# Lookin' good and gettin' the bling flowing



## Bogstandard (Nov 30, 2007)

It seems a waste to restart this one, because there has been a lot of advice given, so I am going to transfer it all into one file then you can carry on from there. 

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Uncle Marv suggested a few weeks back that I should start a post that shows how to make an engine more presentable. I don't mind doing it, but I would like other people to assist as well. 
I don't expect this topic to be a question and answer type, like most of the others, but more of 'this is how I do it', only if the post is ambiguous or not fully explained should a quickie question be fired. 

LET US START 

I am assuming that you will be final polishing with a buffing wheel. An unstitched linen wheel and very fine buffing compound, plus some vienna lime to finish off. 

Nothing looks worse on models that are being displayed as machining marks. 
We all get them, some a bit worse than others. The way I look at it is that if it takes me an hour to machine a part, it will most probably take me two hours to get it to a stage for polishing. Remember polishing, because unless you get your metal smooth, polishing it will make it worse. 
The only correct way to get your metal prepared is to imagine a ripe soft fruit on the tree, with not a blemish on the skin, if you can get your metal to this stage, it is then ready to polish, not before. 
No easy way around this, pure finger aching, skin blistering hard work. 
I use a combination of files starting from smooth to almost a plain piece of metal, none of your one swipe to remove 1/2" here. On brass and ali I do a lot of scraping on the faces, an old hacksaw blade with the teeth ground off, then the edge honed on an oilstone to get it totally flat will work wonders when dragged along a rough machined face, square HSS blanks will do the same job, so will your neighbours best wood chisel. Then finish off with finer grades of either wet or dry paper or emery cloth, not held in the fingers, but wrapped around somehing solid. If you use your fingers you will get hollows forming in the edges, not noticeable at this stage, but after polishing will look awful. This is just on the edges, now for flat faces. 
You have got to keep flat faces truly flat, with nice sharp edges. 
Again the way I do mine is use a hard flat face to work from. You have all seen my tapping fixture that I also use for taking pictures on, well that started life as a small surface plate, so that is my flat surface. Yours could be a very smooth worktop, or like I used to use, a glass plate out of an old photocopier, or go to your local glass merchant and get a piece cut to about 12" square, but ask him to smooth the edges for you. 
What you are after for your metal is a perfectly smooth flat surface with very sharp edges. 
I use masking tape to stick down sheets of abrasive paper, if wet or dry I put a couple of drops of oil on it to keep the cutting edges sharp. Normally I will start with 400 grade and work my way up to 1200. No backwards and forwards or side to side on this operation, it will introduce a curvature to the flat face. The method used is a lapping technique, whereby you move the job in a figure of eight motion, keeping a steady downwards pressure. After a time you will get into a rhythm and will soon eradicate those annoying marks. Perfection takes time. 
You should finish up with a nice, matt, smooth as a babies bum with very sharp edges. Now you can polish it. 
The reason you do not polish out machining marks with a buffing wheel is that after you get the marks out, the surface finish will look like a bendy mirror in a sideshow stall, and the corners will look like they had been done with a roundover bit. Not what we are after. If you prepare the metal as I have said, polishing with a wheel will take seconds and the job will look like it has been plated. That was for work with flat or miller cut radii. For round bits done on a lathe, it is usually rather a lot easier because you can get the machine to do the work for you. 
If you are smoothing curved bits on the lathe then using loose emery strips or wire wool or scotchbrite, work over gently by hand, being very careful about getting near to the chuck, we are trying to polish, not paint red. For straight areas or large inside curves wrap emery around a flat piece of softwood or round dowel and use it in a filing motion to polish the surface. Again when all machining marks are gone, a few seconds on the buffing wheel will really make it shine. 
This was a brief description of how I manage it, other people have different methods, and I hope they will post them here. 

Now a quickie from me. I have been building models for many years from wood and plastics and I can get a great paint finish on them, but getting the paint to stick to metal correctly and achieve a showroom finish has so far eluded me. This would make a fine next post. 

John
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From Cedge.

John 
When I first began researching the machinist forums, I often encountered the question, usually asked by a newbie... How do you get a mirror like finish with a final cut?. The answer is always the same... You don't get a mirror finish from a final cut. You have to do it by hand. I do things pretty much as you've described, but my finest wet dry paper is 2500 grit and I've got a few sheets of lapping paper that go as fine as 3 microns. I finish things off with a metal polish called MAAS, which is somewhat like Flitz or SimChrome. It seems to give me a better finish on more types of metal than the other two products. 

Flat surfaces get lapped. You can do light touch up with a finger, later, but an nice even flat surface finish requires lapping on a nice flat surface. Here is a another tip that no one thinks to tell you. When lapping or sanding aluminum, use a bit of WD40 on the paper. As you work the piece, a gray paste will begin to form, created by the combination of lubricant and aluminum dust. This paste will begin to load up your sand paper pretty quickly. Many users would exchange this slick sheet for new paper when this happens. However, this is when things are just beginning to get right. Here's why. 

Aluminum oxidizes as soon as air hit it. This oxide coating is of the same chemical make up as sapphire or ruby, which are next to diamond in hardness. The best grades of sand paper or emery are made with... Aluminum Oxide(silicon carbide). As the sand paper sheet loads up it is also quickly becoming a very high grade, super fine grit abrasive which is excellent for fine finishing metals. Don't throw the paper away... put it in a plastic bag to keep it dust and swarf free for use, not only on aluminum, but brass, copper, bronze, steel, cast iron, even stainless. 

When polishing out tool marks on the lathe, use a sanding block. Its flat surface will prevent those finger induced ripples. The sanding block also gives you something substantial to grip a bit removed from those spinning jaw chucks. I begin with 100 grit to knock off the high ridges and then follow on with 220 grit. then I jump to 400 or 600 before using 1200 and 2500 grits. I also use MAAS, but great care has to be given to keeping the cloth from mating with the spinning chuck jaws. Never warp a finger or hand in the cloth and only hold it so that if it should snag, it will easily escape your hand and you do not follow it into the vortex. Simple rule... rags and chucks don't get along well. Keep trailing ends well out of reach of those snarling jaws. You need to know where all your digits are and where the rag is at all times. One lapse of attention is all trouble need to invade the scene. If you aren't comfortable with this step, don't do it. It is potentially dangerous if done carelessly. 

Don't underestimate the value of a Dremel tool and polishing felts. They can make working in a contour or a recess a lot less of a headache. A Dremel felt and MAAS will make short work of difficult access spots. I typically prefer hand polishing, but I'm not going to work harder than is required for good results. 

Like John, a good shine is what tells me my engine is truly completed. It only takes a bit more time, but the results are a huge plus, well worth the little additional work it requires. 

Steve
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Some real good tips there Steve. 
I would just like to add that using a buffing wheel or hand polishing is purely a personal choice, they both give the same results. A deep lustre, that when you look onto a flat polished surface it should be like a mirror with little or no distortion. 
Now I forgot about his question when I asked about the paint job. Laquering polished parts to retain the shine. But please try to keep any answers to a neutral product range, not all commercially named products are marketted worlwide. I am fed up of stripping down engines to give them a once over. 

John
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From Gilessim

I've found that the 2 component paint that they use in car body shops now seems to work well even without primer on small bits, the new stuff is also water-based so doesn't stink!, usually the local car body shop will give you a drop in an old can if you ask nicely!, if you put enough paint on ,any blemishes can be "cut out" using fine paper and water as described for polishing metal above, as this type of paint dries very, very hard, though I would leave out the buffing wheel stage on the metal before painting. 
Ally ,on the other hand is more tricky, as you should use what is known as "self etching primer" to get it to stick, I don't have any experience with this although I've seen it used and I expect that these days there are new products to prepare the ally first...Giles
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From Compound Driver

HI 

Ok heres how I brush paint a traction engine. My first requirment from a painted surface is a glass smooth end result with no brush marks runs or dimples. 

The first primer coat is always an etch primer brushed and not sprayed. Pheonix precision paints in the UK do a superb single pack etch that goes on really well. This coat is left for a few days to harden fully. I then apply a coat of red oxide primer and let that dry for a few more days. 
I next apply a second coat of red oxide and after two days flat that back with 140 grit wet n dry almost to the gray etch primer. The third primer coat then goes on with long even brush strokes side to side on the item being painted. Again two or three days between this coat and the next. 

The first colour coat now goes on again full length strokes allowing the paint to flow out from the brush. Once this coat has had seven days to harden fully I rub down with 140 grit to the point that almost all the colour has gone leaving mostly red oxide. 

This procedure is carried out a further half dozen times taking less paint away each time. At the end of the six or seventh colour coat the surface will be blemish free and almost good enough to be happy with. At this stage I go to 400 grit and do the same for another five coats. Im still leaving atleast 48 hours between coats for the paint to harden. 

Once im happy that there are no surface defects the finish coats are applied and rubbed using 600 or 800 paper. il do as many of these as I need to give the glass like finish. By this time the paint should be going on with out any brush marks. 

The very last coat I thin the paint by about 10% and rub before its put on. with 1000 grit or crocus paper. I then leave the part to harden for atleast seven days before the coach lines are painted on. 

What paint do I use? well to be honest the cheapest enamel paint I can find. in general it comes from my local decorating shop. Colours are matched by them and it works fine. 

My brushes are all sable except for my primer brush and thats nylon. I bought my brushes ten years ago and hope to get another few years out of them before i have to replace them. 

An average traction engine tender takes 8 weeks to paint and a weel to line out. 

Cheers kevin
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From Cedge

Kevin 
Good points, all. Something you might try, after the etching coat, is a product called "filler primer". It is formulated to quickly build up in the pits and scratches, making the sanding step a little less arduous. You'll probably find that the number of required coats will drop dramatically before achieving the glass finish you like. It wet sands nicely and makes for a slick finish. Think of it as a primer that wishes it was a body filler. 

The one point you expressed that needs to be noted is exercising patience between actions. Most paint screw ups come from not letting the coating cure before properly sanding or other handling. I'm as guilt as anyone about wanting to rush the drying cycle and I have paid for it every time...LOL. A perfect coat of paint requires a lot more than simply grabbing a spray can and going at it. 

Having painted with heavy commercial equipment in the past, I'm not afraid of spraying vs brushing. Although I've never been all that good with a brush. Both have to be prepped the right way or your finish is going to be less than stellar. 


Steve
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From Compound Driver

HI Steve 

The filler primer is ok but goes on way too thick leading to a ripple on the finish. Its ok sprayed but that defeats the object of coach finishing. 

About twenty coats of paint is the point I aim for. Each coat adds depth to the finished shine. I do sometimes wish there was an easy way to paint the spoked wheels 20 coats on them can dull the senses a bit. 

My Durham ended up with 35 coats on the boiler horns and tender took almost a year to do the paint I must be madd. 

Cheers kevin
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Goodness me lads, 
I was expecting, get these two cans, shake it, spray it, job done. 
You've got to remember I make an engine a month, no way am I waiting that long to start my next project 

Now what about laquer for stopping shiny bits going dull. 

John
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From Wareagle

Bog, I really think that on shiny aluminum you wouldn't get a real good adhesion to the metal. I think it would start to peel and flake after a period of time. On shiny steel, the results may be a little bit better, but again I see it not having anything to "grab" onto and therefore not lasting long. 

Another consideration is the effects that the heat from the engine would generate (assuming there is heat) and the effects of the heat on the finish coat. The finish could dull, change to a semi transparent coating, get a colored tint to it, begin to "let go" of the surface, or a combination of any of these. 

One thing that I will add on painting projects is that cleanliness in absolutely important. I wipe all of the items I paint with acetone or rubbing alcohol (make sure the material is compatible before application)before priming and/or painting. I also handle everything with surgical gloves at this stage as well. A simple finger print can cause problems with the finish and can otherwise ruin a nice looking paint job. 

As with anything in this hobby, the results are in the details!
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Now up to date, you can add from here.

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## Bogstandard (Dec 1, 2007)

For this next bit there are no hard and fast rules, I call it 'skinning'.
When you make an engine from plans, or design your own, usually a lot of unnecessary material is left on the component just because to hold the part for machining necessitates it.
When I have got an engine running to my liking, I then go over each component and remove a lot of the 'spare' material, being careful that I don't cut into any of the mounting holes, thru holes or mating faces. Doing this gives the illusion of a well designed engine and also makes it look a lot more complicated than it really is, rather than a series of square blocks stuck together.
A few basic machine cutters do most of the work I want to do. On the miller a roundover bit, a couple of different sized bullnosed (round tipped) cutters and a 45deg chamfer bit, plus of course standard cutters can get most bits done. On the lathe, a pointed chamfer tool (chamfers both left and right and cuts nice thin grooves using the pointy bit at the end, at a push you can use your threading tool), a profile tool (round nosed tool) and left and right hand facing cutters are usually sufficient.
If you have the 'meat' available, recess the screws and fixings, it makes the engine look a lot more professional. If there are large flat areas, if thickness allows, put say a 15 thou recess into it to follow the contours of the outside edge, then put a bit of colour into the machined recess, this 'lifts' an engine more than anything else. Contrast works wonders, ali and brass side by side look wonderful, black paint and polished metal looks even better.
For the support columns on an engine, just a couple of fine grooves equally spaced at the top and bottom looks like you have taken the time to make it look different. Learn a new technique for doing something, I did on my mine engine with the columns, love them or hate them, you have to admit they do make the engine look different. Drilling a conrod with equally spaced but reducing in size holes gives the illusion of a tapering, super lightweight, machined for performance, after market accessory.
The sky is the limit on something like this, look around you, there are designer bits everywhere, if you see something you like in full size, try to replicate it onto your engine, I have just looked away from my monitor and seen maybe ten things in a few seconds that could be incorporated onto an engine surface that will lift it above the norm, grooves, curves, angles, all make something look 'finished', and with a little practise will allow you to make your 'own' engine.
There is in all honesty nothing difficult in what I do to my engines to make them look different, other than, time, patience, practice, and a few bits in the recycle bin that didn't turn out as expected, but hey, I am only human (contrary to what some people think). 

John


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## wareagle (Dec 1, 2007)

Bog, these are great tips! The fundamentals are straight forward (thought there are a million different ways of doing a task), but the quality, personality, or whatever one wants to call it is really in the attention to the small things. 

Paint work, pin stripping, polishing, and material use on each of the components plays a huge factor in what the model will look like when done. It all takes time and patience. 

The following is a finger engine that I made for a friend of mine, and have a post on the engines forum about it. I spot drilled the circumference of the flywheel to equal depths with a spotting drill, painted the flywheel, then "cut" the paint off of the circumference leaving the painted spots behind. I really didn't take much time to do, and the effect is much nicer than just a flat surface.

The polish job was really a "quickie" as well, and my friend was almost in tears when he saw the finished product thinking that I had spend weeks on his unit. I did all of the polishing and painting between two evenings, spending about four total hours on it, including the set up and clean up time (wood base included). It wasn't a show quality job, but it did come out nicer then just plain old metal.


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## Bogstandard (Dec 1, 2007)

Wareagle,
That is showing exactly what I was trying to get across. The way you have detailed the flywheel lifts it from being just another finger engine, into something that looks just that little bit special. I would be well pleased to have a gift like that.
In fact that is a good idea, I have a couple of very good friends that need rewarding for all the help they have given me. Two quickie christmas presents coming up.

John


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## Bogstandard (Dec 1, 2007)

I was trolling thru u-tube and found this.
It shows what I was on about, just look at the flywheel, absolutely simple but stunning. Anyone with a rotary table could easily do this.

[ame]http://www.youtube.com/watch?v=hLFb1tCMLLY[/ame]

John


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## rake60 (Dec 1, 2007)

Great Link John!

That is an excellent example of what an open mind can do with a 
simple design.

Rick


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## Bogstandard (Dec 6, 2007)

Now we come to what I think if used in moderation can lift an engine more than anything else.

ENGINE TURNING

This, if used to highlight parts gives a WOW factor. Please, before I start, don't ask me how you do curved bits, I'm a flat metal man when it comes to this technique.

Basically it is a process where you put a 'scratched' disc effect onto the surface of the metal, then by using different offsets for each subsequent circle, you build up a pattern on the surface of the metal.
I have mentioned this site before, but this is engine turning taken to a high.

http://www.cs.ucr.edu/~eamonn/et/et.htm

What I use to get the scratches.






This isn't showing everything that can be used, but it does give you an idea. Basically you need something with a flat end face (turned up in the lathe), this can be as shown here, a bit of ali bar, a piece of plastic or maybe a wooden dowel. This is used to trap the scratching agent between your chuck and the metal surface. The scratching agent can be almost any abrasive (within reason, we are not trying to grind a hole thru the metal). I have shown metal polish and fine grinding paste, but if you are good at cutting circles maybe a disc of emery or wet & dry stuck onto the end of the bar. I am lucky in that I can obtain very hard rubber buffers with an abrasive built in, and these are shown on the right. Supposedley you can buy abrasive rods in different diameters specifically designed for engine turning. Your choice of abrasive is based purely on trial and error, when you get the effect you want, that's it.

Doing It.






What you need to do is get the workpiece square to the end of whatever you are using in your chuck. In the pic I have used double sided tape to stick it onto the top of my vice, you could also mount it in the vice, or if using a drill press clamp a rule to the table and just hold and move it along with your fingers to get straight and equally spaced scratched discs.
This is where my method will most probably differ from yours, because I am using a pre-impregnated buffer, I will just spray a bit of WD40 onto the job face. In your case you will either put a dab of cutting agent onto the end of the mandrel or spread it over the surface of the job. If dabbing it on you may have to recharge occasionally.
Then as shown, get the cutting end very close to the job, this will save a lot of arm ache moving it up and down.
This is now what I do. Just using a couple of fingers on the down handle, pull down and just using a small amount of pressure, I then count 1 and 2, then release pressure. You have to get into a regular routine to get the best effects where each disc has the same amount of scratching. 
Then move along a bit (for a basic design I go for half the mandrel diameter), and then repeat the downcut, and just carry on doing the same thing until you come to the end of the job.
Move the job across by half the diameter, and then go down the line again at the same step as used to go up the line. Then just repeat this procedure until you have covered the job. The forwards and sidewards offset can be varied to give different effects. Doing it on the drill press you would move the job along the ruler by your set amounts then offset the ruler by the sideways measurement. Usually much better results can be obtained on the miller because of the more accurate settings. You can do it freehand by using a hand drill, but again the results will vary.
This is purely a technique that is up to the makers liking, and experience plus practice. 

The Results
















The top picture looks rather bland, but the next two show what it really looks like when in oblique light (as you would normally see it), and the pattern effects come to life.

These three runs took just over an hour.

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Now this is how I go about obtaining information from someone on the web. If you notice, I tell them who I am, and a bit about myself in relation to what I want. I included a pic of one of my engines, just to show that I am bona fide. Then carefully mention what you want. I find that this approach usually results in getting what I require.

This is what I sent to Eamonn at the above address, and his reply.

Eamonn,
My name is John Moore, I live in the UK and I am the European administrator (under the web name of Bogstandard) of a fairly new website dedicated to model engineers who make small engines, mainly from barstock.

http://www.homemodelenginemachinist.com

I am just doing an article on 'blinging' up engines to make them a little more special, and when anyone asks about engine turning, I refer them to your site to show them what can really be done.
I have no problem showing them how to do a little bit of engine turning (nowhere near as good as yours), please see attached pic of one of my small engines that I designed and made myself, it is only 4.5" high. 
The main problem is keeping it looking 'like new'.
Without giving out any of your secrets is there any way that the engine turning can be protected from general wear and tear of running these engines, plus trying to keep them in a polished state. Everyone seems to think that if you use a laquer it will just peel off.

Awaiting a reply in anticipation,

Many Thanks

John

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Hi John, thanks for your kind words.

99% of what I do is stainless or aluminum, and needs no protection. I 
have very little experience with copper or brass. When I have done, 
copper or brass, I do them under a few mm of lubricant (just WD40), and 
I dry them very carefully to avoid getting fingerprints on them. Once 
dry, I dust on a few coats of aerosol clear coat. I have not have a 
problem with flaking, but most things I do go into museum, and are not 
subject to knocks or extreme temps etc.

If you do get a single fingerpint on copper before clearcoating. It will 
look fine for a few months, but inevitably the fingerprint will rust 
thru. I assume the same for brass.

It is also possible to powered coat (clear coat) metal, these I sent out 
to a guy.

Hope this helps a little.

eamonn

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Now as Eamonn says,

Hope this helps a little

John


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## shred (Dec 6, 2007)

FYI, Brownells sells the engine turning craytex rods and brushes in the US and some tools to hold them for doing rifle bolts. Those are usually round, but I'm guessing round cylinders aren't a lot harder than flat, except you have to index them as you do each row instead of moving the mill table over.

http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=5179&title=CRATEX ABRASIVE RODS
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=8870&title=DAMASCENING TOOL
http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=609&title=ENGINE TURNING KIT

I believe most of these tools are available elsewhere as well. I do note that Dremel seems to have discontinued their little straight wire brush that would be good for this sort of thing.  I went looking for one a few weeks ago and not only were both big-box stores out of them, the new one didn't even have a space for it on their extensive Dremel display. There's a good tip in with the Brownells brush instructions that a little heat-shrink tubing or O-ring applied over the bristles keeps the swirls nice and tight. http://www.brownells.com/aspx/NS/General/DisplayPDF.aspx?f=Inst-386.pdf


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## Bogstandard (Dec 6, 2007)

Thanks very much for the info you have posted Shred.
All the US members will be able to try it out for themselves now.
I can now see why the stuff isn't generally available in the UK, we don't have them bangy things called guns.

John


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## shred (Dec 7, 2007)

Bogstandard  said:
			
		

> I can now see why the stuff isn't generally available in the UK, we don't have them bangy things called guns.
> John


Well you do, you just don't know it   I talked to a few Brit shooters when I was over on the continent last summer for the European Championships.. They tend to keep a low profile.. so don't have much need of bling ;D


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