How to achieve a 1st Class paint finish

The most important thing to remember with any type of paint application is that the preparation is probably 80% of the work - applying the paint is 5%, and the last 10% is the flatting and polishing procedure. As I may have told you at the Classic Car Show, anyone can produce a top class paint finish as long as time is no object, and the principles are followed strictly. This section intends to get rid of any doubts you may have of spraying your TVR (or any other car for that matter) yourself! (This is a guide to doing your re-spray without a professional spraybooth handy, but if you do have one, so much the better). Please refer to bodywork tools section for info. on products/tools mentioned from here onwards.

• Firstly, sort out any areas to fill or repair - see other sections on this site for details.

• If you are keeping the original paint and want to spray over it, use a "scotch pad" to scuff up the entire paint surface - which will provide a key for the new paint to stick to. I would not recommend spraying the top coat straight on to this without priming first - this will allow you to find any imperfections for fine filling (or stopping, as it's called in the trade).

• For best results, strip off all the original paint right down to bare fibreglass (or steel on other cars) - it's best to know what's under the paint so you don't waste all your hard work when the paint lifts or bubbles a few months later. Again there is a separate section on this subject.

 

Procedure list for 1st class paintwork

1. From bare fibreglass with all filling completed, spray a guide coat (mist of paint) of matt black colour over the all the panels to be prepared. If you use a gloss it will clog the flatting paper in the next process - causing scratches in the fibreglass. As a rule, always use matt black guide coat for light coloured panels, primers or topcoats, and matt white for dark coloured panels, primers, or previous top coats.

2. Dry flat the bare fibreglass using 180 grit aluminium oxide type paper - use the appropriate flatting blocks to ensure surfaces are as flat as possible. This is to prepare the gel-coat for its first coat of paint. Move the block in a backwards & forwards motion along the panels to remove the guide coat, rather than in a circular motion - which will cause swirling that can impair the finish of the next coats. Wet flatting at this stage should be avoided as bare fibreglass can absorb water - which if not dried out will cause paint blistering next time the car gets ice on it (more on that subject later - see section 17). Any high or low spots will become apparent - the high spots will appear first as the guide coat will be removed as will the gel coat if you keep rubbing. To repair these you have to grind down the area, and fill with fibreglass strand/resin mix and flat to the correct level, then fill with polyester filler/stopper. You should only get these on a fibreglass car if a crack or accident damage has been poorly repaired - as a rule they are reasonably smooth in finish. The low spots will show up as you progress - as areas which you cannot flat out the guide coat. Carefully fill & flat these using a polyester filler or stopper - depending on size of defect.

3. Once all the guide coat has been removed, and all high/low spots have been sorted out, blow the bodyshell over with 60-100psi air from a compressor to remove as much dust as possible, then give it a degrease using panel wipe solution (see bodywork tools section for availability & full description). It's best to use special paper for this, with a sheet for applying, and a sheet for removing the solution. Wipe over an area, and before it dries wipe off with the other sheet. Repeat as necessary until all sanding dust has been removed. Again, blow the shell over with compressed air.

4. Now comes the painting area preparation - which will depend on the facilities you have. I built a perfectly adequate spraybooth out of studwork & fire resistant panels including roof, sealed in fluorescent lamps (sealed out of the spraying area), and an extractor fan with fireproof pyrotenax type cabling - all to satisfy my insurance broker's regulations. You may only have the use of a garage, barn, or even driveway! All I can recommend here is that you have at least 1.5 metres (5 feet) around the whole of the car to work with, some form of extractor fan, and sealed lighting - extremely important as a spark could cause a very serious fire - maybe resulting in personal injury/death, as well as a nice garage fire. Basically use your common sense, follow any local regulations for the environment, make sure any of your neighbours aren't the type to go calling the council the minute you tap a hammer, make a sound etc. I know in the UK regulations & neighbours will almost certainly rule out a DIY paint job - but only you will know what is/isn't possible by your own investigations/cunning plans!

The main way to prepare an area is sweep/brush/vacuum all the dirt & dust from the room, then to damp down all the walls & floor, line all the walls & ceiling with a plastic sheet (to prevent existing dust being blown onto the shell by the odd blast of air from the spraygun), and to keep the floor damp up to the point of spraying. Other factors to consider are the flow of air in & out of the area, safety in case of an accident, breathing apparatus, and lighting - both for fire safety, and so you can see the bodyshell to enable an even coat of paint. Lastly you need to take into consideration temperature & humidity:

• I would suggest a fireproof extractor fan at one end of the area, as low as possible (as paint mist sinks), and a filtered air inlet at the other end (filters available at you local paint supplier).

• Keep a fire extinguisher handy, also a fire blanket to cover yourself with!

• An air fed mask with an in-line coalescent filter is the best way to protect yourself from paint fumes - this basically allows you to safely breathe compressed air without the oil/water vapour which is present after air has been pumped. I also seriously recommend a water filter in the airline before the outlets for both breathing and spray equipment, and also a main coalescent filter. This gives you a double safety barrier in case one coalescent filter has a fault, but also ensures that the paint you're spraying doesn't contain impurities which will almost definitely give your paint defects once on the car. Standard filter masks can be used with cellulose paint, but due to the high content of paint dust in the air it is not going to take long for it to block the mask. Also, an air fed system allows your whole face to be covered - therefore preventing paint getting into your eyes, and condensation from the filter mask dripping on the new paint (yes it does happen!).

• Lighting needs to be very good, and as good on the sides of the bodywork as it is above. You will need to fit lamps all round at both high & low levels - I use the reflection from the lamps a lot so the next stroke of the gun will blend into the previous one.

• Temperature - although this cannot be controlled too much - try to spray when temperature is as near to 20ºC or 68ºF as possible. Paint mixing tables always refer to temperature as thinners content varies according to this. In the UK the months from May to August are best.

• Humidity - high humidity can cause 'blooming' of paint - this has happened to me when spraying on cold damp days without heating the building first. It is most apparent on darker colours, but brown, black & red are the worst ones - the paint will dry with a matt appearance instead of gloss, ofter appearing milky. The only option is to sort out some decent heat, or wait for a better day. Remember to never use a heater while spraying - it may be the last thing you ever do!

Now the area is prepared, wheel in the car.

5. Mask up the car using masking paper & tape (again see bodywork tools section). It's easier to jack the car up & remove the roadwheels to save having to mask those as well - the brake discs/drums are much easier to cover. You may also find it useful that a special underbody coating is available which prevents overspray sticking to chassis/suspension components - half an hour spent applying this will save many more hours at the end removing paint with thinners or covering with underseal.

• Mask with special paper (see tools), rather than newspaper - the ink from the print will run & stain any areas underneath.

• Mask all door shuts (openings), window openings, and behind any holes which would allow air to be blown inside the shell. This could be forced back out throwing dust onto the new paint.

• Once masking is complete, de-grease the bodyshell again & use a tack rag to remove all dust/hairs/fibres etc.

6. Now you are ready to apply the first etch primer coat to the fibreglass. This is basically an acid paint which helps the paint stick better to the shell. It should be used on any bare panels, metal or otherwise, and is usually supplied in two parts - a paint, and an acid thinner. Mix to the ratio recommended, and spray a light coat to just 'dust' over the bodywork. The first coat should always be very light - as anything thicker can react on any small impurities that (hopefully aren't) left on the bodywork. This light coat should be left for at least 15 minutes to dry - hopefully giving a sealed & good base for the next coat. This second coat should be applied evenly but thinly to the whole shell, ensuring a good base for the next step in the process. Leave to harden overnight, or dry with infra-red lamps to speed up the process.

7. The next paint to apply is the primer - or filler primer (which is more usually applied these days). There is no need to flat the etch primer applied in item 6. above - as it needs to cover the gel-coat completely to ensure a good key for this stage. Again, mix the paint to the data sheet from the paint supplier, and apply a light, even coat to the bodyshell. I would then recommend at least 3 good thick but smooth coats of this filler primer - apply it thicker to any obvious area of concern (but if you have prepared the bodyshell correctly this will be unnecessary!). Leave this to dry for 12-24 hours or use infra-red lamps again - it needs to be fully cured for the next step.

8. Using your matt black can of paint, spray on a guide coat as in section 1. Again, using sanding blocks along with 240 grit paper and again without water on a fibreglass bodyshell, remove all traces of the guide coat to reveal any high/low spots again. This can be done with wet & dry paper & water, but the less water on the bodyshell, the less likely you will experience blistering at a later date.

9. De-grease the flatted bodyshell again, and use a tack rag to remove any small bits of dust etc. check the masking tape & paper is intact and re-mask if necessary. Make sure any paint slurry that has dried is covered by new tape as it turns back into dust when dry, and could cause a nightmare while spraying. Ensure floor is re-dampened before next stage.

10. Repeat step 7, but apply only 2 coats of filler primer this time, and add a little more thinners to give these coats a smoother finish. Leave to dry & harden for another 12-24 hours or dry with infra-red lamps.

11. Apply another guide coat, and final flat with 800 grit paper & water this time with 2-3 drops of washing up liquid - again with appropriate sanding blocks. The detergent stops the surface tension effect of the water on the new paint (or 'waterproof' effect which prevents the wet & dry paper from cutting into the paint surface). Always concentrate on one area at a time, and have some paper degreasing sheets handy to remove excess paint slurry which will impair the wet & dry paper's cutting ability. Any minor blemishes should now be filled with a fine stopping compound and flatted out using only this 800 grit paper. You may ask why 800 grit has to be used - well, you can use between 600 and 1000 grit paper, but 600 grit tends to only be OK when a two pack topcoat is to be applied - as it is a thicker paint with less likelihood of 'sinking'. On the other hand, 1000 grit seems to be too fine to me - as I like a good 'key' on the last coat of primer for the topcoat to adhere to. Finer paper can cause stone chips or small impacts on the paint to take off a larger piece of paint than would otherwise happen.

12. Fully de-mask, degrease, air gun, re-mask, degrease, then tack rag off the complete bodyshell. Make sure any problems are spotted by this stage as it is your final chance. It may also be wise now before you start the spraying to re-cover your garage with a new sheet of plastic and clean out all paint residue created so far.

13. Once ready, dampen down the floor, mix up your paint to the recommended paint/thinners mix, and apply a light 'dust' coat all over as done before. Allow 15 minutes to dry, then apply a good second coat. Leave for around 15 minutes to dry, then apply a third coat, wait 15 mins., then a fourth, and so on until you have applied around 8 coats. Leave this time for 30 minutes, and now apply the final 2 coats using an extra 10-20% thinners - this will help to blend in any overspray you may have to make final flatting & polishing easier. It's not difficult to create overspray - but can be so rough if the car is sprayed badly that it will resemble 120 grit abrasive paper - this is to be avoided as it's a real devil to flat afterwards and can cause marking. To avoid this as best as possible always try to spray the car like this: Side, front, other side, back, then roof. The last area is always the roof - which will smooth off any overspray which make have settled on it - try it - it works for me! Leave the bodyshell at least 48 hours to harden fully, or around 24 hours after treatment with infra-red drying lamps. As a guide for paint quantity required, I used 10 litres of cellulose paint when spraying this amount of layers on a TVR 3000M. For bodylines and second colours to be sprayed, re-mask the new paint after its 48 hours hardening, and use special 'fine line' tape for the actual paint edge. This is a plastic type masking tape which isn't able to absorb thinners like standard masking tape - so the glue doesn't melt and transfer to the first colour coat you sprayed. It also leaves a much crisper line than any paper type tape which gives a much better visual impact. Try to apply only enough coats to cover the first colour - as more coats mean a thicker layer.

14. At this stage you will probably notice that the smooth shiny paint you saw at the time of spraying has become less smooth - more of an 'orange peel' effect. The extent to which this happens depends on many factors including paint type, quality, mixture quantities, and temperature /humidity conditions. What you are trying to achieve here is a perfectly smooth, shiny, scratch free paint finish that will last for many years. Obtain some 2000 grit wet & dry paper (you will need at least a quire of this (25 sheets)). With a bucket of clean warm water, and a bottle of washing up liquid (like you use on your dishes), soak a strip (1/4 of a sheet) of paper for about a minute, apply a drop or two of washing up liquid to the paper, and start to flat the new paint - until it becomes perfectly smooth and blemish free. Use plenty of clean water - renewing a strip every 5 minutes, and also change the water after each panel. Dry each area off with degreasing paper to check all shiny (and thus indents) are removed. Keep the car masked up at this stage as there will be a lot of mess during the flatting process. Repeat the flatting for the complete body shell. With a bodyline or second colour, do the same, but make sure the edge isn't rubbed out by lightly flatting these areas by hand. Wash the whole car with warm soapy water when finished, and dry off completely with degreasing paper.

15. Using a G3 type cutting compound, and a set of clean & lint free polishing cloths, rub an area with a dampened cloth & G3 compound until it regains its shine. You can use a special polishing mop for this process - but experience has taught me to use this only on flat areas - leave any edgework for hand polishing. This will save the disappointment of 'burning' off your new paint right down to the fibreglass. It is possible to see the paint 'smoke' if done incorrectly with this tool - so you have been warned!! Try to do all the hand rubbing in straight lines, as this will stop the minute swirls you see under fluorescent lights on showroom cars. It will take at least 3 or 4 eight hour days to do this properly - but you will be rewarded with a great paint job. Lastly, use a G10 type cutting paste as you would a wax polish, to get any minor scratches out left after the G3 polishing. Alternatively (and probably just as good), I use a cutting wax which will not only do the final waxing, but will remove the scratches & enhance the paintwork at the same time. As long as you have enough paint on the car, continue using this type of wax to keep any day-to-day scratches away. If you are worried about the thickness of your paint - you could always use a non-cutting type of polish instead.

16. Final advice for fibreglass cars is this: Be prepared to have to flat an area again after a month or two, and again in a year or two once the paint has had some time to cure (with cellulose type paints especially). Due to its high thinners content it takes a long time for it to evaporate, and as the fibreglass gel coat and body filler is made from a similar composition of chemicals, this has an effect on the levels too. Rest assured, this is not major work compared to the initial 2000 grit flatting procedure, and lessens as time goes by.

17. Car covers - important advice: When using a car cover that touches your bodywork, it is extremely important to place a blanket or similar sheet between the bodywork and the cover - especially during months when it freezes. I have seen many fibreglass cars with micro blistering paintwork - caused by water turning to ice on the cover, and literally freezing the fibreglass underneath. This may or may not be due to water absorption into the fibreglass shell from its original post-production pre-painting habitat being left outside at the TVR factory, or it may be due to unfiltered air supplies when a respray was done at a later date again causing trapped water/moisture to be left under the surface. Water expands when frozen, and so with such a mass of ice above the panel it will actually freeze any water in it - causing the paint to lift & blister. I have recently seen warnings on new car covers telling you to put a blanket between the car & body, but not explaining why - so it seems my findings must be more widely known about by cover manufacturers than I thought!

18. If in doubt: If any of the above procedures don't cover a problem or question that you have come up against, please send an e-mail & I will try to answer it with as much detail as possible.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Common myths about car bodywork:Reality

You can't mix a two pack primer coat with a cellulose top coatEither paint type can be used as long as fully cured before next type is sprayed.

White colours are harder to spray than dark coloursWith correct lighting, any colour can be sprayed correctly and easily. Black is the hardest colour to look the best though - as any blemishes are not 'bleached' out as they are with light colours. With poor lighting you can get a sort of colour 'blindness' which results in missed areas - simply sort out the lights.

Red paint 'bleeds' through to a new colour after a resprayThis can only happen if the red paint was enamel or synthetic type paint, and reacts with the new coat - but any colour paint can do this

Two pack paint kills you instantly if you smell itCertainly not immediately deadly, although I would seriously recommend you only use this with proper air fed breathing apparatus - and don't go sniffing cans of paint at all! All automotive paint is bad for you - but two pack is cyanocrylate based and builds up in your respiratory system & tear ducts - it can cause cancer and infertility. Thinners & paint can be absorbed into your blood through your skin - so always wear protective gloves & clothing as well as breathing apparatus.

Use household plaster to fill large dentsYou've got to be kidding! Where's the flexibility in that?

Newspaper & wood are the best ways to start filling a dentA friend of mine once found a chair leg inside a VW Beetle's rear quarter panel which made the edge up above the running board - it still had its metal stud in the base. Not something the bodyworker should be proud of! Newspaper smells, rots, holds water, and is a nice warm place for rats to sleep if you store the car away in a shed!