Paint your wagon

4 Mar

Whether at the culmination of a lengthy restoration, or when the realisation dawns that time has finally taken its toll, and the old dear is looking decidedly shabby, the moment inevitably arrives to turn to the thought of paint.

Some may consider doing the job themselves; for others, this is a task for a professional.

Either way, an understanding of the materials and hence the choices to be made, is essential. Much information is available on the ‘net’ on the mechanics (technique, procedures, etc.) of painting a vehicle, but very little in digestible form on the practicalities, pros and cons, on the decisions to be made long before the lid is taken off a can of paint; specifically, on material selection. Even if you chose the professional route, you will still have to specify what you require. You will still need to talk to the people doing the job, and decide between a bewildering number of options.

The early T-Series cars originally left the factory resplendent in cellulose paint. This has to be qualified in that I have seen sources claiming that whilst the body was painted in cellulose, the wings were finished in enamel, for abrasion resistance. The complication is that other sources refer to cellulose enamel, which confuses the picture somewhat.

For the purposes of this article I have not considered synthetic, oil-based enamels, nor traditional brushing enamels, which are sometimes used for vehicle refinishing. Neither were deemed practical for my needs. Nor have I considered metallic finishes, as although metallics were available in the period, the vast majority of T-Series cars were painted in a solid colour.

The material choice in practice is between traditional cellulose and modern two-part acrylic.

Cellulose paint is still available for work on classic vehicles. Wonderful for originality fetishists, and relatively DIY friendly should you chose to do the work yourself. It is also relatively inexpensive. Cellulose dries by evaporation of the solvent – of which there is a good deal – as for application, cellulose paint is mixed almost one to one with thinners.

The downside of cellulose is unquestionably a (comparatively) woeful abrasion resistance. Stone chipping is inevitable if you intend to drive the car. Some would argue that cellulose never really hardens in the modern sense. It is certainly nowhere near as abrasion resistant as more modern materials. Cellulose also requires significantly more work after the paint is applied – rubbing down between layers and reapplying. This represents a chore for a DIY-er – but significant expense if you are paying someone else.

In the professional vehicle refinishing world, cellulose was replaced several decades ago by two-part epoxy paints. As the name suggests, these comprise the paint itself and the associated hardener – hence the generic description, two-pack or 2K.

2K paint dries by the chemical reaction between the paint and the hardener. In a professional environment, it will normally be baked in an oven immediately after application, but even without baking, it will dry to a very hard finish – very much harder than cellulose. The greater abrasion resistance of 2k materials is something to celebrate by anyone who has chipped a cellulose painted panel during assembly, and the direct-from-the-gun gloss is a revelation for those used to the hours of hard rubbing down & polishing toil inevitable with cellulose.

Two-part paints may conveniently be further sub-divided into what are known (in the UK at least) as direct gloss and clear over base. Most modern cars, whether metallic or a solid colour, are finished (or refinished) in clear over base. A colour base coat, which may either be water or solvent based, solid or metallic, is first applied. This base coat, has a dull, satin appearance and very little abrasion resistance. It must be overlaid (without further preparation) with several coats of clear lacquer, which is normally solvent based. The result is a very high gloss, wet look finish. This high gloss is very popular with restorers of classic cars in the United States. Tastes differ, and whilst I like a shiny car, I find the ultra-high gloss produced looks both incongruous and utterly ridiculous on a seventy year old British classic car. The phrase “over restored”, springs to mind. Your choice!

An alternative may be found in direct gloss 2K. Again, this is two-pack paint, but it is applied without a covering of clear coat. Produces a good gloss finish straight from the gun, but, can also be polished to a very high gloss finish – or not!

Purists will still quibble over the high gloss level of 2K when compared to cellulose. All is not lost, as 2K can be made to closely resemble the appearance of cellulose in one of two ways; either by adding a very small quantity of matting agent to the mixed paint prior to spraying in order to take the edge off the shine, or, (concours folk should look away now) by simply driving the car around a little and letting the inevitable scuffs and polishing scratches dull the shine slightly.

On a car with so much of the underside exposed to both view and road debris, consideration has to be given to the use of stone chip. A high gloss finish on the underside of wings looks good (and original) but will not stay pristine for long if the car is driven. A possible solution is stone chip coating. This is a slightly rubbery paint, which is applied over primer then over coated with colour coats. On a T-Series, it might be used under the front and rear wings. Non-original, yes, but then neither is the acne-effect of touched up stone chips.

Used neat through a proprietary gun, stone chip will produce a stippled, lightly textured finish, but if diluted, and applied though a normal spray gun (with a larger nozzle), it produces an almost flat surface, which looks close to original when over painted with gloss, but also helps to shrug off damage from road debris.

Is painting your TC yourself a practical proposition? As far as cellulose is concerned, it is feasible. A mask and sensible precautions on handling are required but repainting a car at home is feasible – always assuming that you can live with the limitations of cellulose. 

2K is very different.

Any mention of ‘elf-‘n’-safety in our cotton wool swathed times has yawns developing and eyes rolling. The downside of this is that genuine concerns tend to get brushed aside with the fatuous. Health concerns surrounding the use of 2k paint are far from fatuous. The hardener contains isocyanates, which are known to cause asthma. The spray mist is dangerous by both inhalation and skin absorption.

As to the practicalities, a disposable suit and an air fed mask are absolutely vital (ignore anyone who tries to tell you otherwise). The mask will consume a great deal of compressed air. My 3hp, 15 CFm model which is about the largest that can be run from a domestic, single phase supply, will not run the mask and a spray gun simultaneously.

Most important is the selection of somewhere to spray the vehicle, as you have to consider not only your own safety, but that of those around you who may come into contact with the spray mist.

What did I do? Quotations for painting my (dismantled) TC varied between £4,000 and £12,000, and the quality of the finished work, I will put politely, varied widely, and not always in relation to the price paid.

I elected to paint the vehicle myself; partly because a DIY job would help with logistics. A TC has to be painted in a dismantled state; chipping a panel during reassembly necessitating repainting would be inevitable. Painting it myself would make this easier. And so it was to be…!

HSE information on the use of 2K paints here:
http://www.hse.gov.uk/mvr/bodyshop/isocyanates.htm

Martin Holloway

Ed’s note: Martin sent me a selection of photos taken prior to final assembly/panel adjustments, some of which are shown here.

As for technical information: the car was stripped to bare metal, remedial panel work done, epoxy primed, followed by three coats of primer/filler (both 2K), underbody stone chip, and four coats of direct gloss two-pack top coat. It has not been polished up to a mirror shine, deliberately, in order to resemble a cellulose finish.

Total cost of the respray (excluding sundries) from his receipts was £420.

  


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