On the use of steel parts in modelmaking

[starlight]

Hello all,

 

Having spent some time now on this site I have read a number of comments from very experienced modelmakers warning to never use steel parts in models due to corrosion. I must admit that I am a bit skeptic about this viewpoint.

 

In a clean, moisture-free environment, I don't see how steel would not have the same lifetime of say, wood or plastic. Especially in the case of stainless or plated steels, and if kept out of contact with dissimilar metals. And what about if the part is painted?

 

I would be glad to hear what your specific experiences have been.

 

Cheers,

starlight

 

 

[grsjax]

I think you would be fine with stainless but regular carbon steel will corrode from the moisture in the air over time.  Short of completely sealing steel parts in epoxy I don't see any way to prevent them from rusting at least a small amount.  Also some woods will cause corrosion in steel fasteners.

[bruce d]

... and ferric metals will cause discolouration in wood.

[allanyed]

Of which nationality and era are you concerned?  what parts are you looking to make from steel?  Stainless steel was not invented until 1913.   

Allan

 

 

[Roger Pellett]

Stainless steel is difficult to work with; it is “tough” so hard to cut and form and I don’t believe that it can be readily soldered.  It shrinks if welded.

 

I see no reason to use any of the steels; carbon or alloy, when there is an excellent alternative- Brass.

 

Brass is readily available as sheet, wire, rod, and round, square, and rectangular tube.  The square and rectangular tube can be ripped and fabricated to make various structural shapes.  Brass is easily soldered using ordinary soft soldering materials. It also machines well.  It has ample strength for our purposes.

 

Roger

[bruce d]

If your interest is in using steel for structural purposes, I believe Roger has explained the less troublesome alternatives in the post above. On the other hand, if it is because you want something to look like steel then bear in mind that it's highly unlikely anything on an ocean going craft would have been left in a bare-metal finish: it would have been painted. 

 

Still, if you need something to look like natural steel there is a way.  Use nickel silver, which despite the name contains neither nickel or silver. It is an alloy, available in sheet form and is used most often in jewellery and cutlery making (it is the NS in EPNS).

 

Of course this is just speculation since I don't know how you were considering using steel in your model. 

HTH 

Bruce 

[wefalck]

I am guilty of using steel in my models for the very simple reason that there no real alternatives to it for turning long slender parts. There are some hard brass variants that may work in certain instances, but such brass is extremely difficult to buy. I making miniature models and need e.g. belaying pins of 0.2 or 0.3 mm diamater - this simply does not work in brass, even with my watchmaking lathe.

 

On a real ship, there would be very few parts with bare ferrous metal visible. I can think of the meshing surfaces of gear-wheels for instance. Also, if you have a steam-engine visible, various parts would/could not be painted, even on a steam-engine that is exposed to the elements (such as those for windlasses or winches) at least the piston rods would be bare steel. So my choice would be to make them from steel, as nothing looks more lile metal - than the metal.

 

Some 30+ years ago I build a small plouging engine model with various exposed real steel parts. They have been varnished with something that is called zapon-varnished, which is used to prevent tarnishing of silver- and brass-wares. As of today no signs of corrosion, but the model has been stored in a glass-case in a dry environment all the time.

 

A few months ago I had the occasion to visit the workshops of the Musée de la Marine in Paris and talke to the chief-restorer and used the opportunity to ask her, what they use to keep the rust away from those splendid models of iron-clad battle-ships of the 1860s to 1880s, where the armour is bare steel. She told me that they use solutions of 'micro-crystalline' wax (check Google for it).

 

So the answer is, I am using steel, when it is needed fro structural reasons and to represent the look of real steel, but otherwise I would not use it. Particularly, shy away from the combination of 'acid' woods (such as oak or beech) and steel, where the wood itself can corrode the steel.

 

 

 

[Thistle17]

If I may add my experience to the mix. I am just finishing a restoration of an exquiste scratch model that had ferrous parts/fittings. I estimate the model is somewhere in the 60 to 80 year age. It appears not to have been abused and shoved somewhere that was dirty and humid. Nonetheless the ferrous parts have rusted and as pointed out by others will stain the wood in the area. Another case in point. I restored an old machinist chest sometime back. It had ferrous drawer pulls and corner protectors. All the wood surrounding the ferrous parts had blackened. My advice is do not use ferrous fasteners or material for models! And as mentioned other forms of ferrous metal that do not corrode are just too hard to work with. You may not see the effects of environmental exposure in your time but your future beholders will. 

Joe

Edited May 29, 2022 by Thistle17

[wefalck]

The problem with the mixture steel/wood is actually the wood that contains various organic (humic) acids that corrode the steel. The ferric-humic acids compounds that form are black, hence the blackening of wood around iron fasteners or other parts.

 

I never combine steel and wood, so this problem does not arise.

 

Nickel silver is not available in too many different shapes. Another possibility for obtaining bright silver parts in brass is to chemically tin them. Salts or solutions for that purpose are available from electronics suppliers and certain modelling shops.

 

[clarkt]

Several years ago, I bought some blackened annealled steel wire and used it to make some hooks, etc.  Since then the cut ends have rusted.  It was a mistake.

If you want an unfinished steel look, inconel safety wire is available which will not corrode at all.

[starlight]

Wow, I am very glad to see the attention this thread has received, and am grateful to all of you for your comments!

 

I asked the original question to get a general sense of when it is okay to use steel, and the answer seems to be: only when the part cannot be made from brass. As for the specific application I had in mind.... I wanted to use some nickel-plated steel dressmaker's pins, painted black, to represent the long transverse iron bolts running through a gun carriage. @Roger Pellett, you are certainly correct that brass would be much better for this purpose, and in fact I did purchase some thinner brass wire for making eyebolts and the like. Only, I forgot about these transverse bolts and am now looking around for something I can use.

 

@grsjax, @bruce d, @wefalck, @Thistle17: Thanks for your excellent advice on not mixing steel and wood. I wonder how much of a problem this would be if both materials are painted.

 

@allanyed: Alas, PVA glue was invented around the same time but my model is full of the stuff . I concede that you raise a good philosophical point on the degree of "realism" that we can achieve in this hobby and the compromises that we must inevitably make.

 

@clarkt: You've perfectly echoed my worries about rust on the cut ends of steel wire. Glad to hear your first-hand experience.

 

-starlight

[allanyed]

FWIW, many of us have gone to copper wherever possible.  It can be cleaned then inserted, shaped, installed, and so forth, then blackened in situ with diluted liver of sulfur.  The LOS will not stain the wood and works instantly.   As with blackening brass or steel, a clean surface is best.

Allan   

[mtaylor]

There are brass nuts that might (or not) be of suitable size but you'll need to some searching.  Since this is brass, there's Birchwood-Kasey that offers a brass blackening liquid and works very well.   Also, consider what Allen suggested about copper but nuts at scale may still be a problem.

 

I don't remember where I saw it, but I have recollection of small plastic nuts being used and it's the source I don't recall.

[Roger Pellett]

Another material that could be used to provide a bright steel appearance might be German Silver.  I think that this might be called Nickel Silver in Europe.  I believe that this is a nickel alloy that despite its name contains no silver.

 

Roger

[bruce d]

8 minutes ago, Roger Pellett said:

Another material that could be used to provide a bright steel appearance might be German Silver.  I think that this might be called Nickel Silver in Europe.  I believe that this is a nickel alloy that despite its name contains no silver.

 

Roger

Spot on, Roger, one and the same 

 

[Roger Pellett]

Here in the US, sources of brass and German Silver sheet stock, particularly in heavier thicknesses are the suppliers of materials for building muzzle loading rifles.  Three companies are: Dixie Gun Works, Union City, TN; Track of the Wolf, Twin Cities Area, MN; and The Log Cabin Shop, Lodi, Ohio.

 

Roger

[bruce d]

For smaller workpieces try an EPNS spoon or fork from the local yard sale. They are usually well worn and cheap so whatever electroplated silver is left can be wire brushed away.