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plastic polish on lexan?

Posted: Mon May 14, 2007 11:36 pm
by badhoopty
i am teh suck when it comes to painting bodies... i can trim and mount them killer, but when it comes to painting them i always blow it at some stage of the process...

i got overspray on my dahms buggsy body, so i tried alot of things to get it off. the last thing i tried was a scotch brite pad. i knew it was gonna scratch and dull up the body but thats a heck of alot better than silver overspray all over it. its a runner anyway...

anyhoo, any of you guys have any recommendations on how to get it somewhat shiney again?

Posted: Mon May 14, 2007 11:50 pm
by MelvinsArmy
Hopefully I'm wrong, but I'm pretty sure Lexan is extremely difficult to polish smooth again. At work we had a piece of art that had was framed with Lexan instead of the normal Plexi, and it had a huge scuff mark on the face. We were told it would be nearly impossible to get the scuff out, that it would have to be done by a professional plastic man with a buffer, and even after it was done, it would likely have a wavey surface. Lexan is very hard and difficult to polish. Or so I've been told.

Posted: Tue May 15, 2007 12:40 am
by justinspeed79
I have tried to polish lexan before with mediocre results. I found that a large diameter cotton polishing wheel at slow speed with red with red jewelers rouge will give it an OK finish, but nowhere close to new looking, it still has a cloudy look. There's probably a better way to do it, but that's the best way I know of. Hope that helps.

Posted: Tue May 15, 2007 12:52 am
by scr8p
we have a polish at the shop that we use to buff plastic heads lights. seems to work pretty good. i don't know the name of it off the top of my head, but i'll find out. you probably shouldn't have used a scotch brite pad to clean it off. i'm sure it put some wicked scratches in it, even if it doesn't look like it did. some very fine sandpaper would have been a better choice. and much easier to polish out.

Posted: Tue May 15, 2007 1:11 am
by shodog
I've used mothers polish and a buffing wheel and I got good results. you have to be really light on the touch otherwise you will melt the body.

In the future, Nitro fuel will easily remove any overspray you have. I have used it several times with excellent results. you should have seen the knarley bleed I fixed on this body

Image

Re: plastic polish on lexan?

Posted: Tue May 15, 2007 3:50 am
by Whiskers
badhoopty wrote:i am teh suck when it comes to painting bodies... i can trim and mount them killer, but when it comes to painting them i always blow it at some stage of the process...

i got overspray on my dahms buggsy body, so i tried alot of things to get it off. the last thing i tried was a scotch brite pad. i knew it was gonna scratch and dull up the body but thats a heck of alot better than silver overspray all over it. its a runner anyway...

anyhoo, any of you guys have any recommendations on how to get it somewhat shiney again?
Next time you get overspray, let it dry and then hit it with "Brasso" polish or something like it.

After the scotch brite pad, you might have to do what I just got done doing, start with 600 and go to 2000 grit, wet sanding, and then polish your arms off.

Posted: Tue May 15, 2007 7:51 am
by Eau Rouge
Save the nitro fuel and other stuff to take off overspray. Go to Home Depot or Lowe's and pick up a quart of denatured alcohol from the paint department. While you're there, walk over to the cleaning/janitorial section and grab a cheap spray bottle or two.

Denatured alcohol is a MUST HAVE in the workshop. I draw out paint schemes sometimes on the outside of bodies with Sharpie markers, and remove it later with the alcohol. I also use it as a pre-paint body prep as well. It will remove all paint from hands, bodies, parts, and WILL NOT HARM LEXAN at all. I use it to clean just about everything, including my hands at times.

As far as the scratches, the Scotch-Brite was, as my grandfather used to say, pruning a rose-bush with a chainsaw. Extreme measures for overspray, and you probably indefinitely left pretty deep scratches in the body. There is a plastic polish system by a company called Novus that uses three different levels of polish to remove pretty hefty scratches from plastic. I've used it on everything from paint finishing on model cars to my iPod to Lexan bodies to sunglasses. It works pretty well, unless the scratches are massive.

I have polished up used race bodies with it before a Concours and had people think that the car wasn't used in the race before. You can see the Novus line here, though you can find it for purchase at a lot of places. I would recommend the whole system in the small bottles—it will last you forever.


BTW, these bodies were painted and faded (where you need a perfectly clean surface), using the denatured alcohol as final fingerprint removal and prep...

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Posted: Tue May 15, 2007 7:59 am
by Eau Rouge
Oh, and I should mention... don't smoke around denatured alcohol. It's like methanol in that it burns CLEAR flames. Could be a potential problem in the workshop if you start a fire that you cant see.

:shock:

Posted: Tue May 15, 2007 9:48 am
by templeofspeed
Novus is great stuff! There is one other technique for polishing plastics, although it can be potentially disasterous:

http://www.txpinball.com/flame_polishing_pinball_ramps.html

Typically used on acrylics, although it may be worth experimenting on Lexan or polycarb...

I have done this on plexi, but have not tried on a Lexan body... perhaps Mr. Lexan will chime in on this one...

Posted: Tue May 15, 2007 11:09 am
by badhoopty
gawd... i have nitro fuel and denatured alchohol and at the time it never crossed my mind, even though i've read countless threads on how to strip paint off of lexan. as usual i was rushing everything and getting frustrated.

anyway, i wouldnt call the body scratched as much as i would dulled. i actually like how it made the clear windows a little hazy, i may just do it intentionally to windows in the future.

i swear to all of ya the next body i paint will be freaking amazing. i just need to slow down and try not to get it done in a couple hours.

btw doug your paint and schemes are amazing. what do you use to mask with?

Posted: Tue May 15, 2007 11:38 am
by Eau Rouge
badhoopty wrote:anyway, i wouldnt call the body scratched as much as i would dulled. i actually like how it made the clear windows a little hazy, i may just do it intentionally to windows in the future.
I donno how many of you guys race contemporary cars, but that's the current trend with wings. You scuff up the underside of a clear wing with a 3M pad and it gets a frosted look. No paint, and it doesn't get mangled with dirt from being clear. Kind of looks like sandblasted-etched glass.

btw doug your paint and schemes are amazing. what do you use to mask with?
Thanks. I use everything from Liquid Mask (Bob Dively's) to 3M painter's tape and 3M Auto Fine Line tape to airbrush frisket. I've also been screwing up paint jobs since 1983. ;)

Posted: Tue May 15, 2007 11:49 am
by badhoopty
kinda ot, doug i see that you have a really short antenna on one of your 4wd cars. i would assume its a spektrum that you trimmed the antenna on. hows the range with it trimmed? the manual pretty much says it wont make a difference, but i want to ask before i snip it.

you would be proud of me dude, my tuber project is all good stuff.

deans even...

;)

and also, when you use multiple masks on a paint job, do you wait for it to dry before removing the mask? and how do you prep the areas that were under the mask without harming the paint thats already layed down?

Posted: Tue May 15, 2007 11:59 am
by Eau Rouge
badhoopty wrote:kinda ot, doug i see that you have a really short antenna on one of your 4wd cars. i would assume its a spektrum that you trimmed the antenna on. hows the range with it trimmed? the manual pretty much says it wont make a difference, but i want to ask before i snip it.
I use DMS (Spektrum) on everything. 3.6" antenna from the top of the receiver case. Never had a problem in 3+ years of using it—indoors or outdoors. Best R/C invention since the RC10.

you would be proud of me dude, my tuber project is all good stuff.

deans even...

;)
That's how to do it. 100% on those rarities makes them that much more impressive.


and also, when you use multiple masks on a paint job, do you wait for it to dry before removing the mask? and how do you prep the areas that were under the mask without harming the paint thats already layed down?
Usually, I will use only one masking type on a body. If it's LM, it's all Liquid Mask. It has a different process and method of prep than tape.

If it's a tape job, the most important part of the masking is washing the body with warm water and liquid dish soap. Crucial if you plan any fades, candies, chromes, pearls or other paint stunts. Any oil, silicones (from your hands), mold release or other contaminants will show up in your first spray of the gun.

After the body is masked for the first color, I wipe the exposed down with a clean lint-free towel and denatured alcohol. It makes sure everything is perfect before I spray. After the first color (I use a heat gun to rapid dry), most water-based paints are still fragile and scratch or wipe off easily. I will spray the rag and clean off the second and third color areas before shooting to remove tape residue. Q-tips also help in the corner areas. If you're paranoid about washing it again, wait a few days for the first colors to cure and the paint should be hardened enough to quickly wipe down without too much worry.



:D

Posted: Tue May 15, 2007 11:47 pm
by justinspeed79
Wow. That is one of the coolest paint jobs I have ever seen. Very nice work. Mind if I borrow the design?
Eau Rouge wrote:Image

Posted: Wed May 16, 2007 8:15 am
by Eau Rouge
justinspeed79 wrote:Wow. That is one of the coolest paint jobs I have ever seen. Very nice work. Mind if I borrow the design?

Yeah, I don't mind at all. I've been doing that tiger stripe for many years in various looks. ;) I'd love to see other's variations on a theme.