Painting on plastic

[SFLAutoSurf]

So this is what I got:

I sanded this grille to the factory paint..
Cleaned, tacked, primered, then sanded with 600..
Three coats of nason base, then three coats of nason clear (with appropriate timing).
A couple hours later I carefully remove the masking and the very last piece of tape takes some paint with it.
I put adhesion promoter between coats as well.
I’m thinking I should have left the primer at 400. It just looked so pretty and I got carried away.

I guess I’m looking for advice on how to move forward and avoid doing this again.

89CA13BE-C5E8-4B7F-B222-F1DC5E8666F2.jpg

BD3A18EF-0581-41BF-A2D5-DA9534212488.jpg

[Henry]

So this is what I got:

I sanded this grille to the factory paint..
Cleaned, tacked, primered, then sanded with 600..
Three coats of nason base, then three coats of nason clear (with appropriate timing).
A couple hours later I carefully remove the masking and the very last piece of tape takes some paint with it.
I put adhesion promoter between coats as well.
I’m thinking I should have left the primer at 400. It just looked so pretty and I got carried away.

I guess I’m looking for advice on how to move forward and avoid doing this again.

89CA13BE-C5E8-4B7F-B222-F1DC5E8666F2.jpg

BD3A18EF-0581-41BF-A2D5-DA9534212488.jpg

I think this was your weak link:

"I put adhesion promoter between coats as well."
Now, you can let it sit and see if it all hardens. Maybe after a day, see if your fingernail sinks.

Drying is not so much what you're after as is CURING of the products and I'm not sure if the addition of the AP will allow CURING to happen properly.

Hopefully, others will chime in. Keep us posted as we all wish for the best outcome.

Henry

[Len]

I think Henry is right your adhesion promoter should be applied to the plastic before the paint is applied.

You can try to feather the problem area then reapply the AP and paint but you might want to consider removing all of the paint and starting over and apply your AP directly on the sanded plastic. Depending on what products you're using the AP is applied, allow to dry a little then applied again and allowed to dry then paint is applied. Read the technical data sheet (TDS) for the AP that you're using.

[SFLAutoSurf]

I think this was your weak link:

"I put adhesion promoter between coats as well."
Now, you can let it sit and see if it all hardens. Maybe after a day, see if your fingernail sinks.

Drying is not so much what you're after as is CURING of the products and I'm not sure if the addition of the AP will allow CURING to happen properly.

Hopefully, others will chime in. Keep us posted as we all wish for the best outcome.

Henry

I was afraid that might be the case. I wasn’t sure where along the process the ap should go so I figured it couldn’t hurt.

[Henry]

I was afraid that might be the case. I wasn’t sure where along the process the ap should go so I figured it couldn’t hurt.

What LEN says!

Also, this is a grill, The only time it gets touched is when you wash the car or kill bugs going down the road. If mine, I might (and have) bypassed the AP process with no ill effects.

If this is being done for yourself then consider leaving it as is and keep an eye on it. If it holds up and DOES bond then you'll be ahead of the game. Worst can happen is it begins to delaminate and even at that, you can pick WHEN you sand it down and do it over again.

Hey, PRETEND you're in VEGAS and 'gamble' a little bit. (Unlike if this was for a customer, you'd have to fix it quickly.) So all is cool plus you learned something. Keep us posted regardless and thanks.

Henry

[bmarler]

just thought i'd add, you can apply the masking tape on your pant leg before putting it on your project to reduce it's level of adhesion. it's not a cure for adhesion promoter between coats, just a thought for future use if you think you are going to pull paint.

[Henry]

just thought i'd add, you can apply the masking tape on your pant leg before putting it on your project to reduce it's level of adhesion. it's not a cure for adhesion promoter between coats, just a thought for future use if you think you are going to pull paint.

Very good REMINDER of an old trick we all learned from our mentors along the way!

Thank you for resurrecting something good that all should know. It does have its place in this work!

Enjoy your weekend! Do something for YOURSELF...

henry

[SFLAutoSurf]

I Definitely could’ve avoided this by being more careful when pulling the tape. Luckily this is for my truck and I’m not worried about appeasing a customer. It seems to be curing just fine and ’m pretty sure I can lightly sand and re-spray the area and have it look right. I’m just pretty new to this and was surprised at how thin the paint and clear coat seems to be. The front bumper and mirrors turned out well but now I have four doors and a hood to do so I wanted to make sure I knew what probably happened before I move forward.

[bmarler]

I Definitely could’ve avoided this by being more careful when pulling the tape. Luckily this is for my truck and I’m not worried about appeasing a customer. It seems to be curing just fine and ’m pretty sure I can lightly sand and re-spray the area and have it look right. I’m just pretty new to this and was surprised at how thin the paint and clear coat seems to be. The front bumper and mirrors turned out well but now I have four doors and a hood to do so I wanted to make sure I knew what probably happened before I move forward.

don't worry, no grammar police here.

[Henry]

I Definitely could’ve avoided this by being more careful when pulling the tape. Luckily this is for my truck and I’m not worried about appeasing a customer. It seems to be curing just fine and ’m pretty sure I can lightly sand and re-spray the area and have it look right. I’m just pretty new to this and was surprised at how thin the paint and clear coat seems to be. The front bumper and mirrors turned out well but now I have four doors and a hood to do so I wanted to make sure I knew what probably happened before I move forward.

Curious, are you using autobody tape as there is a huge difference. The wrong stuff helps lead to problems.

Had to ask to cover that important variable. Carry on!

henry

[SFLAutoSurf]

Curious, are you using autobody tape as there is a huge difference. The wrong stuff helps lead to problems.

Had to ask to cover that important variable. Carry on!

henry

I’m using 1/2” automotive tape from advanced auto. Like I said I know it was user error. I got impatient and pulled it too fast. I’m just starting to worry about the rest of the paint now. Didn’t expect that it would be so fragile.