Painting Plastic

[Capo]

Anyone with a 4V painted the white plastic expansion tank?
What is the process? I tried some stuff that said on the tin it was for plastics but it peeled right off.

[NAKID]

Krylon Fusion?

[ducpainter]

Anyone with a 4V painted the white plastic expansion tank?
What is the process? I tried some stuff that said on the tin it was for plastics but it peeled right off.

Anything you paint needs to be clean.

How did you do that?

I'd recommend detergent, rinse well with water and dry.

Scuff with a red scotch-brite.

Then clean with alcohol and let dry thoroughly.

[Bill in OKC]

Anyone with a 4V painted the white plastic expansion tank?
What is the process? I tried some stuff that said on the tin it was for plastics but it peeled right off.

Check out the pics about halfway down the page:
http://ducatimonsterforum.org/index.php?topic=9909.30
I have been thinking of a way to relocate and/or paint this thing black for a long time.  I *guess* it means removing the throttle bodies to get this thing out
My goal is to replace the tank with the 748/996 style tank like they did with this Monster:
http://ducatimonsterforum.org/index.php?topic=11215.0
and paint it black - then somehow figuring out how to replace the airbox with some pods.  Deap breath - surgery and/or waste of time will begin soon.  The tank is on its way.

[Ducnial]

Sorry cant really paint and expect it to last.  Its blow molded from HDPE or high density polyethylene.   Plastics like Polyethylene, polypropylene, PET (bottled water containers)  have low surface energy hence almost nothing will stick or attack the plastic except for some very corrosive chemicals.  That why almost every chemical product known to man come packaged in the stuff.  Even if it would stick its still flexible and has high thermal expansion and would crack.   Here's what you might try though,  I've had some success with this in the past, although for a different application.  Purchase some Rite Dye (synthetic fabric dye) in the color of your choice. Avoid intense colors like brilliant blue or red.  Black is probably the easiest.   This stuff is designed to dye synthetic fabrics like nylon, polyester and will dye polyethylene although it will take longer.  First wash the container or test sample in the dishwasher  (with DW soap) and let it go through a full dry cycle (very important) remove and let cool thoroughly   Follow the dye instruction but don't exceed 180°F, about the temperature of very hot water.  Else the risk of thermal distortion.  Run a test part first preferably a PE container of comparable wall thickness.  In a pinch you can use a milk bottle.  No need to dye the whole thing just cut a chunk out big enough to get an idea of color uniformity.    Get a smaller test pot, yes you can use your wife cooking pots, this stuff is not toxic.  Its basically sodium chloride (salt) with dyes and works on the principal that all plastics absorb moisture, the higher the temperature the more water is absorbed.  The dye attaches  to the sodium chloride ion and is carried into the plastic as it absorbs water. Like soaking a chicken in brine to make it plump and juicy except here you are using hot water (not worried about cooking plastic)  to increase the rate of absorbsion.  You'll need to monitor it for the color intensity, cant really leave it in too long.  Probably will take a couple hours, just cover the pot to reduce evaporation and don't splash it on your wife white countertop.  If you do try it let us know how it turns out  or    Either way you wont trash your coolant reservoir completelty, worse case it will  turn dark gray.  The color WILL be permanent and wont chip or scratch  off  because the color extends well into the wall thickness of the container. 

Good Luck

[ducpainter]

Sorry cant really paint and expect it to last.  Its blow molded from HDPE or high density polyethylene.   Plastics like Polyethylene, polypropylene, PET (bottled water containers)  have low surface energy hence almost nothing will stick or attack the plastic except for some very corrosive chemicals.  That why almost every chemical product known to man come packaged in the stuff.  Even if it would stick its still flexible and has high thermal expansion and would crack.   Here's what you might try though,  I've had some success with this in the past, although for a different application.  Purchase some Rite Dye (synthetic fabric dye) in the color of your choice. Avoid intense colors like brilliant blue or red.  Black is probably the easiest.   This stuff is designed to dye synthetic fabrics like nylon, polyester and will dye polyethylene although it will take longer.  First wash the container or test sample in the dishwasher  (with DW soap) and let it go through a full dry cycle (very important) remove and let cool thoroughly   Follow the dye instruction but don't exceed 180°F, about the temperature of very hot water.  Else the risk of thermal distortion.  Run a test part first preferably a PE container of comparable wall thickness.  In a pinch you can use a milk bottle.  No need to dye the whole thing just cut a chunk out big enough to get an idea of color uniformity.    Get a smaller test pot, yes you can use your wife cooking pots, this stuff is not toxic.  Its basically sodium chloride (salt) with dyes and works on the principal that all plastics absorb moisture, the higher the temperature the more water is absorbed.  The dye attaches  to the sodium chloride ion and is carried into the plastic as it absorbs water. Like soaking a chicken in brine to make it plump and juicy except here you are using hot water (not worried about cooking plastic)  to increase the rate of absorbsion.  You'll need to monitor it for the color intensity, cant really leave it in too long.  Probably will take a couple hours, just cover the pot to reduce evaporation and don't splash it on your wife white countertop.  If you do try it let us know how it turns out  or    Either way you wont trash your coolant reservoir completelty, worse case it will  turn dark gray.  The color WILL be permanent and wont chip or scratch  off  because the color extends well into the wall thickness of the container. 

Good Luck

Dude...

I have to disagree.

Not with the science, because everything you say is true...

except the paint manufacturers have adhesion promoters that will make stuff stick to polypropylene, which is about one step up from crude oil.

just about anything can be painted today.

[Ducnial]

Dude...

I have to disagree.

Not with the science, because everything you say is true...

except the paint manufacturers have adhesion promoters that will make stuff stick to polypropylene, which is about one step up from crude oil.

just about anything can be painted today.

Ducpainter, 
You are right about polypro, but the reservoir is made from HDPE. I just collected a small sample from my S4R and put it through my personal pyro-olfactoric-spectograph (OK, I burnt and smelled it ) .  In fact its less than HDPE is only MDPE.   Polypro is a somewhat unique polyolefine because it is attacked by strong oxidizing acids, particularly chromic acid. This is why you see fabricated (welded together) plastic tanks made from polypro and not HDPE  and why polypro is not used near as much as PE.  Also technically you right there are adhesion promotors for just about any polymer, except Teflon.  Problem is none of these are readily available for the average one-off.  They are expensive and dangerous to use.   If the tank were made from polypro or were surface treated what paint would you recommend?  It would have to be flexible, heat resistant and non-hardening overtime.  For its location and appearance requirements I still think dying is the best and easiest solution.

[ducpainter]

Ducpainter, 
You are right about polypro, but the reservoir is made from HDPE. I just collected a small sample from my S4R and put it through my personal pyro-olfactoric-spectograph (OK, I burnt and smelled it ) .  In fact its less than HDPE is only MDPE.   Polypro is a somewhat unique polyolefine because it is attacked by strong oxidizing acids, particularly chromic acid. This is why you see fabricated (welded together) plastic tanks made from polypro and not HDPE  and why polypro is not used near as much as PE.  Also technically you right there are adhesion promotors for just about any polymer, except Teflon.  Problem is none of these are readily available for the average one-off.  They are expensive and dangerous to use.   If the tank were made from polypro or were surface treated what paint would you recommend?  It would have to be flexible, heat resistant and non-hardening overtime.  For its location and appearance requirements I still think dying is the best and easiest solution.

Actually you can buy pretty good adhesion promoters in a rattle can.

Sherwin-Williams makes one as does Fiberglass Evercoat.

I use HOK AP-01. I buy it in quarts.

I've never had any of these products fail me on any plastic.

The trick is to apply lightly and not exceed the recommended dry time...which is pretty standard practice for all products.

For topcoats I use catalyzed urethanes. They work in space, on planes, and on our bikes.

They stay flexible, have excellent heat resistance, and great adhesion.

Keep in mind I'm no chemist...I just use the stuff they dream up.

[Big Troubled Bear]

+1 on that one DP

[Bill in OKC]

Krylon Fusion?

I looked this stuff up:
http://www.krylon.com/products/fusion_for_plastic/

It looks like it might work...  I'll give it a go on a spare tank to see how it works - hoping I can mask off a small strip for coolant level viewing.

[Capo]

I looked this stuff up:
http://www.krylon.com/products/fusion_for_plastic/

It looks like it might work...  I'll give it a go on a spare tank to see how it works - hoping I can mask off a small strip for coolant level viewing.

Let me know how you get on please.

[beatcat]

I've used the krylon fusion stuff of a few bike parts (plastic fairings) and scooter parts with pretty good luck. As with everything--you have to go light on the spray as it does drip more easily than auto paints, and do multiple coats with an abrasive in between. So far my front scooter fairing has survived a year in the new england weather without any chiping or discoloration. Granted---the surface you get is not a glossy effect--really nice flat black though if that's what you want. For a higher gloss I don't have too much experience although I do know that if you try this stuff---DO NOT MIX BRANDS OR YOU WILL BE VERY SORRY!! The fusion works OK with the krylon gloss coat but HORRIBLE with any others (rustolium!) that I have tried. Spiderwebs big time....

Just my two cents--thanks to all for the great posts here!

[COP TZR]

I had just painted my front sprocket cover and timing belt covers.  I used the Krylon Fusion paint for plastics.  I used satin black and the cap color was what I was after (matte looking finish).  After I had started spraying the parts, it kind of looked semi glossy.  I was hoping it was just because the paint was still wet.  None the less its been 48 hrs now and it has a low gloss.  I wanted more of a flat finish.

Long story short, the paint stuck well to the plastic.  Make sure you wash it really good.  I never did any sanding to mine.

good luck

[COP TZR]

here's a pic of my timing belt covers painted with the Krylon Fusion paint.  A good wash down, dry, and multiple light coats.  Now I'll have to attempt color matching my seat cowl to the tank.

[Frodoro]

Sorry cant really paint and expect it to last.  Its blow molded from HDPE or high density polyethylene.   Plastics like Polyethylene, polypropylene, PET (bottled water containers)  have low surface energy hence almost nothing will stick or attack the plastic except for some very corrosive chemicals.  That why almost every chemical product known to man come packaged in the stuff.  Even if it would stick its still flexible and has high thermal expansion and would crack.   Here's what you might try though,  I've had some success with this in the past, although for a different application.  Purchase some Rite Dye (synthetic fabric dye) in the color of your choice. Avoid intense colors like brilliant blue or red.  Black is probably the easiest.   This stuff is designed to dye synthetic fabrics like nylon, polyester and will dye polyethylene although it will take longer.  First wash the container or test sample in the dishwasher  (with DW soap) and let it go through a full dry cycle (very important) remove and let cool thoroughly   Follow the dye instruction but don't exceed 180�F, about the temperature of very hot water.  Else the risk of thermal distortion.  Run a test part first preferably a PE container of comparable wall thickness.  In a pinch you can use a milk bottle.  No need to dye the whole thing just cut a chunk out big enough to get an idea of color uniformity.    Get a smaller test pot, yes you can use your wife cooking pots, this stuff is not toxic.  Its basically sodium chloride (salt) with dyes and works on the principal that all plastics absorb moisture, the higher the temperature the more water is absorbed.  The dye attaches  to the sodium chloride ion and is carried into the plastic as it absorbs water. Like soaking a chicken in brine to make it plump and juicy except here you are using hot water (not worried about cooking plastic)  to increase the rate of absorbsion.  You'll need to monitor it for the color intensity, cant really leave it in too long.  Probably will take a couple hours, just cover the pot to reduce evaporation and don't splash it on your wife white countertop.  If you do try it let us know how it turns out  or    Either way you wont trash your coolant reservoir completelty, worse case it will  turn dark gray.  The color WILL be permanent and wont chip or scratch  off  because the color extends well into the wall thickness of the container. 

Good Luck

I definitely agree with you Ducnial. The fact that not all the paint is flexible. It depends on the stuff are you going to paint.