Posted by Torvald [162.158.107.172] on Tuesday, May 31, 2022 at 12:56:53 :
In Reply to: Ebonite Steering Wheel posted by Todd Miller [172.70.214.153] on Sunday, May 29, 2022 at 20:51:58 :
Yes, the wheels are rather soft, which makes sanding the repair material very tricky unless one doesn't care about removing great quantities of the ebonite. To prevent digging into the ebonite always back up your sandpaper with something hard so that it doesn't dig in. I prefer to initially use small files so that I can remove only the repair material. Also, it’s probably best to only apply repair material where it is needed rather than smearing it all over the wheel (makes for less material to be removed later). The flexible bumper adhesive that Adam suggested might be better than the epoxies that I used. I recently rebuilt my steering wheel; here is the procedure I used:
The steering wheel was severely cracked (see 9640 – 9644).The cracks ranged from barely discernable hairlines up to 1/8” gaps. The goal of repair was not just to make the wheel look good, but to also restore its structural integrity for decades to come. With that goal in mind, three categories were set for repairs; hairline cracks, somewhat larger cracks, and gaps. The cracks and gaps had to be not just filled; the fill also had to be bonded to the existing material. The hairline cracks were repaired with penetrating superglue (Loctite 420). The somewhat larger cracks were repaired with regular liquid super glue (Loctite 45209). The gaps were repaired with 2 part epoxies; J-B Weld Plastic Bonder (preferred), and a 5-minute epoxy.
1. Before repairs, the wheel was thoroughly scrubbed down with Simple green to remove caked on oils the would interfere with adhesion of the repair materials.
2. All gaps were then cut/filed/ground out to at least 3/16” to allow the epoxy to penetrate to the bottom of the gap (see 9648).
3. The super glues were applied to the cracks, sometimes taking several applications to fill the cracks.
4. Since the epoxies were a bit runny until set, they were also usually applied in a few layers until the epoxy stood a bit proud of the ebonite. Care was taken to only apply the epoxy to the gap, not smear it all over the area.
5. After sufficient epoxy and super glue had been applied to entirely fill gaps and cracks, the portions that were proud of the ebonite were very carefully filed down with jeweler’s files (6” long files). After filing to near final surface, the surface was finished with 320 sandpaper backed up with a file or other hard surface, and then 400 wet-or-dry.
6. After filling cracks and gaps, the wheel was painted with an automotive primer and sanded again with 400 grit wet-or-dry. Final coats will be enamel paint. Do not use lacquer; the oils in your hands will attack it.
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