By Chris Bird Note: Both Keith and I have detected a change in the Halfords satin black with less matting agent. I would not now use it on a boiler but would use the matt black instead.Introduction There are many approaches to painting locos and this is just one. It is not the only one and is not necessarily the "correct" one for you. It is the approach I first used 25 years ago - but have modified it since then to make it easier (well for me anyway!). I have only used it with aerosol car sprays and with special model sprays from Phoenix Precision Paints - I have never used an airbrush, but it is probably not much diffferent. The five locos pictured here are examples that have been painted with this method. Bert Webster, on the top left, had the dome, cab and tender sprayed with Phoenix P. 30 LMS Crimson Lake gloss (it is more maroon in real life). Betty, in the middle was sprayed with Acrylic gloss car spray (Rover Brooklands Green) and the boiler with Halfords Satin Black. Skylark on the right was sprayed with Halfords Satin Black. Bottom left Charles Pooter Hesperus was sprayed with Halfords Satin Black (including the ecternally fired boiler) as was bottom right Argyll Summerlands.      A Warning! If in doubt - don't start with your pride and joy! Instead, practice on a tin can, then something that doesn't matter too much, and then when you are more confident, give it a try. Or send it to a professional while you keep practicing!! Essential Equipment To use this method, you must have 1. A shed or workshop for the spraying - NEVER in the house - not even if you live alone! 2. A proper paint spraying mask - the ones with the two drums on. A dust mask is NOT good enough! 3. A large cardboard box to make your spraybooth. This wants to be at a good height - so mount it on a folding workbench or on a table. 4. A 2 kw domestic fan heater. 5. Access to a domestic oven (not essential, but easy). 6. Offcuts of wood - blocks and flat bits plus large nuts and Bluetac to mounting the pieces to be sprayed. Paint The following notes are simply from my experience - they are not a definitive guide so if in doubt, ask the manufacturer or test it! Primers 1. For steel - use normal automotive grey primer. You can use an etch primer, but it is not necessary. 2. For brass/copper/bronze, aluminium - use the correct Etch primer which will bond to the surface. - Phoenix Precision Paints do a two pack one for brush (or maybe spray too). I have not used this but Tag Gorton swears by it. - Phoenix do an aerosol single pack etch primer which is very easy to use and works every time (well every time I have used it!). - Upol Acid Etch 8 - many folk report that this does an excellent job, although it does not say it is for brass. I now use it all the time and it is excellent. Top Coats Gloss Acrylic Aerosols. In my experience, Acrylic gloss car sprays are fine for all of the loco platework, but are not suitable for the boiler or smoke-box. I know this because I sprayed the boiler on a Cheddar Iver and managed to touch it with a tissue while in steam. It stuck. This is just my experience - and I know others have found it too. These paints are designed to give a high gloss finish without any final rubbing down. Matt and Satin Acrylic Aerosols The matt and satin Acrylic sprays contain much more pigment and seem to be fine on the hot bits. And it's great if you like black locos! Note: The Satin Black Acrylic can soften a little on the first few steamings - Keith Skillicorn suggests baking at 150 degrees for boilers to overcome this. I have not tried it but have painted a number of boilers with it without problems - but then I tend not to touch boilers when they are in steam! Cellulose Aerosols Although there theoretically should be the same as Acrylics, in practice they seem much better able to stand the boiler heat. At least that is my experience. They do not give a high gloss finish - but are intended for rubbing down using 1200 or 2000 grade wet and dry followed by T Cut or similar. However if you do not want the gloss - they give a nice finish. Beware the mixed to order aerosols. Some have a terrible nozzle and seem to need a lot of shaking. These are not for the faint-hearted. It is ESSENTIAL to practice first! High temperature paints. There are many types and I guess that all will be okay. I have only used matt black BBQ paint on smoke-boxes and it is excellent. I used a brand named "Hot Spot" which gives a very matt, almost grey finish (beware that white spirit will remove it!). Rustoleum BBQ paint gives a smoother matt finish. Tom Meader has reported that Wickes black heat shield paint has very poor adhesion unless cured at very high temperature - best avoided! Enamel Paints These are suluble in turps, white spirit and the makers' own brand "thinners" - not cellulose thinners. I have used Phoenix aerosols - which are not easy as they deliver a huge amout of paint very fast. They seem to okay on boilers and hot bits, and of course they have lots of authentic railway colours. I have tried the old Humbrol enamels on small parts, but have not used them on a boiler. Preparation Preparing the metal Existing paint If in doubt about the adhesion of the existing paint - strip it using a gel paint stripper (follow the manufacturers safety precautions). Rinse with water. Note that the really active ingredient of strippers - dichloromethane - has been banned. Even the well known brands take hours when they used to take minutes. It is worth painting the stuff on and putting it in a plastic bag over night. Have lots of brass scrapers to hand! Another key factor is the type of paint. A simple rule is that enamel type (using white spirit or similar to thin) will go over acryic or cellulose (using thinners to thin) but NOT visa versa in my experience. Both types will go over two pack as used by Roundhouse. The danger is with older or home built models - check with a rag dipped in thinners to see what you have. If it comes off, you can use either type. If it doesn't, check it with white spirit - if it shows colour on the cloth, then thinners type paint will probably react. If it is okay ( such as existing commercial paint finishes) then degrease using an automotive degreaser (such as gunk, or preferably a less smelly version). Then hose it off with water. I then key the surface ith a fine 3M fleece type abrasive as this is kinder to rivet detail. You can use 400 wet and dry but beware you don't take the rivet tops down to bare metal. Then degrease again with white spirit - and again. Let it dry thoroughly - I use the fan heater. Bare Metal Abrade it with a fine 3M fleece or use 400 (ish) wet and dry. Ensure it is well keyed. Scrape off any solder runs and remaining paint (in the corners etc.) Degrease it with a clean cloth using Cellulose thinners (use mask). Do it again. Do it again. (yes - Phoenix recommend three times).  Here are the parts of a Billy conversion ready to spray Preparing the spray area. This is what I do: I clear a space (often the most difficult bit!) I then mount the spray booth (one side is cut from the box). It needs good light to see the work while spraying. Then I turn on the fan heater - this will warm the room and any dust that is going to be shifted will be - before you start. The room needs to be 15 degrees C plus and preferably 20 degrees. I do not sweep the room as some suggest! I open a window for ventilation I check the mask - it is essential - under no circumstances would I do this without a mask. I turn the domestic oven on to 80 degrees C - no higher if using cellulose. You can use 100 C for the etch primers. Preparing the Paint Make sure the paint is at the room temperature and shake the aerosols for the full two minutes and more. Preparing the work Mount each part to be sprayed on a block or piece of wood. Make sure edges are not touching the wood or the paint will connect the two - I use nuts and odd bits of wood to raise it up. They need to be secure enough to be moved about on the wood. I then warm them by placing them in front of the fan heater. Masking If you are spraying on the loco, then time needs to be spent masking. I use normal masking tape and cling film to wrap the parts I want to protect. Watch out for those slight gaps - paint can find its way through the smallest one. Always remove the masking tape before baking in the oven - it marks the new paint if you leave it on!! As above, warm the loco in front of the fan heater. Spraying With mask on - I put the piece, on its wood, in the spray booth and if necessary, raise it up on a tin can or similar. Etch Primer Here I use the thinnest of coats. With the nozzle 200 ish mm from the piece it is the shortest of sprays. Say "Ts" and that is how long it needs to be - under half a second! If you go "Tsssss" or Tsss-sss-sss" then you will have paint running everywhere! Move the can as you spray to even it out. When it is just covered, turn the piece (by turning the mount) and repeat until all has a light coat.  Then put the piece in front of the fan heater to flash it off (for the solvent to evaporate). When it looks dry - check for missed bits and repeat if necessary. But you are not looking for thick coats - just a covering. Take it to the oven and bake it at 80 -100 degrees C for 30 mins. If no access to oven, place it a foot or so (300mm) from the fan heater to bake.  Normal Primer On steel - I do the same as above, but with regular automotive primer. I do not build up layers. On existing, keyed paint - I normally do not use primer, but you may wish to if there is a big colour change. Top Coats (Acrylic or Cellulose sprays) The same short "Ts" method as above - with the can moving (as if you were striking a match - but smoother). If in doubt - practice on a bean can first - you can always bin the can and eat the beans..........  Then put it straight in front of the fan heater to flash it off. Cellulose paints need a good ten minutes in the warm before re-coating, whereas Acrylics can be done very quickly. Repeat until you have about five coats on. Flash off the final one then leave in the warm for ten minutes or so before transfering to the oven to bake for 30 mins at 80C. Note this is the max for Cellulose in my experience. When cool, check for any blemishes and if necessary rub down with 800 grade wet and dry used wet - do it very gently! Bubbles will suggest you have not let the paint go off enough before baking. Then repeat as above for a final coat or two. Top Coats (Enamel Spray) The Phoenix enamels take a lot longer to flash off as the solvent is less volatile. Indeed, they recommend 24 hours between coats. I have put five coats on in a day with this method.  Use the "Ts" method and from at least 300mm - it is better to use thin coats, and more of them, than to even think about a thick one! After each coat is flashed off (doesn't run) - transfer to the oven for at least an hour before applying the next coat. When cool - check it feels hard and rub down the runs if necessary (it was for me!). And ensure it really is flashed off before baking - or it will bubble in the oven!! Here you can see most of the parts completed (buffers and beams from two locos!) - it was a couple of hours from starting. In fact I rubbed down the cab with 800 grade wet and dry (used wet) after this and did one more top coat.   And here, a few weeks later, is the finished loco - based on a Roundhouse Billy chassis and boiler, it is Roy wood's take on the Talyllyn loco "Douglas". For aeronautical reasons Roy decided to call it "Dakota".......... You can see it in action here too on Roy's Holt Wood Light Railway.    |
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