14 replies to this topic

[mike.]

About 6 months ago I sprayed a couple of my alloys, not got round to doing the other 2 yet but my car's nearly back on the road so need to sort them out.

The finish was fine and was good for what I wanted, but even though they've not seen the road yet, the paint has started chipping off from around the wheel nuts. Obviously caused by the wheel nut socket, but I was careful with it, it just seems to chip very easily and now they're chipped, the damaged keeps spreading.



I'm thinking I must of done something wrong during the spraying or the paint didn't take too well to the filler primer.

They were degreased, sprayed with a coat of grey etch primer, 2 coats of filler primer and then 2-3 coats of gloss black followed by a coat of lacquer.

Before the paint went on, I gave the dried filler primer a quick key with some 800 grit wet&dry but didn't go too mad with it.

So i'm going to try again, not decided if i'm going to strip the 2 painted wheels right back and start from scratch or not yet though.

Either way, i'm going to use all same brand paint as the filler primer didn't make much of a difference anyway. So i'll be using all simoniz paint: http://www.ebay.co.u...c#ht_2250wt_905

As its available cheap off ebay, so gona get 2 grey primers, 4 gloss blacks and 2 lacquers which works out about £30.

What is the best way to get a durable finish? I'm assuming I must of gone wrong with the prep somewhere, but if i'm going to the effort of starting again with new paint I want it to last

Any ideas?

[Mini-Mad-Craig]

I'd just avoid the filler primer for the final coat before colour and try red primer or something else, maybe you got a bad can

[mike.]

Yeah I only went for it because the surface of the alloy was quite rough, but it nowhere near covered it anyway. I'm hoping using all one brand of paint will rule out any compatibility problems.

[Alex_B]

I would key the high build up better, for my spotlamps, etch, highbuild, guidecoat and then take it down with a p350 soft pad and then a p500 soft pad, then black and lacquer.

Worked well on my Bmx which i sprayed last year, only chipped that once putting it back together and dropped it off the bench, but i did put a lot of lacquer on which helps add a bit of protection :)

[mike.]

Yeah I only did one coat of lacquer, maybe more would help.

I did see this too but its twice the price of normal gloss black: http://www.ebay.co.u...#ht_2404wt_1037

Whats the ideal paper to use to key the primer before paint?

[ryan22_lgm]

yeh i was going to what grade of paper did you use to key the primer up because looks like a lack of adhesion

[mike.]

I used 800 I think, but it really was just a quick rub over to remove any high spots or anything stuck in the primer.

[Alex_B]

I would use a p500 soft pad, really handy, enough grit to key up the surface correctly and the fact its a bit like a sponge it means you wont get finger marks from flatting which you will with just normal production paper.

http://www.fishermot...dflex-soft-pads

These are what i use, but they arnt cheap (i get mine from college, handy having a full paintshop )

[ryan22_lgm]

yeh p500 is perfect for flatting the primer down

[Alex_B]

But make it easier on yourself, when its primed just dust some black over the wheels and then you have a guide on how much to flat it down, when all the black is gone then you know that any low spots are gone and its smooth all over :)

[mike.]

mmm any idea if theres anything similar but cheaper? I'll have to have a look around

[Alex_B]

I will ask around at college, as those soft pads i could only find on a roll and the box is quite big and you wont need that many really its more for garage use, but i suppose you could glue a thin sponge to the back of a standard p500 sheet, then that way it will help with leaving finger marks and is cheaper?

[Alex_B]

Scotchbrite! that will be a cheaper alternative!

SCOTCHBRITE GRIT CHART
3M Scotch Brite Nylon Pads:
7445 - White pad, called Light Duty Cleansing - (1000) 1200-1500 grit
7448 - Light Grey, called Ultra Fine Hand - (600-800) 800 grit.
6448 - Green (?), called Light Duty Hand Pad - (600) 600 grit
7447 - Maroon pad, called General Purpose Hand - (320-400) 320 grit
6444 - Brown pad, called Extra Duty Hand - (280-320) 240 grit
7446 - Dark Grey pad, called Blending Pad (180-220) 150 grit
7440 - Tan pad, called Heavy Duty Hand Pad - (120-150) 60 grit

So you would need maroon then green i would suggest :)

[mike.]

Ahh yeah scotchbrite I was trying to think of the name. Can pick those up pretty easily: http://www.ebay.co.u...b#ht_500wt_1054

[AdamBilsy]

If your going to use simoniz paint, check your local pound shop, they sell grey primer, white primer and black gloss here all £1 each.