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[pettyofficernick]

Hi folks, 2 posts in one here, firstly, I have seen photo's of a TVR1A with all the aluminum parts anodized, it looks really good. I couldn't find any companies nearby who do this sort of work and was wondering if Carrs chemical blacking solution for aluminum would be suitable. Has anyone ever used this stuff with any success?
Second question, Is Purified water BP (from the chemists) distilled or de-ionised, the pharmacist doesn't seem to know, I have been running my boilers on it for a few weeks now and dont want to cause dammage by using dodgy water.
Thanks in advance,
Nick

[boatmadman]

Have you thought of anodizing the parts yourself?

http://astro.neutral.org/anodise.shtml

Re the water, I am led to believe that BP purified water is de ionised.

Ian

[steamboatmodel]

I did a search and found this:
http://pureklenz.co.uk/Products.html
"Our Water is prepared using Reverse-Osmosis (R.O.), Deionization, UV Sterilisation and 0.2 Micron Filtration. "
There is some debate about using Deionized water, some claim that it replaces the ions from the boiler material.
I have usually used distilled water ether bought and marked as distilled or gathered from the drip pan of my dehumidifier. I have in the past used tap water which deposited some calcium inside the boiler easily removed with vinegar. I have knowen of a couple of modellers who always use pond water with no problems. I haven't tried Carrs blackening or any blackening on aluminum, but there have been a few modelers in the Toronto Society of Model Engineers who have done anodising in there own shops.
Regards,
Gerald.

[pettyofficernick]

Have you thought of anodizing the parts yourself?

http://astro.neutral.org/anodise.shtml

Re the water, I am led to believe that BP purified water is de ionised.

Ian

Thanks Ian, had a look at that site, possibly do-able, I have some 50% sulfuric acid and caustic soda is easy enough to get hold of, but the proprietor may have something to say about using the kitchen!

[boatmadman]

She wont know if she is out!

[derekwarner]

Nick.... we discussed the quality of differing waters on the Paddleducks WEB site some years ago

The recomendations from this were not to use  de-ionised water as it creates a galvanic cell & leaches out the less noble elements from brass and sorrounding elements in the copper boiler shell to silversoldered joints

Naturally distilled water is just that.....boiled then condensed so most imputities are removed

Derek

PS...here is another posting from today under Steam attenuator......

Watch out that the water you buy is in fact distilled. In this part of the world you can also get what is labelled "Purified Water" or "De - Ionised Water" which should not be confused with the distilled stuff. De - Ionised water does its best to recover the ions which have been removed and the best way it can do so is by taking ions out of the metal of your boiler fittings. The scale caused by tap water is not usually too bad and can be dealt to bi boiling up with descaling compound in the water. If you cant get distilled water I would suggest rain water collected in a plastic container is the next best thing and having to use tap water is not the end of the world. Cheers, Ian.

[boatmadman]

Interesting discussion, why then is de - ionised water used exclusively in industrial large, high pressure boilers?

In my experience, the water is treated only for pH by the addition of tri sodium phosphate. So, if its an issue for scale boilers, why not just ensure the pH is neutral, pH is only a measure of the ion content of the water after all.

Ian

[pettyofficernick]

Interesting discussion, why then is de - ionised water used exclusively in industrial large, high pressure boilers?

In my experience, the water is treated only for pH by the addition of tri sodium phosphate. So, if its an issue for scale boilers, why not just ensure the pH is neutral, pH is only a measure of the ion content of the water after all.

Ian

Ah, I have pH papers, what color should they be when the pH is neutral?

[boatmadman]

That depends on the paper you have, take a look here:

http://www.bbc.co.uk/schools/ks3bitesize/science/chemical_material_behaviour/acids_bases_metals/revise4.shtml

[derekwarner]

Ian asks........"why then is de - ionised water used exclusively in industrial large, high pressure boilers?"  .......Ian ...when I suggested less noble elements ...it was the zinc in brass...as copper is of higher nobility and therefore is unaffected until an amount of the zinc is depleted by galvanic action

The result of this is severe pitting which ultimately reduces the strength of the close by brass tube or and silver soldered joint 

The pH value of a fluid [in this case water] is a measure of the scale between alkalinity to acidity

Derek

[oiler]

A decade ago I made the mistake of using deionized water in my Accucraft C-16 and after about 3 months the boiler started leaking. When I sent it back to Accucraft Cliff asked me what water I was using and to actually read the container. I was surprised it was deionized and not steam distilled and he said that many people are having the same problem. In fact I didn't even know what deionized water was along with many people. Since then I use a purified water I get from the tap.

So there you have it. First hand experience of what Deionized water will do to solder joints. Just glad they were nice enough to give me a new boiler.

[bobdylan62]

Dear pettyofficernik, I find that painting is the safaced way for the best results, your giving yourself a hole lot of trouble ussing chemicals to blacken your new engine parts....ttfn 

[pettyofficernick]

Dear pettyofficernik, I find that painting is the safaced way for the best results, your giving yourself a hole lot of trouble ussing chemicals to blacken your new engine parts....ttfn 

Thinking along those lines myself, I have done some tests on various pieces of aluminum with Carrs Chemical Blacking for Aluminum and have been unable to get consistent results....

[HS93 (RIP)]

there is a place in birkenhead that sells blacking ill try and find the address for you.

Peter

[bobdylan62]

Hello again Pettyofficernick, buy yourself some eatch primer you'll get much better results indeed...cheers Bobdylan 62