As the title says, I'm interested in knowing what type of plastic sheet material will be easiest to paint with automotive paint. I realise that with the right primer and/or plasticiser you can probably paint just about anything, but I'm sure some types of plastic will lend themselves more readily to the task than others. Ideally I want to be able to paint everything on the bus (ie. steel, aluminium, & plastic) in one go, rather than having to mask off the plastic and treat it separately, with all the risks of colour differences etc that might cause.
I remember from my modelling days that paint wouldn't stick properly to lexan / polycarbonate (or would flake off due to flexing), and certain solvents would melt ABS. Does anyone have experience of applying paint to any of the other commonly available plastics (polypropylene, acrylic, PVC etc)?
Jeremy
Jeremy,
Do you have any snmall scraps of the same plastic that is on your bus that you can experiment with? or can you get some small pieces? Jack
As you said most any plastic can be painted with the correct preparation and additives. Fiberglass, Carbon Fiber, and SMC are the most similar to metals in the refinishing process. The more flexible the plastic the more important that you use the proper primers and flexible additives. Your best bet is to avoid an plastics from the olefin family as they actually feel oily and are the more difficult plastics to get good adhesion on. If the plastic is flexible and needs a flex additive you can add the flex additive to all the paint. This can be a benefit especially on an aluminium surface it will expand and contract a little better than without. The flex additive will also add a little additional adhesion characteristics to the paint as well as as little slower dry time which will give a little better flowout of the finish. It will also resit stone chips and bugs a little better.
Hope this helps
Tom
The folks at PPG - told me that LEXAN actually paints better than almost anything else - including new car bodies
They were right - I painted 4 frameless lexan windows (Older RTS STyle) on my RTS - They Still looks perfect
JackC:
There is some (unknown) plastic on the bus that is currently unpainted but which I wish to paint, but also I want to add entirely new plastic as well (basically, there are existing plastic strips several inches wide covering the gaps between the windows, and where windows are being moved or removed I want to add-to and/or replace the existing strips with similar but wider ones. This is flat plastic sheet, not a 'moulding' of any sort).
Tom:
Sounds like good advice - does the 'olefin' type include any of the commonly available sheet plastics? I can imagine engineering plastics such as delrin or self-lubricating nylon would have those properties, but obviously I'm not planning to use anything like that
I have used the plasticiser / flex-additive stuff when painting boats before, but I'm not sure if it has any 'downsides' - is there any reason why I couldn't paint everything with paint that had treated like that?
RTS:
That's interesting as I would prefer to use polycarbonate if I could. The specific situation as I remember it with regard to painting lexan was that most paints would simply fall off, but some paints (particularly cellulose) would chemically alter the lexan and make it very brittle - lots of horror stories about bikers getting their lexan helmets custom painted, then having them shatter in an accident.
Jeremy
Jeremy
If what you are looking for is flat panels I think your best bet is Fiberglass.
As far as Flex additive in the entire paint job, the only down side is the gloss level is a little less, but unless you are going for a Show Car finish I don't think anyone would ever see it.
Tom
A good scuffing with 220 grit,DP primer finish sand ,and shoot .if the primer sticks so will the paint.Good luck
It is better if you are inquiring to those who are selling reliable and well – known automotive paint. The fact that most of the plastic did not accept this paint and it will be useless. You can bring the plastic that you wanted to paint and the seller can give you a best option.
If Lexan accepts paint well, I would stop right there. Lexan is very easy to work with, the main drawback in it's typical use is that it hazes and micro-scratches somewhat easily so you can't see through it perfectly. Problem solved if you paint it in the first place! It is very easy to work with, I use my bandsaw to cut it and shape it with wood rasps, drill with normal drills (other plastics shatter when drilled with a normally sharpened drill). You can bend it easily, and it is strong as the dickens. I think painted Lexan would be perfect for your application. FWIW I use it to make race car windscreens.
Brian
Jeremy, I went through this exercise this summer when I painted my golf cart as part of the body is "plastic".
You have to use an "adhesion promoter". It comes in a spray can )as well as in a can)and is like primer. It apparently softens up the plastic so paint will adhere. Very easy to use and works well.
You can read about it here
http://www.buggiesgonewild.com/body-paint/22929-prep-work-painting-plastic-bodies.html (http://www.buggiesgonewild.com/body-paint/22929-prep-work-painting-plastic-bodies.html)
Ditto what Fred Mc said, I have used it a lot and it works great.
Ray D