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Posted: Tue Jul 27 @ 10:51 pm Post subject: 1981 Gottlieb Black Hole Pinball Restoration
Several weekends ago; a local pinball friend (thanks Joe!) offered me a deal I couldn't refuse on a 1981 Gottlieb Black Hole Pinball Machine. So being my first restoration of a Gottlieb machine; I'm sure I'll learn a lot. Besides; Someone has to do some modding around here.
Unlike the 1979 Bally Star Trek I did last year; this GTB machine is considered "high-maintenance" and has frequent electrical issues. My goal is to return the machine to near new condition; and do most if not all of the circuit improvement suggested by Marvin's fixit site: http://www.pinrepair.com/sys80/index.htm in a effort to reduce this machine to a "it just works" machine.
This machine is a project machine which will require cleaning and releveling the Playfield inserts on both the upper and lower playfields. Many of the inserts have either fallen or risen due to heat and glue break down. Like the Bally machine; Both PFs will receive auto clearcoat to protect the playfield. The Black box will also need some door repair.
I have lots of plans for the machine as far as mods go... I think the machine will receive a set of flipper led mods since the buttons are identical to the Bally Star Trek. I'm thinking of doing something special with the pop bumpers - but you'll have to wait and see on that one.
As with all pictures in the worklog; remember to click the pictures for higher rez shots.
Here's the machine as it was unloaded from my truck:
Lower PF via blue window in the center of the upper PF:
Posted: Tue Jul 27 @ 11:38 pm Post subject: Re: 1981 Gottlieb Black Hole Pinball Restoration
I wanted to start on the lower PF first; since it was smaller and had less componets to remove on the top side. It also has the most insert lifting but nearly no PF wear. So I pulled the lower playfield out of the machine and pulled off the dirty plastics.
The first thing I learned is I H-A-T-E those GTB press-on acorn "nuts". They are nearly impossible to remove (or I don't know the trick) without damaging the platics. Those press-on standoffs would be the first to go when reinstalling the PF parts. Terry at PinballLife.com sold me a set of the newer standoffs which have #6-32 threads on top; those will be used in combination with some stainless steel acorn nuts with make removing PF plastics easy-peazy.
Here's the very dirty Lower PF with plastics removed.
Yeap - very dirty. And yes; there is some rust on some peices.
Take another angle shot; so you can remember where to return the parts on the PF:
Next step is to remove all the top side componets, screws, rails, bulbs, etc... and clean it well. For this I used mean green and a melamine foam sponge as was done in the Bally Star Trek worklog. This time the underlying PF was not flaking or signifigantly worn - and I took care not to be agressive with the cleaning.
I made sure to tape off the drop target holes as I did not remove them from the under the PF. I also taped off the filpper holes to prevent build up of soot and/or auto clear coat.
Next I used a heat gun, a rubber mallet, and a steel ruler to "level" the three captive hole blue inserts:
Now it's time to put the one light and one heavy coat of clear on the PF. Why? The clear coat to protect the PF from wear from the ball. Unsure if GTB had any protection on these early machines; but I'm guessing that like the Bally's of this era the only protection is "wax" put on over the painted PF.
Apply two coats of Dupont ChromaClear G2-7779S clear coat w/ 7785S Activator-Reducer. These two are mixed at a 4:1 ratio and allow for a flash of 20-40minutes between coats. Apply in thin light coats; don't go overboard of the clear coat won't cure.
I applied the coats using a HarborFreight HVLP Gravity Feed Spray Gun. Set the pressure dial to 20PSI so I got ~10psi when trigger is depressed.
Allow the two coats to cure overnight.
The next evening after work; It was ready for the orbital sander with 100grit discs. This was done to level any remain Playfield areas such as center dipping or ball wear. It's also done to remove the inital orange peel seen in the previous clear coat.
I then wiped away the sander dust to verify the inserts are flat:
TAKE CARE; do not blow through the clear coat and destroy your original paint! (I learned that lesson in the Bally ST worklog)
I then applied one lite and one heavy clear coat as a final protection. Again; at least 20minute flashes between coats and an overnight cure.
Then like the bally; the final sanding begins to remove the orange peel and restore that PF shine. Orbital Sander @ 150grit and the 220grit. Hand sand with wet/dry (wet) with 320grit, 500grit, 800grit, 1000grit, 1500grit. Then use the buffing wheel to apply two rounds each of rubbing compound, polishing compound, and carnuba wax.
Nice, shiney, and smooth:
Sandblast away the rust, Polish the visible metal peices, and return the parts and plastics to the lower playfield:
With that; The mechanical work on the lower PF is complete... however, the electronics will need some fixes per marvin's suggestions.... I'll tackle that later when I get a digikey order created and purchased.
Posted: Sun Sep 05 @ 9:39 pm Post subject: Re: 1981 Gottlieb Black Hole Pinball Restoration
Now that the Star Trek Conventions are out of the way; Attention returns to the Upper Playfeild where I begin by disassembling all the top componets as like bottom PF; it will get automotive clear coat to protect the PF... and some touchup paint.
Click Images for hiRez
Unlike the lower PF; the upper playfield had some serious sinking playfeild inserts; so these ares are going to need to be fixed as well as the areas near the PF window which have been rubbed to wood.
To raise the inserts; I used a heat gun to loosen the glue in the insert and the used a nut driver and a rubber mallet to raise them. Once I had them above the PF; I used a metal ruler and the mallet to "level" the insert to the PF. If the Insert was really loose; A couple were; I used some clear glue around the insert before leveling.
Once the inserts were level; I created some arrow shaped outline templates in corel draw; then proceeded to cut them out on the laser cutter out of transfer paper. I then carefully layed them over the inserts to redo the outlines:
Applied black enamel with a testors pen:
While I was at it I touched up other areas of the PF... namely the black where the turbobumper mylar use to be. Also touched up the areas around the PF winder were there were chips and wood showing through.
Finally removed the transfer tape:
With the touchup complete; I put 4 coats of automotive Clear Coat with 20minute flashes between the coats. Then I sanded the PF flat - begining with 100gril orbital, 150grit orbital, and then 220 orbital. There were still some areas around the inserts (between inserts and wood) where there were some valleys so I used some clear and a small artist paint brush to fill with clear coat. 4 more coats of clear now that the PF was level. Then 220grit orbital, 400grit, 500, 800, 1000, and finally 1500 grit hand sandings of the clear coat. Then rubbing compound, polishing compound, and then carnuba wax to make the PF shine.
Posted: Sun Sep 05 @ 10:00 pm Post subject: Re: 1981 Gottlieb Black Hole Pinball Restoration
I needed to order some parts from the Pinball Resource before I could begin to re-assemble the top PF; so I decided to spend some time on the shooter of the machine. Lets start with original pics of the shooter trim:
Ick! That won't do.
I could have bought a new shooter trim plate; but I wanted to experiment a little. So first I began by sandblasting the plate of it's rust. Then I polished it to a shine using 40, 80, 100, 280, 500, 800, 1000, 1500 grit sandpaper. Following up with rubbing and polishing compound.
There were still some minor nicks and valleys in the trim; so I decided to try some experiments and settled on the following.
First, I scanned in the Manual logo and converted it to vector in Corel Draw. Then put some fiberglass tape on the plate where I laser vector cut the black background into the fiberglass tape using 100% power and 8% speed:
Then using my exacto knife; I carefully removed the letters from the tape:
Out came the powder coating gun and oven:
Remove the fiber tape:
Overlay some Transfer Tape and Laser etch the foreground lettering:
The carefully remove the detail areas with a set smt tweezers:
Sandblast with iron oxide:
Examine our work:
And then coat with some final clear powdercoat to protect the metal from future rust and grimmy hands:
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