Suggestions for polishing plastic cigarette lighter?

[Chris Bamford]

The one on the left is the original unit... reasonably shiny but overheat-damaged where the black meets the base.

 

The replacement unit in the middle is a lucky $3 find at the Red Deer AB swap meet on Friday... identical but kind of scuffed and dull.

 

The treasure at right is a freebie throw-in with the middle unit and intended for practice polishing.

 

Looking for suggestions on how to polish the black plastic knob on the replacement unit to roughly equal the appearance of the original. Thanks in advance!

 

[auburnseeker]

I've used mother's Mag and Aluminum polish with great success.  Flaws can bve wet sanded out with 1500 grit paper first.  Buffing compound for buffing paint like that made by presta or 3M will work as well.  Mother's is handy for all types of polishing projects. .  Use it on the chrome parts as well to polish that up.  I have done this to literally 100 cigarette lighters and then sold them looking like brand new on ebay. 

Edited May 8, 2018 by auburnseeker (see edit history)

[Chris Bamford]

Thanks Auburn, much appreciated  — would you use a power wheel for this, or buff by hand, or...? 

 

I occasionally shine up brass bits with a cloth wheel in a bench grinder and either red or white "compound sticks".  It would be handy if I could simply use that wheel with some of the Mother's polish.

[Spinneyhill]

Just be careful on that wheel coz the plastic will be a lot softer than the brass!

[auburnseeker]

As mentioned,  I would probably avoid the wheel.  I bought baldor's really good 2 speed buffer for doing both metal and plastic and it really turns to fast for the plastic and burns it.  Either do it by hand or use a small right angle air grinder at a fairly slow speed with a wool type 4 inch or smaller buffing pad. (the cheap tool vendors sell them at car shows usually with a velcro backing.   If you do that though,  you will really need to use a regular car polish.  The Mother's works really good by hand,  it just takes a little effort. 

Any deep scars could be sanded out with coarser grit papers,  but you still need to work your way up to 1500 grit before polishing with mothers to get the sand marks out. 

It's small enough it won't take long even by hand. 

[Chris Bamford]

Thanks again for your suggestions, and I'll give it a go this week.

[Frank DuVal]

Have you tried the Novus line of plastic polish? Works great on plastic radio cases. Try #2 followed by #1. If heavily damaged, go with #3, but  not until you try #2.

[auburnseeker]

For small parts I like the Mother's approach as it's a 5.00 can of polish with tons of other uses.  I have even buffed cars out with the stuff.  It works well and has had no adverse effects on any of the finishes I have used it on in the last 20 years. Paint, Chrome, Aluminum, stainless, plastics.  As with anything,  on painted surfaces,  you need to try it in a non conspicuous  area just to be sure.  Some of these cars I still own.   Paints have included,  Lacquer,  Acrylic enamel, Base coat clear, etc.   The reason for the warnings on the can are like any polish,  it removes a little bit of the surface,  which is what you are trying to do with polishing.  I once told my friend who was buffing out some aluminum,  to use a much coarser grit like 220 on the part he was polishing,  because you need to get down to the bottom of that scratch or gouge before you can polish it out. 

[Tim Wolfe]

I've used tooth paste to polish plastic, I used it to clean and polish a plastic sign years ago and it worked. It takes some rubbing.

[Eric Wahlberg]

When polishing knobs I get a screw or bolt that's the same size the knob attaches to and cut the head off the fastener.  Screw it into the knob and then chuck it into a drill or drill press.  It's best if your drill is variable speed to prevent overheating the knob as it is being sanded, compounded, polished, etc.  Just be certain the drill is turning clockwise, so the knob doesn't become unthreaded while you are working on it.

[AJFord54]

On 5/8/2018 at 12:19 AM, Frank DuVal said:

Have you tried the Novus line of plastic polish? Works great on plastic radio cases. Try #2 followed by #1. If heavily damaged, go with #3, but  not until you try #2.

That's what I was going to suggest.  Wonderful stuff.

[jrbartlett]

Strongly urge you to try hand polishing first. My experience on buffing plastic is that the first touch to the buffing wheel will gouge it almost immediately. I've tried it on a few junk pieces just to experiment.

[auburnseeker]

3 hours ago, Eric Wahlberg said:

When polishing knobs I get a screw or bolt that's the same size the knob attaches to and cut the head off the fastener.  Screw it into the knob and then chuck it into a drill or drill press.  It's best if your drill is variable speed to prevent overheating the knob as it is being sanded, compounded, polished, etc.  Just be certain the drill is turning clockwise, so the knob doesn't become unthreaded while you are working on it.

You could also put it in a drill press.  I've done that before on a few occassions.  Most of it is hand polishing,  or using the right angle air die grinder as it's variable speed.  Be sure to use the face whenever possible.  If you use the edge,  it's very easy to gouge it.