LEXISM

iTrader: (2)

I had my rear bumper re painted a couple of months back and when I got it backI noticed it had a bit of orange peel ....not alot but it has some... I was wondering what is the best way that I can have it taken off? I dont want to take it back to the shop

toy4two

wet sand it, easy enough to do.

picus

The only way I know of to do this is to color-sand. The problem with this, regardless of whether or not the paint is single or two stage, is that it can compromise the integrity of the clear coat (or the enamel in the single stage paint), and you'll get fading and oxidaztion. I've done a lot of wet-sanding on paint chip repairs (which doesn't really help op) and color-sanding *while* painting, but would not attempt a color-sand after the fact.

If the paint is single stage you could try it (I believe some folks over at my.is have), but I would seriously consider investing in a paint thickness gauge before I did, or you might find yourself getting another repaint soon.

LEXISM

iTrader: (2)

there is no way of being able to get rid of the peel w/ my porter cable ?

jfelbab

I'd take it back to the shop and make them wetsand and respray the clear. By sanding the clear you are running the risk of damaging the cc. Much of the UV protection is right at the surface of the cc.

Guitarman

As mentioned, it's a risk that isn't worth taking in your case, unless you decide to have it resprayed again at some point.

If the orange peel doesn't match the oem paint texture (which DOES have some orange peel) then the only real way is to block wetsand it, at the risk of the paint's longevity. The time to decide to do it is BEFORE the painter paints, so you can agree to spend a bit more $$$ on an extra coat of clear, which will be sanded off in the process of eliminating the orange peel. Then the ratio of removed material vs UV inhibitors won't be excessive.

If you do it, or have someone do it for you, 2000 grit and as few passes as possible to match the oem paint is key. Don't try and remove ALL the O/P. The rule is not to remove more than .3 of 1 mil of paint (clear or pigmented, doesn't matter) and the only way to know if you've done less than that is to measure first, as mentioned by Picus. You will still be likely shortening the lifespan of the bumper's paint, but just how much involves too many variables to say for sure. Sun load, amount of the UV inhibitors removed , wax or sealant used and how often will all factor in.

Is the O/P texture THAT excessive that it sticks out against the body panels paint?

933005spd

Just a quick note on UV break down of coatings....

Photodegradation involves multiple steps. You need a combination of UV light absorbers and Hindered amine light stabilizers to achieve optimum coatings protection.

You cannot 'remove' uv inhibitors from paint (unless you have a UV magnet.. lol) by polishing, compounding, washing whatever. You remove paint.

If you did not have UV resistant base coats, your clear coat - regardless of how robust - would delaminate. Of course you need the UVA AND HALS in the clear also because it protects the underlayer while protecting the topcoat from embrittlement - helping to maintain its adhesion to the underlayer. Ever since water borne systems became prevelant in industry, the orange peel of coatings has increased. Cheaper formulations have worse flow.

If your unhappy with the finish, have them do it again and do it right.


Also, for what its worth, most gloss loss is caused by the degredation and subsequent erosion or pitting of the coating polymer at the film surface. This leads to the exposure of pigment or filler particles at the surface, resulting in light scattering. In clear or tinted coatings, you will encounter micro cracking at the surface which affects the gloss.

I might not be able to paint worth a darn, but I can tell you whats inside the can, or box.

toy4two

No, not strong enough. I have tried multiple compounds, even the harshest with yellow cutting pad. Gotta wet sand, just get some paper and block, dip it in water and off you go. Then PC it to get the shine back.

Guitarman

Sorry to say, but you're incorrect there 3005 speed. Look here, this is supported by all the vehicle manufactures and is distributed to the dealership techs and also inside the warranty info book. Nothing new here. In fact, this thread on Autopia takes a direct quote from the BMW warranty booklet;

http://autopia.org/forum/showthread....ighlight=ketch


What you're missing is...if you're removing PAINT, you're removing UV. Simple as that. The UV is IN the paint.

933005spd

Perhaps, mr. guitarman you misread...

I was not wrong, that is what I was saying is that you remove paint. That you cannot remove uv inhibitors I belive that was clear when I wrote:

I have managed and led dozens of degreed paint chemists. Some with PhD's
I started up the paint business and led it to a multi million dollar unit for a fortune 200 company.

I wrote a published a uv paper in conjunction with Ciba - the leading supplier for UVA's and HALS. Published in Paint & Powder in 2002, Another paper I wrote about exterior weatherable coatings was published in Powder Coatings and presented at the Waterborne Symposium

Unless you know what a UVA and HAL is, please do not run around quoting techs and dealerships. We all know what experts they are.

Oh, and by the way, I have two different film thickness gauges mentioned in the link. I own them, not the company. I also own a hand held spectrophotometer. Just because the film thickness is up to par, it doesn't mean that you will have good UV resistance. Especially if the paint vendor uses only a UVA in the clear and no UVA or HALS in the base coat.

Guitarman

1).Please check your ego at the door.

I stand on what I posted for the good of the members her to understand the process and the "cause & effect" on their paint. Your tone is unwarranted, you need to come here and be PART of the discussion and respectful in your manner, and I won't warn you a second time about that..

I am not new to this, and you may think you know it all about paint , but a cocky attitude is not needed here. I'm a very good guitarist actually, but I don't profess to know everything about playing it, and I can always learn something from others. I can spout credentials as well, but we don't need an "ego war" here. That won't help CL as a group.

So...Remove paint and you remove UV. That's really all they need to know to prevent them compromising the longevity of their paint. We don't need to get into semantics (we already have actually) on the meaning of words.

BTW, I have NEVER had to do this in this forum before. This thread is closed, the info is sound and hopefully helpful. Next time, try the proper attitude before you disagree with something, you may get further and win others over.