Introduction

KAWASAKI H2 has a heavy vibration (you know well, right?), so sometimes parts are missing during a running. I once missed one black knob of a side cover and I disappointed for it. I got one NOS knob with a collaboration of my US good friend, Tom-san and one from Y.T. in NAKTC (thank you Tom-san and Y.T.!), but I concerned that if I dropped it again. I remember that Japanese classic car magazine featured about a plastic parts reproduction. I tried to make it because it doesn't a matter if the missing part is "Reproduction".

Step 1 : Buy Materials

I bought silicone (Silopulene RTV-2K 1406, Toshiba-silicone co., ltd.), urethane resin (Hobby cast), black toner (for coloration), oil clay and some polyethylene disposable cups (I use them again and again...) in a hobby shop.

Step 2 : Making a Base with Clay

Make square shaped clay block and bury a half the original knob into the clay then enclose around the clay with plastic plates. You can make the half mold after you pour the silicone into the enclosure but you should consider so that you can remove the original after the silicone is fixed. For example, if you bury a Pepsi bottle into a sand upside-down, you can make a sand mold easily but if you do the same thing with Coke bottle, the mold is collapsed when you remove the bottle from the sand because the bottle has a pinched-in waist. Oh, I've forgotten to tell you a important thing. You should make two or three holes on the clay surface with pencil etc. This will be a guide pin for a connection of two molds. Do not forget it!

Step 3 : Pour the Silicone!

When you completed the above, weigh the silicone in a plastic beaker with kitchen scale (do not tell it to your wife!) and add a stiffener and mix well with plastic spoon. The quantity of the stiffener is about 25 drops per 100 grams (please see the instruction of the silicone). Make sure the stiffener is mixed well, then pour the silicone gradually. Do not pour it at once. First, you should pour the silicone in a holes and hollowed surface of the original with the silicone dropped like a thread from the mix spoon. When the silicone is filled in the holes, add the silicone so that the original knob is hidden enough.

Step 4 : Pour the Silicone, part 2

The silicone is fixed after 4 to 5 hours. Remove the plastic enclosure and the clay. When you remove them, you have to take care so that half of the original knob is still in the silicone mold. To make an upper mold, set the plastic enclosure again around the silicone mold. Apply a diluted kitchen detergent (do it when your wife is out!) with small brush on the surface of the silicone mold to prevent sticking the upper and lower silicone molds. Allow to dry and then pour the silicone with same manner.

Step 5 : Complete the Silicone Molds

The silicone is fixed, separate the upper and lower silicone mold. Then, remove the original knob. The molds are completed. To pour the resin in the mold, make a pour port and air exhaust port with a cutter. Port design is very important to eliminate a bubbles in the product (it's sound like two stroke engine tuning, isn't it?).

Step 6 : Pour the Resin in the Mold

Connect the two molds and fix them with rubber bands. Weigh a resin and a stiffener (same weight each) separately and add black toner a little into the resin. Place the resin and the stiffener into a plastic beaker and mix it soon. Pour the resin in the mold through the port of the mold until the resin is out from the air exhaust port. The pot life is very short, 2 minutes, so you should complete the work quickly.

Step 7 : I've got it!

Separate the molds carefully after the resin is fixed. Yeah! I've got it! Oh it has a same shape as the original (no surprising matter). The minor troubles are remained tiny bubbles in the plastic and the color is getting gray because the base color of the resin is white. I'll try it again with black resin!

As I mentioned above, reproduction of plastic parts is not so difficult so I would try to different parts. The next target will be aged YAMAHA fuel tank emblems for HX 90.

The photos above are the result of reproduction using a black resin. The left photo is for H2/H1 (knob diameter approx. 40mm) and the right is for S1/S2 (knob diameter approx. 32mm) . The right knobs in the both photos are the original knobs. Please note the tag of H2 knob said "KAWASAKI AIRCRAFT CO., LTD." which is the old company name of KAWASAKI.

If someone who would like to take these re-production parts, please click the joke tag shown below.

If you have any queries about the plastic casting, please get in touch with me via e-mail.

Hey! Let me take to the main page, baby.