, but it shouldn't get very far, especially if you make sure to do your soldering quick with a soldering iron set to very hot. A bit of wicking is likely a good thing to make a slight gradual stress relief rather than having the wicking stop within a sub milimeter area and then having the braid always bend at that exact spot (copper loves to snap from work hardening).I suppose if you really wanted to minimize the amount it wicks you could also dunk the other end of the heatsink in water, you will get water wicking up the braid and in between the heatsink surfaces so that way you get additional much stronger cooling from evaporation. Tho that might need a more powerful soldering iron to overcome the extra cooling.

author: coppercone2
author_rank: Super Contributor
timestamp: July 20, 2025, 09:04:50 pm
content: keep in mind, for solder resist there is a benefit if its good, especially this pigment, which I have still not tried, because it should survive a kiln or hot plate or hot oven.As much as I want a water cooled micro soldering clamp to run through the oven some how, its not practicalI am actually VERY interested to know if you can 'draw' where to keep the parts for big lap joints in the oven, so they don't drift, so you can draw a mask that washes off. You will find that without indexing pins or some fixturing, solder parts like to slide around and rotate. this is annoying. Trying to figure out how to make it sit right is alot of work actually, which interferes with the supposed notion that soldering is the lowest design effort way to joint things.of course we are not talking high precision alignment with paint but it should be alot better and can possibly make things viable

author: tooki
author_rank: Super Contributor
timestamp: July 21, 2025, 09:45:09 am
content: Quote from: coppercone2 on July 20, 2025, 09:04:50 pmOriginally you were talking about braid; solid substrates (solid wire, PCBs, sheet metal, etc. — anything that doesn't wick or absorb) are an entirely different beast. For solid substrates, you could just use commercial temporary solder mask, like the peelable or washable masks sold for PCB wave soldering. One brand is called "WonderMASK". They're basically like a latex goo that you apply to mask the areas you don't want soldered, let it dry, and then after soldering, you just peel off (or wash off, for the washable kind). They used to exist as water-soluble tapes, too, but those seemed to be discontinued when I looked recently. And of course you can use temperature-resistant adhesive tapes as masking tape, for example Kapton tape. (I think they do still make peelable tapes intended specifically as masking tape for wave soldering.)I can't say whether they are enough to keep larger parts from drifting away. I think that depends on the joint itself.Quote from: coppercone2 on July 20, 2025, 09:04:50 pmWho says it's the lowest-effort way to join things?!? It certainly is a way, but it hardly seems to me that it's commonly seen as the easiest.

author: coppercone2
author_rank: Super Contributor
timestamp: July 21, 2025, 11:47:25 am
content: I thought the orche could resist silver brazing temps and possibly fire because its like ceramic. i guess for just soldering its OK to use a PCB mask on metal but I think it might be a braze mask, though... silver flows well so I have my doubts.I think its the most conveniant way to join stuff because you don't need to find a screw, a drill, and do alot of operations. the reagents dont go bad, so using glue when you actually need it is like a 7 day waiting period.I feel nice and calm when I figure out i can solder something. screws, rivets, etc.. not relaxingthere is something about making a bolted joint that makes me face palm.and glue reminds me of having to use the pressure washer. there is always a fucking situation with that god damn thing.and seriously for a home shop, glue is like... ok. do i even renember what the consistancy should be (is it expired) ? did i clean it enough? glue gives you the unique stressor of having to wait hours or days before you know you screwed up. if you have a policed stocklist at work with expiration dates, then ok.. it might be easy. But even that< I bought brand new epoxy a few weeks ago. The back of the tube was broken in the factory and covered my taBLE IN EPOXY when I was squeezing it.it's just always something with the glue. I like had enough of dealing with the trollish aspects of glueand how about pvc cement. did you ever have a pVC cement that actually worked when you needed it? You gotta buy 4oz each of two part compound, use about 2 mililiters, then throw it out when you open the can when you need it next time and its screwed up. They might as well sell a kit that comes with two 3ml tubes of pvc cement for $15 so you can make one joint and just throw it out ahead of time with less waste instead of lying to yourself that you got a great deal because its like hundreds of pipe joints for twenty bucks. Yeah that or you build a pipe organ out of PVC pipe to get your moneys worth. i think i have seen something like that in the subway before. i thought it was musicians but I am thinking maybe its just some plumbers, its the only way they found to profit from all that glue they give you, or perhaps you can do all the plumbing in biosphere 3lol its like buying a 4 poound can of black olives at the bulk storeI really think that glue is one of those things that starts to work well.. for a big organization. well if your boss is honest at least.. What I see happen is there a $550 can of glue substance that ends up with the consistency of oat meal and it has the value of a childs favorite blanky. the place is gonna catch on fire and hes gonna run in there to save the can of supposedly non expired loctite lol