Re: Painting my \'40
Courtesy of the Cobra club site. It may not all be applicable but will give you an idea.....
HOW MUCH? a wise man once said me "You pay peanuts. you get monkeys! Painting your car is going to be the biggest worry you will probably face when building your Cobra, apart from explaining to the loved one that you have gone a bit over budget and need a few more quid for the wheels and tyres. If you have spent in the region of £15/20k on it, which most seem to do these days the last thing you need is an ok paint job which most people will walk by and say "Hmm, ok". What you want is a body job that people will walk up to and say "canine gonads, look at that finish, not only is it shiny but the doors fit and it's straight as a die", that's when your £15/20k will have been worth it. Anybody can paint a shiny car, but when you look down the sides does it look like the North Sea on a rough day? Can you see the interior through the door gaps, and, do the door edges rap your fingers when you polish it. Can you shut the door like a production car? Or do you have the Kit Car "Klunk" type? Well some of those things are the difference between painting a car and getting it to fit and look correct. We have finished probably 99% of the makes of Cobra kits around and a few others. Some are good, some are bad, some want using as a fish pond liner, but most suffer from nearly the same faults, which I'll list later! I will not comment on specific makes (as it could get expensive!) but must say that some of the best bodieswe have worked on are wait for it THE PILGRIM SUMO!!!
Just because you paid 15million for your kit doesn't mean it's the best. The SUMO was spot on, its doors shut, it was fairly straight and one of the best things was it DID NOT MOVE once it was finished and on the road. I WILL EXPLAIN. Glass fibre (GRP) cures by chemical reaction, therefore if the shell is left in the mould (or buck) for two weeks, as some claim, it should be set...well almost! With any curing process heat will speed this up and affect it even after it has cured. Your body is painted and out in the hot sun, the car you cannot touch because it is so hot. All of the inner panels are fixed/bolted/riveted to the chassis, the body rests on some of these and the chassis, the body is set on foam or a chassis mastic, heat causes the mastic to soften and the body under it's own weight settles down onto it's final resting place. What happens to the inner panels? they stay where they are put. Up come the marks for the rear bulkhead, inner wheel arches etc. only answer? Refinish the complete job. Double skinned bonnet and boot lids, fine, air expands when hot, all of these air pockets then expand and contract and will leave marks where any of the two skins touch.
Bits of wood and steel that have been bonded for fixings can all give problems. High power engines giving off a lot of heat will cause the bonnet finish to "peel up" (i.e.; it looks like a very bad paint finish). There is nothing you can do about it apart from give it another flat and polish. I have the same problem with the 460 lump in mine, solution? get rid of the crap GRP and get an ally skin made like what I've got coming (phone for details). The manufacturers are trying to sell you something so they will tell you what you want to hear. Now the bit you all want to know, how to go about it. Most of this you can do yourselves, but, some of the work you are going to have to decide "Can I do it?". "Will it look any good?". "Will I balls it up and have to pay someone to correct it?". "Should I listen to someone who's been doing this for many years and pay them for their skill and expertise?". YES! When you order your body get it in black gell coat. It does not matter to the bodyshop what colour it is, if they say it is a problem then give them a miss. Put your BLACK body on the lawn or in the drive for the summer and let it cook in the sun. This will sort out nearly all of the problems provided its out in the HOT sun for a length of time. If your neighbours complain or it kills the grass as mine did (I dislike cutting the grass so it did me a favour) then get it to a bodyshop with an oven and ask them to bake it for a while. Its up to you to keep a check while its in there. However, the hot sun is best. Next, once you are on the road and ready to go, drive the car in its gell finish. I know some of you will not be seen dead in anything less than the finished article, and that "Richard Cranium" is already at the meetings in his, then fine, be ready for the marks to appear. I finished my own Cobra in Oct 87, ran it through the winter until April 88 and then painted it. To date there are only two marks that have appeared. One where the ally engine bay sheeting has been pushed up into the body, and the second where the bonnet support was drilled too near the scuttle. These marks are only so slight that they have to be pointed out. Shaking the car down is one of the best things you could do before painting. Not only that, but if the engine plays up do you really want to lean over a fresh wing and mark it with your 501 studs. You will have to watch bonnet edges at the tops and some boot edges at the bottom. If you pull these shut tight onto rubbers they will give over the years and these edges will start to lift up. GRP is an OK medium, but, it will not take excessive sidepipe/manifold heat. It will not stay still like steel, but then its light and it does not rust! You pays your money and takes your pick. As stated earlier, if you want the ultimate get an alloy body (I just happen to be talking to a supplier in the states, phone for details if interested). Provided you are now happy with the body and fit, we will now run through the painting process. If you have never painted a car before then forget it. You will need a BIG compressor, a big dust and fume extractor and understanding wife/mate/neighbours. We had a friend who did his own prepping under my guidance at home, that was two years ago and his wife is still wiping dust from the upstairs cupboards. You will need several sanding boards, 6" ‑12" approx. These are rubbing boards that attach sanding sheets by Velcro, use them much like a large wood plane. Fix on an 80 grit paper and start to rub the whole body. Try to rub a small amount of shape into the body and stop worrying about the scratch marks. That bloke that said rub the flash marks off with wet and dry is going to see his paint fly off when he does more than 25 m.p.h. as it has nothing to adhere to. You will start to see hollows appear where the blade has met the high spots, don't worry, just carry on over the whole vehicle using the small blade for tight areas and by hand in the very tight areas and curves. Do this to all the panels as well, (but not the backs of the bonnet, boot and doors, key these up with a 180 grit by hand or with a foam block). These are 4" long, Velcro and made of soft foam for complex curves and rounding off. In the wrong hands they can mess up a job so leave well alone unless you are sure. Fit your doors bonnet and boot lid. If the doors shut on a seal and onto the trim then fit them at this stage as the doors will move, and, if you fit the trim after it could alter the final line of the vehicle. Always leave the doors proud of the body if you cannot get them to fit spot on. The reason being if the doors are in and you fill them to fit you will end up with a door with an edge that is half an inch thick. If the door is proud and
you fill the wing and sill nobody will be able to spot the thicker door return, and who is to know it was not produced like that. If you have to fill a door edge then fill the leading edge, you can not see it with the door shut and you will find it even more difficult to see it with the door open and the edge pointing to the front wing. Technical Note, we use only PP50 filler as it is so easy to use. Bondocrap? Supefill? GET RID OF THEM! Any major filling should be first filled with FIBREFILL. This is GRP chopped up in a resin you mix with hardener and spread like filler. Use this to bulk up any major repairs before filling with PP50. Apply the door princi­ple to the bonnet and boot lid areas. Fill any low spots in the bodywork. Rub all of the filler with your long blade and 80 grit paper. When you are happy with the filled areas apply a light guide coat of matt black paint and again lightly rub the area. This will show up any low areas you may have missed. These first stages are the most important, if you short cut here then it will never be right. Door, bonnet and boot lid gaps can now be tackled. When filling gaps always fill the shuts. If you try and build up the edges the first gentle tap will break it off. To get an even gap fold a piece of 80 grit paper around a piece of plastic filler spreader both sides and rub up and down the gaps all around. This way the gaps will be even all around the parallel. Always carry out these operations with the locks, hinges etc fitted and in the shut, locked position. Next the good bit, you get to paint.
Firstly paint types. I am not going to go through the various types as there is only one option, TWIN PACK, 2K, call it what you want. I would guess that 99% of todays vehicles leave the factory with this. It's hard and durable, won't fade and it will put up with most types of abuse. Also, believe it or not, although you have to wear air fed breathing equipment the product itself is very easy to use and quite forgiving. Red oxide primer, give the whole lot one to two coats of this primer, it is very similar to a self etch primer but is a lot easier to apply. All of the mixing ratios and amounts will be on the tins you use or ask for a data sheet when you buy the prod­ucts. Polyester spray filler, this is what it says, its a very thick substance in the tin, basically runny filler. Mix it with its hardener and spray it all over the car and panels. Paint the panels separate to the body and try and put on about 3 good coats. This obviously depends on your body condition and your filling attempts. With this product you have got about twenty to thirty minutes pot life, after that it starts to set and if it sets in the gun because you have gone inside to watch the telly or your on a promise then you are going to have a good few hours picking it out. I'm not going to go on about it but you must wear AIR FED BREATHING EQUIPMENT! The gun wants to be of the gravity type with a 2 tip and needle arrangement, and you will need to mask up everything you don't want paint on. A little tip, twin pack sticks to everything (like poo to a blanket), so mask up the underside of the vehicle otherwise it will float up into your engine bay. Fit your doors, boot and bonnet on with all locks and catches and give it all a black guide coat. Get hold of the long rubbing blade with an 80 grit paper, put a bloody good dust mask on and start to SHAPE UP YOUR BODY! Don't just attack it flat out because you will only get great big hollows everywhere and you will be knackered after ten minutes. You boys who say to the girls you are stayers then this is the job for you. It will probably take you the best part of two to three days if all goes right. Try for a gentle even rub all over so that the guide coat has just been rubbed out. Any major low spots refill and spot coat, any minor low spots can be spot re‑polyestered or, if you want to, polyester spray the complete vehicle again and rerub.
THIS IS THE BIT TO GET RIGHT!
there is no such term as "that will do", its either right or not. Leave any bits now and it will show up in the finish. I know you are p****d off rubbing and your arms are aching but tough s**t, stop whinging, get on with it and finish it off properly. Finish the door shuts and edges with some worn 80 grit paper. Provided that all is ok with you and there is a suitable amount of polyester left all over the vehicle rub the complete lot with the various size blades with a 120 grit paper very lightly. This is just to take away the various rubbing marks and make the finish slightly smoother, at this stage do not try and shape it all over now, be patient. Now take the car outside and dust it down. If your very green then lightly brush off most of the dust and then blow off with an air line. If you don't get on with your neighbours and their car is still wet from washing and the wind is in the right direction then blow the lot off and watch their car change colour as if by magic. Mask up the body ready for priming. Apply one to two coats of red oxide primer as above, let it dry for fifteen to twenty minutes before apply­ing the undercoat. The undercoat we use is a high build type, this means it gives good build and allows a good blocking. Whichever type you use follow the mixing instructions. Apply one grip coat and three to four good wet coats to all of the body and panels. This lot can now all be painted separately When dry you will need a rubbing block, not the rubber type you can buy from "Hellfords" chuck them in the bin. You will need a nylon block approximately six to eight inches long and about two inches by one inch, nice and flat with square edges, make sure these are rounded off slightly Wrap a piece of 600 grit wet and dry paper around it and with the undercoat guide coated start to rub in a circular motion all over. This stage is blocking out all of the minor imperfections. Do this all over the panels and body, keep changing the water and paper. If you go through to the polyester don't worry, you can always apply more undercoat and reblock. If you are not too happy with this finish then re‑undercoat the lot again, give it several days to dry and re‑block. Any minor marks can be made good with a fine surface stopper and spot primed. Tackle the door shuts and all returns this way. By now the body should start to look good. Re‑assemble and finally check (for the last time!) the doors, boot and bonnet for fit. If they need some work then do it now before its painted. MAKE SURE THE BODY IS DRY, put the heater on, drag it out in the sun, but whatever you do make sure it is dry! You may have seen some paint jobs with tiny little marks on the surface just like measles, this is called micro blistering, caused by moisture on the surface. If this happens the only remedy is that it all has to come off, you can polish it out but it will return six months later.
Now the shiny bit. I will only cover solid finishes here as base coat and clear systems should be left to a body shop as they can be difficult, especially with the lighter range of pearls now on a lot of modern vehicles, even the temperature can affect these finishes. Mask the car again, damp down the floor and walls to prevent dust and mix up four to five cup‑fulls of the top coat ready Start with one grip coat and three to four wet ones, if you get a run then leave it alone and walk away, flat it down when dry and start again. By now you should see why the hard work was all in the preparation because when you start to look along the side while you are painting it should look nice and flat. Carry this out for the panels as well. In an oven you could flat and polish after one to two hours, but as most of you will be at home leave it a couple of days, no longer. Use brown half sheets of 1200 wet and dry, wet the paper and rub it with a block of soap, this will stop the paper clogging and marking the surface when you are rubbing. Go over the complete car until the surface is dull and all of the peel has been removed. Be very careful on edges, it is very easy to rub through in these areas. Once you have done this, you will know when because your hands will be stained the colour of your car for at least three to four days so everyone will get a sneak preview of the colour of your car. You will now need a polishing machine (hire one) its a bit like a 9" angle grinder but it runs at only 1800 rpm, a foam polishing head and a tin of G3 polishing compound. Wipe a small area with the G3 and spray it with water to keep it damp while polishing. Move the polisher back and forth over the area, keep applying small amounts of G3 and keep it all damp with the water spray, before your very eyes the paint should start to shine. Do this all over the body and panels until all of the dull areas have gone. Caution, be careful of the edges. Once this is done get a pot of 3M Fineseil (I think thats the spelling) and machine the whole lot with this, again damp it down during polishing with water spray When this has been done hand wax the whole lot. If there are any problem areas you can compound by hand with 3M's own product which is basically a "T Cut" for twin pack paints. A note of caution, T Cut is no good for twin pack, it should only be used on cellulose paints that it why it smells of amonia (it helps to polish cellulose). There thats all there is to it. It takes years of practice to learn all of this so don't be dissapointed if you mess up your first paint job, we all have to start somewhere. After all you would have only spent £500 to £700 on materials alone. Getting it right takes time, knowing what to look for takes time, and doing it properly takes time. So next time you phone up for a quote and your told a figure don't say "HOW MUCH?" you now know what goes into a professionally done paint job. You are paying for someone else's skill and expertise and quality never comes cheap. David Smith
Classic & Sports Car Services
Now if that doesn't put you off doing it yourself...nothing will!!! /ubbthreads/images/graemlins/smile.gif
