Backglass Repair

This page details the Backglass repair processes I performed on a 1976 Williams Blue Chip Backglass. The procedures closely follows the steps described in Clay's document:

http://www.marvin3m.com/restore/index.htm

The backglass was not in the best of shape. It had peeling & flaking and was missing paint in several areas. Below are the steps I took to make it a little more presentable.

	STEP 1: Seal the Backglass
	STEP 2: Touchup the areas that are OPAQUE
	STEP 3: Touchup the areas that are Translucent
	STEP 4: Cover the touchup areas with Silver paint
	STEP 5: Enjoy the Finished Product
	Conclustion

STEP 1: Seal the Backglass.

I used Krylon Triple Thick for this. This stuff really smells bad. I did it in the basement with little ventilation and the smell gave me a headache! Being the middle of winter, I didn't have any other place to do this where the change in temperature wouldn't cause damage to the backglass. The product worked great. It sealed the backglass and help to "lay down" a lot, but not all, of the lifting paint.

Here a picture of what the can of KRYLON CRYSTAL CLEAR GLAZE looks like. This product is a GLAZE and can NOT be found at Home Stores but can be found at Arts and Crafts stores like MICHAEL'S.

Right below the triangles is the product number "No. 0500".

Here is a picture of the FRONT of the Backglass before any work was performed.

In the game with the lights on the areas that jump out are:

	Red MATCH area at top
	the Red word WILLIAMS above the word BLUE CHIP
	the light blue areas by the words BLUE CHIP
	by the word GAME OVER

The same shot without the game lights. Here you can see how bad these areas are:

	Red MATCH area at top
	the light blue areas by the words BLUE CHIP
	by the word GAME OVER

What you can't see in the pics is the areas of paint lifting in the bottom Yellow & White sections of paint.

Here is a picture of the BACK of the Backglass before any work was performed.

Notice how bad the areas are:

	MATCH area at top
	by the Steel Workers
	by the words BLUE CHIP
	by the word GAME OVER

Here is a picture of the Backglass AFTER being sealed. Notice the Score Reel and Credit areas are covered - I used business cards cut to the right size and held down by large nuts obtained from the hardware store.

Remember to start outside of the Backglass and use a sweeping motions ending past the Backglass.

Do TWO wet coats - one going North/South and the other going East/West.

STEP 2: Touchup the areas that are OPAQUE

The Krylon Triple Thick worked great. Several times I had to remove the paint I placed onto the back of the Backglass. To do this you have to use water, which is a Backglass worst enemy. With the Backglass being sealed, the only thing being exposed to the water is the water-based Acrylic paint I put on.

I went to DEE's CRAFT store to purchase my water-based acrylic paints. The ladies there really, really helped me out on color matching. I took my backglass into the store with me! We took samplings from the bottles and placed them on the front of the backglass to see if they would match. This helped narrow down the colors (and shades) that I needed to purchase.

The ladies thought I was a little nutty, but were really interested in my project - they hadn't heard of this hobby before (restoring pinballs). I think they thought it was neat that a MAN was in the store. I was there for two hours and I was the only guy in there. They know who I am - I've been back several times and they always ask me how my pinball projects are going.

There are two major tricks with backglass paint matching.

Acrylic paints dry DARKER.
Paints will be darker on the back of the backglass than the front.

This combination means that if you find a match by placing the paint on the front of the backglass is will be way too dark. You have to find a color/shade that is too light and then when it drys and is placed on the back of the backglass is will darken to the correct color. Tough to master at first but you get used to it - eventually.

	Here is a picture of the back of the Backglass after being touched up. Notice the rainbow of colors (Red, Yellow, Light Blue, Green & White). These are in the Non-Translucent areas and will be covered up with Silver Metallic Paint.
	Here is picture showing me trying to match the LIGHT BLUE area. I couldn't find an exact match so I had to start mixing paints. You can see where I placed samples on the Backglass to see which combination matched. This is the tedious & boring part. Mix a batch, touchup & let dry.
	Here is picture showing me trying to match the ORANGE area. I couldn't find an exact match so I had to start mixing paints. You can see where I placed samples on the Backglass to see which combination matched.

STEP 3: Touchup the areas that are Translucent

Same process is done for Translucent as non-Translucent. Its very hard to match Translucent areas, so its not recommended you do them unless you are VERY good and know what you're doing OR your less than perfect work is better than what's currently on the Backglass.

The issues here are you can see

	the brush strokes
	the different thickness of the paint when light passes through it

Its practically impossible to get the paint thin enough, a consistent thickness and to not leave brush stokes.

On the attempts I made, I failed so I only tackled the word GAME in the Game Over area because all of the paint was missing and this rarely shows up. When the game is over, only the word OVER shows up, which gets the message across to the player. I touched up the word GAME so the backglass would visually look good. I had to put Silver Metallic paint on the back to mask out the light.

One thing that might work (but I haven't tried) would be to mask off the area to be painted, thin the paint out and then use one of those air-brush kits for model cars. This should solve the problems. The trick will be in getting the paint thickness to be extremely thin, but still cover the area.

STEP 4: Cover the touchup areas with Silver paint

Here is a picture showing the application of SILVER paint which will make the paint NON-TRANSLUCENT and help to visually blend your touchups into the original silk-screen product.

STEP 5: Enjoy the Finished Product

	Here is a picture AFTER the Backglass sealing & touchup - NO Lights
	Here is a picture AFTER the Backglass sealing & touchup - Lights

Conclusion

Here are the colors (name, code, company) I used on the project:

	Red -> Cadmium Red (DA15) - Americana
	Yellow -> Lime Green (20213) - Apple Barrel
	Green -> Mistletoe (DA53) - Americana
	White -> Ice Blue (DA135) - Americana
	Brown -> Dark Chocolate (DA65) - Americana
	Black -> Black (20504) - Apple Barrel
	Silver -> Silver Metallic (DA70) - Americana
	White for mixing -> White Wash (DA02) - Americana
	Yellow for mixing -> Yellow Light (DA144) - Americana
	Orange for mixing -> Burnt Orange (DA16) - Americana
	Light Blue for mixing -> Dutch Blue (20522) - Apple Barrel

Here are the ratios used during paint mixing:

	Orange -> Yellow Light & Burnt Orange - 5:2 Ratio
	Light Blue -> Dutch Blue & White Wash - 3:2 Ratio

None of these colors were perfect matches. If you studied the backglass up close you could find the touchups. However, if you are playing the game or casually strolling by the touchups are nearly impossible to detect.

The only portion of the project I am unhappy about is the fact I couldn't touchup the Translucent areas. The backglass would look so much better if the words BLUE CHIP and WILLIAMS could be touched up and still translucent. I can touch them up, but I would have to cover them with Silver Metallic so they would not allow light to pass through.

These areas actually look better with the game lights on then when the game is turned off. So the choice was to have them look good with game off vs. game on. I decided to leave them alone. Maybe one day I'll find the magic pill on how to touch up the translucent areas.

This page was last updated on 04/11/03