help needed with automotive

[HF AIRBRUSH]

hey guy's..
ive got some problems...
ive painted my zundapp but there seems to be something wrong with the way i painted it...
i sanded everything and sprayed it in primer...after this i painted everything in color ( all spray can's)...
after this i painted the art with my airbrush ( createx )
and at last i used 2k clearcoat...looks all very nice and im very proud of it...
but today i made my first ride with it...and the zipper of my jacket damaged the paint????...
the paint came right off and you can see the metal??

tell me...what did i do wrong?....

henk

[prepsage]

What kind of paint was in the rattle-can? Was the Clearcoat rattlecan as well? I'm no expert but I would chalk it up to either one of those two.

-Warren

[HF AIRBRUSH]

the rattle can's are from a well known brand here in europe...they are from Motip...
and the clearcoat is from Colormatic...this is a 2K clearcoat...you must mix them in a spraycan...it always worked great.....but somehow not this time...
the paint is not fresh or so...it's painted a few months ago....so it should be dry enough right now...


henk

[AlpineAirbrush]

Havn't done any automotive myself, Henk, but I would sugjest you post this question in the forum at http://www.airbrush.com/ . There's lots of folks that do automotive over there, and quite a few that work with the Auto-Air paints.

[HF AIRBRUSH]

sorry....not my kind of people...

henk

[joe_jones]

Did you mix up the 2K clear or did the pait store mix it?
I didn't think you could get a 2K clear in a spray can.


Joe

[HF AIRBRUSH]

http://www.motip.nl/

the rattle can is with a small rattle can....you schould put the small one on top of the big one...this way you mix them....just shake and you got 2K clearcoat ready to use...

today i degreased it and sprayed a second clearcoat on it.....


henk

[joe_jones]

is your clear still soft? can your leave an impression with your finger nail?

More clear won't help if the type of clear is staying soft.

I could find and info about the clear on that site.

Joe

[prepsage]

I found this on airbrush.com which might explain it...

One erroneous idea I hear normally intelligent people often say is that they can use any primer for any paint. And example would be the use of "rattle can primer", which is often lacquer primer. True, you can use it to prime for waterbase but you'ld better let it cure a day & SAND it! Only lacquers have the chems to bite unsanded lac primer; waterbase will just sit on top.

[HF AIRBRUSH]

the clearcoat is very hard and you can't scratsh it with your nails...but when you drop you key on it or maybe even a coin...the paint jumps off...and you can see te metal...
so as far as i can see is that the paint is good on the primer and the clearcoat is good also...otherwise...if the paint isn't good on the primer you would see primer...and not the metal...at least thats what i think....

the primer is good and the laquer also..this is the same brand and made for eachother....even the manual said i use these...
the thing is that i used it more..and never had any problems....so what did i do wrong this time ?

henk

[joe_jones]

What grit did you use to sand the metal with?

Joe

[prepsage]

I think you're on it. Sounds like something went wrong in the first few steps. The paint doesn't sound like it's holding onto the metal. Or at least the primer isn't. Did you wetsand the metal before this? Was the metal cleaned? Was it dry?

If this is case, I wouldn't go and strip down the bike again. I'd ride it out until it gets bad enough to warrant another paint job.

[HF AIRBRUSH]

i sand it with dry paper nr.1200
i sure won't strip it down....ive been bussy building this zundapp for a year now...so i will ride this year and wait till it isn' t prettu anymore...till then i will enjoy the ride :cool:
here's a link to it...http://home.wanadoo.nl/hf-zundapp/prj.htm
sorry it's in dutch....but there still great pictures to show how i did it.. ;)

henk

[joe_jones]

you use 1200 on the metal?

1200 is used before polishing. You need something more like 240 before primer.

Joe

[HF AIRBRUSH]

:( but i used it before....would you think thats the problem?...
i will try it next time......

henk

[joe_jones]

1200 is way to fine for paint to grab on to.

I would use 80 or 100 before primer then sand it smooth.
and work up to 400 then spray your base, then clear.
then you can use your 1200 to knock down dust in the clear
and runs to get your clear flat then 1500, 2000 and the polish it.

here's some info on sandpaper http://www.autobodystore.com/material1.htm

Joe

[prepsage]

I heard 320 wetsand.

That's what I used on the helmet.

[billiam]

i was surfing ab, the zundap pictures bring back memories of when i worked at a motorcycle shop almost 40 yrs ago. one was with us when i got my first speeding ticket. life was great then. i like the indian maiden and wolves. scuff and rough it up good the next time. bill

[HF AIRBRUSH]

hey bill, sure they are great and bring back memoiries...when im driving it feels like im 16 again...hahahaha...
about the sanding....i think that it could be the problem...but wet sanding isn't a option...on bare metal i don't use any water.....

henk

[prepsage]

ooooh right! *slaps forehead...

[Rodman]

seems to me that if you drop a coin on it and the paint pop's off....then....the adhesion problem would be on the last layer that did'nt pop off...understand? for helmets and harleys...i hit them with wet and dry 600 grit(wet)....I use a automotive rattle can primer...house of kolor paints...automovive clear....Rod-Man

[HF AIRBRUSH]

yes i think it's in the sanding....the paint jumps of from the bare metal....but sin's im using a very good and proffesional primer i thought this could not be the problem....so i will try sanding with another grid next time....

henk

[Penny220]

One I wouldn't have used rattle cans but here goes...
Is the bike aluminum? If so, that's the problem from the beginning. Here's the stages, see if you missed something.

1) sand and do any body work

2) prep-sol

3) prime - self etching sandable primer

4) wet-sand, prep-sol, re-prime and repeat if necessary otherwise after prep-sol and tack cloth...

5) paint selection of paint is important, recently I tried to paint an acrylic over rustolium and I had problems, be sure to spray same type paint as primer. As before wet sand, prep-sol, tack cloth and repeat as necessary.

6) wet sand, prep-sol, tack cloth repeat as necessary then paint. I don't make a secret of what I think of using a waterbased paint on automotive but the choice is yours.

7) denatured alcohol or prep-sol and clear coat making sure that clear coat is compatable with color (base) layer of paint.

If the paint is cracking/chipping off I would think the problem occured in the metal to primer or the primer to paint stage. It sounds like your clear coat adhered well enough.

[His Painter Airbrush]

Hi Henk,

I have used Createx on automotive before but I prefer using urethanes now on anything automotive or hard surfaced. (House of Kolor and PPG paints)Urethanes seem to be made to adhere to metal much better than waterbase. (IMO) Createx has a line of Auto Air paints that I have used also. The newer ones are supposed to be better than the old line of paints....I haven't tried their new paints yet. I also use a mask for organic vapors and latex gloves when handling urethane paints because they are very toxic.

Did you use a degreaser? I use PPG330 DX to degrease, wet block sand, then and paint. I send it out to be clearcoated by an auto body shop nearby. If you have a local auto body shop nearby, maybe check them out? Do panel tests with metal sheets and find out what works before you do your work on something more expensive. That's what I did.
http://www.hispainter.com/eagletailgate.html

Sometimes you do get what you pay for with paint. Rattlecan clearcoats are what I used to clearcoat a kids helmet after doing artwork on it that I knew would last only a season tops.

[HF AIRBRUSH]

hey hispainter,
looks great....i don't have any problems with the createx on cars....and i don't use createx on bare metal....i used a good carpaint first...but thats were the problem is....just with the primer or the carpaint....but i think the problem is indead with the sanding and the primer....

henk