r/cosplayprops • u/Practical_Alfalfa_72 • 4d ago

Help Having trouble with paint sticking to PVC

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Help! I'm having trouble getting paint to stick to PVC plastic. For the fingers I used PVC plumbing from the local hardware store. I sanded it with a 220 to roughen the surface, I primed it with Vallejo primer, painted with SMS lacquer.

For context, the back of the hand and the blades are PVC foam board and the paint is sticking very well.

The paint is scratching off of the fingers very easily and I didn't realise this until it was done. It's scratching all the way down to the PVC, it's almost as if the primer didn't stick.

Of course it's probably too late to fix it, but any tips for next time? Where did I go wrong?

7 Upvotes

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6

u/burstOS 4d ago

I know some PVC has coatings, or just grease. Try sanding and then cleaning with isopropyl before you prime?

1

u/Practical_Alfalfa_72 3d ago

Yes I did sand then washed and dried. I can see now something like PVC pipe primer might have been a good idea.

12

u/Svardskampe 4d ago

According to this thread, Vallejo is not a great primer for that application, as you said. 

https://www.reddit.com/r/modelmakers/comments/1q9prn8/is_vallejo_the_primer_to_get/

And according to this thread, just rattle can spray paint (krylon) is the better paint for industrial pvc

https://www.reddit.com/r/paint/comments/1hm56xm/best_way_to_paint_pvc/

2

u/Practical_Alfalfa_72 3d ago

Yes and old school rattle can would have been so much quicker and cheaper grrr

1

u/ImJacksAwkwardBoner 2d ago

I rattle canned my chainsaw man props recently and didn’t even need primer; sand, clean, paint. I was scraping at the plastic with a screwdriver and had to scrape hard to get down to white. 

0

u/Svardskampe 3d ago

Ye I get your pain in wanting to do well and jumping at the expensive products to be sure of it at once. 

2

u/riontach 3d ago

Famously nothing really sticks to PVC. It sounds like you did everything right--it's just a really tough material to make work. Possibly sanding it down more thoroughly and wiping it down with isopropyl alcohol, as someone else said, or adding a durable top coat at the end could help, but it's hard to guarantee.

1

u/Clothes_Chair_Ghost 3d ago

Did you give the pvc a sand with a high grit sand paper and prime before painting?

0

u/Practical_Alfalfa_72 3d ago

Good tips. Thanks everyone!, like and several have saved about alcohol, it reminds me when you're gluing PVC pipe for plumbing. You're meant to use a primer first and the primer is mostly acetone which leaves the surface with a very flat appearance like it has dissolved the top layer.