respray problems?

[mugen_ctr]

iev resprayed my lip twice now, over the last 6 months because it keeps on chipping an cracking... is there something iev done wrong?

steps iev used are sand 400, 600, 800 than 1000 grit sand, primed an 4 layers of paint, an 2 layers of clear...

ps its a oem sir lip so not the fake lips

[julian_s13]

Have you got old paint underneath it?

[sxmachine]

Best advice I can give u is rub all the paint off take it back to plastic
Primer it 4coats
Next day rub it 400 than 800 wet
Wax and grease remover it wipe on wet, wipe off with a dry cloth.
4 coats of paint or if more is needed for coverage give it 1 or 2 more....
2 coats of clear if it was me I'd give it 3 coats of clear for nicer finish

[mugen_ctr]

Have you got old paint underneath it?

Iev always sanded it back down to plastic before starting again

[Bulbasaur]

try primer it probably isnt sticking to the plastic. primer just goes on like normal paint after you sanded it and before you painted it but it also needs to be sanded smooth again before painting over.

[grifty]

it because you didnt use primer, without primer the paint has nothing to stick to.

[flipfire]

what products are u using?

make sure you use plastic primer

[mugen_ctr]

i always prime it before painting it :)

been using that 3m stuff from supercheapauto, paint an primer

[aznstyler]

are you using the right paint?

[GSi_PSi]

maybe ur just scraping the lip, cause thats what happens when it gets bumped,

[jdm_b16a]

I've just painted two items - a new plastic rear lip, and both sideskirts off an EG5.

I used 3M Plastic Primer

http://lasoomedia1.com.au/imageicon/SCA/PROD/J00510496/C_001/Page_001/SCA_PROD_J00510496_C_001_Page_001_i220351.jpg

On the unpainted rear lip. I cleaned up with W&GR, then primed with above, then applied two coats of Acrylic Primer, then colour coat.

Result was that the colour coat cracked and just lifted off the surface. I think my mistake was applying the acrylic primer.

I also did the two unpainted sideskirts. I sanded lightly, cleaned with w&GR, applied Plastic Primer - three light coats over about an hour (allowing generous drying time inbetween). I then sanded lightly and left it overnight.

Next day I applied colour coat - no acrylic primer.

Colour is good and paint had adhered nicely.

My conclusion - clean the plastic well, sand lightly between coats, allow plenty of time for each coat to dry, and apply colour coat lightly as well, and again, allow plenty of time to dry between coats. Don't rush.

If you find it's still not adhering, then there may be something leeching out of the plastic. Alternatively, try this product (or similar):

http://www.getprice.com.au/images/uploadimg/1277/350_220352.jpg

Peter

[quangsuke]

best bet is its ur primer that ur using. its not letting the paint stick.

[mocchi]

it keeps on chipping because it's laquer/acrylic paint. it's weak. esp. on the battlefield. (bonnet, front bar & lip)

ideal: get full face mask with independent filtration system (not bayonet type filters), and paint it with 2k/urethane paint in sealed environment.

real life: full face w/ separate filtration cost thousands, so go to shops and get them to paint in urethane.

urethane paint is much more chip resistant and durable. acrylic isn't.
acrylic is cheaper to use, urethane isn't.

bish bash bosh.

but cracking does seem to be adhesion problem. so you should listen to the gurus above ^


edit: you sanded the bar with 400 - yada - yada - 1000 grit? after the 1000 grit you then primer it?

1000 is too smooth for paint to grip. sand with 400 then primer, and base colour.
after base colour then you sand it smoother to reduce orange peel. or sand after clearcoat.

[mugen_ctr]

thanks people, ill give all the ideas a try when im free to do another respray, helps alot... im starting to think it is the primer, but i wouldnt know for sure, guess i gotta start all over again.. do it once do it right

as far as im aware, the car sits high enough to not get scraped in my drive way lol, so thats sorta a relief, but checking underneath it does get scraped a bit, but the occasional back road an freeway drive does get rocks flicked up at it

[MWAKU]

maybe its how ur painting it, do you do one light layer for the paint to get sticky, and then put on proper layers after that?

[mugen_ctr]

yeap, one light layer, than after than 3-4 full coats of paint

[CVCEM1]

hey dude, theres heaps of techniques people use to prep and paint, but from my experience in a panel shop what we do is.
is it back to plastic make sure you apply plastic adhesive, then hi-fill/primer.
after primer, guide coat black then use 320 to get rid of the guide.
then 600/800 wet...
then prepsol/wax grease remover make sure theres no silicon floating around or you get trouble in the results of your finish.
and if your doing a backyard, dust you cant really help it.
but make sure temperature is warm enough for a decent finish.
first light coat..
then 2 and 3
fourth if need then continue with your clear. give it intervals between coats...
good luck..
i got a couple of jobs to backyard this summer! cant wait to get my compressor out and paper trolley and my spray gun gunna be a fun diy in the backyard.

[dougie_504]

I use K&H matte black paint with some cheap primer. All my mates and I are having the same issues, but I think it's because we've put on too much paint.