Need some help

Dimitris

Mac-Valve Maestro!
Hi everybody,
a while ago I practised on a friend's plastic front part of his scooter...and things didn't work out as expected :D:Dlol, no adhesion promoter, just scuffed, painted and clear coated.

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Yeah you can laugh as much as you want and make funny jokes, no problem there, I did! :D:D:D

But now I need your help! How do I remove all this junk from a plastic and repaint it? I mean I know there has to be applied a adhesion promoter, then paint it, and then clear coated right? But the main issue is how do I remove all this to bear plastic again?

Didn't get any money for this, he volunteered so I can practise, so no hard feelings for it. Just want to do a clean lasting work on it! Thanks in advance!
 
Well, since it's on plastic and chipping, how about just continue to chip and peel it away? Wouldn't want to use a solvent or paint stripper. It will most likely melt the plastic too. Maybe sanding or scrubbing it down to the plastic is the best solution. Just my two cents of advice.
 
Well, since it's on plastic and chipping, how about just continue to chip and peel it away? Wouldn't want to use a solvent or paint stripper. It will most likely melt the plastic too. Maybe sanding or scrubbing it down to the plastic is the best solution. Just my two cents of advice.

Thanks Hellbird,
to tell you the truth, I wanted to avoid sanding it cause it's boring! :D:D:D
Paint stripper it's a no-no so I think I just have to face the concequences...damn, it's boring...
 
You could try "sand blasting" with silica or aluminum oxide beads instead of sanding, but you have to have the right set up, mask, and be very careful. It will bore holes in plastic quickly. Not stuff you or anyone else want to inhale any more than urethanes and 2k clear coat either!
 
I would sand it. It wont take that long to do albeit boring it will be the safest way to remove it. You need it right back to the plastic to prep it properly so you can paint it again. If you don't you will have problems when you repaint. You can guarantee that if you leave a spec of old stuff it will bite you in the arse and peel. So back to plastic, give it a good wash with warm soapy water, wax and grease remover and maybe even tac rag it before adhesion promoter then primer. From there you can do your artwork and clear as necessary.

Lee
 
I’ll put another vote for sanding. Blasting would be so much quicker, but Id almost certainly shoot holes through plastic LOL.


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I would sand it. It wont take that long to do albeit boring it will be the safest way to remove it. You need it right back to the plastic to prep it properly so you can paint it again. If you don't you will have problems when you repaint. You can guarantee that if you leave a spec of old stuff it will bite you in the arse and peel. So back to plastic, give it a good wash with warm soapy water, wax and grease remover and maybe even tac rag it before adhesion promoter then primer. From there you can do your artwork and clear as necessary.

Lee
nice jord, thanks.
About the primer, I got from the store one for metal and one for plastic. I used a little bit (plastic primer) on a scuffed piece just to see how it performs but was like spraying paint on an oily surface. Haven't used primer for plastic and have no idea how it's supposed to be. Any vid to educate me? :)
 
Sorry @Dimitris no vids, but i'm sure there are some. Try Frankies Speed Shop on youtube https://www.youtube.com/user/BackstreetCustoms He's done a lot of videos on how to prep, prime, paint, clearcoat etc.

What I have said is just what I would do. I'd also work in light coats with the primer after you have used the adhesion promoter to give it chance to adhere properly. This is also why I would wash with warm soapy water and use a wax and grease remover.

Lee
 
I’ll put another vote for sanding. Blasting would be so much quicker, but Id almost certainly shoot holes through plastic LOL.


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Yeah, I just threw that out there because I have seen it done. Guy where I worked one summer was in a hurry and the first areas he worked on sort of resembled a concrete wall that someone had taken a machine gun to! lol Once he figured out less air pressure was needed, things looked better.
Not sure it saved that much time either because of all the goofing around with the gear and the clean up afterwards. Couldn't really say anything since it was the boss of the company doing the work! :whistling::whistling::whistling:
 
Yeah, I just threw that out there because I have seen it done. Guy where I worked one summer was in a hurry and the first areas he worked on sort of resembled a concrete wall that someone had taken a machine gun to! lol Once he figured out less air pressure was needed, things looked better.
Not sure it saved that much time either because of all the goofing around with the gear and the clean up afterwards. Couldn't really say anything since it was the boss of the company doing the work! :whistling::whistling::whistling:
Haha, machine gun look would definitely be my style LOL.


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Seems like what you have is injection molded ABS, but look for the marking on the back somewhere, theres a chance its HDPE.
If it is ABS;
Sand, Clean with alcohol, spray with regular old lacquer primer for metal.
Like Tony said though, go in light layers, acetone (which will almost certainly be in your primer) attacks ABS. Thats good for making it stick but a heavy wet layer will cause damage
Id skip the adpro.... since the S is for styrene its one of those plastics that the wrong adhesion promoter can easily do more damage to than good.

If its HDPE you'll need to change your plan of attack entirely. Heck, even newly made vacuum formed ABS I would treat differently.
Most scooters ive seen have a mix of ABS and HDPE panels.

Your primer should spray on no different than if its going on to metal....if it looks different then something is wrong.
 
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Got it @Robbyrockett2 , thanks. Searched the back of the plastic but nothing's written on it. :( I'll try primer first since it's a hard plastic, it doesn't bend or anything...And see after a couple of months what will happen... there may be a 3rd time, who knows...
BUT still, you all have given useful info as always which will definetely be useful in the future!
 
Got it @Robbyrockett2 , thanks. Searched the back of the plastic but nothing's written on it. :( I'll try primer first since it's a hard plastic, it doesn't bend or anything...And see after a couple of months what will happen... there may be a 3rd time, who knows...
BUT still, you all have given useful info as always which will definetely be useful in the future!
Seems you already know this but;
If its light and hard its probably ABS. HDPE is pretty flexible, also doesnt sand real well.

On ABS that im sanding i usually only go to 320grit then primer then 600 until fine lines show then primer again but thats just how i like to do it. Seems like it would give better tooth but ive never tried another way that I can think of so IDK if its actually better than normal.
 
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