UltraSonic Cleaners & grit blasters.

[Richard Gawler]

I have had a go at a couple of loco bodies with a solution of one part distilled malt vinegar (white vinegar, Sarson's) and three parts tap water. This ratio was completely unscientific, it was simply a whole bottle of vinegar plus enough water to cover the model.


This is the "after" photo, they don't look bad but I was hoping for better.

I started with the body of the tender loco. Ten minutes without heating seemed to achieve nothing. After this I tried ten minutes at 30 deg C and, while the model didn't look a great deal cleaner, the solution was turning grey. Then a further ten minutes but at 40 deg C, and the solution was a darker grey. Finally the body of the tank loco received a total of 25 minutes at 40 deg C, and by now I couldn't see the bottom of the wire basket.

The tank loco has developed three dark spots on the side near the back (photo), I have no idea why.

I had previously cleaned both models in a proprietary ultrasonic flux remover, but looking in the tank afterwards this didn't seem to achieve very much - perhaps I had been suitably dilligent with the Viakal. But after cleaning with the vinegar solution there were traces of a grey sludge in the tank . . . I can only imagine this was fragments of solder or whitemetal being dislodged by the vinegar.

 

[OzzyO]

Hello all,

Richard you will not get a bright shiny surface out of an ultrasonic cleaner unless it's shiny when it goes in, but even then it may come out looking like your two loco bodies.

I received my order from Slater's for twelve pairs of all steel coach wheels, they looked nice and clean but I could see remains of cutting fluid on them. So into the U/S cleaner they went, using the green Cillit Bang (degreaser).
The cleaner before.



The cleaner after.


The chances are that this will be dissolved oil in the fluid. Now to get the paint on them before I get the free rust.

ATB

OzzyO.

 

[Richard Gawler]

Richard you will not get a bright shiny surface out of an ultrasonic cleaner unless it's shiny when it goes in, but even then it may come out looking like your two loco bodies.

To all.

Hmmm. This makes me wonder whether I really want a bright shiny surface. I know I can obtain a shiny finish with Solvol Autosol, but this is going to leave a residue on the surface and the model will need another ultrasonic bath before painting. I have got to decide whether to apply any polish at all, before the handrail knobs go on. I am thinking, a dull but clean finish will be fine for the etching primer, and I should stop pursuing a shiny finish now and accept what I achieved so far . . . please, does this sound sensible?

Edit (postscript) - I suppose, the etching primer stuck to my three brass wagons without difficulty and without using any metal polish, and so I have the answer to my own question. Just make sure the metal is clean.

 

[OzzyO]

I would say do a test piece of brass with one side shiny and the other as it comes and see how it comes out. Both sides will as clean as each other you could then do a test using etch primer and se if it sticks to one side better.

HTH

OzzyO.

 

[Richard Gawler]

Richard you will not get a bright shiny surface out of an ultrasonic cleaner unless it's shiny when it goes in, but even then it may come out looking like your two loco bodies.
. . .

To all.

Hmmm. This makes me wonder whether I really want a bright shiny surface. I know I can obtain a shiny finish with Solvol Autosol, but this is going to leave a residue on the surface and the model will need another ultrasonic bath before painting. I have got to decide whether to apply any polish at all, before the handrail knobs go on. I am thinking, a dull but clean finish will be fine for the etching primer, and I should stop pursuing a shiny finish now and accept what I achieved so far . . . please, does this sound sensible?

Edit (postscript) - I suppose, the etching primer stuck to my three brass wagons without difficulty and without using any metal polish, and so I have the answer to my own question. Just make sure the metal is clean.

I have had another go at cleaning my brass model over the weekend. It seems to me, tarnish on brass is the first stage of corrosion. The meaningful ways to remove this are chemical e.g. tomato ketchup (being an acid in paste form) or mechanical e.g. very fine abrasive paper or a proprietary metal polish. Having deployed all of these in a manual way, it seemed reasonable to use the ultrasonic cleaner to neutralise the residue and for this I used a mild solution of bicarbonate of soda - about two heaped teaspoons per litre of tap water.

Anyway, this seems to have worked. I won't try a bath of vinegar again, it left the metal looking awful and I suspect just as vulnerable to damage or paint problems as a residue from acidic solder flux.

 

[OzzyO]

Hello all,

before I painted the bogies for the JLTRT BG I cleaned them using this.


I just made it up using the recommend mix for about 1 litre of fluid. Using hot tap water.



The mix after cleaning the two bogies, before use the fluid was just about clear., some of this will be dust, oil etc. Then it was onto the painting cleaning the wheel treads etc.


I bought this from the bay of E but I can't remember the price.

ATB

OzzyO.

 

[simond]

Ozzy,

it's useful to look up the MSDS (material safety data sheet), both to know if it's actually hazardous, and often you can find out what it is.

It is apparently a mixture of citric and glycolic acids. No idea about the latter, but citric acid is cheap and easily available - homebrew shops & ebay for example. Makes decent flux too. You might want to limit it to brass, it'll likely eat WM!

atb
Simon

 

[OzzyO]

Ozzy,

it's useful to look up the MSDS (material safety data sheet), both to know if it's actually hazardous, and often you can find out what it is.

It is apparently a mixture of citric and glycolic acids. No idea about the latter, but citric acid is cheap and easily available - homebrew shops & ebay for example. Makes decent flux too. You might want to limit it to brass, it'll likely eat WM!

atb
Simon

Hello Simond,

it's not eaten any W/M yet!

ATB

OzzyO.

 

[Richard Gawler]

The safety data sheet for Citranox shows citric acid and glycolic acid.

There are download links here: Citranox Acid Cleaner and Detergent | Alconox Inc.

So (and this is where I get lost) we can use citric acid as flux; and to clean up the model afterwards

 

[simond]

yep, it would seem so.

It does make good flux, and is dead cheap - only downside is that it tends to leave a sticky residue, but that washes off easily in hot water. I put some IPA in mine to act as a wetting agent, I think @adrian thought it was better without.

I tend to use Flash in my ultrasonic bath, if I've been soldering, but give the object a toothbrush-and-jif scrub first, and a rinse in hot water. The u/s is more for getting the crud out of the corners and crevices where the brush doesn't do very well. And for getting the jif off too, of course.

 

[Richard Gawler]

I have just used my ultrasonic bath in anger for the first time. For a loco I have been building from brass, this soldered together using 9% phosphoric acid for flux. I've been cleaning up each day using Viakal and those plastic abrasive flap wheels.

I split the model body into its two subassemblie, the smokebox/boiler and the cab/footplate. I used 1.3 litres of water (enough to cover each part, one at a time) with a tablespoon of IPA (12 ml for a tablespoon so about 100:1) and the temperature at 30 deg C for ten minutes each part. Completely empirical.

The water turned a light pale grey. Nothing untoward happened, none of the castings held on with epoxy fell off. Afterwards, as I poured the water away, I found a few streaks of dirt in the bottom of the bath, these were dozens of tiny specks of something fine and black.

Please, do we know whether this sounds typical? I could buy a bottle of flash and decant it neat into the bath but I'm not sure this is necessary. Of course, as a beginner, I may have been cleaning up almost too diligently at the end of each soldering session.

 

[Gadgie]

Sounds about right from my experience. I tend to use hot water from the kettle at about 50C, a slosh of Aldi own brand kitchen detergent, and 3-6 mins of ultrasound. There are sometimes pleasing eruptions of dirt from hard to get at corners, but sometimes little evidence that much has happened — apart from the gritty residue of filings and other bits that appear when the bath is wiped down with kitchen roll.

 

[Les Golledge]

Sounds about right from my experience. I tend to use hot water from the kettle at about 50C, a slosh of Aldi own brand kitchen detergent, and 3-6 mins of ultrasound. There are sometimes pleasing eruptions of dirt from hard to get at corners, but sometimes little evidence that much has happened — apart from the gritty residue of filings and other bits that appear when the bath is wiped down with kitchen roll.

Hi All,

There is a You Tube guide to building Ultrasonic Cleaners in three parts:-

It's probably best to watch the first two parts before you even start to build your own as he finds several pitfalls along the way and explains solutions. The third part is building a large cleaner in a laundry sink.
Certainly food for thought.
I have heard it suggested that you should not use IPA in ultrasonic cleaners due to a danger of fire or explosion, may only apply to neat IPA and not to weak solutions.
Regards,

Les.

 

[Easterner]

Good Morning All,

Having been able to get back into modelling recently, I'm edging closer to needing to paint some of the locos I've been building over the last few years.

I have 3 x J67/J68/J69s - Mainly Brass construction, with Whitemetal Fittings & A couple have scratch built plasitcard cab interiors which I now wish I'd made removable! In addition I have a Ragstone Models Y5 which is mainly white metal. Having sat about for the past few years, the brass has started to tarnish and having been a while since I've painted I just wanted to "Brush Up" on the best techniques!

In addition, I've also been asked to paint strip and re-paint a Roxey Moldings Radial tank, I was planning on starting this with soaking it in Cellulose Thinners and going from there.....

Having read this thread, and speaking to a few people I've been toying with buying a £120 6L Ultrasonic Bath, but wondered before I made the investment if others who have recently made the plunge thought it was worth it? And also wanted to understand what cleaning products I may want to buy to compliment it and get the best results.

It's been a while since the last post in this thread, so wondered if anybody had discovered any new cleaning solutions and products that have worked well for them during the course of the year?

Thanks in Advance!
Josh