Bobby Middlemass asked about powder coating. Many 'stove enamellers', who can be found in 'Yellow Pages' , will also offer powder coating. I use this process in the course of my business, so I asked some about painting Meccano. There are some snags which may be difficult to resolve for Spanners' purposes.
The first problem is the quantity. Most processes use a kind of fluidised bed, which requires an initial charge of powder. This varies with the size of the plant but you might expect around 10kilos. There has to be a certain minimum amount for the bed to work correctly, so there must stillbe a few kilos left at the end of painting process. The process iseconomical on paint because the overspray ( the paint which does not stick to the work or the support fixture) is returned to the bed. Also, nearly all the unused paint can be recovered. The standard pack quantity for the paint is usually 25kilos. The cost varies between about 5 and 10 pounds Sterling per kilo. You may be lucky and find someone who has free stock of a suitable colour, however, they may still want a reasonable quantity to justify the filling and clean-up of the plant.
The second problem is the quality of the finish. 'Orange peel' is a common and persistent problem, which I even see occasionally on Calais-made plates. 'Lumpiness' is a less common but equally nasty effect on a smooth surface. These can only really be overcome by tuning the process on a large run of parts of similar type. I have avoided these on my own work by specifying a textured finish where the common faults are just not noticed: we use conventional enamels where a smooth surface is required.
There has been some discussion about making narrow strips or adapting standard strips. The latter is a non-starter using an industial process. No safety officer in the civilised world would allow a gilloutine to be used on a half inch wide blank. The tooling cost to adapt strips on any kind of press would comparable to that of a tool for punching out the whole part,(a couple of thousand pounds) and the labour costs would be much more than starting with sheet or strip. It is much cheaper to make new ones, provided you can make enough!
I have considered making them myself, and this is what I found: The first problem was material. Calais narrow strips are made from cold-rolled steel in strip form, which is very hard and springy: a necessary characteristic, because of the thin material and the small width of metal either side of the holes. Unfortunately, this is not easily available in the sheet form I need in small quantity. I was quoted a minimum order quantity of 3 tonnes! At this stage I started thinking about using stainless steel. It doesn't need finishing, which easily offsets the higher material costs. It doesn't usually rust, but paint does not adhere well. Heretical material! What are the NZ strips made from?
Using an NC punch-press I would have to cut an 8 x 4 foot sheet in one go, which would make about 600 of 25 hole strips. I would also need to have a fly-press tool made, for cropping and rounding the ends, at about 250 pounds Sterling. Clearly, the cost of that tool would have to be amortised over a lot more than a single sheet for it not to dominate the cost of the parts. Would anybody want stainless-steel narrow strips between 11 holes and 25 holes long in quantities of hundreds? Did I?
At this stage I ordered a few hundred short narrow strips from John Linder. I shall bolt them up two thick and console myself with the knowledge that long narrow strips are too flimsy to be useful, anyway.
The recent request for narrow strips with holes at quarter inch pitch reminded me of a new part, which I have been planning to make for some time. This is a narrow strip with five holes on quarter inch pitch made from 3mm brass. The centre and outer holes would be tapped and the other two would be plain. This would have many of the same uses as my nut plates, but others too. For example, they could be used as fixings in rolled cylinders, as substitutes in some applications for the rare and expensive 5-hole couplings and in conjunction with narrow strips and angle girders. The number and disposition of the plain and tapped holes could easily be varied.
So why haven't I done it? Economics is again the problem. I have to buy a blanking tool for about £120 Sterling and I have to punch a complete sheet (fortunately a smaller one!). The batch size would be about a thousand. Would anybody be interested at 45 to 50 pence each? Expressions of individual interest should be sent to me directly, please. I will make a comment on Spanner, if appropriate.
Extreme Heretical Regards
From: Dave Feinstein
'Orange peel' is a common and persistent problem, which I even see occasionally on Calais-made plates. 'Lumpiness' is a less common but equally nasty effect on a smooth surface. These can only really be overcome by tuning the process on a large run of parts of similar type. I have avoided these on my own work by specifying a textured finish. Where the common faults are just not noticed we use conventional enamels where a smooth surface is required.
I have been Powder Coating Meccano old parts for 2 years now vey succesfully and comment as follows:
Orange peel is cause by excessive powder - caused by too high voltage and the stringing process using tin wire or high electrical resistance wire. Ideally this should be copper wire.
Lumps usually indicate poor preparation - dirt on parts. ie old paint, zinc or nickel plating residue and most commonly dust in the atmosphere. The coating has to be done in a dust free environment on bare metal.
Rust causes spatter as it pops in the baking oven.
A supplier of powder coatings in the UK follows, they, I am sure could put any interested party in touch with a paintshop that applies the Powder Coat in most large cities in the UK.
INTERNATIONAL PAINT LTD. (CORTAULDS POWDER COAT DIVISION) STONY GATE LANE, FELLING - GATESHEAD, NEWCASTLE, NE10 OJY. ENGLAND. Tel(0191) 469-6111.
For anyone looking for a source of Meccano-colour paint, I have found a local firm who will mix-and-match to any colour sample (including gold) and supply the paint in tin OR AEROSOL. They sell direct to the public with no minimum order stipulated (ie they will supply a single can).
They charge £6.50 + VAT per can, reducing to £4.80 for 5 or more of same colour, with a one-off charge of £5.00 + VAT for mixing to match. Further details on request.
There is an old watch-makers trick to repair a broken clockwork motor spring that I have used successfully many times. The spring cannot be drilled as it has been tempered and is too hard for this approach. To remove the temper from the latch of the spring (where you need to drill the hole) heat just the end of the spring over a candle or gas burner until it is red hot and then allow to cool slowly. Now the fun part - in most cases the required hole is square, not round! To punch a square hole in the end of the spring is a lot easier than it appears, you need a punch and die of the required shape of the hole. The punch is made from an old file, grind the tang (the point that goes into the file handle) of the file to the square (or oblong or trapezoid) shape of the hole required in the spring. The die is just a flat block of lead, usually a fishing sinker is more than big enough. Place the end of the spring where the hole is needed on the lead block, put the ground file tang where you want the hole and give the other end of the file a good whack with a hammer. You will find you have punched a perfect hole the exact size and shape of the punch! It is not necessary to re-temper the end of the spring.
Regards, Ian Laing
I would suggest staying well away from WD40 either for lubrication or storage. It is a penetrating oil designed to loosen tight nuts, etc. so it is very thin and evaporates quickly. As you noted it leaves some kind of "gunk" behind that is hard to remove and certainly does not lubricate.
Clockmakers, who know a little about springs and gears), still debate the correct type of lubricant to be used on springs. Some swear by the new synthetic oils like "Mobil 1" while others swear by some form of grease. We probably can't take too much from clockmakers in terms of pivot lubrication as clock pivots turn very slowly requiring special properties from the oils they use. (For more clockmaker information on lubrication and springs go to http://www.webcom.com/~z4murray/repair.html" and click on "27. Lubrication Summary from the mailing list Clocks" and "35. Clock Mainsprings, everything you always wanted to know". The later is particularly good as it describes how to clean and lubricate a spring.)
I will note that clockmakers usually do not lubricate the teeth of gears and pinions as they are usually made of dissimilar materials, (brass and steel). For some strange reason the coefficient of friction between dissimilar materials can be lower that between similar materials. Meccano models typically break this rule but if you are "really serious" you can run steel axles in brass bushings and mix plastic and brass gears in a train. Also the clock guys use very tiny amounts of oil when they do use it, the reason being too much oil is likely to collect dust which will act as an abrasive when it mixes in with the oil.
One of life's more rewarding exercises is fixing the spring on a clockwork motor. The first (1970s) #1 Meccano clockwork I bought (as an adult) was broken in one twist of the wrist (in the wrong direction), as this unit was apparently designed for left handed winders (or maybe for persons south of the equator - old joke here). There was an arrow embossed on the side of the motor indicating the correct direction, but the enthusiasm of youth overtook me! Repair is usually quite easy. The springs break and at one end or the other.
Dissemble the motor, freeing the spring completely. Then one heats an inch or less of the end with a match or candle to lose the temper, and then use drill and file to recreate a duplicate of the broken end, finally bending to the correct contour if applicable - and it usually is. One may need a few extra hands to reassemble, but then it will work just fine. Pay careful attention to what goes where during dissembly.
As for the electrical unit, its probably better to get a new(er) electric train transformer of proper capacity, as the safety considerations on old equipment are often marginal. If you want to get in there for the fun of it, that's your choice. Anyway, welcome back. And have fun trying to get all that spring back in a small enough coil.
I recently sprayed some cranks with a brass coloured paint:
Testors Model Master Custom Enamel, if that means anything to you!
It came in a 1/2oz (15ml) bottle. The type of paint you buy for model aircraft and other modelling work. Anyway after leaving it for about 6 weeks I was about to put the cranks in a model and I put some sewing machine oil on them. Well by the end of the evening the paint was soft and I had to wipe all the paint off with a cloth!
The paint in the bottle seems to be a suspension of brass coloured flakes that have to be shaven before you use it. I've never had this problem before with any paints. What I was trying to do was imitate the 1978 brassed or iridescent finish.
Any suggestions for a better paint?
Cheers, Wes Dalefield firstname.lastname@example.org
Thank you for the idea of baking the enamel. I'll try baking some parts that I have painted but not used yet. If this does not work I'll look into Tremclad. To be fair on the modellers paint that I bought I don't think that they expected it to be used in an engineering situation.
350F for 20 minutes. Any problems that my oven is not a fan oven?
Powder-coating is incredibly cheap to have done - PROVIDED you do all the preparation. It's charged by the area occupied - in our case about AU$10 per square metre. Now you can fit a h*ll of a lot of strips and girders into a square metre, but not quite so many plates, of course. I understand that powder-coating has undermined the more traditional electro-plating in lots of areas, so that pc-ing is now probably even more readily available than is plating. But its cost does depend on just how much you are prepared to do. I take along a minimum of half a dozen square metres of stuff at a time. I assure you that the pleasure of picking up you first load after coating falls not far short of that wonderful morning, years ago, when you woke up to your first L set.
PS Just make quite clear to your man precisely what colour you want. A load of red, when you wanted green, might take the shine off this story! And as we all know, from trying to strip Calais parts, once coated, it's there for keeps!!
From: Chris Bourne
Horolene (Brasso with added elbow grease) is a wonderful brass cleaner. Must admit that I've never used it on nuts & bolts though.
Horolene is the name of a brass cleaning product made for the clock repair trade. It is probably only available in the UK. There are equivalent products available from clock repair supply houses in all countries. If you can locate one give them a call and ask them for their recommendation, (see item 45 on the web site referenced inthe next paragraph).
There are also recipes for "home brew" versions of these cleaners - take a look at http://www.webcom.com/~z4murray/netftp.shtml and click on item 25. (That site has a lot of interesting clock related information.) Also, some time back, Ian Laing suggested the following:
I have just been told of, and have tried, a method of cleaning brass parts that has amazed me with the results.
Put a teaspoon of cooking Tartaric Acid (normally available in the food section of supermarkets in sachet form) into a plastic bowl, add a teaspoon of washing up liquid soap and then fill the bowl with very hot (boiling?) water - wash the brass parts in this mixture. The brass comes out shining in a few seconds, no elbow grease required. Rinse off in clean water.
I have used my mixture a few times now, storing it in a bottle and heating it up again when next used. For a list of Clock materials suppliers take a look at item 45 at the above site.
To which Dave Williams replied:
I tried out Ian's first mixture yesterday with good results. Perhaps it was a bit weak, but I left the parts soaking all day. This one gear had a stain that would not come out using Wenol - after a day's soak the gear turned a coppery colour with the stain removed! Wensol removed the coppery finish no problem - now the gear looks like new!
I suspect that the principle of this mixture is similar to another mixture I read about in an older North Midlands Meccano Guild publication - mix vinegar and salt together for cleaning nuts and bolts. This mixture also turns parts coppery. I'll have to add both mixtures to my Meccano web pages.
Last evening I tried another test. Yesterday I purchased a batch of post (sets 6A & 8A) and pre-war (?) Meccano - the pre-war gears were black! I soaked the gears in the remnants of Ian's mixture - this morning most of the tarnish was gone. I'll refresh it and try again.
By the way, I used "Cream of Tartar" - that's what it's called on our store shelves. I can buy Tartaric Acid also as its used for home winemaking.
On the same theme Roger Hill wrote:
I published an article in the Johannesburg Meccano Hobbyists Newsletter in May 1996 on the subject of restoring/cleaning brass parts. The article was contributed by Bill Steele. Here it is:
"Granny Steel's Recipe
Bill's Granny, known affectionately as Jinny, developed the following recipe for cleaning jewellery. Bill found that it worked perfectly on Brass Meccano parts.
Take one level dessert spoon of Cream of Tartar (Tartaric Acid) and one level table spoon of ordinary washing-up liquid. Put both ingredients into a tumbler or similar sized vessel. Fill up the tumbler with warm water and stir the contents well. Put in your brass Meccano part(s) and stir around until clean - which should take only a minute or so. Try it!!" Short but sweet. I hope this is useful.
Tony Press had the last word on this subject:
During earlier postings on brass cleaning mixtures, there was some discussion about Cream of Tarter and Tartaric Acid. Ian Laing's original suggestion was for Tartaric Acid and Roger Hill's recent note about Granny Steel's recipe suggested Cream of Tarter and Washing Up Liquid. Apparently the two are closely related according to an encyclopedia which states that Tartaric Acid is from Grapes and Cream of Tarter is refined Tarter which is found as residue in old wooden wine casks (probably containing Tartaric Acid). Maybe Cream of Tarter is a weaker form of the acid. Possibly another brass cleaner could be made using Acetic Acid (vinegar).
Here is the process used by Lloyd Spackman of the Auckland Meccano Club to replate parts:
Remove as much of the paint and rust as possible. Take the parts to your electroplater, who will give them a final clean in an acid bath. He will then plate them with NICKEL and PALLADIUM (not Cadmium, as I thought.) The Palladium acts as a hardener. Keep the parts slightly oiled. (This may not be really necessary.) Good plating (I can't think of a pun). Doug Harris
Yes, I understand that copper should be used on steel before chromium for a permanent job - I would assume that any plater who knew his job would do this if it was required under nickel/palladium, being a layman, I am not privy to such information, merely passing on the basis of the technique for the benefit of others.. Doug
Hi Doug, Nickel over iron without a copper bath is going to flake. I prefer cadmium, its cheaper and has excellent solderability (lead/tin). All of my nickel plating flaked at the corners and holes. The parts that are unused are OK. If you've already tested the process and it works, give us some info on how they do it. all the best Jacques
I have never sand blasted Meccano, but I have restored a lot of equipment using sand blasting. Obviously, a lot depends on your equipment, but sand blasting can be dirty, and less effective than you might think. Most people use common sand which is very cheap, but I have found that in spots where paint is thick (or well bonded to the metal), it can be very slow (usually very good on rust though). More aggressive abrasives are available such as aluminum oxide, however they are expensive, and you would want to have a way of recycling the media. If you have a blasting cabinet, you're all set. Also be aware that harsh abrasives can cause 'pitting'. I'm told that glass beads, and media like walnut shells will not pit the metal.
Also remember that older parts may have used lead based paint, so take precautions not to breathe any dust.
As an alternative, I have had great luck with oven cleaner. In the US we have a product called 'Easy Off', which is an alkaline, foamy spray. You put your parts in a pan and spray them, then let them sit for a few hours (use rubber gloves wile playing in the foam). The paint will just peel right off (if not, wait a while longer). I have never tried it on zinc plate, but I would expect that it would remove all the zinc as well. Wash your parts thoroughly in warm water when done, dry them, and you're ready to paint.
Dishwasher tablets strip paint... found out in error trying to clean up some dirty old bits... it stripped the paint in seconds however you must be sure to dry everything well before it rusts.
Peter J Gronous
I use caustic soda to strip the paint off of any parts I'm going to repaint. I can also confirm that it takes Zinc plate off most effectively (and the metal under the Zinc is often in perfect condition).
Dr Paul Dale
OK, I've got my 'Easy Off' can in hand. It does say that it's sodium hydroxide (Lye) which is (I believe) an alkyline. While the can doesn't say, It may very well attack steel, however that process must be slow. I've used this to remove paint many times and have never had any noticeable damage to the metal underneath (actually far less than sand blasting), nor did I have problems getting the cleaned metal to hold paint. I would say again though, that it is important to throughly wash the parts after removing the paint, dry, and apply some sort of protectant (repaint) to stop rusting.
Like many products that actually work, this stuff can be dangerous. Wear eye protection and rubber gloves. I originally suggested this as an alternative to sand blasting. In most instances, sand blasting is a good deal more hazardous.
But doesn't it affect the underlying metal? Searching for details on caustic soda the first page I found was on safety precautions (nice stuff, this NaOH):
You asked about sand blasting Meccano and whether it may be too efficient? One of our members here in Melbourne had some parts cleaned by this method a few years ago. By his account the results were disastrous. The parts exhibited extreme pitting and were deformed. I guess you that if you choose this method you will be in the hands of the operator.
I buy commercial solid Caustic Soda from the hardware store and make up a solution that is just strong enough to remove the paint. The rule is that caustic will remove everything including your skin so the weaker the better. However strong solutions strip paint faster than more dilute. I have some old photographic development trays that can hold up to 12.5 inch pieces comfortably and a garden shed with a stout lock. So I favour longer time in a weaker solution. As far as your zinc coated parts are concerned, dilute Hydrochloric acid will strip this fast. Put the parts into a container that is big enough to contain the frothing so that you avoid spills. As the spilled solution evaporates the acid will become concentrated again and could do damage.
Finally, I dip parts for painting into a commercial rust converter/passivator before spraying. Restoring parts is messy, tedious and consumes time better spent building. By passivating the parts I get better adhesion and resistance to rusting. If you go looking for this, try to locate a product used in the auto trade for rust proofing panels. I have some unpainted test pieces that have survived more than ten years and show no trace of rust, even in the creases of the angle girders.
One of our members has been refinishing his yellow, black and silver set to original colours. He has located an aluminium paint that looks authentic and he hopes will bear up better than the original. I can only suggest that you look around in paint suppliers, automobile parts suppliers, etc.
One other little trick that is not generally known is that paint manufacturers make a hardener, which if stirred into the paint prior to application makes the finished surface more able to resist physical abuse. I guess that it produces by chemical means the hardening that results from baking.
I have a HPLV gun and compressor and built myself a crude spray booth in the shed. I have had colours from various eras computer matched. In theory, parts painted in a colour of my choosing are quite easily had. What I need is 48 hour days.
In terms of what colours to use, I finish pre WW11 parts back into their original colours. However, paint post war parts in whatever colour I need to balance stocks. It's your hobby, they are you parts, I guess you can finish them in any way that pleases you.
One last comment, all of the chemicals I've been talking about arepotentially dangerous to you, if mishandled, and to your children and grandchildren if not disposed of responsibly. The local state government here has a controlled, noxious chemical disposal program so batches of diluted chemicals go out that way.
Hope this is helpful to you. Mail me direct if you have any questions.
Don't totally disregard sandblasting!!!
I equate what you describe as trying to push in a pin with a sledge hammer! There are sandblasters and their are sandblasters. Obviously too course a grit and too much pressure. It sounds like a machine has been used which would be more at home blasting a bridge!
I am a monumental mason (headstones) and all the lettering is cut into the stone with sandblasting. We operate two separate booths one with very fine media (200 grit) and the other with 60 grit. Both aluminium oxide, so I am fortunate in having my own facilities. The fine booth is generally used for etching glass (a sideline) and fine shading work on granite. I blast Meccano in the coarse booth at 80psi through a 3/16 nozzle.
I have blasted much Meccano over the years and when painted, the results are great. Beach sand is not used for two reasons. It does not have the hardness/abrasiveness of Aluminium oxide or Silicon Carbide, and breaks down rapidly on use, usually can only be used once or twice. If not washed properly before use it leaves a salt deposit on the work which contributes to rust. More importantly the sands here in New Zealand are a health hazard! They contain a large percentage of silicon, which if inhaled causes silicosis.
The paint/rust is removed quite rapidly leaving a perfect finish for painting. A flanged plate would take about 1 min, rotating in the gloved hand. We have a reputation here for 'gentle blasting' and we do a lot of vintage car parts, bike frames etc as a sideline. There is no pitting on clean metal. The only pitting evident is where rust is removed back to the bare metal. but I rarely restore parts in such a bad condition.
To me (but I am biased) there is no better way of removing paint. Perhaps if spanners would befriend their local monumental firm, or ask around for a more gentler blaster, you could have the same benefits and results?
One of the best method of cleaning old paint is explained on Jim Picton Web site at http://users.uniserve.com/~jpicton/ I have tried it and it is very easy and does a very good job. Of course I don't know if the products mentionned are available in Portugal . Best wishes Robert Gibeault
Cleaning off old paint. Caustic soda (NaOH) from the local supermarket is what I use, taking precautions as learnt in school over 50 years ago. Soak overnight, move with kitchen tongs to a bucket of water, scrub with a nailbrush, rinse and dry.
Cleaning off rust. Nothing appears to be cheap, easy and effective. My present practice is to use a heavy-duty nylon wire brush, bench mounted in an electric drill. Pieces can then be passed across the brush bit by bit, taking off rust and giving the metal a good rough surface which I believe helps the paint to stick. It is very good for strips, fairly good for angles, and fairly tedious for plates. I am trying out the tea suggestion to see how it compares.
Painting. I use 300ml cans of spray paint from the local hardware store or paint supplier. Several brands are available in a variety of colours, most of which fail to match a Meccano colour that I want. Green, for example is usually too dark or too light, although one of the cheapest brands came out with an emerald green this week which appears to a reasonable "Medium Green". Considering how much Meccano colours varied from time to time, it is good enough for me. If I was a bit younger I would try Lindsay Carroll's idea of setting up a proper little spray booth and getting a proper paint spray gun. As it is, I use my garden shed. I set out the parts for painting on metal support frames made from strips of steel used for wrapping pallets of bricks. I have one set with V-notches cut to support angle girders. Spray one side, then turn over next day and spray the other. Leave for another day and then bake in the sun for several days (plenty of this available in Perth). Someone suggested leaving several months for further hardening before using. I agree. If hot sun is not readily available, I suggest you try out Jim Picton's ideas for oven baking. Quantities: I have just painted a Set-10 quantity of strips and girders etc using a gold metallic spray. Three cans was just not quite enough.
Spanners - I have a friend who does professional (ie people pay him big-time) restorations of toys and trains including painting. He is able to have colors duplicated and supplied to him in spray cans (for small jobs) or in reasonably small bulk quantities (for use with a spray gun). Don't UK train hobbyists in particular must have similar sources for their Hornby products?
Powder coating uses a polyester based material. It involves what is called a seven-tank process for pre-treatment starting with a rub down, followed by baths in organic and inorganic solvents/solutions for cleansing, with thorough rinsing between every stage. Each item is then strung up on a hook and rail - wardrobe style - and taken to the coating chamber. Powder is applied using a fine spray gun and adherence is by way of electrostatic attraction. The parts are then moved to the heating chamber and raised to 150C which 'fixes' the powder to the metal. This heat setting takes about 2-1/2 hours.
Powder coating is available in three finishes : matt, satin, and glossy. 'Glossy' uses a pure polyester based material whereas the other two can be got with a polyester hybrid 'powder'. Use Satin finish for Meccano. A small coating shop is generally able to coat components up to 7' in length. They will charge you by the sq.ft or sq.m. - remember they will bill you for BOTH sides of the Flat Plate.
Advantages : It looks very good, is cheaper than quality spray painting, and is more or less permanent if applied in just adequate thickness. The 'chipping' at edges is due to over-enthusiastic coating. You can strip powder coating off only with a strong acid which eats away the metal, so...
Disadvantages : You have a limited choice of colours. You cannot mix-and-match like paints. You cannot do it at home. The commercial workshops hate to do small batches, because powder coating is a messy business and they have to clean all the tanks and chambers thoroughly before they can change the run colour. They particularly dislike small parts because of that tedious hand rubbing and rinsing.
Note : there is a glass-clear powder coating available, too.
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