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Post by Roger on Jun 11, 2020 18:34:54 GMT
I decided just to use an air gap to act as an insulator. I was concerned that the intense heat radiating down from the grate might get the inner ashpan too hot if I insulated it. So instead, I'll forgo a bit of insulation in order to avoid that risk. 20200611_173420 by The train Man, on Flickr So the heat shield is attached by the standoffs I showed yesterday, here being riveted over on both sides at once using the rivet press. That was a bit of a tall order for it, so I had to move it around to nip the edges else it wasn't man enough to deform the heads. 20200611_173205 by The train Man, on Flickr And here's a sanity check with it fitted to the boiler and the same sitting between the frames. I wanted to make sure the it didn't foul the axle in the upper most position and also check that I could still fit the ashpan tray underneath the whole arrangement. Anyway, it all looks good and I fitted the axle to double check. It's actually a couple of millimeters away from the axle at the top of travel, so that's fine. Hopefully this will have the desired effect. The viscosity of the oil is going to be significantly reduced if the temperature is elevated. It seems to me that this is more likely to be the reason for excessive wear on this axle rather than from ash getting into the bearing. It certainly won't do any harm, and as always, it's nice to do something a little different! 20200611_170823 by The train Man, on Flickr
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Post by andyhigham on Jun 11, 2020 19:10:26 GMT
leaving out the insulation means air can circulate between the two layers, keeping them both cool
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Post by Roger on Jun 11, 2020 19:12:25 GMT
Yet more preparation for painting, this time it's for holding the smokebox so I can paint around the outside and rotate it while doing so. This took no more than ten minutes from having the idea so the printer making a start. The print uses about 3 metres of filament and took just over an hour. So that's minimal effort and negligeable cost. What's not to like! 20200611_001053 by The train Man, on Flickr The idea is to prime and paint the area where this attaches separately. It's not going to be visible, so it doesn't have to be a perfect finish. 20200611_195215 by The train Man, on Flickr I just made holes that were M4 tapping size and tapped them for the screws that hold it on. 20200611_195231 by The train Man, on Flickr
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dscott
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Post by dscott on Jun 11, 2020 23:27:16 GMT
That is lovely Roger and now can say being of an age when these were so wanted in our lives? SMALLER of course to fit inside 45s!!! Wonderful tease as to the speed at which you get to turn the handle. So reminiscent of early Movie Cameras where a steady roll of film through the camera was needed. Such primitive equipment we once had. Talking of PRIMITIVE. Someone forgot to charge certain Batteries last night and we are back on a Corded Mouse of last Century technology where it was held in wonder. More of a workout as it will not go where I want it to.
You could do several WRAPS. And do a covering of card and practice with a few rotations before the expensive paint hits the metal.
David, and Lily who finds employment as Chief spray can rattler.
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Post by Roger on Jun 12, 2020 6:29:57 GMT
leaving out the insulation means air can circulate between the two layers, keeping them both cool That's what I thought. It also is a technique used in the automotive industry on exhaust pipes or manifolds, and they don't use insulation between.
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uuu
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Post by uuu on Jun 12, 2020 6:56:13 GMT
I was thinking it's like the Land Rover "Safari" roof.
Wilf
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Post by simplyloco on Jun 12, 2020 7:10:12 GMT
I was thinking it's like the Land Rover "Safari" roof. Wilf Like this one on the Landy I bought and had shipped home when working in Qatar. There were six vents in the roof which when opened utilised Bernoulli to provide remarkably cool air! Trouble is, in 48C I had to be doing around 70mph before it was any use! John ![](https://i.imgur.com/6dHoyOv.jpg?1)
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Post by 92220 on Jun 12, 2020 8:41:20 GMT
Hi Folks.
If you use an airbrush like the Badger 200, with of 50mls bottle feed, it is quite capable of spraying large areas. The spray cone can be adjusted for 1/16" dia right up to at least 2" dia so that is more than enough for painting a 5" g loco. You do need to be able to get 50psi at the airbrush though, for large area painting, and experiment with the amount of thinning for the particular paint you are using. Don't buy an airbrush with a small paint reservoir integral with the main airbrush body. They are fine for small jobs but far too small for large area where you want a lot of paint. If you are able to spend the money on an Iwata airbrush, they have a large gravity fed paint can, and a nozzle for spraying a fan pattern on their top-of the range airbrush. I have a Devilbiss mini spray gun and also a Kite, but neither are likely to be used on the loco.
Bob.
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Post by Roger on Jun 12, 2020 10:38:29 GMT
Hi Folks. If you use an airbrush like the Badger 200, with of 50mls bottle feed, it is quite capable of spraying large areas. The spray cone can be adjusted for 1/16" dia right up to at least 2" dia so that is more than enough for painting a 5" g loco. You do need to be able to get 50psi at the airbrush though, for large area painting, and experiment with the amount of thinning for the particular paint you are using. Don't buy an airbrush with a small paint reservoir integral with the main airbrush body. They are fine for small jobs but far too small for large area where you want a lot of paint. If you are able to spend the money on an Iwata airbrush, they have a large gravity fed paint can, and a nozzle for spraying a fan pattern on their top-of the range airbrush. I have a Devilbiss mini spray gun and also a Kite, but neither are likely to be used on the loco. Bob. Hi Bob, I think the take home message from what you're saying is that not all Airbrushes are created equal. Maybe this is why others haven't had much success on larger items. Anyway, being able to do larger items with an Airbrush is a huge advantage in my opinion. That's because unless you have a very plain model, there will be detail that's difficult to spray with a larger gun, such as the steps and hand rails and the fillers and other details on the Pannier Tanks. Switching guns between doing the large flat side and the ends seems like it's more likely to introduce blemishes. So if you use a larger gun, I imagine you're forced to spray the detailed parts with that too.
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Post by Roger on Jun 12, 2020 10:42:12 GMT
Here I've copied the Smokebox mount, thinned out the ends and adjusted the diameters, just a five minute job. 20200611_212317 by The train Man, on Flickr I can see me designing mounts for all of the difficult to hold items. The boiler cladding can be supported like this and can include something to engage with the open side so it guarantees to turn it rather than slide round since it's not balanced. 20200612_113009 by The train Man, on Flickr 20200612_113023 by The train Man, on Flickr
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Post by barlowworks on Jun 12, 2020 10:44:18 GMT
Another thing to take into account is if you are going to spray your own etching primer you don't want to spray it through your best spray gun and etch the insides away. I have an old Badger 150 with a bottom feed bottle that has quite a wide spray pattern and I use it exclusively for etching primer.
Mike
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Post by Roger on Jun 12, 2020 10:57:56 GMT
Another thing to take into account is if you are going to spray your own etching primer you don't want to spray it through your best spray gun and etch the insides away. I have an old Badger 150 with a bottom feed bottle that has quite a wide spray pattern and I use it exclusively for etching primer. Mike Hi Mike, Is that really a problem though? I can see if you were spraying day in day out then it could be an issue, but surely we're not using it for long enough to significantly damage the insides?
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Post by andyhigham on Jun 12, 2020 10:59:13 GMT
Professional airbrush artists use paint with a very small pigment particle size, more akin to ink. This allows amongst other things good coverage with a very thin layer
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Post by jon38r80 on Jun 12, 2020 11:57:14 GMT
Having spray painted lots of awkward shapes and anything from the size of an egg cup to whole cars and having a wife who frequently puts scratches on her car I have found that a car touch up paint gun, sort of half way between an air brush and a full sized brush that uses a bit more air than the air brush but a lot less than a full size gun , to be invaluable. the cup is about the size of a tea cup so doesnt run out of paint so fast as an air brush. I have two, one has a spray pattern like an air brush, the other has the more complicated nozzle that sprays a fan , the latter is better for bigger flatter areas. No brand names , all bought from that huge emporium , China, except the full size one I bought years ago ( in the 70's) when I first resprayed a car. Despite the hype, I havent found that the branded gun I was given by a friend is any better than the knock off guns I have.
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barlowworks
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Post by barlowworks on Jun 12, 2020 14:20:49 GMT
Hi Rodger, probably not a problem with the amount of painting we do in 5 inch gauge. In O gauge I didn't want to spend a fortune on a top of the range Iwata airbrush then spray etching primer through it.
Mike
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Post by Roger on Jun 12, 2020 16:23:21 GMT
Hi Folks. If you use an airbrush like the Badger 200, with of 50mls bottle feed, it is quite capable of spraying large areas. The spray cone can be adjusted for 1/16" dia right up to at least 2" dia so that is more than enough for painting a 5" g loco. You do need to be able to get 50psi at the airbrush though, for large area painting, and experiment with the amount of thinning for the particular paint you are using. Don't buy an airbrush with a small paint reservoir integral with the main airbrush body. They are fine for small jobs but far too small for large area where you want a lot of paint. If you are able to spend the money on an Iwata airbrush, they have a large gravity fed paint can, and a nozzle for spraying a fan pattern on their top-of the range airbrush. I have a Devilbiss mini spray gun and also a Kite, but neither are likely to be used on the loco. Bob. Hi Bob, There's a lot of skepticism about the use of Airbrushes for painting larger areas, so I wonder if you could give an indication of the technique you would use to get a full gloss finish on say a flat piece measuring 100mm x 100mm which clearly can't be covered by the spray pattern of an Airbrush? The sort of questions that come to mind are these... 1) Just how thin does the paint have to be? 2) How would you set up the Airbrush for that kind of job? 3) How quickly would you expect to traverse across the job? 4) What kind of spray motion would you use? 5) How thick would the coat be in one pass? ie would you expect to get a continuous film or would that only happen when you go back and forth? 6) How many times would you expect to pass over each given spot to achieve the glossy finish. 7) What sort of time would be typical for straying something like this? 30 seconds, 5 miinutes? Obviously each job is different and it's unrealistic to attempt to tie you down on any of these since there are so many variables. However, it's hard to get any kind of handle on what we're talking about here without some expectation of what this job might entail.
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Post by andyhigham on Jun 12, 2020 16:41:03 GMT
Why not buy a cheap airbrush and practice spraying water (possibly with with a drop of ink in it) on to paper, it should give you an idea of its capabilities
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Post by simplyloco on Jun 12, 2020 16:41:25 GMT
Roger Spraying locomotives, whether with an airbrush or a minigun, is like learning to bullshine Army boots. No instructions are of any use, you just have to do it until you get it right! John
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Post by jon38r80 on Jun 12, 2020 16:53:55 GMT
As John says there is no substitute fo just doing it. When I was learning to spray paint my first car there was no substitute for practicing with real paint on something that resembled the article you intend to paint as there are so many variables in setting up the the gun or airbrush to suit the compressor and the paint you use. Cellulose was a lot easier than the modern two or one pack paints. it was a lot more forgiving but nowhere near as tough when dry. there is no substitute for good preparation and cleanliness of the gun and the piece to be painted. little black flies are a pain in the a**e as they will settle on your perfect finish After you have just finished the perfect paint job! tack rags and degreaser (alchohol) are your friends.
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Post by Deleted on Jun 12, 2020 17:16:17 GMT
How Roger, get yourself a small-sized HVLP spray gun and just practice and don't stop, that is, test before each application. You will be surprised at how good a finish you can get. Personally I wouldn't try large areas with an airbrush, certainly not when talking gloss. You need that larger pattern and heavier load of paint to get a good flat gloss finish that can flow out, or at least, I do.
Pete
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