FirstPost: Need Sintra Help (Painting)

[PacoDeth]

So yeah, first post and all, I'd like to start of by saying this website is awsome, while searching high and low for acceptable information for building a costume, this is by far the most informative and useful resource.

Anyways, to the point: I'm using the Sintra material to build my own Halloween costume, but am having trouble with painting it. To achieve the color I am looking for, I have to paint with Silver first, then top with a Transparent Red to get a metallic red sort of look (looks great BTW). The problem I am having, is that the paint is very easily scratched off. Mind you, I have only used a test piece, and I only gave paint coats about an hour to dry before applying the next coat (I think this was fine, as most say they dry in 15mins or so, but do say 24hours "to handle"). The progression of layers was to start with a White Primer spray (not sure if a good idea or bad), then a Krylon Silver Metallic spray, followed with 2 layers of Testors Transparent Red, and lastly with Krylon Gloss Coat. All painting layers got 2 coats (or 2 pass-by's) while painting, except the red got an extra set of coats after the first dried (as 1 set of coats is too light).

So I have my test piece, and I can pretty easily scratch the paint off with my finger . I had hoped the top coats of Clear Coat would protect it from that, but to no avail. Any recommendations how I can paint this stuff to where it won't easily scratch off?

Lastly, while I am a Star Wars fan, I'm not actually building anything Star Wars related (please don't stone me!). The attempt here is to pull off a custom made Iron Man armor (custom I say, because matching the exact look of the new movie armor would take me years, and this is the first time I have worked with Sintra). I will post some progress pics as I get to them. Thanks in advance!

 

[PacoDeth]

Which reminds me, biggest worry is I will be attempting to use Rivets to attach pieces of Sintra, especially at flexing joints so hopefully the armor will be flexible (such as at the knees, etc.) and I am mainly worried about the pieces of Sintra scraping against each other and freely taking off paint.

 

[ShatirLavan]

One of your problems could be mixing different brands of paint. I've heard bad things about Krylon reacting with other brands. On my own custom Mando bucket, I mixed two brands (one paint, the other clear coat) and the paint started looking like mudcracks.

 

[PacoDeth]

Maybe I should try a different kind of Primer. I'm using this basic home "Sandable Primer" stuff, but I keep seeing people mention "Self Etching" primer, but I'm not quite sure what that is, or don't think I have seen it in stores (off hand). I'll be making a trip on out to Lowe's shortly to see what they have, I might also try out the paint made specifically for plastics, but really only need it for a primer.

 

[PacoDeth]

So a pretty positive update. I went to lowes, and found this Home Traditions spray paint that is made for spraying onto plastics. And it's actually a Plastic Primer that sprays on clear! So today I sprayed this stuff on another test piece, followed it up after the recommended hour with the Krylon Silver with a couple of coats, waited another good hour, and finished up with a coat of the Transparent Red Testors.

So, only giving the Testors a good 30mins or so to dry, it's dry to the touch but still a little sticky, but the paint isn't coming off to the touch. Unforunately, using a fingernail scratch test, just takes the red paint off with ease, leaving the silver coat underneath showing. This however is a step in the positive direction, as before I was taking all 3 coats of Primer/Silver/Red off with the fingernail. I will test tomorrow in case the paint needs even more time to dry, but I doubt things will change.

What I am guessing I am looking at here from other posts about painting, is that the Testors doesn't much like to go over the Krylon. Unfortunately Krylon doesn't appear to make any sort of Transparent Red, so I suppose I could try to track down some Testors Silver, but spending $3 a pop on those tiny 1/3-size cans is going to get old quick.

Any ideas or recommendations from you veteran Sintra painters?

Lastly, I purchased a Riveting Gun at Lowes ($18) to test out, and it works GREAT for attaching pieces of Sintra. If anyone cares to use rivets, you also need to buy the rivet "washers" to get a good solid rivet that isn't going to rip through if you put alot of strain on the material. Provided you don't mind the look of seeing the small rivet disc on the outside of your armor, it provides a good flexing and moving join, which should do wonders for knee-joints and the like.

Will post some pics of work so far when I get batteries my camera likes.

 

[GCNgamer128]

You did sand the Sintra... did you?

 

[Stormrider]

I use krylon fast dry. Its at wal mart. ITs like 3$ a can.

I use gray sintra, so scratches arent as visible.

I use a coat of primer, then the silver, then a clear, then the paint.

I also use a release agent to peel back the paint and it works well.

A little scratching wont hurt much. And a clear coa over the top, will harden it up also, just make sure you pick your type of coat properly. Gloss, satin, matte etc.

ciao

 

[PacoDeth]

You did sand the Sintra... did you?

Hmm, no I didn't sand it, was hoping I didn't have to, but what grade sandpaper would you recommend?

Well good news, except for my wallet, my last test involved a couple coats of the Plastic Primer, followed by some Testors Silver, and finally topped with Testors Transparent Red, and the paint no longer scratches off easily! I can still put some markings on the paint with my nail, and break the paint if I really try, but I think that will be better taken care of once I give it a couple clear coats. By the way, I plan to use Glossy Clear Coat to help keep the metallic shine if you all think thats a good idea.

Once you hit me back with what grade of sandpaper to use, I will start sanding the Sintra as well, because it couldn't hurt.

Here are a couple of pictures of my test piece. The first is the topside, with the old paint scheme that as you can tell, has many scratch marks where my fingernail was easily taking the paint off. The rivet top in the picture is about as big around as a AAA battery, and actually looks and paints real nice. And as you can tell with the white unpainted Sintra being exposed, it's definately rotate-able:

This next picture is the last test, that is pretty well scratch proof, and you can also see the underside of the Rivet here, the only drawback to using Rivets. The metal isn't sharp or dangerous at all, but it does stick out a bit:

 

[darkjediknight]

Unfortunately Krylon doesn't appear to make any sort of Transparent Red

Krylon does make a transparent red. Its made to be used for a stained glass look. Heres a link

http://krylon.com/main/product_template.cfm?levelid=5&sub_levelid=8&productid=1797&content=product_details

 

[PacoDeth]

hmm, wonder if I can find that locally, will have to go out and look as that will save me a ton o' money

 

[General Grievous]

I'd use Krylon Fusion for the Primer. Just make sure you wipe the plastic with mineral spirits first.
Thin coats of fusion.
Then top coat it.
I'd use this setup:
http://www.duplicolor.com/products/metalcast.html it's available at walmart.
Works pretty Good.
Hope this helps.
Wayne

 

[PacoDeth]

For some reason my Wal-Mart sucks at spray paint selection. I wound up finding better luck at a Meijer in town, if you are lucky enough to live in the Mid-East, these Wal-Martesque stores have an awsome selection of paints (except they go a bit heavy with Rustoleum, which doesn't seem to be a fan favorite).

Picked up this Duplicolor Self Etching primer, which unfortunately only seems to come in Puke Green color, next picked up some Rustoleum Metallic Red and some Duplicolor Metallic Red. Just got done coating two test pieces with the Self Etching Primer and sprayed one with the Rustoleum and the other with the Duplicolor. I kinda like the sparkly effect and the idea of only dealing with one can of paint (as opposed to a silver layer, and then a red layer). So we will see in about 30 mins. if these come out ok, or which comes out better (my vote goes with the Duplicolor).

 

[PacoDeth]

Well I found my formula, and it works great, and nigh impossible to scratch. Start off with the puke green Duplicolor Self Etching Primer, then coat with Duplicolor Autumn Maple Metallic. Previous paint tests (testors and the like) were tough to scratch, but I still could make marks and impressions in the paint with the backside of my fingernail. This two step Duplicolor setup prevents any sort of marking with the backside of my fingernail and as much pressure as I can put on it.

I have already drilled the holes for my first test boot pieces, and will be painting them up tomorrow and will post them on here if I can. Thanks for the help!

 

[GCNgamer128]

I sand with 60 grit, then 100 grit, then 200 grit, then wetsandi with 400 grit.