Topic: Painting plastics

[swbeebe]

I have a question about painting plastics. I currently paint anything and everything with a rattle can. I was looking into getting a HVLP spray gun and try to learn how to paint with that. Now here at the TV shop I use MEK (Methyl ethel ketone) to surface prep plastics before gluing them. It's kind of acts like the primer you put on PVC pipes before the joint cement. Now for painting plastics at home, I use FUSION for plastics from Krylon. I see on the label, the only difference between "normal" spray paint and the Fusion paint is the Fusion says it contains Ketones. Would you be able to add a small amount of MEK to the paint mix for a HVLP sprayer to make the paint bond better to plastics? Or would it have compatibility issues with the water based paints? Would I have to try a solvent based paint? Or do they make a special additive to add to the paint to make it bond better with plastics? Figured someone on here might know the answer...

[BigBird#32]

Hi !  I use PPG paint everyday !  I scuff the plastic part well with a scuff pad,  Then use SEM or Bulldog and spray it on the plastic part,  Let that dry for a few mins and your ready to paint,  If you want to spend a little more you can buy a nice primer from akzo nobel called color build and you can NOT scrape it off plastic , SEM or Bulldog can be purchased at most any paint store like NAPA.   I hope this helps ! 

[RedDeere]

They make special additives; the one I like to use is Bully Dog. It is an adhesion promoter you can mix in the paint or/and spray on the surface to be painted.

[Burwell555]

OK, I guess I will be the third guy to chime in and say use the Bulldog Adhesion Promoter...Good stuff!! Not the cheapest, but well worth it. I have used it on several different applications over the past couple years including Interior pieces of trucks, gauge pods, bumper valences, and yes even mower parts including my dash and dash valence!! First clean your pieces with wax and grease remover, then scuff with scotch brite, spray the Bulldog on (I use spray can), but make sure its evenly and do NOT try to lay it on thick..it WILL run. One light coat is really all it takes, then add paint. Unless its the grille for your mower and you plan to bloc sand it all nice and smooth, then add your filler primer first!! Then you are in business. That is all the tricks I have ever used with nothing but good results. Remember though...the key to nice paint is ALL in the prep work. Dad taught me "if you can see it in the primer, you WILL see it in the paint". 

[swbeebe]

Thanks everyone! I will give that a try. Luck for me I have a NAPA about 2 blocks from where I work, they seem to get quite a bit of business from me. lol.

[Burwell555]

Soi doesn't my local napa...they all know me by first name and have me set up on shop pricing lol

[BigBird#32]

Same here!  Except on fleet pricing.

[2budzracing]

all are right,Bulldog is a killer adhesion promoter ! you can even paint glass with it....if you try putting MEK in a paint gun expect to buy a new one...even if it would work you would probably DIE from the fumes !!


if you are painting Really flexable parts you need to get flex additive also it mixes with most paints.

[swbeebe]

Exactly what I was wondering about. I have seen the duplicolor promoter, (sticks to chrome) but have never tried it. I was mainly concerned about the flexing of the plastic pieces. Do you happen to know the name for the flex additive? I was hoping to pick up a sprayer this weekend or next and get learning on it. Any suggestions on a decent entry level gun? (Getting a little off topic) I know some are for oil, some are for water and others say for solvent based. Isn't most paint they sell anymore water based? I have been using spray cans so long now, I figured going the HVLP route would get me more coverage per dollar. (Not to mention more colors)

[RedDeere]

Exactly what I was wondering about. I have seen the duplicolor promoter, (sticks to chrome) but have never tried it. I was mainly concerned about the flexing of the plastic pieces. Do you happen to know the name for the flex additive? I was hoping to pick up a sprayer this weekend or next and get learning on it. Any suggestions on a decent entry level gun? (Getting a little off topic) I know some are for oil, some are for water and others say for solvent based. Isn't most paint they sell anymore water based? I have been using spray cans so long now, I figured going the HVLP route would get me more coverage per dollar. (Not to mention more colors)

Bully Dog is also a flex additive. I have heard spray guns from Harbor Freight work well if you are not using it for production purposes. I would suggest if all the stuff you are painting is small get a detail gun or a mini gun you will waist a lot less paint. Also check out DeVilbiss guns they have some entry level stuff that works well.

[mowvette]

Yep, Harbor Freight the pro HVLP at 49.95 rated 5 stars. They really do have some good deals.

[2budzracing]

OK look guys I have painted everything from bbq's to show cars , your biggest concern is in prep and materials.If you start mixing materials to save money forget it if you don't know what you are doing ! I just did a spot repair on a bumper with a dupli-color spray bomb kit with clearcoat and it turned out with a better finish than the original paint.IT'S A MOWCHINE unless you want a show piece, which some I know....then just get a good cleaning process going and make it shiney and don't scratch it.

The flaws in a paint job only show up if your going slow or sitting still,concentrate on being safe and all the shiney stuff is just a bonus !!!

[Burwell555]

As mentioned before...if you are just painting mowers, a touch up gun can waste a lot less paint...but then again, a touch up gun is not a good idea to try and lay clear coat on a panel, especially for your first time spraying. Their is an art to clear, it is not as easy as everyone says. If a guy tells you ' I don't run my clear', he aint puttin enough on for that super sweet look!!!
As far as guns...we had an 89 dollar napa gun, was pretty good. But the Devilbliss we have, is absolutely top of the line...it is THEE nicest gun I have ever used and I've had my hands on a few. But you get what you pay for...at 500 it wasn't cheap, but they have a cheaper line as well that I'm sure you will do fine with. A lot has to do with tip size as well...I spray filler primer through a 2.0 tip, sealer and paint through a 1.4 and clear through a 1.5. All have totally different abilities and purposes.

[BigBird#32]

Most cheaper guns do work well,  I would buy one with a tip of 1.4 that is a good size to use as a primer, paint and clear gun.  At the shop I use SATA guns,  They are awesome but high priced but when you do that for a living then the extra money is well spent, 

Lets move to clears.    What do you guys use ?  Product and Price, 
             
                                   I have shot ALL the clears,  At the shop its all PPG but on the mowers I use a product only sold at PPG platinum stores call JC 60 it can be purchased as kit for less the $100 per gallon.  Also I have used and it worked well clears from USC the kit runs just under $50.00 per gallon.   A word to the wise before you buy a clear ask someone if they have shot the clear and how well or not it did,  You can save time and money doing this,  Because lets face it some clears are just junk ! 

[Burwell555]

It all depends...we used to use dupont...but have used a lot of the nason that comes in the green gallons. We have found the 497 is a little better than the 496. But for cheap clear that is good, I have had good luck with the Acme stuff from napa...30 for a quart and activator and you. Can lay it on real thick, without orange peel, and still only use half a quart.and it is quite shiny to boot We also used some stuff called big skyy made by montana once...it turned out really nice. And yes I will totally agree, some clears flat out suck!!