Sticky tacky spray paint on PLA plastic?  

RE: Sticky tacky spray paint on PLA plastic?

I recently painted a few large objects using Krylon's granite look paint. Took a while to cure - but the pressure in the cans was so high it blew the parts over and there was zero control - no such thing as a light coat. So the long cure time was expected in my case. Other Krylon and other paints I have used on PLA work just fine.

Krylon used to be good paint - after my latest experience with the granite, I have doubts.  

ps: There's always a chance the can of paint you have is just bad - stored wrong /frozen before purchase, bad batch, etc.

RE: Sticky tacky spray paint on PLA plastic?

Is this direct spray or did you use a primer?

It sounds like some solvent is penetrating the plastic and re-emerging at leisure.  Does a thin section of PLA soften when sprayed?

Cheeio,

RE: Sticky tacky spray paint on PLA plastic?

@diem

Good catch - it is a lacquer ...

RE: Sticky tacky spray paint on PLA plastic?

Thanks everyone!

No, I didn't use primer, and that's probably the problem. I shoulda thought of that. 

Probably some solvent in the vehicle is melting the PLA.

I'll probably just do a reprint rather than try to remove the paint and prime and repaint. 

Welp, off to Home Depot. 

Thanks again!

RE: Sticky tacky spray paint on PLA plastic?

Painting PLA is not as tough as PETG,  

RE: Sticky tacky spray paint on PLA plastic?

@annier

YOUR A GIRL!?!

RE: Sticky tacky spray paint on PLA plastic?

@annier

They make paint just for plastic, but PLA is almost not plastic - very hard to get anything to adhere to it.  Try their plastic paint - the metalics are going to be very hard to get to stick to PLA - they're more enamels than laquers.   An acrylic water based paint will also stick very well to PLA, but you will need to follow that with clear acrylic to keep if from washing off if it gets moist again.

RE: Sticky tacky spray paint on PLA plastic?

@dan-rogers

Or, Use a plastic or pla compatible primer to increase adhesion.  

RE: Sticky tacky spray paint on PLA plastic?

@annier

Probably some solvent in the vehicle is melting the PLA.

It may not be dissolving the PLA, it might just be wicking into the part along the lay.  Conventionally printed PLA is not waterproof.

Cheerio,

RE: Sticky tacky spray paint on PLA plastic?

Posted by: @diem

@annier

Probably some solvent in the vehicle is melting the PLA.

It may not be dissolving the PLA, it might just be wicking into the part along the lay.  Conventionally printed PLA is not waterproof.

Cheerio,

I have to concur.  If someone knows of a solvent to dissolve PLA, please let me know.  

RE: Sticky tacky spray paint on PLA plastic?

Posted by: @cwbullet

Posted by: @diem

@annier

Probably some solvent in the vehicle is melting the PLA.

It may not be dissolving the PLA, it might just be wicking into the part along the lay.  Conventionally printed PLA is not waterproof.

Cheerio,

I have to concur.  If someone knows of a solvent to dissolve PLA, please let me know.  

Is that a question Chuck or just more unrelated commentary? If a question, I suggest you do a search of the forums because solvents for PLA have been discussed many times.

RE: Sticky tacky spray paint on PLA plastic?

@tim-2

I suspect the melting in the vehicle is heat related with PLA.  I asked an honest question.  I forgot the question mark.  Here you go:  Does anyone know of a solvent that melts PLA?  It is not that unrelated because it was mentioned above.  

RE: Sticky tacky spray paint on PLA plastic?

Posted by: @swiss_cheese

@annier

 

YOUR A GIRL!?!

Yeah, uh, if you haven't figured it out by now. 

And I'm probably old enough to be your mother! (If not your grandmother.)

But back to the topics at hand ...

They tell me that methylene chloride will dissolve and smooth PLA, kinda like acetone will with ABS. That's the stuff in those holiday bubble lites.

I haven't tried this yet but I've had good luck smoothing ABS prints with acetone and a mop brush. 

RE: Sticky tacky spray paint on PLA plastic?

@annier

Thanks.  I try that.  

RE: Sticky tacky spray paint on PLA plastic?

There's a fine line between "good sticky" and "bad sticky" sometimes. I'm with Chuck: This might be something that has other potential worth exploring. For paint finish, softening the plastic is definitely a bad thing. If you want an adhesive or smoother as in Chuck's case, it might be a good thing. @AnnieR - Sounds like these pieces are a write-off, but perhaps spray a couple and smush them together to see if it eventually hardens into a good adhesive? Are you getting any sort of smoothing effect, or just a sticky mess?

I've used various spray primers on PLA, but only acrylics directly on the plastic. My son has been airbrushing PLA scenery and miniatures I've printed for him. I'll ask what formulation he's using. Also curious if Krylon's plastic stuff is PLA safe.

I always enjoy Simone Giertz and Limor Fried's work. Creativity is universal and we all learn from each other!

RE: Sticky tacky spray paint on PLA plastic?

Posted by: @dan-rogers

@annier

They make paint just for plastic, but PLA is almost not plastic - very hard to get anything to adhere to it.  Try their plastic paint - the metalics are going to be very hard to get to stick to PLA - they're more enamels than laquers.   An acrylic water based paint will also stick very well to PLA, but you will need to follow that with clear acrylic to keep if from washing off if it gets moist again.

 

I’ve used an enamel on PLA with no issues drying. 

RE: Sticky tacky spray paint on PLA plastic?

Posted by: @annier

Posted by: @swiss_cheese

@annier

 

YOUR A GIRL!?!

Yeah, uh, if you haven't figured it out by now. 

And I'm probably old enough to be your mother! (If not your grandmother.)

But back to the topics at hand ...

They tell me that methylene chloride will dissolve and smooth PLA, kinda like acetone will with ABS. That's the stuff in those holiday bubble lites.

I haven't tried this yet but I've had good luck smoothing ABS prints with acetone and a mop brush. 

Well, if I'm being honest I don't really pay much attention to that around here, but you don't look that old in your picture 😋 

But before you put yourself in the grave, old enough to be my mom would put you closer to 100 then I bet you are.

I suffer from the same thing on the internet, I always think everyone is a 26 year old kid.

Especially when they are a smart ass like me.

Enjoy, 😉 

Swiss_Cheese

RE: Sticky tacky spray paint on PLA plastic?

@annier

It is oh so genderist to say that only males 3d print.   Females to participate in mostly mail hobbies.

RE: Sticky tacky spray paint on PLA plastic?

Posted by: @cwbullet

@annier

It is oh so genderist to say that only males 3d print.   Females to participate in mostly mail hobbies.

Ok Charles, you've gone to far with that comment, the postal service is a fine institution, and many females work there as professionals, not just as a hobby.

Honestly I don't know what your thinking most of the time, please try to refrain from such comments in the future, it's very impolite, some might say chauvinistic.

Good Day to you sir,