FAQ's

[gingapaint]

Hi all, This board is aimed at the frequently asked questions that everyone wants, and perhaps should know prior to taking on a bodyshell painting project.

i'll keep this board locked, so it does't fill up with the usual banter, that can sometimes clog up boards. i will however add to it as a new scenario comes into question.

If you have any questions or queries that you believe should be included, please do not hesitate to pm me these requests. please note this is intended for general topics, and not specialist finishes, effects etc etc.

[gingapaint]

from Da Cookie Monster... OK, first question for Mr Paint, what is the best way of lining up body post holes and wheel arches for cutting out???

ok, this is not a hard an fast rule, but it's the one which works best for me. give it to someone else.

That not being an option (it rarely is.. :() the easiest way i find is to set the uncut shell on the chassis of the car, centering the shell around the FRONT wheelarches. and ensuring the gap between the wheels and the side of the shell is uniform. this is easiest with new, straight body posts!!

Grab yourself a permanent marker (i like overhead projector pens, accurate, readily available and cheap etc etc) and looking directly down on the shell/car, mark the four points which the posts hit the shell. if your posts (and car!!) are straight, you should be able to judge this off certain details of the shell.

Next, grab your weapon of choice, dremel, reemer, screw driver, soldering iron (please, the last two were a joke!!) CAREFULLY place the four pilot holes in the shell where you marked. and try tis on the car again, just to make sure. the rule here is
MEASURE TWICE, CUT ONCE!!
if your happy, go ahead and drill those bad boys out. again, trial fit. when your happy, go on and do the aerial and trandponder holes in the same way.

next, with the shell mounted and chassis at ride height, trim off the excess material from the front splitter, skirts etc etc. easy way.. get your overhead projector pen (OHP) ad with the car on a flat surface, roll the pen around the base of the shell.. this will leave you with a line aprox 2-3mm off the ground, and level the whole way round. if your happy with this, go ahead and cut.

this should leave you with the roof height at min 120mm, and the lowest portion of the shell, as low as possible, whilst still having clearence for yaw, pitch, roll etc etc..

Now, set the car etc down, on a table, and mark the centre of the axels. this will be the centre point for your circle cutter (assuming you have one). simply adjust this to the radius of chosen tyres (will differ for rubber/ foam/ indoor etc) it's better to be a little big, and avoid the shell ctahcing on the tyres, but too big looks a bit poor...

if you dont have a circle cutter, it's alittle more difficult. use an old (but full size!) tyre as a template, and draw around it on the shell with your OHP. you can repeat this for all 4 tyres, or you can cut out that arch and use it as a template.

if you've got a steady hand, it's best to use a scalpel, but curved scissors will work too. if you use scissors, be sure to round off any rough edges etc etc that may occur.

That should be your shell mounted! be sure to wash it thouroughly to remove all of the oils etc etc from your hands, and any contaminants that may have come in contact with it.

Good Luck.

Chris

[gingapaint]

Whats the best way to prepare a bodyshell for masking/painting?

I find the easiest way to do this and the most effective is thus: Hot water and dish washing liquid.

But this is getting ahead of ourselves.
The reason why you need to wash the shell well is down to the manufacturing processes involved in producing the bodyshells themselves.
The shells are moulded using a process known as vacume forming, im sure everyone knows what this involves, so i'll save the patronisism (think i just invented a word)
The problem comes from releasing the mould from the freshly formed bodyshell. due to the heat involved and thermal expansion/contraction typically the moulds are difficult to remove from the moulding, so the manufacturers use an oil based releasing agent, which is all over the mould, and obviously thus, the bodyshell as well.

being an oil based product (or of similar qualities at least) it's not the best surface for paint to adhere to. this is why it must be removed, and the best way to break oil down (if you remember primary school science) is with "fairy liquid"

this is why it's best to wash the shell down with fairy liquid and hot water. the dish washing fluid will break down the oil, making it mix with the hot water (the heat in the water speeds up the "reaction")

I find it easiest to use a soft clean sponge, and make sure you really get into evey last corner.

Rinse the shell well with more warm/hot water, and make sure all of the soap is removed, then dry the shell by any means as long as it doesn't leave any contaminants on the shell (lint dust, oils etc etc)

after this process, try to avoid touching the inside of the shell, as fingers carry natural moisture, and this is as bad as the releasing agent itself.

[gingapaint]

How do i get the best results with aerosols?

As not everyoe has the time, patience or resources to purchase and get used to an airbrush, aerosols are the quick and easy answer. They are quite cheap, versitile, and when used correctly, can provide excellent results.

The main problem with aerosols, is that often they tend to apply too much paint, and people are often tempted to try and cover the shell in just one quick coat. Jus tbecause you can doesn't mean you should

OK, mount and prep the shell as described above, mask off your chosen design, and your ready to go.

With your chosen paint, hold the can at least 6" away from the shell and LIGHTLY dust the area of the shell. we're barely looking for a colour here, just enough to tint the surface. the paint shouldn't really appear to be wet at all (however, it will be, dont touch!)

leave this to dry. as it's a very light coat, it will be quite fast to dry, minuites in fact.
once this is dry (touch testing on the masking is an easy way to check, repeat this dusting and drying process until the paint becomes more and more solid.

By dusting the paint on, and slowly building up the paint, not only will the paint have much better resistance to cracking and chipping, but as the paint goes down lightly, it seals the masks, and prevents bleeding, leaving you with a much tidier and professional looking result.

once you are satisfied with the smooth coat, and the depth of colour, back the paint up with white (for a bright look), silver (for a metallic look) gold (for a deep metallic look) or black (for a deep inky look)

Wait for the paint to dry, remove masks, and repeat the process for the next colour.

TIP: warming the cans slightly heps to increase the pressure inside the can, giving you an improved, finer spray, and reducing "spitting" making fading look better. however, don't heat the can's too much (comfortable for you to hold your hand in at an absolute max, preferably less) as cans can explode if subjected to too high temperatures.


Good luck.

Chris.

[gingapaint]

alot of top drivers shells are VERY light... mine are a little heavier...why? to make the shell lighter is it better to apply extremely thin coats?

cheers ginger

Matt Rice

This is a point i try to get across to a number of drivers a lot of the time... and no-one listens!! when it comes to chassis prep we're all into weight saving and as low a centre of gravity as possible, then we go and wack on a load of paint onto the highest part of the car!!!

now im aware that a lot of people are saying "codswallop" to this, but i have figures to prove it!!

losi xx-4 HW shell... painted badly with spray cans (pm for who did it, he should see the funny side...lol) weighs 34grammes

and a properly airbrushed xx-4HW weighs in at a realativly measly 25grammes. now in fairness, these wern't weighed on the most advanced machines available (moms digital kitchen scales....) but it's clear that there is a differential in wieght.

how much did that alloy screw kit lighten your car now?

ok, the weight of shells can be deducted by three ways.
a) cutting chunks out of it.
b) cutting down on decals.
c) planning ahead, and using less paint!

ok, an airbrush will help you due to lighter coats etc, but you can help yourself with cans, and proper planning.

quick way to drop weight is to abide by the "darker colour first" rule. this does two things, it stops later applied colours fading through, and means that it needs less backing, ie less paint. this may mean more masking and work is needed, but the end result will be a lighter weight shell.

we'll take MR Spashett's shell as an example, as everyone should know them. everything is masked off, bar the "purple" sections. the colour is applied, using very light dustings of the colour, until the paint is at a satifatory density. at this point, it's simply tinted. the main colour is then backed with a secondary colour (not saying which colours are used, as Dave's shells use unique colours and im sure he'd like to keep it that way) they are still see through, and then they are backed with chrome, and a dusting of black. this combination of chrome and black works out more expensive, but adds lustre, and weighs less than normal silver.

after this, the orange line is cut, and painted in fluro orange, again as lightly as possible. it's then given a dusting of white to seal it (not final coat yet) then the back is removed and the faded yellow line and white is painted on. this acts as the final coat for the orange line as well.

also painted in all light/grille detail and window surrounds weigh less than apply decals. this however will be very difficult with aerosols, and the weight advantage is minimal. to be honest, i think they look cool.... 8)

if you get a chance to get close to any pro painted shells. you should be able to hold them by the roof, and count your fingers through the paint, without using a direct light source.

When using cans, the easiest way to get the shells slightly lighter, is to heat the cans SLIGHTLY as this gives a finer spray due to increased pressure, and allows you to have the can further away for a finer dusting everytime..

hope this all makes sence!!

Chris