Vader armor painting troubles

I bought a chest armor from a member here awhile ago. Its of fiberglass construction, but thin and not the thick GT ones of old. Like with every cast I've worked with, I prepped it in this manner: washed with warm soapy water to remove any mould release residue, sanded with 180 grit, 360 grit and 600 grit sandpapers, hit with primer, filled the bubbles and imperfections, sanded again and primed again until I get a nice smooth surface.

My first attempt, I painted the gun metal first. Left it to cure for 24 hours, masked the appropriate parts and spray painted the black. After the paint dried, I peeled off the masking tape and it was so tacky that it left a lot of residue on the surface, and even pieces of tape itself. No amount of WD40 or lighter fluid could effectively remove the residue. Thinking it was the masking tape I used, I stripped the paint, resanded, reprimed, repainted it gun metal, used 3M painters tape to mask and painted the black. Same result.

This time I thought it was the gun metal paint and its long curing time that was the culprit. So I stripped the paint, resanded and reprimed again, and painted the armor black. Left it to cure for 4 days and then masked, and painted gun metal. That's the one in the picture below after I peeled off the masking tape.



I'm gonna try to remove the residue later and resand the black parts. But I'm really hesitant to put any more masking tape on this armor as I have wasted so much time, effort, sandpaper and paint on it to redo it again. I'm officially at my wits' end. I've used the paints on other projects before and they've always turned out fine. Am I prepping the surface wrong?

Forgot to mention all the paints are rattlecans. Some how I don't think the problem is the paint, but more to the cast itself.

Sadly I can't help, but really hope someone can. It's really annoying when things that should work just decides not to. Hope there's a way around it. Since you've tested the issue with both paints it seems the issue may be the masking tape. Maybe it reacts badly to the paint? Perhaps try a different brand of masking tape?

Or, have you considered just brush painting the black on in thin layers in case the masking tape option fails completely? If you do this, then it is probably easier to use matt black and then gloss clearcoat afterwards to create the gloss look.

I know it's not optimal, but it may give an okay result.

Thanks for the suggestion, Carsten. To date, I've tried 4 different types of masking tape and they all yielded the same result. I've read before that some fiberglass surfaces don't cure completely resulting in the tacky-like finish and it was suggested that such casts should be left to dry under the hot sun until it cures properly. My worry is that this cast will warp if I leave it under 38 degrees celcius for too long.

Too Much Garlic said:

Sadly I can't help, but really hope someone can. It's really annoying when things that should work just decides not to. Hope there's a way around it. Since you've tested the issue with both paints it seems the issue may be the masking tape. Maybe it reacts badly to the paint? Perhaps try a different brand of masking tape?

Or, have you considered just brush painting the black on in thin layers in case the masking tape option fails completely? If you do this, then it is probably easier to use matt black and then gloss clearcoat afterwards to create the gloss look.

I know it's not optimal, but it may give an okay result.

Click to expand...

I feel like you putting masking tape over paint thats dried for only 24 hours is the issue. Ive never masked over paint that hasnt cured for several days.

My second attempt I actually let the paint cure for 4 days before masking. Same result.

The problem is your paint and maybe the resin used in the fiberglass. If the resin didn’t have enough accelerant, or was poorly mixed you may have spots that will never cure.

That said, 2 layers of filler primer, and a couple of standard primer should isolate that problem. There are still a couple of things you can do.

First, try reversing your paint order , gray gun first, black last. That way you don’t have to mask black painted areas.

The masking tape adhesive is reacting with your paint. So protect the paint before masking. Put on some car wax on the areas your going to mask. Once masked slightly sand over the areas you’re going to paint , just to be sure you’re not painting over wax.

Try switching your type of paint. If you’re using acrylic spray, try using enamel, or oil based and viceversa. As something in the paint you’re currently using is reacting with the tape’s adhesive.

Also don’t let the masking tape sit under the sun. High temp may melt the adhesive. Let the paint dry under shade.

If it’s just glue residue and not surface damage, there’s a cleaning liquid called GooGone made of citrus oils, i find it better than wd40 for cleaning.

Lastly, as they said, you can go with matte paints and do a clear gloss coat finish.

Good luck!

jcgardea, thank you for that valuable insight and suggestions!

If the problem is the material use some thin coats of epoxy resin(very thin layers) over the complete armor and sand it later down.If the cast is reacting with the paint you must seal the bad stuff first ,before you can paint it.What stuff of paints are you using?Acrylic or ace resin based color?Perhaps that could also make the problems with the material.

Yeah, I'm guessing its probably the cast itself. I'm gonna try jcgardea's suggestion of spraying a few coats of filler primer over it to seal the bad stuff first, as you put it. Hopefully that will work.

I'm using Tamiya spray paints. They've always worked fine previously.

I may be remembering completely wrong here, but I've heard Tamiya paints can have serious issues when applied to certain materials. Can't remember if fiberglass was one of them. Would definitely recommend you switch to automotive paints for this and find something close to Rolls Royce colors.

tamiyapaint are alcohol based.That should be no problem with fiberglass.But who knows from what stuff this armor is made from?
But automotive paint is the way to go.

And about the primer:If the material has problems with the paint you can spray tons of primer on it but it will not work.Primer is also only a paint.A thicker one.

Just FTR, what I’ve used so far is Duplicolor paints from Autozone, which basically car paint in a rattle can. They may be a little pricey, but it is nice and thick and they have a big assortment of colors. I personally like their jet black and honda grey.

Kal,

i've had problems painting various resin, FG stuff in the past.

I found that hot soapy water just didn't do the job, so i use cellulose thinners on a clean cloth....that did the trick.

Rich

kalkamel Keep us updated I’m sure all of us would like to know how you solved it

Thanks for all your suggestions, gents!

I have yet to strip the last paint attempt but will do so soon. But one thing I noticed is that the cast, through two layers of regular (not filler) primer and two coats of gloss black/gun metal, the surface still dents quite easily (just pushing it with a finger), as if the surface itself has not really fully cured.

If your surface is not fully cured and stable, then you're going to continually have problems with paint.
First and foremost you need to get that squared away before thinking about paint. Your surface should have no tack. Do a fingernail scratch test. If your fingernail can dent or scrape up any material, its still a no go. You'll either have to trash the casting or re-skin the surface with a super thin coat of bondo.
Once you've got a stable surface to work on you're ready for paint.
ALWAYS use a primer first.
For vader armor I would only use automotive paint. You can buy it in a spray can if you don't have a paint gun.
ALWAYS use the same brand of paints. Same brand primer and same brand color coats. Otherwise you risk a bad reaction with the paints.
Make sure you paint in temp as close to 70-80 degrees F as possible. Don't let the object you're painting get too cold or too hot before or after you paint or in between stages.
Use professional 3m vinyl masking tape. For large areas you can use the low tack blue painters tape, but you'll have to double up on the layers. Don't skimp on cheap tape.
Use light coats. No super thick wet coats or you'll get runs drips or just too think of a layer that will take forever to cure/gas off.
If using automotive paint, you can mask it off after about 8 hours. If you're not in a rush, just do a different color each day. Primer day 1, gunmetal day 2, black day 3.
The original vader pieces did not use a clear coat, so just polish them with a polishing lotion and a soft cotton cloth. If you're not concerned with that level of accuracy, you can clear coat, just make sure you use the same brand as all your other colors and don't handle it until after a few days after the clear goes on. Clear coat takes a long time to cure and is susceptible to damage if you mess with it too early.


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That's an awesome step-by-step, GINO! Really appreciate it!