H1 , Chapter 6.

The next chapter of my H1 build has lots of nifty stuff in it.  At this point, I'd gotten most of my engine back together, and have most of the shiny bits bolted back on. While I was at it, I put some stiffer clutch springs in. Fortunately, it seems as though the clutch it's self was replaced not to many miles before I bought the bike, so it didn't need to worry about that.

With most of the bike it's self down to painting and bolting stuff on, the rear fender is the last big "fabrication required" project. A plain smooth fender like I've got is fine for a race bike, but this one will be street ridden. That means it's going to need blinkers and a tail/brake light. I started planning them as soon as I started planning the fender. I didn't want them to look like tacked on afterthoughts like you see on so many customs, and even a lot of factory bikes. I explored lots of options. What I decided on is very custom, very visible, and most importantly don't stick out like sore thumbs.

The blinkers are made out of 1/2" Lexan. I cut 1/2" off the bottom of the fender, 'glassed on some tabs, bolted the Lexan down and sanded to shape. I then ground out the back sides for some LED strips. I've got 21 LED's shining out through the Lexan. More on the blinkers later, but here's a rough pic so you get the general idea:

Next up is the tail/brake light. This one took some finesse to get looking how I wanted. It's a straight forward process, but involves a lot of fitting. Like the blinkers, this lens is going to sit flush with the fender so it doesn't interrupt the lines.

I'm using the oven method of plexiglass forming. I'd like to use Lexan, but it's not as forgiving as plexiglass when baking it in the oven. First thing I did was make a plaster cast of the back of the fender. I just used some modeling clay to make the walls after I'd figured out what size and where I wanted the lens.  Mixing in some plain white Elmers glue will greatly increase the strength of the plaster.  You don't need much, around 5%-10% of the water added to the plaster mix works well.

I let the plaster cure/dry out for about a week. It can take awhile for all the water to finally evaporate out of the plaster.  warming it in teh oven can help too, as long as you don't heat it up too fast(or it could crack).  Then I cut a piece of plexiglass, set it and the plaster mold in the oven and baked it at 300*F for 10 mins or so. It gets soft enough that, with some gloves on, you can smoosh the plexiglass into the plaster buck. It took a few re-heats to get the shape just right. Also, you can see the pencil on the plaster, that's about where the lens is on the fender. I found that if you draw it straight on the fender, the pencil line will transfer nicely to the plaster.

With some rough trimming, you can see how well it conforms to the fender.

The next part take a lot of grind, check, grind. Took me about a day of messing around to get it perfect. Once the hole is cut in the fender, the lens can be cut, ground, filed, and sanded to fit just right. When you're done, you've got a custom flush fit lens that perfectly matches the contours of the fender.

Then I dyed the lens. It's pretty easy, but it took a few test pieces to get the time & temperature right. Plexiglass can be easily dyed any color you want with Rit fabric dye. The secret is to heat it up. If the dye is to cold it won't take, if it's too hot the plexiglass can get soft and warp. Just under boiling seems to work best. I've had the best results with the dye heated on the stove to about 190*F, and a cook time of around an hour. More or less depending on how dark you want it, and a meat thermometer works great for watching the temp. The same process works for dying the clear fuel line the color of your choice.

If you want to use Lexan(polycarbonate) instead of plexiglass, there are a couple things to note.  First, Lexan absorbs moisture like a sponge.  If you just try to heat it to it's forming temp, you will end up with plastic full of bubbles.  This is caused by steam forming in the plastic and having nowhere to go.  You MUST pre-dry Lexan before forming it.  The general rule of thumb is to bake it at 250°F for one hour per .010" of thickness, so 1/8" Lexan should be baked for 12.5 hours.  Second, Lexan forms at a much higher temp than plexiglass.  It needs to be heated to around 375°F to be moldable.  Third, You cannot dye Lexan, it just won't work.  If you want some color other than clear, you either need to start with that color plastic, or use one of the few paints on the market that will stick to polycarbonate(regular spray paint won't stick well).  The paints made for RC car bodies(NOT standard model paint) are made for polycarbonate and are available in translucent colors.





Now, back to the blinkers.  The first thing I did was get one of THESE $10(shipped!!!) 40 LED 3rd brake lights(and if you don't shop DealExtreme, you should. They have all kinds of nifty stuff at dirt cheap prices. Shipping is sloooooow, but it's free.  The price you see is the price you actually pay, no extra shipping or handling. Stuff is so cheap, you can't afford not to buy it :D  http://www.dx.com/p/40-led-third-brake-tail-light-for-vehicles-12v-10524#.Vf97V5cqvXw

Then I opened it up, and cut the circuit board in half, giving me two 20 LED strips. I got out the Dremel and ground a slot in the back of the Lexan for the LED strips to sit in. Unfortunately, Lexan(polycarbonate) doesn't dye like Plexiglass does. The dye just doesn't take. I tried some other things, but couldn't get consistent results. That means I had to paint it. I used white, then black on the top(the white base coat helps reflect any stray light). I used SEM Color Coat, which sticks to Lexan fantastically.  The edge and bottom are painted with Duplicolor's Metalcast red. It's basically a red tinted clear in a spray can, made to give chrome an anodized look.  It also sticks to the Lexan like a champ.
http://www.duplicolor.com/products/metalCast/

Here's how it looks. It's just taped together for now, the final pieces will be siliconed together to weatherproof the circuit board. It lights up nice and bright, and reasonably evenly. The dark strip is one of the bolt holes through the Lexan. You can't really tell in the pic, but unlit, the lens is a nice deep red.  Off:

On:

Just for kicks, here's what the blinkers look like lit up when they're installed.

That's all for this chapter.  The end is approaching... :)