The Spray Painting Thread

[o_man_ra23]

I started from fibreglass, so had to prime. Anywhere you rub back to plastic needs to be plastic primed. I would go a full coat of primer (thin) just to give an even base to work off, otherwise you will get a patchy job.

[andy]

thanks for the help guys, + rep for all.

oman, my mate doing the spraying says we will use the black instead of primer, and then go with green or red once its right. so the black is like the base that we will sand back till its right. lots of layers. is there still much chance of a patchy job?

[twentyEight]

Don't use Black as a base if you want to paint it Red!!!

It'll take 20 coats to cover!

Now you might think, that's ok, I have plenty of paint, but the more coats, the more weight!

Use a light brown undercoat, whether it be a primer or a colour coat...

[o_man_ra23]

Use a primer... they fill small scratches better (like the ones you get from 400-800 grade wet/dry). Also use a colour thats as close to the colour your spraying with as possible, but lighter. Never start from a darker base unless your very experienced and are looking for an effect not achievable with a lighter base.

[andy]

Now you might think, that's ok, I have plenty of paint, but the more coats, the more weight!

your kidding right?
thats a very f&f thing to say.

[twentyEight]

F&F?

I'm not kidding actually... 1 Litre = 1 Kg!

If you use 3L of paint to do a 0.5L job, your bike will be 2.5kg heavier...

[andy]

really? but isnt most of the body of the paint the thinners and other liquids that evaporate?
the acrylic particles in the paint is just plastic. i just dont believe that such a thin layer of plastic could weigh 1 kilo.

[o_man_ra23]

1Litre of paint will certainly have a portion that evaporates. But let us consider density for a second. A litre of paint is more dense than water, and as such weighs closer to 1.25kg than 1kg. The portion of that which evaporates is less dense than water. So if 30% evaporates, its about .25kg that goes into the atmosphere.

I think 1Litre paint = 1kg finished product is a fairly close approximation. Remember that you add most of the thinners that evaporates... so we dont take the quanity of thinners used (about 4Ltrs) into the mass equation.

Also, doesnt matter how many coats you use, you will have less lustre and it will be darker when using black as a base.

[ian]

dont forget , you can tint the undercoat with a red tinter or a bit of the red that you are going to use as a top coat
ian

[andy]

would i have the same problem with green? like a kawasaki green.

[o_man_ra23]

Use a light grey, or light blue primer. Black undercoat will come out shit... and yeah, same problem in any top colour other than black.

[Neverland]

Hey Great thread I'm in the process of preping my car to paint aswell
One question I have, sorry to hijack the thread, I'm going to paint my ta22 purple. what colour primer would you recomend?

[ian]

it depends on what shade purple
the general rule is, that light tint undercoat for light colors dark tint for dark colors
but i have seen some excelent jobs the other way around cos say with a dark purple over a light undercoat, it is easier to see how it is covering that way it reduces the chances of it being patchy ,confusing eh, what i do for most solid , colors is just use the grey primer and i tint the under coat for metalics,i guess it boils down to pesonal choice if you have some spare panels laying around use them for practice
ian

[o_man_ra23]

Neverland, I would suggest a light blue primer, or if the purple is dark, then a red primer.

[ian]

hi owen
that would work well
ian