Saturday, July 23, 2011

Testing out decals

Today I did a test run of applying decals and experimenting with clear overcoat on the powder coating. 

In a typical restoration, like a featherweight, it is my understanding that you first apply the decals to the painted surface and then apply a clear coat finish over the top of the decals.  The clear coat adds a protective layer over the decals so you don’t have to worry about fabric, zippers, etc. rubbing them off when you are sewing.

However, my restoration is not very typical (as you have probably figured out by now).  I’m planning on powder coating Ms. Rusty and applying decals to the powder coated surface.  The problem is that you cannot apply standard clear coat paint on top of a powder coated surface.  It is just too slick for the clear coat to adhere.  In fact, I’m not entirely sure the decals themselves will even adhere to the surface – which is why I am doing a test run using scrap decals and scrap powder coated metal.

In a previous post I powder coated a scrap hinge to practice my powder coating skills.  I’m using that piece and a single straight line of gold decal for my test.  The first step is to place the decal in some water to help loosen the decal from the background paper (see photo below).

Scrap metal & decal

After soaking the decal for about 30 seconds I placed the decal and paper on the powder coated hinge.  If you look closely, you can see the decal is already separating from the decal.

decal sliding off paper on metal

Once you have the decal where you want it, the paper is pulled away from under the decal leaving it adhered to the surface.  It helps if there is a bit of water under the paper (or on top of the metal) before laying the decal.  It also helps if you trim the piece to the proper dimensions before soaking the paper.  You’ll notice in the photo above that I didn’t do that step so I had to do the trimming after the decal was slide off the paper and sliding around on the surface – not fun and not recommended!

Then take a small moist brush to brush out any air bubbles from under the decal and remove the excess water.  I found it helped to use cotton swabs for the water removal.  Then you simply let the decal dry for a few hours or overnight.  Here are some photos of the results.

applied decal - 2applied decal - 1

Next was testing out the clear coat.  Because the powder coat is like a plastic surface I decided to use Krylon Fusion spray paint which is specifically designed to be used on plastic surfaces.

This can be purchased a NAPA or other local auto/home shop - Krylon clear coat

I sprayed on two quick coats and found it covered the decal quite well, but left a milky appearance as shown below (compare hinge half with decal to half without decal)

Hazy finish (2)Hazy finish

Fortunately, the directions on the Krylon® can state that this is perfectly normal and disappears within 24 hours.  I was a bit skeptical, but it turned out to be true. 

no hazeno haze!

Had I tried this for the first time on Ms. Rusty, I guarantee the milky appearance would have completely freaked me out so I am VERY glad I ran this test first.

I then ran a few other tests on the finished test product, including a serious dousing with kerosene and applying sewing machine oil (Obviously I did this one after the other and not at the same time.)  The good news is that the finished piece passed with flying colors.  In fact, I think the sewing machine oil could be used as a good polish for the finished piece when Ms. Rusty is all done.

I also tried peeling off the clear coat and/or the decals with my fingernails and the tip of a screw driver.  If I really tried hard and dug deep with the screw driver I could scrape off a layer of the clear coat, but I believe the clear coat will hold up pretty decent to normal wear and tear.

Conclusions:

  1. Decals can be safely applied to powder coated surfaces
  2. Krylon clear spray paint works provides a decent layer of protection to the decals.

2 comments:

  1. fascinating blog. can't wait for the next installment!

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  2. Thanks! It helps keep me moving forward with this project knowing there is someone out there wanting more.

    Btw, I enjoy your blog as well :)

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