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Whats on your 2mm Work bench


nick_bastable
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3 hours ago, CF MRC said:

You don’t need jointed rods Don, you simply put the rods on backwards - hanging over the back (or front). 
 

Tim

 

Yes you can do that but with jointed rods  when using either half you can give it a nice run with no worries about contact with pony trucks or bogies

on curves.

 

Don

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Calling all chemists and/or metallurgists.

 

I have been using dish washer rinse aid in an ultrasonic cleaner to see if it proves to be more effective at removing the paste fluxes (Fluxite) from the nooks and crannies that can't be reached with a brush and Vim. While it seems to work okay I am a bit concerned (but only a bit) that it seems aggressive enough to effect the metal.

 

The photos below show that the nickel silver discolours. The copper hue will brush out with a fibreglass brush so it is presumably a deposit rather than the nickel silver breaking down as first thought. Probably no problem as there are brass bits soldered on so the copper is probably leeching out of that. Suggests in interesting reaction though. 

 

It also looks as though the chemical is capable of breaking down the solder. Some of the seams that have been sealed with a wipe of the iron have reopened. Obviously the tinned layer is extremely small but I hadn't expected the chemical to be able to break it down. Happens on both 60/40 tin lead cored solder seams and the 145 degree low melt areas. I don't use the lead free stuff.

 

Chemical in cleaner is methylchloroisothiazolinone and methylisothiazolinone plus perfume plus limonene. Probably diluted about 1:50 with tap water.

 

Should I avoid this stuff?

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Edited by Hendreladis
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Hi Hendreladis,

 

I've had a similar experience using detergent in an ultrasonic cleaner.

 

I noticed the tarnishing effect was worse at higher temperatures.

 

I now just use water but would be interested to know if there is a commonly available detergent that doesn't cause the tarnishing.

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Thanks Argos. 

 

The copper tone is definitely deposition not just discolouration. The inside of the body in the immediate proximity of unexposed brass is significantly pinker and the layer harder to remove. 

 

A few experiments have revealed that the cleaning product does seem to attack the low melt solder in particular. Small joints around handrail knobs, for example, have gone completely. 

 

Curiouser and curiouser. 

 

Andrew 

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Any items that I solder are put in a warm solution of caustic soda washing soda (sodium carbonate) in an ultrasonic cleaner. It neutralises the flux (Powerflow) and generally does a good job of cleaning metal surfaces.

 

David

 

Edit: Definitely NOT caustic soda! :fool:

Edited by Kylestrome
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4 hours ago, Kylestrome said:

Any items that I solder are put in a warm solution of caustic soda (washing soda) in an ultrasonic cleaner. It neutralises the flux (Powerflow) and generally does a good job of cleaning metal surfaces.

 

David

Hi

 

Does this have any detrimental effect to any resin parts that might be attached?

 

Cheers

 

Paul

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5 hours ago, Kylestrome said:

Any items that I solder are put in a warm solution of caustic soda (washing soda) in an ultrasonic cleaner. It neutralises the flux (Powerflow) and generally does a good job of cleaning metal surfaces.

 

David

Do you mean caustic soda which is sodium hydroxide or do you mean washing soda which is sodium carbonate?

Sodium hydroxide reacts with metals such as aluminium, zinc, tin and lead (and copper when hot) producing hydrogen. It also corrodes skin and turns the skin oils into soap.

 

Regards Roger

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I use warm water with sodium bicarbonate (like David, to neutralise the flux) and a little squirt of washing up liquid in my ultrasonic cleaner; followed by a good rinse under the warm tap. It’s served me well for many years. 
 

Pix

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Indeed; although noticeably cheaper when purchased as Sodium Bicarb via eBay compared to Baking Powder in Tesco!

 

I’m not sure if there’s anything in it; but I’ve been using Fairy Platinum which appears to have a slightly different composition. I didn’t pick it for any scientific reason; it was just what was under the sink at the time.

 

Steve 

Edited by Pixie
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3 hours ago, Roger.s said:

Do you mean caustic soda which is sodium hydroxide or do you mean washing soda which is sodium carbonate?

Sodium hydroxide reacts with metals such as aluminium, zinc, tin and lead (and copper when hot) producing hydrogen. It also corrodes skin and turns the skin oils into soap.

 

Regards Roger

 

What I have, is freely available in supermarkets in Germany so it should be sodium carbonate. As I keep it in a large screw-top jar, I don't have the original packaging any more. Sorry for the mistake over names – chemistry was not one of my subjects at school.

 

David

 

PS. I have edited my earlier post to avoid confusion.

Edited by Kylestrome
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As a former organic chemist I'm the wrong sort of chemist for this discussion. Alloys aren't really my strong point, but looking at the rinse aid ingredients in the sort of rinse aid you are using, I think the problem may simply be that you are not quenching the reaction. The zinc chloride in your Fluxite is continuing to do its thing.  Others have suggested use of a weak base to neutralise the acidic fluxite.  Sodium carbonate (washing soda) or sodium bicarbonate (baking soda, sodium hydrogencarbonate  - not baking powder which is bicarb plus an acid and will fizz rather than do what you want) will do the job as will any alkali-based cleaners.  There's nothing that jumps out in your rinse aid to act as a base. I'm not convinced that the compounds you've mentioned are the problem simply because even before dilution they aren't particularly concentrated. Limonene  (fragrance etc) and the isothiazolinones (biocides because they are oxidising agents) are prominent on labelling as people tend to get sensitised to them and suffer skin irritation. The surfactants, which are the major constituents of rinse aid, should have no effect on your model. Teaching you to suck eggs but have you tried water only in your ultrasonic bath to see what effect that has as a control?

 

Simon

 

Edited by 65179
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Ultrasonic cleaners work by 'cavitation'.  They produce what are essentially vacuum bubbles which implode and as a result remove any debris on the surface of the object.  Other than the requirement to neutralise any acid flux, water should work equally well.

 

I use solder paint for most of my soldering and clean things up by spraying them with one of the proprietary domestic cleaners, such as 'Mr Muscle', giving things a light brush with a stiff artists brush and then a good rinse.  It always brings the metal up very bright.

 

Jim

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Thank Simon. Really helpful.

 

The problem becomes obvious when someone points out the flaw in my thinking! So presumably by failing to neutralise the active ingredient in the flux cooking it all up in an aggressive environment simply exacerbates the potential for corrosion. That explains the attack on the smaller joints presumably.

 

The dishwasher liquid certainly does a good job of degreasing but lesson learned. Clean it all up as much as possible, rinse, neutralise the active ingredient, rinse, then degrease and rinse. Then put it all back in the gloat box for a few years and forget about it . . . 

 

In answer to your final point re a 'control' in water. Because I use the gungy flux water alone doesn't eliminate the residue in the nooks and crannies. All the displaced crud in the bath usually ends up sticking to it.

 

Truly grateful.

 

Andrew

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Fluxes are a very personal thing. I don’t use a resin type flux for locos, preferring weak phosphoric acid flux: a liquid which is easily washed away.  I spend time cleaning up after soldering, so the amount of flux around is minimal at the end of the process.  Final clean up after a session is with a commercial kitchen cleaner / JIF etc. 
 

Powerflo flux is difficult to remove: I know a professional painter who won’t touch a model that has used this in construction.  Before painting, my locos are usually grit-blasted to give a good surface for the paint. Exposed edges will be chemically blacked.  
 

Tim

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I'd like some help redesigning this tender. The main thing I want to change is to move the motor backwards. However, the nut that holds the body to the chassis is directly behind the motor, so that needs to move too, but where to put it? Moving backwards from the nut we come to the pivot point, then a spacer over the rear axle, then the end of the tender. I don't really want to put anything behind the rear axle because I need to save room for the coupler. I don't really think modelling the bogies as bogies would actually help, but I can if I need to. I'd like the save the tender sides, but a new floor will probably be needed, so don't hesitate to suggest one. 
Maybe the screw should go through the front frame spacer with a locating pin at the back?
Thanks for you help
 

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The prototype for reference:

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2 hours ago, garethashenden said:

I'd like some help redesigning this tender. 

Hi Gareth,

The pivoting platform looks to be above the tops of the side frames near the pivot point, so maybe you could add a cross piece to this, and have one fixing screw either side of the motor rather than a single screw on the centre line? 

There appears to be plenty of room in the sides of the tender for this, and you could slide the motor as far back as you like. You'd just need to make sure the screws were positioned so you could access them between the rear pair of wheels.

Nick.

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