need info to spray car bumper

[DJ_B4L]

i got a dolphin grey metalic bmw i brought two spray cans from halfords they made them from the paint code i wanted some help

any body know what coour primer i meant to use under this colour

and was the best way to spray the bumper and get a great finsh?

as its a metalic would it require laquer

thanks

[mrLEE30]

go for a light silver primer but as light as possible.

remove the bumper from the car for best results, its better then masking.

what are you painting by the way? the bumper or the valance . if you are spraying plastic it will normally crack due to the flexing, you are supposed to add a plasticiser into the paint (normally only possible if you are using a spray gun) but that would only really be a problem if you were spraying something like the lower valance for a tech2 kit.

and yes metallic should have a clear lacqure coat.

first sand down the old paint with 200-400 grade wet sand paper to rough the old paint and allow the new paint to key (hold) onto something.
spray with primer two coats.use 1000 grade wet sand paper after the primer coats to flatten the paint, apply more primer coats if necessary (and filler to fill small holes/cracks etc), then spray with two good coats of final colour, and sand again in between coats. then one or two clear lacqure coats, with a final sand using 1000 or 2000 grade wet paper. then polish with polish paste and buff with wax and should look good.

as with all painting the final finish is proportional to the time spent doing it.
if you can do it in a garage it will be best as dust in the air will stick to the wet paint and ruin the finish. if possible damp down the floor of the garage with a hosepipe or bucket of water to stop any dust in there getting on the paint.

good luck

mrlee

[E30Mark]

go for a light silver primer but as light as possible.

I think you mean grey primer - make sure it's a primer ment for plastic!

remove the bumper from the car for best results, its better then masking.

what are you painting by the way? the bumper or the valance . if you are spraying plastic it will normally crack due to the flexing, you are supposed to add a plasticiser into the paint (normally only possible if you are using a spray gun) but that would only really be a problem if you were spraying something like the lower valance for a tech2 kit.

It's a bumper as per the title, like you said without a plastisiser mixed in the paint it may chip and crack over time....

and yes metallic should have a clear lacqure coat.

first sand down the old paint with 200-400 grade wet sand paper to rough the old paint and allow the new paint to key (hold) onto something.
spray with primer two coats.use 1000 grade wet sand paper after the primer coats to flatten the paint, apply more primer coats if necessary (and filler to fill small holes/cracks etc), then spray with two good coats of final colour, and sand again in between coats. then one or two clear lacqure coats, with a final sand using 1000 or 2000 grade wet paper. then polish with polish paste and buff with wax and should look good.

i would use more than two coats of the colour base, and only sand between coats if necessary, where in the world can you get 2000 grit wet & dry??? the lacquer will take a week or two to fully harden, polish it once it is fuuly hard / dried, otherwise it will just sink as the remaining thinners dries out from it. And never sand the final colour coat before applying the lacquer!

as with all painting the final finish is proportional to the time spent doing it.
if you can do it in a garage it will be best as dust in the air will stick to the wet paint and ruin the finish. if possible damp down the floor of the garage with a hosepipe or bucket of water to stop any dust in there getting on the paint.

Personally i don't like the idea of wetting down the floor, as when the water evaporates all it does is raise the hunidity within the area which can cause micro blistering beneath the paint... more of a problem when spraying metal panels...

good luck

Agreed!

As you can see everyone has there own opinion on how to do this! practise makes perfect.... i would be prepared to paint the bumper, then if it don't work out, to strip it again and paint it again until your happy with the results.

Don't be tempted to rush the job, leave plenty of time for this.

[DJ_B4L]

thanks for the info guys the bumper im spraying is my fibreglass reiger gts rear bumper

so i wouldnt need the palsticy spray thing on it i have made all the corners and bits hard by using sum fibre glass its really good and is vibration resistant . i brought a white primer some one told me that if i use a grey primer it make the final paint darker and wouldnt come out right

they said that you shoudnt use a grey with a grey not sure if this is correct tho.

[Widge]

Just for another opinion, I always wet the floor down to stop dust, but then it's a well ventilated area so the evaporation will get carried away and not cause a rise in humidity. And I don't leave the panels to dry in the same area anyway.

[drewjak]

i would take it to a local body shop it wont cost you much theyll match the colour for you and get a better finish than a spray can can ever get, plus they put plenty of lacquer on which will help keep the stone chips at bay? it worth the extra cost in the long run, trust me!

[DJ_B4L]

it was originally sprayed by a body shop but it got hit on the motorway in the third lane by one of those old skool metal petrol cans that carry around 20-40 litres of petrol

must of fell from some ones jeep or lorry the front bumper missed it as it came through the back it damaged the bumper and took off the exhaust sleeves i fixed the bumper and made it much stronger jus needed to spray it i might get it done frm the bodyshop

[Widge]

Heet man sounds like you were lucky it didn't come through the windscreen

People should get locked up for stuff like that.

[mrLEE30]

where in the world can you get 2000 grit wet & dry???

Bahrain!!! will try to get you a picture!!

wetting the floor will be preferable to dust on the paint

yes i meant a light grey couldn't think of the colour!!

the undercaot should not affect the final colour at all, if it does you are not putting enough top coat on, hence the idea of the primer being a different colour

never thought about not sanding the top coat, but thinking back i didn't dothat last time, but i did sand a few of the colour coats before the final colour coat, cheers for the good tip!!

mrlee
and if its fibre glass i will almoust guarentee cracking, get it done professionally if you cant get the right paint (hence why i asked if he ment the bumper of something different!!