Remove laminate from flex cable.

[silviasol]

I have a nintendo virtual boy that I am fixing.  On the lcd boards there is a flex cable that goes bad.  There is a way to fix it just just soldering the contacts restoring the connection but my repair did not work.  I found this site that a guy used crystal drain opener stuff which has NaOH in it.  Was going to try it but figure there may be an easier way.  Any suggestions?

http://www.projectvb.com/displayfix.html

My failed attempt
http://imgur.com/a/eR084

After this guy removed the laminate with NaOH

[mdszy]

If it comes out looking that nice, why not just use drain cleaner? It's not hard to get NaOH based drain cleaner or Lye from hardware stores or online sources...

[silviasol]

naoh is sodium hydroxide correct?  I ordered some of it.

[Gregg]

Many spray can oven cleaners use NaOH (sodium hydroxide) as the active ingredient along with foaming agents and surfactants.  These make good paint (and skin) removers as well as great de-greasing agents for things like cast iron engine parts.  However, they eat aluminum. 
For your purpose, it may be a lot easier to use than drain cleaner as you can mask off what you want to remove the coating and control the spray amount.  The oven cleaners tend to stay where they are sprayed and the foaming keeps it from drying too fast.  Your mileage may vary, try it on something that isn't valuable first.

[Ampera]

They put that stuff in pretzels. Just use it. (NOTE Don't eat it)

[mdszy]

naoh is sodium hydroxide correct?  I ordered some of it.

Yes.

[Cerebus]

A little trick I have for using NaOH when I want to control where it gets to, is to make up a gel with Xanthan Gum and then dissolve some NaOH in that. It makes a thixothropic paste that can be brushed on but won't drip off.

Xanthan Gum is quite commonly sold in supermarkets (some people use it in making gluten free cakes and breads). I use a 1% solution of Xanthan Gum and it needs a liquidizer or a hand held electric blender to make a smooth mixture. I've used as much as 10% NaOH in this mix without any problems, but that mix is too concentrated for most uses.

Safety:

• Make the gel first before adding NaOH.
• For any stage involving NaOH use a glazed ceramic, stainless steel, glass or plastic vessel. Basically, something that won't react to NaOH and will take some heat. Do NOT use aluminium, NaOH will eat it.
• Dissolving the NaOH is an exothermic reaction, the mixture heats up, significantly. Add slowly and stir continuously. When I've been a bit lax about the stirring in the past the heat from the dissolving NaOH granules has been enough to 'tattoo' the bottom of a polythene jug. Keep stirring until all the NaOH has dissolved.
• Wear nitrile gloves and eye protection.

If you get NaOH into your skin you won't notice the pain until the burn has already happened. Speaking from experience it bloody hurts, proper full shouting in anglo-saxon hurts! If you feel a 'soapy' feeling on your skin that's the first sign that you've got NaOH on you and it is converting the fat in your skin into soap which will let it penetrate faster, make more soap, penetrate faster still etc. At any hint of that soapy feeling stick the affected part under a running tap and keep it there until the soapy feeling has gone away and then for another minute at least.

[Red Squirrel]

Is the coating a plastic by chance?  What I've done with ones that use plastic is used a putty knife and a heat gun.  Place putty knife to act as a shield for rest of cable and blow hot air on the part of cable you want to remove, then genteelly slide the putty knife across the plastic and it will just wipe it off as it will be melted. Did this for a monitor I was trying to repair, the flat flex connector would not stay so I just soldered the board directly to the contacts.   

[Halcyon]

They put that stuff in pretzels. Just use it. (NOTE Don't eat it)

What on earth kind of Pretzels do you have in America? In Australia, we use good old Sodium Chloride. Then again, you guys use all kinds of weird stuff in your foods. For example: You rarely find things like high-fructose corn syrup in foods over here, unless it's imported and in the "International Foods" aisle.

[mdszy]

They put that stuff in pretzels. Just use it. (NOTE Don't eat it)

What on earth kind of Pretzels do you have in America? In Australia, we use good old Sodium Chloride. Then again, you guys use all kinds of weird stuff in your foods. For example: You rarely find things like high-fructose corn syrup in foods over here, unless it's imported and in the "International Foods" aisle.

I have no idea what that guy was talking about when he said that. There are definitely no pretzels with NaOH in them here... That'd be poisonous!

[Cerebus]

Pretzels and NaOH.

I hate to disabuse the neigh-sayers (that's a lie, I love doing it) but NaOH, or more commonly KOH, is involved in giving pretzels their characteristic colour and flavour.

The dough is made, shaped and left to prove. It is then run through a bath of hot, even boiling, KOH (or NaOH) solution immediately before it is baked. It's the reaction of the alkali and heat with the starches, sugars and proteins in the dough that gives preztels their characteristic even deep brown surface colour and flavour.

Let's look at a proper pretzel, by which I mean the delicious salty, soft, chewy German/Austrian beer adjunct, not the vile, president choking, hard things that pass for pretzels in the USA. It is slashed before it is baked and the surface that is exposed by the slashing has not had contact with the alkali and is light coloured in contrast with the rest of the surface.



Exposure to CO₂ in the oven converts any unreacted alkali to a harmless carbonate.

Damn, now I have a hankering for some proper German pretzels and beer, and they're not that easy to find in the East-end of London.

[amyk]

https://en.wikipedia.org/wiki/Sodium_hydroxide#Food_preparation


Back to the original question: heat may work but only if the insulation is thermoplastic; often FFC will use thermosets, which won't melt but just char horribly when it gets hot enough.

[tooki]

Let's look at a proper pretzel, by which I mean the delicious salty, soft, chewy German/Austrian beer adjunct, not the vile, president choking, hard things that pass for pretzels in the USA. It is slashed before it is baked and the surface that is exposed by the slashing has not had contact with the alkali and is light coloured in contrast with the rest of the surface.

And now it's my turn to disabuse you of your misconceptions about pretzels in USA. (I hate to say it, but it's typical British, taking cheap shots at USA based on incomplete or incorrect knowledge.) In USA, pretzels have a long history on the east coast, thanks to the German and Swiss immigrants that settled in the 1800s. Pennsylvania is the epicenter. Anyway, we Americans have both soft (fresh) pretzels just like in Germanic countries, and we have hard pretzels (which are delicious) as well -- just like in Germanic countries. (Any grocery store here in Switzerland carries hard pretzels, too.)

Damn, now I have a hankering for some proper German pretzels and beer, and they're not that easy to find in the East-end of London.

When the topic of pretzels came up, what actually came to mind was the Jewish bagel ("beigel") shops that you have, for which I am endlessly envious. Not exactly a pretzel, but damned delicious, and open 24 hours. (You have NO clue how much I miss salt beef, which is more or less unavailable here in Switzerland. I used to cook it all the time in USA, where we call it corned beef. It's not in a can to us. )

[tooki]

They put that stuff in pretzels. Just use it. (NOTE Don't eat it)

What on earth kind of Pretzels do you have in America? In Australia, we use good old Sodium Chloride. Then again, you guys use all kinds of weird stuff in your foods. For example: You rarely find things like high-fructose corn syrup in foods over here, unless it's imported and in the "International Foods" aisle.

USA has fairly authentic pretzels in the Germanic tradition. Of course they have ordinary sodium chloride salt in the dough and on the surface. But the lye wash is a) real, and b) absolutely traditional. (The surface salt is sprinkled on after the lye wash, when it's still sticky.)

USA has corn syrup in everything because it's super cheap, thanks to farm subsidies on corn. It's so much cheaper than sugar that food manufacturers redesigned their recipes to replace sugar (and other sugars) with corn syrup wherever possible.

I have no idea what that guy was talking about when he said that. There are definitely no pretzels with NaOH in them here... That'd be poisonous!

Nope, Cerebus is 100% correct. In fact, here in Switzerland, pretzels, pretzel rolls, and pretzel croissants (!!) are everyday items, and they're called Laugenbrezel, Laugenbrötli, and Laugengipfeli, respectively -- literally "lye pretzel", "lye roll", and "lye croissant". (Oddly enough, hard pretzel sticks, the kind that are about 4mm thick, are just called Salzstengeli -- "salt sticks", despite having the lye treatment.)

It is my understanding that potassium hydroxide and sodium hydroxide are commonly used in commercial bakeries, but for home use, baking soda (sodium bicarbonate) appears to be common, though the results are inferior.

[noidea]

Safety:

• Make the gel first before adding NaOH.
• For any stage involving NaOH use a glazed ceramic, stainless steel, glass or plastic vessel. Basically, something that won't react to NaOH and will take some heat. Do NOT use aluminium, NaOH will eat it.
• Dissolving the NaOH is an exothermic reaction, the mixture heats up, significantly. Add slowly and stir continuously. When I've been a bit lax about the stirring in the past the heat from the dissolving NaOH granules has been enough to 'tattoo' the bottom of a polythene jug. Keep stirring until all the NaOH has dissolved.
• Wear nitrile gloves and eye protection.

If you get NaOH into your skin you won't notice the pain until the burn has already happened. Speaking from experience it bloody hurts, proper full shouting in anglo-saxon hurts! If you feel a 'soapy' feeling on your skin that's the first sign that you've got NaOH on you and it is converting the fat in your skin into soap which will let it penetrate faster, make more soap, penetrate faster still etc. At any hint of that soapy feeling stick the affected part under a running tap and keep it there until the soapy feeling has gone away and then for another minute at least.

A big plus one on the Nitrile gloves,
NaOH breaks down latex gloves only slightly slower than it starts turning flesh into soap. I inadverdently found this out years ago when I was cleaning some home brewing equipment one evening and decided to swap the thick chemical resistant gloves I normally wore for some latex ones as I was cleaning some small items and wanted better dexterity to hold them whilst I scrubbed them with a toothbrush and NaOH.

I still remember the feeling and pain and was almost at the stage of going to hospital but my hands were hurting too badly to hold the steering wheel and there was no one around to drive me. I think when I realised initially what had happened I poured a bottle of vinegar over my hands then kept both under a running tap for about 30 minutes. 

[Cerebus]

Let's look at a proper pretzel, by which I mean the delicious salty, soft, chewy German/Austrian beer adjunct, not the vile, president choking, hard things that pass for pretzels in the USA. It is slashed before it is baked and the surface that is exposed by the slashing has not had contact with the alkali and is light coloured in contrast with the rest of the surface.

And now it's my turn to disabuse you of your misconceptions about pretzels in USA. (I hate to say it, but it's typical British, taking cheap shots at USA based on incomplete or incorrect knowledge.) In USA, pretzels have a long history on the east coast, thanks to the German and Swiss immigrants that settled in the 1800s. Pennsylvania is the epicenter. Anyway, we Americans have both soft (fresh) pretzels just like in Germanic countries, and we have hard pretzels (which are delicious) as well -- just like in Germanic countries. (Any grocery store here in Switzerland carries hard pretzels, too.)

Not taking a cheap shot at the yanks, just making sure that people knew I was talking about the delicious type of pretzel, not the vile hard type. If I wanted a cheap shot I'd just mention Herr Drumpf. But back to pretzels: my experience has been that as far as the US goes, the vile type are way more popular over there and way more available. I suspect that it's hard to find a proper pretzel outside of New York/Philadelphia/Pennsylvania area.

When the topic of pretzels came up, what actually came to mind was the Jewish bagel ("beigel") shops that you have, for which I am endlessly envious. Not exactly a pretzel, but damned delicious, and open 24 hours. (You have NO clue how much I miss salt beef, which is more or less unavailable here in Switzerland. I used to cook it all the time in USA, where we call it corned beef. It's not in a can to us. )

I'm, at most, a 15 minute drive from the Brick Lane Beigel Bake which is indeed open 24 hours, and I have never been there when there wasn't a big, steaming slab of Jewish salt beef in the window (as opposed to English/Irish style salt beef). They also do a nice line in rye bread and some very acceptable platzels but sadly no pretzels (I have actually begged them to start doing them but so far, no luck. What's a goy got to do to get a pretzel?). The few remaining Jewish businesses in the Brick Lane/Spitalfields area are a bit of an anachronism now. The area was where traditionally new groups of immigrants got their foothold and then diffused outwards once they were settled. The Jews mostly moved to North London a very long time ago and the area is now Bangladeshi and hipsters but for some reason a handful of Jewish bakeries have stuck there.

[tooki]

How does Jewish salt beef differ from the English/Irish kind?

[helius]

I believe it is usually the brisket that is used. The English and Irish immigrants to the US got to know it well, and it forms the core of the "New England boiled dinner" which is traditionally eaten around St. Patrick's Day.
http://www.smithsonianmag.com/arts-culture/is-corned-beef-really-irish-2839144/

[Cerebus]

How does Jewish salt beef differ from the English/Irish kind?

Ah, that's going to depend where you come from in the British Isles (in terms of what cut, how it is cooked and served - usually some sort of stew) but the common difference is that the curing ("corning") process normally involves nitrates as well as salt, where the kosher way of doing it is with just salt as the curing agent. The British version generally comes out very pink and a bit wobbly compared to stuff that's kosher.

As it is, salt beef (or corned beef as it is traditionally called in English, from the 'corns' of salt used in the curing process) has almost disappeared from the British isles. I certainly haven't seen any cured beef outside of a kosher butchers in a very, very long time.

I suspect most inhabitants if asked what 'corned beef' was would start talking about the type that comes in tins from Argentina with no mention of the other, older kind. I also suspect, but don't really have any evidence to offer, that the popularity of the tinned variety has waned as well and you have to be a bit older to have a taste for it.

Anyways, way too long off topic. Perhaps we need a 'gastronomy' section. Which diodes make the crunchiest salad? Is transformer oil a good substitute for olive oil in Aioli to be served with electric eels?

[tooki]

You sure about the curing? Every Jewish corned beef I've ever had used nitrates.

As for the name: being American, I fundamentally know it as corned beef. Only in England did I encounter the term "salt beef" for it, and when I've asked English people about "corned beef", they have always understood the tins from Argentina.  (I suspect your intuition about the tinned kind is correct, I don't know any younger people who like it.)

I believe it is usually the brisket that is used. The English and Irish immigrants to the US got to know it well, and it forms the core of the "New England boiled dinner" which is traditionally eaten around St. Patrick's Day.
http://www.smithsonianmag.com/arts-culture/is-corned-beef-really-irish-2839144/

Yeah, that article pretty much agrees with my understanding of the history of corned beef in USA and Ireland. The only thing I suspect is that they interpeted the old documents incorrectly: "corned" means not "salt the size of grains of corn", but rather, "salt the shape of individual seeds of grain", because in British English, "corn" meant "grain" (they use "maize" for the stuff that comes on cobs). And what does that salt look like? Look at kosher salt in USA (which should correctly be called "koshering salt", since it's not salt that is kosher, but rather salt used to make meat kosher.

[Cerebus]

You sure about the curing? Every Jewish corned beef I've ever had used nitrates.

Perhaps commercial ones use nitrates but one of my school friends' mums used to make her own (Hi, Mrs Zaft if you're still alive) and definitely didn't. Even if the commercial kosher butchers use nitrates they typically use less than the Irish do just judging on the colour of meats that I've seen (I've not seen commercial cured beef in an English butchers for longer than I remember, except for pastrami).

[silviasol]

A little trick I have for using NaOH when I want to control where it gets to, is to make up a gel with Xanthan Gum and then dissolve some NaOH in that. It makes a thixothropic paste that can be brushed on but won't drip off.

Xanthan Gum is quite commonly sold in supermarkets (some people use it in making gluten free cakes and breads). I use a 1% solution of Xanthan Gum and it needs a liquidizer or a hand held electric blender to make a smooth mixture. I've used as much as 10% NaOH in this mix without any problems, but that mix is too concentrated for most uses.

I have the naoh how but haven't had time to open the virtual boy again.  I was thinking of trying your gel method.  I am a bit confuse though.  To make this you use a up to 10% naoh, 1% xanthan gum and the rest water?  Can it be stored after making it or must you use it right away?

[Cerebus]

A little trick I have for using NaOH when I want to control where it gets to, is to make up a gel with Xanthan Gum and then dissolve some NaOH in that. It makes a thixothropic paste that can be brushed on but won't drip off.

Xanthan Gum is quite commonly sold in supermarkets (some people use it in making gluten free cakes and breads). I use a 1% solution of Xanthan Gum and it needs a liquidizer or a hand held electric blender to make a smooth mixture. I've used as much as 10% NaOH in this mix without any problems, but that mix is too concentrated for most uses.

I have the naoh how but haven't had time to open the virtual boy again.  I was thinking of trying your gel method.  I am a bit confuse though.  To make this you use a up to 10% naoh, 1% xanthan gum and the rest water?  Can it be stored after making it or must you use it right away?

I've never kept it more than 20 days or so, but it's been stable and usable after 20 days. I suspect it'll keep quite well because if the NaOH hasn't broken down the Xanthan gum by 20 days then I don't think it's going to.

Yup, 1% by weight Xanthan gum in water, mix very thoroughly and let gel. For the basic gel, hand mixing will not be enough, you'll need a liquidizer or similar as the gel powder tries to form clumps. If you let it gel for a few minutes you can judge for yourself if the viscosity is right for your needs and adjust with more water or gel powder as required.

Then up to 10% NaOH (by weight) dissolved in the gel with continuous stirring by hand until it is dissolved.

So for a nominal 100ml batch I might use 1g dry Xanthan gum, 100g water and 10g NaOH.

See the full instructions above for necessary safety tips. I use this mixture with around 1-2% added SDS (Sodium Dodecyl Sulphate aka Sodium Lauryl Sulphate) detergent as a degreaser/cleaner for burnt on crap on kitchenware such as the blackened outside of chip pans and as paint stripper. If it'll do both the former it'll happily strip flesh, so please do follow the safety tips given previously above in the thread.

[silviasol]

Ok sounds good.  What is the gum called in the supermarket?  Where/what should I look for?  I have nitrate gloves, seen oven cleaner burns before.  I have no mixing tools, I do alot of cooking.  I know it is tough to get some stuff to mix right without clumping.  Will it help to heat up the water first.

[Cerebus]

Ok sounds good.  What is the gum called in the supermarket?  Where/what should I look for?  I have nitrate gloves, seen oven cleaner burns before.  I have no mixing tools, I do alot of cooking.  I know it is tough to get some stuff to mix right without clumping.  Will it help to heat up the water first.

Here it's just called Xanthan Gum. YMMV. Here it's usually with all the gluten free stuff, as I say it's used to 'improve' gluten free doughs for bread and the like. Otherwise bakery ingredients section?

I've never tried warm water but I suspect that would make it clump even more by speeding the gelling reaction that then shields the unwetted stuff in the middle of the clumps.

[silviasol]

Well after pulling the cable off of a damaged one, which I now regret, I found that what is holding the cable to the circuit board is some kind of glue/conductive stuff.  Must be a mix of glue and tiny pins or balls, like elastomeric connector only held by glue.  So I heated up the entire thing to 70c then had 200c hot air blowing on the glue/conductive end of the cable while I press the glue back down with a metal end of my tweezers trace by trace.  This had restored a completely dead display to a glitchy display.  Did it again and same exact issue.  What that project virtual boy site did not mention is that the other problem is the motherboard end of the flex cable is also a problem.  I plugged it in half way and perfect display!  Seems the contacts become damaged from the pressure of the connector over time.  So I found a permanent fix a more professional way then burning off part of the cable, atleast I hope, only time will tell.  Worked on my failed attempt display also, trying my other two displays from my last virtual boy now.

http://imgur.com/a/yzTY6