I'm not an expert by any measure, but along the way I've picked up a few tips that sometimes come to minds as I read the great resto threads on this groovy forum. O0 These sort of general rules are just the sort of info I was looking for when I knew nowt at all. However we all have different ways of skinning the cat, and these are not hard and fast. For example you can paint top coat over wet primer if you're daring - "wet on wet". Saves some sanding sometimes and good adhesion. I say daring because if something is going wrong with the primer you've just top-coated it! 1. (This came up recently somewhere). Etch primer and zinc primer should be applied sparingly - see-through coats - I know it's hard to restrain yourself - you want to see it all one colour! 2. In general, the less paint the better. There are lots of reasons for this. When you're attacking your resto you'll see the original paint is very thin, but probably high quality. For VW it dried quicker, less paint costs less. But also less paint - better finish as it can't get too peely. And the thicker the paint the more easily it chips when it's done. Good quality paint is a winner. 3. Get a good gun. I got a devilbiss GTX for £100 on Ebay and everyone on our estate borrows it. You'll get your money back when you sell it and you WILL get a MUCH flatter finish from the gun. First time, you WILL get a finish you don't have to do anything further to. That's why they all want it. I get favours back. 4. Orange peel. Hmmm - I like a wee bit - not too much. There's going to be arguements about this, but IMHO unless your panels are arrow straight polishing them to a mirror finish will make them look worse. 5. Painting the inside. Are you really going to flat back the high build primer inside? I bet you're not unless you have more staying power than... whatever it is. So if you're using high build, thin it right down and use as a surfacer. Over to you guys.
Now we did flat back the high build primer on the inside Zed, we used a very fine wet paper (600 grit?) simply because the finish was quite smooth & we wanted a bit of adhesion with the top coat. My Dad sprayed Gusbus' inside with a Clarke Spraygun (top reservoir type) but he's also got a Devilbiss gun tucked away! The Clarke gun is great but doesnt hold vast amounts of paint! (Topic sticked as it has some good advice written in)
He's 72, worked his apprentiship for BREL in Derby then ran part of the test labs at BR Research, he's still working now....he wants to do another bus when we have done Gusbus!!
Back to the topic chaps. Here's another - don't kid yourself - if you have 80 grit scratches in the filler, they'll still be there when you've polished the top coat, except they'll be even more obvious. Seam sealer - after the primer - like new cars. As with thick paint/stone chips, the less paint over sealer the less likely you'll get cracks.
Just a few pointers to add, some will seem common sense, but are quite often overlooked, Try to dedicate one spraygun for primer, a cheapie is fine for this, and use a large fluid cap (eg 1.7), always clean well after use and run through with thinners until clean. Etch and zinc primers as said, should only be applied as dust coats, resist the urge to larrup it on! When flatting down primer, be it 2k, or cellulose, use a guidecoat (light dusting of aerosol matt black is ok and cheapest) to show up any low spots, use circular strokes/motion, preferably do it by hand For solid colour topcoat, you can flat primer as low as 400 grit paper, dry. For darkish metallic topcoats 600 grit wet will give good results, and for light colours, especially silvers/golds 800 grit wet would be required. Over filler, Results of the above are dependant on the standard and quality of repairs underneath, With filler repairs, there should be 3 good coats of primer covering a repair finished with a minimum of 80 grit paper, Its always nicer to prime over 180 grit, but be wary of easily taking too much out in the quest for a silky smooth finish, its not necessary as its the filler primers job, to fill in the gaps. Filler repairs, Use a suitable flat sanding block (Generally 8"), as generally buses are straight without curves, a softer sponge faced block might be useful, but be wary of pushing too much into repairs, When checking for contours you MUST use your whole hand, push your palm lightly when rubbing your hand over the panel/repair,, Theres no point just using your fingers, some people say use your non dominant hand, but generally just use what feels natural. Dont expext to apply filler just the once, sometimes you'll get lucky, but for most repairs 2-3 skims I'd say is the average, and often more for large repairs. Learning to get filler right will not come overnight! Try not to mix different types of fillers into repairs, as quite often one will rub down easier than another making it difficult get a decent result. Light solid colours hide ripples and poor repairs better than dark colours, and remember buses are full of ripples from the factory. Topcoats, A good gun can help, but a cheapo clean gun can give the same results, Sealey £25 guns using a 1.3 cap, are easily suitable for topcoat/laquer (I can prove it for the doubters!) Dont apply cavity waxes etc before painting topcoat - as will result in a silicon fisheye soup knightmare, paint and wax have never mixed! Overpaintable stonechp/stoneguard is fine though. Blow off thoroughly before masking, :-X Neat masking without dust traps, and dont use newspaper - its pikey! Use soft edges where necessary, to prevent hard paint edges, you can fold the edge of masking tape along its length by a few mm to cachieve this. or just buy the soft edge foam on a rll for this purpose. Make sure the area you are spraying in is as good as it can be, wet the floor to suppress dust, close doors and avoid the wind and through drafts, ensure the lighting is reasonable, the area is generally tidy without trip hazards, the compressor is out the way and not going to blow dust everywhere as soon as it kicks in, wear some clothing kit you feel is suitable and try to minimise the amount of paint/vapour/fumes you breathe and come into contact with. Use a degreaser to clean and wipe panels down before painting, 2 cloths, wipe on and wipe off, dont spread/introduce existing waxes onto additional panels/areas, make sure cloths are clean and change as necessary. And finally before painting, Tack off! Methodically use a new tack rag to remove final bits of dust etc Read the manufacturers data sheet (instructions for use) for the paint you have, or have someone demonstrate whats what, Understanding the use of slow>fast hardeners, paint viscosity, thinners and ambient temperature/humidity/dampness and other factors such as gun setup, air supply, cleanliness, methodical working are what will really determine how a paintjob comes out, and this is generally only picked up with experience. To add to what had been said above, Wet on wet, painting on wet primer, is fine for inside the van, and generally would not be used on our resto's because the time between priming and applying topcoat is often months or years ;D Applying too much paint, generally means a poorer and heavier finish, and thus more rectification work after. If doing a full bus, break it up into stages, inside outside, doors.
Just to share a good air cleaning tip: In case anybody has never tried this, it's a great inexpensive way to help keep your air clean while you sand/paint. It's just a common furnace filter on a cheap box fan.
Keep an eye on your airline as you go along spraying you dont want it touching or dragging on the fresh paint you have just layed
great thread all advice taken on board .....and will probably (but hopefully not) be forgoten when I spray mine ;D .........in the garden
Do you paint the inside first and then mask up the windows and doors? I'm a long way off from paint but just thinking
These are a few things I've discovered lately: 1. If you're a complete novice like me, get something to practice on before messing up the real thing. I've been at it now for about 2 months welding, grinding, filling, sanding, painting, then rubbing it off and trying again. This is on a rubbish rear hatch so I've not started on the bus yet. I've learned a lot following the ideas of the experts above. 2. Filling has been hard to get right over a largish area. I was using P38 and then Upol Easy1. Both are old technology it seems, maybe good for the first skim or small areas only. I got loads of pinholes so was knife stoppering it for days. I've now gone to Upol Fantastic which is much smoother to apply and gives hardly any pinholes. 3. It seems obvious but if you want to reuse the plastic spreader they give you with the filler clean it off thoroughly before the filler sets as otherwise you'll be dragging bits of hardened filler through the next layer and leaving grooves in it. I've now got a set of metal spreaders which seem to work better than plastic. I've cleaned them with thinners but am interested to know what's the best method. 4. I don't know if this is a good idea yet but I've got some guide coat powder. Instead of applying from an aerosol you use a large powder puff. I saw it used in a You Tube video. You apply it and start sanding immediately. Is there a down side to this?
im nearly ready to paint mine and all them tips are really useful ;D does any 1 know how many litres of paint i will need , im doin top half white and bottom blue its my xmas project
Unused about a litre of high build primer on just the lower half of my bus. Probably over done it but hey ho
