# Primer colour. How important is it?



## Dave Spalding (Apr 16, 2008)

https://www.detailingworld.co.uk/forum/showthread.php?t=421513&page=3

Following on from the thread above. I note have paint that is a much better match. Previously I painted over the original base coat which was sanded with 400grit. This time being that the bumper is already darker than it should be. Which option should I use

1. Scuff and 3 coats of base then a drop coat.

2. Prime with grey primer (factory seems to be grey)

3. Prime with white primer to keep the colour as light as possible as I'm worried it will turn out darker again even though this new paint looked a good match when wet on a mixing stick.

Any help much appreciated. Will be overcoated with 2k aerosol clear. My preference is 3 or 4 coats and then flat and polish. Is this too many coats?

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## Barbel330 (May 3, 2016)

I would not prime the paint again unless there was damage (there's obviously not in your case). If you really wanted to lighten the ground colour (I don't think it's necessary) then give it a coat of white basecoat before the new basecoat. You'll only ever be guessing as to what effect light coloured ground coat is going to have on the finished colour match unless you did an exact replica on a spray out card. Ie: basecoat with the blue that's too dark, then white, then the new shade which is not really the way forward.

When you have a mixing scheme and you enter your vehicles paint code, it generally tells you if that colour needs a certain colour surfacer underneath it. Ie: black surfacer.

If it was me, I'd do a spray out card with the new shade, offer it up to the wings and if it matches I'd paint straight over the bumper which I'd have prepped with P800 or a grey scotch and scuff paste.

Here's an example from my Spies Hecker paint scheme. This is VW Blackberry which is the colour of my Caddy and it shows that it requires a black surfacer.


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## Dave Spalding (Apr 16, 2008)

I believe the original primer is grey. This is based on small stone chips that I feathered out on the bumper. 

So do test sprays of

New base over old base

New base over white 

New base over grey

You mention not to prime. Is there an issue using primer over old base or is it just that base would do? 

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## Barbel330 (May 3, 2016)

Just unnecessary to prime it again. You’re adding an extra stage that doesn’t need to be there and also the less coats of unnecessary paint on any panel the better. 

Just do a spray out card of the new shade. If it matches the wings then go straight over your prepped bumper with the new base and I’m pretty confident it’ll be fine. In the scheme of things your bumper is only shades out, it’s not a completely different colour so it’s unlikely to affect the outcome.


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## Dave Spalding (Apr 16, 2008)

Excellent, thanks. Your advice is much appreciated. I just hope this match is good enough. 

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## SamD (Oct 24, 2015)

Barbel is spot on knock back the clear with 800 to remove the previous orange peel for a smoother surface for your base coat, scotch it up and apply base and clear.


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## Dave Spalding (Apr 16, 2008)

Will do. I have both already, 800 is quite fine for base coat I thought but shows what I know, as a novice painter. I went with 400 last time which I was worried was too rough but was what someone recommended. In fairness no sanding scratches are visible. 

Just out of curiosity is there a range that's suitable like say 400 - 800 depending on preference or is it much more specific? 

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## SamD (Oct 24, 2015)

Dave Spalding said:


> Will do. I have both already, 800 is quite fine for base coat I thought but shows what I know, as a novice painter. I went with 400 last time which I was worried was too rough but was what someone recommended. In fairness no sanding scratches are visible.
> 
> Just out of curiosity is there a range that's suitable like say 400 - 800 depending on preference or is it much more specific?
> 
> Sent from my SM-G960F using Tapatalk


I always finish any prep work off with grits between 500-800.


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## Barbel330 (May 3, 2016)

I tend to use 800 these days but that’s because I use water based paint. For solvent paint it used to be 600 generally. Water based is slightly less friendly when trying to cover sanding scratches so it’s recommended to go a step finer.


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## Dave Spalding (Apr 16, 2008)

This is the new colour. On the left on first picture. Sprayed over grey primer on playing cards compared to old mix over the same primer. Second picture is new colour compared to bumper with bad match paint. Third is new paint compared to wing in the area it meets the bumper.

In people's opinions is this new colour a good enough match?























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## Barbel330 (May 3, 2016)

It’s going to be really hard to say looking at pictures on a screen as you can’t see the details. It’s critical to be able to look at it from different angles and and in different light. I wouldn’t want to say “yes that matches” then you paint it and it doesn’t look good against the wing.


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## Dave Spalding (Apr 16, 2008)

Thanks, I appreciate that its hard to tell. It certainly appears to match with the card pressed flat against the panel and moving the angle I'm viewing it from. 

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## SamD (Oct 24, 2015)

Looks a lot better, bearing in mind you have concentrated all of the metallic onto such a small card I would suggest buying a few correct spray out cards and give yourself a bigger area to spread out the colour.

Again I’m not sure if spraying onto card or paper would give you a true colour indication.


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## Dave Spalding (Apr 16, 2008)

Yes it is a bit hard to get a true representation on such a small card. I primed the card to give a neutral base. Hopefully it's OK.

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## Dave Spalding (Apr 16, 2008)

Another quick question on the subject of primers. I can't find overcoat times for any halfords primers. There doesn't seem to be technical data sheets. Is 30 mins enough time for primer to dry before base coat? I have some unpainted parts to do at the same time that will require primer. 

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## Dave Spalding (Apr 16, 2008)

Thought I'd update this with a picture of the painted bumper fitted. Colour match is a lot better.

Thanks to everyone for their help and advice

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