[oliverhadi]

Hey guys.

Yesterday early morning I spent about an hour sanding down my rubbing strips....

Used grey plastic primer.....and waited a good two hours or so for that to dry...

Then used some silver and sprayed them up nicely.

I then let them set overnight indoors....and this afternoon I lacquered them.

As I was putting them back on the car...(incidentally....how do you do this! I cant seem to do it!)...

One end of one of the longer strips dropped off the clip and hit the ground.

Upon hitting the ground it tore off the paint and the black plastic was visible beneath.

I couldnt believe this.

I had a closer look and saw that it in fact peeled off! I rubbed it a little with my thumb and lo and behold it all came off!

It peeled right off!

I cant believe it....they looked so perfect......

Now what do I do?

Im just irritated that I spent 20 pounds on paint and such like and its failed.

I cant even seem to get the things back on the car!

Cheers

Oli

 

[AndBurG]

sand them back and get hold of some etch primer from your local paint shop, once sanded give them a clean up with some sugar soap to remove an grease, then spray the etch primer, 3/4 coats then leabe to dry for 24 hours ina warm place, then sand back smooth and apply another final coat, repeat then do the same wil colour and lacquer.

incidentally which band of primer did you used??

 

[Rec]

when you took the rubstrips off did you take off the door cards and pop the clips back through the holes? or did you pull the rubstrips off leaving the clips in the door?

if you did the latter of the 2 then there wrecked and you will have to glue them back on as when you pull them the clips bend the back of the rubstrip and wont go back on.

 

[oliverhadi]

I just unclipped them from the oustide!

Thats what I was told to do on here!

Didnt take the door cards off.

The clips are all fine!

Now Im worried.

It was Halfords Plastic Primer I used, Halfords Paint, and also Halfords Lacquer.

Wont be doing that again.

Oli

 

[Rec]

i started to do it that way but after popping the 1st one it didnt seem right! so i took the door cards off!

the clips on the inside are like arrow heads you have to squeeze them together to take them out of the door and release the plastic trim!

the one that i did pull off i took the clip out of the door and couldnt get it to go back into the trim at all! as soon as i tried it it just fell off!

i dunno if you could maybe glue them back onto the strip or something???
sorry mate.

 

[troy.mclure]

I thought that Halfords plastic primer was an etching primer? Wonder why it didnt hold well. Unless the surface was greasy maybe?

Or am I wrong about Halfords plastic primer being an etching primer?

 

[empsburna]

need loads more coats then by the sounds of things :s2h:

 

[oliverhadi]

I used two bottles of plastic primer and 2 bottles of paint!

Then a LARGE bottle of lacquer.

Defo not because I didnt use enough.

The clips are not squeezeable. They are simple clips.....just rectangular shaped....

Oli

 

[Rec]

I used two bottles of plastic primer and 2 bottles of paint!

Then a LARGE bottle of lacquer.

Defo not because I didnt use enough.

The clips are not squeezeable. They are simple clips.....just rectangular shaped....

Oli

is that the bit you can see left on the door of the car?

 

[E_T_V]

Simple answer is that either you didn't degrease or roughen the rubbing strips before applying the primer, and you definatly didn't leave long enough for the primer to set. Plastic primer takes ages to harden (at least 24 hours at ambient temperature). This means that the top coat sticks to the primer but the primer isn't stuck to the rubbing strip and the solvents remaining can't escape to the paint peels off at the slightest bit of damage.

Let the plastic primer cure for longer next time.

 

[E_T_V]

You don't need etch primer as that is for bare metal not plastic. It'll have no effect on plastic as it can't etch it!

 

[W4RDT]

You used 2 full cans of both primer and paint?
Way to much there, the paint will be so thick, it wont have had time to harden in the time you have completed the work.

 

[ashy]

I don't know what all this garbage about the clips is, but it's unecessary to take the door cards off and they won't be ruined if you simply pull the strips off. That's how most do it. The clips simply pull out when you turn them 90 degrees and they go back in easy as pie with a firm push. You need to put them back in the strips first before pushing them home in the door.

As for Halfords paint there is nothing wrong with it. Infact as far as tins go It's one of the best out there.I've never had a problem with it.

You must have used white spirit or turps on the strips before painting. These leave an oily residue that paint won't stick too. You need to clean the surface with a solvent such as electrical contact cleaner which is ideal and you can buy from Halfords for about £3.

You also need to key the surface first too, so the paint has something to grip.
A even covering coat of plastic primer is all that is needed, no need to go overboard. 3-4 coats should do it.

I've never waited 24 hours befor painting and I very much doubt bodyshops do either as they use heat to cure it.
You can do the same with a hair dryer. Leave to dry naturally for 30 mins then blast it with a hairdryer for another 10 mins and you should be fine with the paint on top.
This has 2 effects, one it will cure the paint and two, it will adhere better to the plastic.

If you do the same thing with the paint and then the laquer and then leave overnight it should be just fine.
I've done it this way many a time and not once had a problem with paint coming off. Not even on my skirts that get all sorts of crap on them.

 

[oliverhadi]

I left the primer to harden for at least an hour before painting though.

This is what I dont understand.

I did my fog surrounds (which are the exact same plastic) in exactly the same way and they have been totally fine.

I did however...use MG-Rover paint with them and not Halfords.

Ashy....what do you mean key it? I dont want an uneven finish....

I sanded them down......then wiped them down with a damp cloth...and then let them dry before putting primer on them.

I really dont know what Ive done wrong with this one....maybe too much paint?

But they didnt look that over-painted to me. It was a pretty nice finish before I realised you could peel it off lol.

Cheers

Oli

 

[ashy]

Keying means rubbing the surface with grit paper so it's not quite smooth. Paint doesn't like smooth surfaces. Primer will easily cover this up.

 

[E_T_V]

Yes as said above pros use heatlamps and low bake ovens to speed up the paint curing process. Plastic primer is very different to normal primer. You need to put it on thin and one or two coats is enough. You need to let each coat dry completely before applying any other coats. I had EXACTLY the same problem when I sprayed some wheeltrims. In the end I couldn't be bothered to wait for the plastic primer to dry on all of them so I just used normal primer instead on a few and all was fine. What has happened is the bottom coat is still fluid and the top coats have hardened on top of it. If you try rubbing the paint sometimes you can get it to wrinkle or even slide off the base.

Either use heat to help cure the primer as it takes ages for plastic primer to dry or leave them to dry for a couple of days in the warm somewhere. Normal primer on a warm day is ready to spray over in 30-60mins whereas plastic primer isn't.

 

[oliverhadi]

Ok guys cheers...

Ive just been out the back and sanded them all down (again)....

And got all the remaining paint off them.

Ive plastic primed them and left them in the garage....

Ill check back on them in a couple of days and spray them up and leave them for another day.

Gonna be patient this time.

Cheers for all your help.

Oli

 

[chiefgilray]

best thing to do is sand down the plastic, prime it then use a fine sand paper and lightly go over the primer, then put a second thin layer of primer, I sanded don every layer of primer and paint apart from the final coat(3rd fine coat) and laquer (2 coats) and got a gorgeous flawless finish, I took my time 3 days but its worth it in the end, just mind and be sparing with metalic paint one bad move and it'll go tits up

 

[technozen]

Not all plastics are the same, it's impossible for one primer to cover all the types.

Most of the professional plastic primers musn't be allowed dry fully before the basecoat is applied.

Two tips, buy a 5 litre can of cellulose thinners and use this for cleaning, also there is a wonderful (and cheap) product called Easikey which takes all the effort out of sanding, it's a very abrasive powder that you apply with a damp cloth.... about 5 mins to prep a side strip.

 

[aboard_epsilon]

Etch primer contains phosphoric acid and is meant for bare metal.

You need to wipe them with a solvent called, pre-paint wipe/panel cleaner .......about £14 a gallon
available from your local car paint factors ...who will deliver it to you for free ,when you buy it off them .most do.


Without this ,water will leave a smattering of lime scale on the surface.

Remember my pictures of a few days ago ..........looks like there is a knack to this ........and the secret is held by a professional painter .......who looks at this forum.................perhaps the plastic is incompatible with any paint.........some plastics are naturally greasy.

When I manage to power wash the rest of the paint off mine, they will be treated to a coat of shoe polish when ever they become dull.


all the best.....mark