paint peeled off/chipped

Eveliina

Gravity Guru
Hi peeps!

I painted carbon fiber helmet as a practice piece. I finally got it cleared and waited 48 hours before I removed tapes but when I did that I noticed that as I pulled the tape off it also took some of the paint off too from the border. It kind of chipped to the base layer. I'm sorry I dont have any pics right now, but I can add some later.

Now what I ask from you, fellow artists, is opinions of what caused this chipping and poor adhesion to primer since I want to learn for next time. And also it would be nice to know what do you think
, is the whole artwork gonna come off eventually or could it still dry and cure stronger with time?

I'm sure I did a lot of mistakes during the project even if I tried to learn the basics of painting a helmet. I have mostly painted plastic, wood and textiles and Ive ever experienced anything like this with those materials. Anyways, here's shortly what I did:
- washed the helmet
- wet sanded with 1200 grit sand paper
- washed it again and removed any dirt with acetone
- sprayed filler primer what my paint store recommended
- sanded primer again with 1200 grit sand paper and viped off sanding dust
- applied Auto Air autobourne black as a base color as my paint store recommended (i believe it's more for detailing tho..)
-painted flames and skulls using wicked detail and auto air transprent
- wiped with silione remover wipe
-Clear coated with 2k automotive clear which i got from car painter. He said it to be super strong kind of clear.

Did I sand the primer too fine or did I use too thick layers and didn't let them dry enough?

What do you think? Anyone experienced anything similar? Thank you SO MUCH for your time! I appreciate any suggestions and thoughts. :)

- eve
 
I'm far from an expert but if you used a low tack masking media it sounds like you may not allowed enough cure time between layers / steps. Maybe if you can provide some pics someone may be able to give a better answer..good luck!
 
I'm not sure if you normally sand the primer. .... fair enough sand your filler but I thought the primer is ready for base without sanding??? Someone with vastly more experience than i willbe along soon evelina to get you on track
 
Thanks for both of you for quick reply! I will put in picture as soon as i get home from work. And this filler primer was type that needed to be sanded but i used finer paper that instructions said cos i just felt that it was better smoother finish. I normally use 800-2000 grit wet sand for plastic. Depending on situation. But this was first time i used this primer. I can look up the name too when i get home.

And i dont mind if you arent a professional. Its the spirit of learning with you that helps me anyways. :)
 
1200 is too fine and you need to use base as a sealer for adhesion.. here >>http://www.createxcolors.com/PDFs/hard_surface_guide.pdf is the tech sheet for AA but it is basically the same for borne. also light coats are recommended
hope this helps
PS a lot of great info on the site

Oh thank you ko! Wish those guys in the paint store should have told to you that yoo. But now i know better. But is my work completely ruined? I could do it all over again but i kind of hope i wont need to. Maybe i just have to wait and see...
 
If it is for you no problem If it is for a customer or something you really like?? your call
 
I have had similar issues on helmets when I have left the masking tape on too long.
Also I tend to lock in layers by using an inter coat clear if an area needs to be remasked. In the past I have got ton carried away and forgot the inter coat clear and had the last layer lift when removing the mask.

As for primer ... I always sand it down as part of the prep process (usually dry sand with 600/800 grit wet and dry. This denibs a bad spray job (my usual kind) but also helps fill in minute defects etc.
Once happy with the primer I will apply the base coat (usually black for my type of work). At this point I may decide to let the base dry thoroughly and will remove my masking and then remask again once I have skuffed the paint with a scotch brite pad. This is how I prepare most of my dibond sheets prior to putting artwork on them.

Andy
 
Now I have picture for you of the issue. I'm not pleased with the border even without that chip but the main thing is to learn so that if I do a helmet custom painting for a customer I can offer quality. This one is for my friend and she knows I havnt done helmet before and we agreed that it can fail. She doesn't really need it she has others but of course she wants to use it if she likes it . I should try removing tapes between layers. Maybe it helps getting borders of masking cleaner and better. Oh and the primer was u-pol high #5 primer.

For some reason I can only access this site via mobile data not Wi-Fi so I have to add the pic from my phone. Let's see how that goes.
 
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How long was the masking tape on for because this looks very similar to the issues I had. First thing I noticed was what looks like glue residue on the edging strip which tends to be left behind when the masking tape has been left on for a while.
I also suspect that your base coat black has probably not received enough scuffing near the edge of the helmet (this can happen when you can't remove the rubber edging strip) causing a localized lack of adhesion.

Another thing to watch out for ... and has caught me out very recently is ... all masking tapes are definitely not equal with different amounts of tack (they vary from can't get the buggers to stay stuck in place to the equivalent of super glue that won't come off and leave residue behind). Stick with a good automotive type masking tape such as 3M or similar. Avoid cheap stuff in sales as the adhesive changes over time and is usually sold on the cheap as it is old stock. Cheap stuff can also be porous as I discovered to my horror on my latest project! :upset:
 
As stated. 1200 is way to fine. You are almost polishing at that grit, not scuffing. I wouldn't go over 800 grit, and usually try to stick to 400-600. I do like to wet sand my primer coats, but again, it usually with 600. Then I also try to remove any masking as soon as possible after painting... especially clear coats. If you have heavy over spray on your masking, once it dries, it doesn't know that there is a difference between the mask and the painted surface. Peel it off before it completely sets, and you'll have a much easier time. I used to have this problem when I was painting a lot of guitars, a while back. I only used lacquers, not 2k clears, but ran in to the same problems. If you absolutely can't remove it before it sets completely, then you can use a razor and score the edge of your mask... that can help. You could also try removing and re-masking between each coat of clear. That will help keep the over spray from building up on the mask.
 
Wow there were good things pointed out, and good tips too! I will definitely check that my masking tape is good quality to prevent problems talla mentioned and not leave it on for long time. I do know that glue changes over time and i used the ones i already had cos i thought they are ok. And i will definitely look into scuffing more and learn about adhesion promoters as well. This is what practice is for and thanks for helping me learn more. :)
 
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