Wright writes.....

[CF MRC]

That Wikipedia page suggests that toothpastes contain phosphoric acid - they most certainly don’t!  Dicalcium phosphate (DCP) is simply a powder acting as a mineralising source of calcium and phosphate ions in toothpastes, it’s also a slightly abrasive. However, not mentioned in Wicki is the fact that 37% phosphoric acid plays a major role in adhesive dentistry. It works by selectively demineralising enamel and dentine to allow resin penetration and hence nano/micro-mechanical bonding. The deleterious effects of acidic drinks (such as colas that contain phosphoric acid) on the dentition are of course well recognised. 

 

I use a lot of phosphoric acid flux when soldering. I make sure the area is well enough ventilated. The strength doesn’t need to be that high as it concentrates when boiling in situ.  If you are sensitive to such fumes when soldering then, of course, alternatives are advisable. 
 

Hope that helps

Tim

[Steamport Southport]

1 hour ago, Andy Hayter said:

If you drink a glass per day of cola (or lemonade - I don't think wiki mentioned that) per day, you will be taking in more phosphoric acid internally than you will use in a couple hours intensive soldering - where it all stays outside the body.

 

Please stop the scare stories.

 

A bit of difference between what is a trace element in a soft drink and someone messing about with a couple of litres of a dangerous chemical that most chemists wouldn't even sell to the general public.

 

Clue. If it needs a COSHH warning, then it's dangerous and should be treated as such.

 

https://www.chemtek.co.uk/data_sheets/PHOSPHORIC_ACID_75.pdf

 

 

Scare stories? No. Just facts.

 

 

Jason

[cctransuk]

1 hour ago, micklner said:

It takes rust off metal ....  

 

So does Coca Cola!

 

CJI.

Edited October 6, 2022 by cctransuk

[DougN]

I recall reading some where if you have no Flux, use coca cola as the concentration is about the same. OK I have stopped consuming Coke after reading that. As a total aside I also head why it is added to soft drinks is to increase the volume of sugar in the solution. Dont know how true that is...

 

I will continue to use the 10% red label I have as I would rather not have to clean off the sugar/ caramel left from Coke.  Then again your probably more likely to be hit by a car than any condition from soldering our trains together... 

 

 

 

 

[St Enodoc]

2 hours ago, DougN said:

I recall reading some where if you have no Flux, use coca cola as the concentration is about the same. OK I have stopped consuming Coke after reading that. As a total aside I also head why it is added to soft drinks is to increase the volume of sugar in the solution. Dont know how true that is...

 

I will continue to use the 10% red label I have as I would rather not have to clean off the sugar/ caramel left from Coke.  Then again your probably more likely to be hit by a car than any condition from soldering our trains together... 

 

 

 

 

I bought some sterilising fluid from a home-brew shop, which just happens to be 10% phosphoric acid.

[polybear]

7 hours ago, Steamport Southport said:

 

A bit of difference between what is a trace element in a soft drink and someone messing about with a couple of litres of a dangerous chemical that most chemists wouldn't even sell to the general public.

 

Clue. If it needs a COSHH warning, then it's dangerous and should be treated as such.

 

https://www.chemtek.co.uk/data_sheets/PHOSPHORIC_ACID_75.pdf

 

 

Scare stories? No. Just facts.

 

 

Jason

 

That SDS is for 100% Phos. Acid though.  I'd be more concerned about the fumes from the Solder itself rather than the flux (though it doesn't come close to concerning me enough to stop soldering).  If you're worried then there are small fume extractors available cheaply, for example:

 

https://cpc.farnell.com/duratool/d00374/fume-absorber-bench-top-esd/dp/SD01238?mckv=s_dc|pcrid|605262956863|kword||match||plid||slid||product|SD01238|pgrid|138313689055|ptaid|pla-1787859551668|&CMP=KNC-GUK-CPC-SHOPPING-9262013734-138313689055-SD01238&s_kwcid=AL!5616!3!605262956863!!!network

[Jesse Sim]

16 hours ago, micklner said:

As to Flux I wouldnt go anywhere near Phosphoric Acid ever again, simply very dangerous to your health. Hence coughing !!! you should also wear a Face mask at all times if you do use it or similar.

 

https://modelshop.co.uk/Shop/Item/Flux-non-acid-safety-100ml/ITM6286

 

It works just as well, no odour , fumes etc.

 

Pearsons Glass also sell similar and cheaper which I use all the time . It is out of stock at the moment on their website , just keep checking.

But if I wear a mask I can’t have cigarette whilst soldering….

[Tony Wright]

If I may add my two penn'th to the flux debate........?

 

I don't believe everything which is posted on the interweb. 

 

Any phosphoric acid flux I use today is not as strong as the EAMES 40 flux of yore, which means I don't cough when soldering (well, only occasionally if I forget not to breathe when applying the iron!). I don't wear a mask (it fogs up my specs), but my workshop is well-ventilated. 

 

I've tried alternative fluxes for metal kit construction (white metal/brass/nickel silver) and none of them works as well as 12% phosphoric acid; that's my experience, anyway. 

 

Though trying not to be flippant, this year I've been to relatives' funerals who are (were) younger than me and, as far as I know, none of them ever built a metal locomotive kit in their lives. I used to smoke (a pipe, but very badly), but they never smoked at all. They were all probably fitter than I ever was, but strokes/heart attacks are indiscriminate. 

 

That's not to say I'm not aware of elf-'n-safety, but I doubt if I'd ever have made approaching 600 locos as 'easily' without the use of phosphoric acid flux. 

[cctransuk]

10 hours ago, Steamport Southport said:

 

A bit of difference between what is a trace element in a soft drink and someone messing about with a couple of litres of a dangerous chemical that most chemists wouldn't even sell to the general public.

 

Clue. If it needs a COSHH warning, then it's dangerous and should be treated as such.

 

https://www.chemtek.co.uk/data_sheets/PHOSPHORIC_ACID_75.pdf

 

 

Scare stories? No. Just facts.

 

 

Jason

 

COSHH warnings are issued to help us use the material SAFELY; not to discourage their use.

 

Unfortunately, POTENTIAL dangers are increasingly treated as reasons for withdrawing products from sale when no effective alternatives exist; viz. Nitromors.

 

The State seems to think that it has an overriding duty to protect us from ourselves, no matter how stupidly or irrationally we may act.

 

CJI.

[Rhys]

I'll agree with Tony Here.

I've been soldering with 85% phosphoric acid in well ventilated areas for quite a while now.

The SDS doesn't raise any red flags for me for long term exposure effects in this application as long as some common sense is used.

 

Cheers,

Rhys

( Practicing research chemist for 30 years)

[Andy Hayter]

10 hours ago, Steamport Southport said:

 

A bit of difference between what is a trace element in a soft drink and someone messing about with a couple of litres of a dangerous chemical that most chemists wouldn't even sell to the general public.

 

Clue. If it needs a COSHH warning, then it's dangerous and should be treated as such.

 

https://www.chemtek.co.uk/data_sheets/PHOSPHORIC_ACID_75.pdf

 

 

Scare stories? No. Just facts.

 

 

Jason

 

 

Sorry Jason but not a trace element - around 1-2% in coke and lemonade IIRC - compare with my flux at 9-12% depending on where I have bought it.

 

Yes do take precautions.  Protect your eyes.  Work in a ventilated area.  But using it is not about to give females within a 2 metre radius osteoporosis.  

[Rhys]

14 minutes ago, cctransuk said:

 

COSHH warnings are issued to help us use the material SAFELY; not to discourage their use.

 

Unfortunately, POTENTIAL dangers are increasingly treated as reasons for withdrawing products from sale when no effective alternatives exist; viz. Nitromors.

 

The State seems to think that it has an overriding duty to protect us from ourselves, no matter how stupidly or irrationally we may act.

 

CJI.

It's not the state, I always get the feeling that its Chemical companies legally covering their asses against being sued.

[cctransuk]

Just now, Rhys said:

It's not the state, I always get the feeling that its Chemical companies legally covering their asses against being sued.

 

Agreed!!!

 

CJI.

[St Enodoc]

54 minutes ago, Tony Wright said:

I used to smoke (a pipe, but very badly)

When I went to University, I couldn't afford to smoke, drink, drive a car and go out with women, so I gave up smoking. I'm still not sure that I made the right choice...

[polybear]

1 hour ago, Tony Wright said:

Any phosphoric acid flux I use today is not as strong as the EAMES 40 flux of yore, 

 

The flux sold by LRM is called Phosflux 6 (for W/M) and Phosflux 12 (for Brass & N/S) - I assume this means 6% & 12%, so no-where near the "40" (if that indeed means 40%).

 

The Wiremen, sorry, Wirepersons working in the Wiring shop where I worked using to be periodically tested (blood tests?) for any nasties as a result of electrical soldering tasks, though I never recall any red flags going up; their benches were equipped with mini fume extraction equipment that seemed to be used as required, rather than on all the time.

[Barclay]

1 hour ago, Andy Hayter said:

 

 

Sorry Jason but not a trace element - around 1-2% in coke and lemonade IIRC - compare with my flux at 9-12% depending on where I have bought it.

 

Yes do take precautions.  Protect your eyes.  Work in a ventilated area.  But using it is not about to give females within a 2 metre radius osteoporosis.  

I'll always remember our chemistry teacher at school dropping a filthy penny in a glass of cola. By the end of the lesson it was pink and shiny!

[t-b-g]

As usual, when a subject like soldering comes up, there are many different views on how it should or can be done.

 

I stopped using Phosphoric acid flux for brass or nickel silver soldering some time ago as I was beginning to really feel the fumes stinging in my nose when I breathed in. I still use it for whitemetal as my preferred "Temper's Telux" paste flux doesn't work well at the lower temperatures I use for whitemetal but in truth I rarely build whitemetal kits nowadays. I much prefer the crispness of either etched or cut sheet metal.

 

With the "Telux" paste flux, maybe it gives off fumes or maybe it doesn't but there is nothing detectable by my nose.

 

When it comes to fitting things like cast chimneys and domes, two part epoxy is used as it gives me time to adjust things and get the straight and square. I don't gets such thing right first time like I used to and trying to undo soldered on chimneys and domes isn't easy.

 

When I do solder whitemetal, I would back up those who have talked about heat and temperature. You need to get enough heat into the job but not too much temperature. Having experimented with my temperature controlled iron on scrap bits of whitemetal, I am happy that the stuff used in most kits melts at somewhere around 200 degrees C. So nowadays I set my 150 watt iron at 180 degrees and I can solder whitemetal as if it is brass or nickel silver, using 145 degree solder.

 

That seems to give the perfect combination of heat and temperature.

Edited October 7, 2022 by t-b-g
typo

[APOLLO]

 

 

Brit15

[Tony Wright]

51 minutes ago, t-b-g said:

As usual, when a subject like soldering comes up, there are many different views on how it should or can be done.

 

I stopped using Phosphoric acid flux for brass or nickel silver soldering some time ago as I was beginning to really feel the fumes stinging in my nose when I breathed in. I still use it for whitemetal as my preferred "Temper's Telux" paste flux doesn't work well at the lower temperatures I use for whitemetal but in truth I rarely build whitemetal kits nowadays. I much prefer the crispness of either etched or cut sheet metal.

 

With the "Telux" paste flux, maybe it gives off fumes or maybe it doesn't but there is nothing detectable by my nose.

 

When it comes to fitting things like cast chimneys and domes, two part epoxy is used as it gives me time to adjust things and get the straight and square. I don't gets such thing right first time like I used to and trying to undo soldered on chimneys and domes isn't easy.

 

When I do solder whitemetal, I would back up those who have talked about heat and temperature. You need to get enough heat into the job but not too much temperature. Having experimented with my temperature controlled iron on scrap bits of whitemetal, I am happy that the stuff used in most kits melts at somewhere around 200 degrees C. So nowadays I set my 150 watt iron at 180 degrees and I can solder whitematal as if it is brass or nickel silver, using 145 degree solder.

 

That seems to give the perfect combination of heat and temperature.

Good afternoon Tony,

 

'So nowadays I set my 150 watt iron at 180 degrees and I can solder whitematal as if it is brass or nickel silver, using 145 degree solder'.

 

I'm astonished you can get away with such a low-Wattage iron set to such a low temperature, using 145 degree solder and still solder white metal kits together.

 

I never use an iron below 50 Watts, never have the temperature below 250 degrees and can never solder white metal kits together with 145 degree solder, and never use anything but phosphoric acid as a flux.  

 

As you say, differences of opinion.

 

Regards,

 

Tony. 

[Tony Wright]

Yesterday, I had the privilege of photographing Ian Wilson's under construction HO Gauge American railroad. 

 

 

 

 

 

 

 

I followed this train around.

 

 

Then one came the other way............

 

Since all the locos and rolling stock are mainly made of plastic, then no soldering (of any kind) was required.

 

Edited October 7, 2022 by Tony Wright
to add something

[Dunsignalling]

18 hours ago, micklner said:

Read this

 

https://en.wikipedia.org/wiki/Phosphoric_acid

 

Your choice !!.

 

Interestingly, whoever compiled that seems to have been unaware of its use as a soldering flux.

 

I knew somebody who tried using Coca Cola when he'd run out, and it did work on well-cleaned brass.

 

John

[t-b-g]

1 hour ago, Tony Wright said:

Good afternoon Tony,

 

'So nowadays I set my 150 watt iron at 180 degrees and I can solder whitematal as if it is brass or nickel silver, using 145 degree solder'.

 

I'm astonished you can get away with such a low-Wattage iron set to such a low temperature, using 145 degree solder and still solder white metal kits together.

 

I never use an iron below 50 Watts, never have the temperature below 250 degrees and can never solder white metal kits together with 145 degree solder, and never use anything but phosphoric acid as a flux.  

 

As you say, differences of opinion.

 

Regards,

 

Tony. 

 

Try reading that again Tony. I think you may have seen it as a 15W iron but it has a bit more "oomph" than that due to the extra 0 on the end of the 15.

 

The ERSA was a very expensive bit of kit but it is a real "Rolls Royce" of a soldering iron and having it improved my soldering considerably overnight. I wouldn't be without it now as I haven't yet found a soldering job that has beaten it. Even laminating three layers of 18thou brass on a 7mm scale smokebox wrapper was easy for it.

 

[gr.king]

I can confirm that 145C solder can be used on whitemetal. I carelessly picked up the wrong solder some years ago and had built half of a Little Engines J11 before I realised why I'd been having to use more heat than seemed usual in order to get the stuff to flow! Remarkably, I didn't destroy any whitemetal castings, but any mechanical cleaning up of rough joints was harder work than it would have been with the preferred lowmelt (73C?) product.

Edited October 8, 2022 by gr.king
spelling mistake

[D.Platt]

Afternoon All

All this talking about soldering I thought I would share my latest offering , it’s a djh A3 chassis , one of two that I’m currently building , in the photo you can see I use a fume extractor, didn’t cost a lot , also has I’ve said before I use the ready available yellow tube flux , yes it does require cleaning afterwards , I’ve found a quick brush with some cellulose thinners does a good job .

Better late than never but over the last few years I’ve invested in  , a 75W temperature control unit , supplied by Circuit  Specialists  (excellent after service ) the extraction fan  and most recently the Proxxon drill  (after years of putting up with an underpowered mini drill ) 

I know these items come with a cost , but I wish I’d invested in these tools a lot earlier in my modelling days .

 

If you look at the chassis can I point out the motor , a few months ago on the RM Iooking for a new source of flat can motors I came across the Mabuchi range  , so I order three off eBay from China , I’ve used these in a B1 , Jubilee and a Britannia and found them excellent , I bought another ten  at a grand cost of £18 , yes £1.80 each including postage , the motor was produced for car CD players  , it’s RPM is 17500 , search on eBay ref FF -050SK-11170 shaft is 1.5mm

[Tony Wright]

3 hours ago, t-b-g said:

 

Try reading that again Tony. I think you may have seen it as a 15W iron but it has a bit more "oomph" than that due to the extra 0 on the end of the 15.

 

The ERSA was a very expensive bit of kit but it is a real "Rolls Royce" of a soldering iron and having it improved my soldering considerably overnight. I wouldn't be without it now as I haven't yet found a soldering job that has beaten it. Even laminating three layers of 18thou brass on a 7mm scale smokebox wrapper was easy for it.

 

Ah,

 

I am due an eye test!

 

Regards,

 

Tony.