Again with flux removal

Den fredag den 26. maj 2017 kl. 18.45.13 UTC+2 skrev Jeff Liebermann:

did you not put salt in machine? afaiu the reason a dish washer needs salt is that it is used to regenerate the ion exchange water softener

True. See my previous rant on the effects of the water heater on lime concentration. Cold water doesn't hold very much lime. Hot water, run through a water heater that has the bottom of the heater encrusted with lime deposits, is going to have a much higher lime concentration. I have a steel tea pot on top of my wood burner. I boil water in it when the wood burner is running to keep the humidity high in the house. I would guess about 2 liters per day for the last 5 months. The lid and spout, where there is a temperature drop and the steam condenses, it encrusted with white rocks. It's not a huge amount like in the photos, but spread over a large area, like a pile of PCB's, it will be quite visible.

For extreme concentrations, like that at a former employers, we tried to drain the water heater through a garden hose into a large bucket. When the water cooled, there was a thick layer of hard lime on the bottom of the bucket. Adding vinegar to the empty water heater produced far more lime than we wanted to deal with.

Some photos of water heater lime deposits:

Incidentally, when I bought my house in 1973, the water heater was about 15 years old. There was quite a bit of lime buildup on the bottom, but I didn't notice. Other then water spotted dishes, I didn't notice a problem until the lower electric heating element blew up. When I removed it so that I could replace it with a new heating element, it was covered with a very thick layer of lime, and the bottom of the tank was encrusted with more lime. Of course, the drain didn't work as it was also clogged. The lime on the heating element had acted as an insulator preventing heat conduction to the water, and resulted in an overheated and later burned out heating element. I gave up the idea of a repair and bought a new water heater.

The first thing I did to the new water heater was to remove the plastic drain fitting and replace it with a brass ball valve. That's so I can drain and clean the tank bottom. I also replaced the minimal aluminum anode with a more substantial aluminum anode. The anode type and size are the only differences between a 6, 9, or 12 year warranty water heaters.

Water heater sedement cleaning:

"Water heater clean out"

"Water Heater Cleaning - Removing Scale and Sediment" Plenty more videos on how to flush a water heater on YouTube.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I've actually had good luck with this. WD-40 and a toothbrush, followed by pure methanol. Mostly converted to water-based fluxes now, much easier to deal with.

Nope. No salt and no water softener full of salt in the system. When we asked about a water softener, someone found that it does something bad to the water soluable flux that we were using. I don't recall the details.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Jeff Liebermann wrote on 5/26/2017 1:43 PM:

A water softener doen't clean the water in any way, it replaces heavy ions like calcium with the light sodium ion which doesn't affect water the same way. They are also called "ion exchange". The regeneration Lasse is talking about is *inside* the water softener to "regenerate" the ion exchange beeds (replace the heavy minerals with sodium).

If sodium is not good for your board wash, you don't want to use a water softener. Filters are not effective against dissolved ions unless they are very, very fine such as reverse osmosis filters. That's a whole other level of cost though.

--

Rick C

Think about what is wrong with this picture. Steam is *pure* water. Condensing steam won't add any minerals to the surface. However, if the pot is actually boiling you get wet steam which has tiny water droplets. They aren't going to deposit much minerals on a surface even if that surface is cooler because the minerals were able to be dissolved when the water was cool.

In this case mineral deposition happens when the water is boiled away leaving the minerals behind.

In your water heater the minerals are deposited very little, but over a long time it adds up.

--

Rick C

Are you from Califonia? They must've been adding something to the water so their entire population is zombified...

If you look at most any solvent sold in home improvement stores all over the country you would almost certainly find some note kinda "Not for sale in California"...

It is definitely harmful if you have to breethe it 5 days a week for full 8 hours but sniffing it occasionally from time to time is no more harmful than going outside and taking a breath of "fresh air" filled with all kinds of pollutants. Even pure hydrogen dioxide is lethal in proper doses...

--
****************************************************************** 
*  KSI@home    KOI8 Net  < >  The impossible we do immediately.  * 
*  Las Vegas   NV, USA   < >  Miracles require 24-hour notice.   * 
******************************************************************

That makes good sense and I would normally agree 100.0%. However, that's not quite what I'm seeing. Here's the teapot in question: Unfortunately, I scraped off most of the lime that had built up during the winter from the edge of the stainless lid, and around the rusted area of the teapot. It's difficult to see on the white teapot, but there was a substantial encrustation. You can sorta see it in this

2010 photo (different teapot but same brand and model): I also scraped off some lime from the inside of the pouring spout, but couldn't reach it all. When I started, the entire inside of the spout was encrusted with lime. Also, notice the lime spot on the top of the wood burner. The bottom of the tea pot has a solid layer of lime over the entire surface.

Some of the aforementioned lime deposits came directly from the water, with its increased lime concentration would be expected to be responsible for the bulk of the lime deposits. Yet, around the lid and inside the spout would be coming from condensed steam. If it were pure dry steam (no saturated liquid water), then I agree. It's pure steam and would contain no lime. However, at lower temperatures, the steam contains quite a bit of water droplets, all loaded with lime. That's where the lime around the lid, spout, and wood burner surface are coming from.

Incidentally, the label on the teapot says 2.3qts (2.2L). SLV water runs about 300 ppm TDS (total dissolved solids) in 2015: ppm is the same as mg/liter, so my 2.2L teapot deposits 2.2L * 300mg/L = 660mg of lime from each filling. I refill the teapot an average of twice per evening, for 150 days of winter. Total deposited is: 660mg/teapot * 2 fillings * 150 days = 200 grams (about 7 oz). That's about 2 of the small salt shakers in this photo: Most of this gets caked onto the bottom of the teapot, but a fairly large precentage is sprayed all over the pot and the wood burner.

Note: I don't drink water from this teapot or use it to make tea.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Soapy water (when it gets to a bit of high-rosin-concentration solvent) makes little beads out of it (suspended globules of hydrophobic stuff in a soap-film sack). That suspended particle is no longer sticky, and rinses right away.

If not enough rinses away, or if there's no soap, you expect the more concentrated rosin-and-alcohol strata to stick to the board, like paint. When the alcohol evaporates later, the rosin 'paint' gets a blush just like varnish on a humid day, because it leaves a solid rosin matrix with a few voids filled by slow-evaporating water. It could be that the lime in the water isn't required to make a white-looking residue.

A few minutes under a heat lamp might soften the rosin and drive off the trapped water, and take the 'white' off, if it's a blush and not lime residue.

Drug-store isopropyl alcohol comes in two varieties, 70% alcohol (balance water) and 90% alcohol (this is what you want. Denatured alcohol starts out as 99% alcohol, but absorbs water from the air over time. One can also get technical isopropyl alcohol from electronics supply houses.

There is a trick here. If one uses the Xylene alone, it tends to smear the rosin (or whatever) around. If one uses the alcohol alone, it doesn't dissolve the rosin. If you mix the alcohol and xylene together, the rosin is removed quickly. Why? The zylene evaporates very quickly, and the rosin is left as dust in the alcohol, which is easily washed away.

Joe Gwinn

Drug-store isopropyl alcohol comes in two varieties, 70% alcohol (balance water) and 90% alcohol (this is what you want. Denatured alcohol starts out as 99% alcohol, but absorbs water from the air over time. One can also get technical isopropyl alcohol from electronics supply houses.

There is a trick here. If one uses the Xylene alone, it tends to smear the rosin (or whatever) around. If one uses the alcohol alone, it doesn't dissolve the rosin. If you mix the alcohol and xylene together, the rosin is removed quickly. Why? The zylene evaporates very quickly, and the rosin is left as dust in the alcohol, which is easily washed away.

Joe Gwinn

Drug-store isopropyl alcohol comes in two varieties, 70% alcohol (balance water) and 90% alcohol (this is what you want. Denatured alcohol starts out as 99% alcohol, but absorbs water from the air over time. One can also get technical isopropyl alcohol from electronics supply houses.

There is a trick here. If one uses the Xylene alone, it tends to smear the rosin (or whatever) around. If one uses the alcohol alone, it doesn't dissolve the rosin. If you mix the alcohol and xylene together, the rosin is removed quickly. Why? The zylene evaporates very quickly, and the rosin is left as dust in the alcohol, which is easily washed away.

Joe Gwinn

Drug-store isopropyl alcohol comes in two varieties, 70% alcohol (balance water) and 90% alcohol (this is what you want. Denatured alcohol starts out as 99% alcohol, but absorbs water from the air over time. One can also get technical isopropyl alcohol from electronics supply houses.

There is a trick here. If one uses the Xylene alone, it tends to smear the rosin (or whatever) around. If one uses the alcohol alone, it doesn't dissolve the rosin. If you mix the alcohol and xylene together, the rosin is removed quickly. Why? The zylene evaporates very quickly, and the rosin is left as dust in the alcohol, which is easily washed away.

Joe Gwinn

Thanks Joe, Is that good for high Impedance stuff too?

(I've got a board with 100 - 100 Meg gain resistors. All but the 100 meg are smd. We're now building this board in house and the 10 meg are leaky. Water soluble flux. At the moment 10 meg (and 1 meg) R's are pulled, cleaned resoldered with '44' and cosmetic clean with acetone.

I'm thinking we should just make the whole thing with '44' and clean it.

Or make the 10 and 1 meg through hole. Through hole 0.1% resistors are getting cheaper.

George H.

You didn't say if the water in the pot actually boils or not. That makes a huge difference as boiling puts droplets in the air which contain minerals. The issue of the steam being dry or wet is not really the concern. Steam can start out dry and condense as it cools to become wet. Then it still has no significant minerals.

So if you pot is boiling it is throwing minerals all over the place. I wouldn't be surprised if everything in the room developed a fine mineral dust if you boil two pots of water a night.

--

Rick C

Yes, that is the typical ignorant response to health effects of substances. You are free to breath what you wish. As I mentioned, the impact of individual substances are often not so great so as to warrant banning outright. There is a thing called augmentation. Two substances cause infrequent cancers with separate exposure. Combine them and the rate of cancers becomes much higher. They can't possibly test against all possible combinations of the tens of thousands of chemicals we potentially can be exposed to. So a little caution can go a long way.

Cancer rates continue to climb. It's not like you don't have any control over what you are exposed to.

--

Rick C

True, but boiling was implied in my comments that I use the teapot to humidify the house and that I replenish the water 2-3 times an evening. However, it doesn't boil all the time. It takes about 10-15 minutes from starting the fire to begin boiling and sometimes stops boiling when the fire dies down late in the evening.

Good point. So the question is how much of the water comes off as steam and how much is water vapor, where only the water vapor contains lime. I can't measure or even guess the ratio.

It might, but it's difficult to see under the layer of fine ash dust deposited around the house every time I stupidly open the door without first opening the damper (so that the ash goes up the flue pipe and not out the front door). I still have a few places in the house with some of this dust. It does look somewhat light colored. I'll test it under a microscope with some vinegar and see if it fizzes.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Water vapor is no different from steam. They are both gasses. Water droplets are not vapor.

--

Rick C

Man, you should not be scared by _EVERYTHING_ . Gluten, xylene, parabens, ketones, cholesterol, meat, whatever else they come out with today.

Just in case -- xylene is a component of infamous "Goo Gone" and "Goof Off" adhesive removers that are sold in each and every store all over the country (except, may be, California.) Pure Xylene is also on the shelves of every home improvement store all over the country (except, may be, California.) There are also plenty of other stuff with even more harmful and dangerous components (e.g. Hydrofluoric Acid, Tetrahydrofuran, etc) around you. Lots of such chemicals added to your everyday food and it doesn't matter if they are syntetic or "organic." That is not even starting on what you inhale with your every breath. IPA is not also all that healthy.

The only way to avoid all those is to just stop living.

BTW, Xylene is not considered as cancirogen and no long-term effects of exposure to it are known. Toluene is more harmful that is why it is not sold in Home Depot and others of its kind. Xylene (actually it is "Xylenes" or Xylol as it is a mixture of o-, m-, and p- isomers) is freely available in any of those stores.

Here:

PS: Watching CNN is orders of magnitude more harmful for one's health :)

--
****************************************************************** 
*  KSI@home    KOI8 Net  < >  The impossible we do immediately.  * 
*  Las Vegas   NV, USA   < >  Miracles require 24-hour notice.   * 
******************************************************************