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Post by 92220 on Apr 24, 2023 8:20:38 GMT
I am in the process of refurbishing a 'Noble' water truck, which has now been internally tanked-out using glass fibre. Water tight and strong! Any advice on what paint to use to paint the internal of this glass fibre tank? I have plenty of red oxide rust proofing paint, so tempted to use. Thoughts? Hi. Ordinary paints will not withstand being permanently submerged in water. You can use either a swimming pool lining paint, or the bituminous paint on this website (Rylard Axalta Water Tank Coating) :- www.boatpaint.co.uk/acatalog/Rylards_Water_Tank_Coating_.htmlHope that helps. Bob.
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Post by 92220 on Apr 20, 2023 13:45:44 GMT
Any vehicle enamel SHOULD be petrol resistant. The paint is formulated to use on vehicles without knowing what fuel is to be used, and which can be splashed on during refuelling. If it isn't fuel resistant it shouldn't be called a vehicle enamel.
Bob.
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Post by 92220 on Apr 20, 2023 13:39:31 GMT
If you have bolted or rivetted pieces that have been degreased, if there is too much degreaser it will be drawn into the joint by capillary action. It then comes out of the joint, again by capillary action. Only ever wipe with a lint free cloth DAMPENED with thinners, not wet. After degreasing, get the joint and associated parts, warmed up and leave to stand in the warm atmosphere for at least 12 hours and preferably 24 to drive any solvents out of the joint. The time depends on how large the sandwiched area is. Larger means longer!
Bob.
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Post by 92220 on Apr 20, 2023 8:07:08 GMT
Hi Roger.
There is no problem with your moisture removal system. It should clear any moisture with no problems. Excellent! I agree with you. It does seem as if the paint has a problem. Also, I've never come across a paint that fizzes/bubbles when a solvent is used on it. That really is strange. I have a tin of Craftsman. I must play around with it and see what goes on, first hand.
Bob.
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Post by 92220 on Apr 19, 2023 13:06:44 GMT
Hi Roger.
Chris is right regarding the difficulty of getting water out of the airline. How far from the spray nozzle, is the water trap or drier? The atmosphere at this time of year is quite damp and it takes a lot to get all the dampness out of the compressed air. The air hose supplied with the Badger airbrush, is the ideal distance from the spray nozzle, to the water trap outlet. The further away it is and you will run the risk of condensation forming again in the airline after the water trap. The colder the atmosphere the more drying, of the compressed air, is necessary.
What size water trap do you have fitted? Is it the standard type that works by centrifugal force spinning the water vapour out of the air, and has a vertical glass bottle to collect the condensate below the unit? If this is your set-up, you need the smallest size water trap that is made, with a glass bottle around 25 to 30mm diameter. Any bigger than this and the air won't spin fast enough to clear all the water droplets. Chris's idea of the water drier is also a good one. A combination of the two is ideal, and the drier should be the last thing in the airline, AFTER the water trap. The other point to bear in mind is that the lower the spraying pressure, the more difficult it is to get rid of the water. The compressed air needs to travel as fast as possible to throw the water condensate out during it's centrifugal rotation, in the water trap, so the larger the trap, the higher the air pressure needed to spin the air dry.
The following is a section from the booklet I wrote many years ago, on painting models, which may help. The difficulty of sorting out painting problems is that, ideally, the painted surface needs to be actually seen. Photos go so far, but do not "tell the whole story":-
If the paint is not properly atomised, as with too little thinners, the dry film will take on the appearance of the skin of an orange. Hence the term 'orange peel effect'. The remedy is to rub down smooth and re-spray using more thinners in the mixture. This effect can be seen before too much paint has been applied.
When the first coating is applied the initial droplets will appear to be quite pronounced, but as more paint is applied the droplets join up and form a fully cohesive layer thus hiding the background. With orange peel effect the droplets build up without flowing into each other properly. When the viscosity of the mixture is correct, the droplets flow into each other and form a layer of paint of uniform thickness, thus providing a smooth finish.
Another fault which may occur when spraying is a bubble appears on the surface of the paint, and when it breaks, the paint does not flow over the area where the bubble was. This is almost certainly caused by water droplets in the airline.
Despite what many compressor manufacturers state in their literature, water traps are ESSENTIAL for ALL compressors when being used for spraying solvent based paints. Every compressor, if used for more than about 20 minutes, gets warm. When this happens the warm air can hold more water vapour in suspension. When the water vapour enters the airline to the spray gun it condenses into water droplets. These travel up the line and eventually emerge from the nozzle as droplets of water which coalesce together to form larger droplets before falling to the surface of the model and forming bubbles under a microscopicly thin film of paint. The only remedy is to rub down and re-spray.
Some suppliers fit a water trap directly to the outlet of the compressor. This wil be almost useless. Unless there is some means of cooling the compressed air between the compressor and the water trap, the water vapour will not condense and be collected in the water trap.
Water traps usually rely on centrifugal action to remove the water condensate. The idea is the air is cooled after leaving the compressor. When cool the water condenses out in the airline. It then travels along the airline to the water trap. Inside the trap is a series of vanes which direct the airflow into a circular path around the bowl of the trap. This circular path induces a centrifugal force onto the condensate which is thrown outwards until it meets the wall of the water trap bowl. The water then runs down the inside and collects at the base to be expelled when the valve is opened.
Unless some kind of intercooler is fitted to the compressor, the next best thing is to provide 5 or 6 feet of 1/4" bore airline hose between the compressor and the water trap. One well known supplier provides an intercooler kit comprising about 2 feet of copper tube coiled up. This is better than nothing, but is still nowhere near as good, or as cheap as 5 feet of standard airline hose.
A miniature filter/water trap and a mini combined filter/water trap/pressure regulator are available from Phoenix Precision Paints at very reasonable cost, and are matched to the requirements of miniature compressores for use with airbrushes and mini sprayguns.
The ‘combined’ unit is a refinement that is very useful for close up work. When a regulator is incorporated, though, it is only suitable for piston compressors which have an air reservoir/tank much greater control over the spraying characteristics is available. A typical use is when you wish to spray part of a model without masking, such as making soft joins between colours of camouflage on an A.F.V. By reducing the pressure to around 15 p.s.i. it is possible to spray from a distance of a fraction of an inch with a consequential reduction in over-spray. This is not possible if you cannot control the air pressure. With air pressure control spraying into corners is also very much easier because the pressure can be reduced so that spray ‘bounce back’ is almost eliminated.
Bob.
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Post by 92220 on Apr 17, 2023 13:47:59 GMT
Hi Roger.
In the post at the top of this page, you say the paint is staying very sticky. How long after application is it still sticky? How does this compare with the advertised drying time for the Craftsman Enamel? They say 16 hrs at 20C. If the sprayed coat stays tacky for 16 hours or more, there is possibly a problem with the paint. At a lower drying temp, the 16 hours may extend to 20 hours. One thing I did find out about Craftsman enamels, they say DON'T mix whitespirit with their enamels. I'm not sure why because in the paint industry, Enamels, especially Coach Enamels (which Craftsman describe their paint as) are commonly thinnable with whitespirit or turps substitute, so maybe their formulation is not really an enamel,and white spirit should not get anywhere near the paint, even as a surface cleaner, for which it really isn't volatile enough anyway. The only solvents safely usable as a degreaser are cellulose thinners or Acetone.
Bob.
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Post by 92220 on Apr 17, 2023 13:19:38 GMT
I'd be curious to know how much thinners there is in Aerosol Spray Cans. I get the impression that there's a lot, especially when you see how fine the mist they produce is. Hi Roger. Aerosols usually have around 50% thinners. Some slightly more. some slightly less, depending on the viscosity of the base paint formulation. Bob.
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Post by 92220 on Apr 16, 2023 8:53:37 GMT
Hi Roger.
Just had a thought...What distance are you spraying from? Too much and the paint will start to dry before it gets to the surface. That can also give a finish like you are getting. The ideal distance for spraying a model is around 2" to 3". The pressure needs to be adjusted to suit. This is where the trial sprayings come in. If the pressure is too low, this can give a blobby finish. If it is too high, the spray will start to dry before it gets to the surface, also giving a bumpy finish. The working temperature can also be a factor. Too high or too low can cause bumpy finishes as well. Too low and the paint won't flow out; too high and the paint will have started to dry before it gets to the surface and so, again, won't flow out. The ideal working temperature is 60F (15.5C).
You say the paint finish stays tacky for a long time. Mix up your paint, in the tin, and just brush out a sample patch around 50mm square, and allow to dry naturally. If the sample brushing dries according to the manufacturer's quoted drying time, or nearly so, the paint is OK. If it doesn't, there is a problem with the tin of paint. I don't know if Craftsman make their own paint or buy it in ready made for them. If the drying time of the brushed sample is a problem then it is almost certain that there is a shortage of driers in the paint mix, as you are using the correct thinners.
Bob.
Edit: What spray gun are you using? Ideally the steps, and small details like them, need an airbrush to ensure not too much paint is applied. It also give much more control over the spray pattern. Large areas can be sprayed with a mini spray gun but it should be one that the spray pattern can be manually adjusted like an airbrush. Also, I personally, prefer to use a single action airbrush, like the Badger 200, rather than a double action one, but that is just personal choice.
Bob.
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Post by 92220 on Apr 15, 2023 8:21:12 GMT
Hi Roger.
What sort of paint are you using? Is it 2-pack or vehicle enamel? I enlarged your photo and it does look as if the blobs of paint are just not flowing out. If this is so, it would indicate that the paint needs to be thinned more. If you have used 25% thinners, increase it to 30% thinners, or 33%, and try it on a scrap piece of plate. With vehicle enamels, the supplier can usually offer a quick drying thinner, which will allow thinning up to 50% thinners. This would make getting a full gloss finish more difficult though.
Bob.
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Post by 92220 on Apr 12, 2023 12:33:37 GMT
Hi Roger.
That's a really nice bit of machining!! It looks just like a pressed/formed unit, rather than machined!
Bob.
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Post by 92220 on Apr 9, 2023 15:51:54 GMT
Just as a silly bit of info....did you know there are 33 different "British Racing Greens"!! Every car manufacturer/racing team, that used or supplied cars painted in the colour, had their own version of it. Some were very close, but some were quite a different shade to others, though all were mid to dark green.
Bob.
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Post by 92220 on Apr 9, 2023 8:37:40 GMT
When painting a small model petrol engine. What type of paint is most resistant to fuel splashes? Railway enamels or Halfords type spray cans? Thanks Vehicle enamels are petrol resistant. They have to be otherwise there would be major problems when filling a petrol tank on a car. Halfords paint should be vehicle enamel, and Phoenix Paints definitely is. I think Craftsman Paints are too. Bob.
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Post by 92220 on Apr 9, 2023 8:30:49 GMT
Hi Roger. Acetone is ideal as a degreaser, but take care when using it. Try not to breath in the fumes though, as they are easily absorbed by the body. Acetone was the original basis of cellulose thinners, until they changed to solvents with a higher flash point (Acetone has a flash point of -18C) and less toxicity.
Bob.
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Post by 92220 on Apr 8, 2023 18:36:40 GMT
Hi Roger.
I must warn you. Single Pack Etch primer has a life. Because the acid is already mixed in with the primer, unless thi9ngs have changed quite dramatically since I retired, and I don't think that is possible chemically, it will be OK for about 9 months from date of manufacture, then it will start to lose it's etching properties because the acid will be neutralised. This is typical of all single pack etch primers...they have a short working life. Two-pack etch primer has an almost infinite life as the acid is kept apart from the primer until mixed for application, but the primer must keep near it's formulated consistency.
Your problem with the 2-pack that you have, may be because you are getting to the bottom of the tin, but you cleaned the surface with white spirit. I'm afraid that is not strong enough to get rid of ALL greases. The ideal solvent, available to the public, for degreasing is cellulose thinners, which will get rid of all oil and grease. Ideally, wipe over the surface with a clean lint free cotton cloth, wetted with cellulose thinners. Then when dry, wipe over again with a lint free white cotton cloth, just dampened with cellulose thinners. If you have any rivetted parts or bolted up parts that are going to be painted, put the parts to be painted, in a warm atmosphere, to get quite warm, to drive any solvents out from between the rivetted/bolted surfaces, otherwise, when you paint, any trapped solvents in the joints, will come out by capillary action, and ruin the paint surface.
Bob.
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Post by 92220 on Apr 4, 2023 7:08:08 GMT
I have used the paint colours mentioned above, from Halfords, They are not as good as they used to be, They keep changing the Recipe, And after a few years my model started to fade to a more pinkish colour, i would use the phoenix stuff for sure, More expensive but the right colour and will last. Yes. The main points in favour of Phoenix is accuracy of colours, the paints are formulated for best quality vehicle enamel, and so will last as long as the paint on your car, and the colours don't fade with age. Bob.
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Post by 92220 on Apr 3, 2023 16:26:33 GMT
Hi Harry.
Unfortunately, LMS Crimson is a lot lighter than Midland Railway Crimson. And LMS Coach Maroon (1946 to 1948) is quite a bit darker than Midland Crimson.
Bob.
EDIT: Also, bear in mind that a colour that looks right on a O-gauge model, will be too light on a 5" gauge loco, because to look right on a O-gauge, the colour has to be lighter than the fullsize colour. A 5" gauge loco looks OK with the fullsize shade.
Bob
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Post by 92220 on Apr 3, 2023 11:09:01 GMT
Hi Roger.
Yes it is for insurance purposes.
Your loco is way above the quality of normal 15xx models. Find the cost of buying a top-of-the-range model, and at least double, or even treble, the cost, as an insurance value. You have to consider what it would cost the insurance company to have a replacement made if your model was stolen.
Bob.
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Post by 92220 on Mar 31, 2023 9:33:53 GMT
Hi Roger.
An excellent/cunning idea. I shall be very interested to see the end results and how well it delivers oil. It's got to be better than using my 250mls plastic lab wash bottles, which get oil to the right place, but also to all over the job and machine area. I can never find them when I want them (I've got 2) anyway!!
Bob.
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Post by 92220 on Mar 30, 2023 16:53:54 GMT
Hi Alan. No Terry Holt sold his business. Kirjeng Model Engineering Supplies is now run by 101 Tooling 101 of Loughborough. I believe, they intended stocking everything that Terry did though I haven't looked at the catalogue for some time. Bob. This is their website. 101 Tooling | Loughborough www.facebook.com › ... › 101 Tooling Kirjeng M.E.Services from Terry Holt.
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Post by 92220 on Mar 27, 2023 15:21:21 GMT
Here is another website pointing out the falacies concerning the use of water softener softened water:- wcponline.com/2019/03/15/water-softeners-and-corrosion/I've copy and pasted the website so I hope it acts as a link. If not, just copy and paste into Google and the website for Water Conditioning and Purification International. It makes very interesting reading about corrasion in systems. Bob. I've just checked the "link" above. It does work by clicking on it.
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