Sunday, September 2, 2012

Part 23 - Raising the forward controls

On the first test ride, I scraped the Forward Controls badly during low speed maneuvering. To raise the forward controls higher off the ground, Forward Control adapter plates were hand fabricated from 3/8" steel plate. The dimensions were determined by measuring the existing mounting points.  A simple model was created to offset the mounting points - eMachineShop is great free software for basic 2.5D drawing and modelling.

The design was printed using 1:1 scale and the resulting template was transferred to the 3/8" steel plate. An angle grinder with 0.045" cut-off wheel made quick work of creating the basic shape. 

Basic shape transferred to 3/8 plate suing a sharpie

Rough cut 

Abrasive disk takes care of detail shaping 

Original mounting holes are countersunk and new holes tapped

Similar process for the right side 3D model

After rough cut and smoothing with abrasive disk
Making holes - 3/8 clearance holes for original mountings and 3/8-16 tapped holes for new mounting points

Countersinking the original mounting holes
Completed left side forward control adapter plate

Left side adapter plate mounted using 3/8-16 flat head bolts

Right side -  offset is up and slightly forward to clear the exhaust

The forward controls simply bolt to the relocated holes on the left and right adapter plates. Proper countersinking of the flat head bolts is essential so that the controls bolt to a flat surface. Test ride after installation was a major improvement.

Saturday, July 21, 2012

Part 22 - Sealing the gas tank

This is a highly contentious topic. The chopper forums are riddled with strongly polarized opinions. Bottom line is that your custom gas tank has welded seams, mounting points, petcock bungs, crossover bungs etc that could all potentially leak. Leakage is caused by microscopic pinholes that occur during the welding process - these allow a tiny amount of gasoline vapor leakage to the atmosphere. Over time this causes the paint to bubble destroying your paint job. If you paid for a custom paint job, you are easily anywhere from $2000 to $5000 in the hole so you decide whether you are prepared to risk it. A properly welded tank should not leak.

I welded crossover bungs into my tank. While it appears to be fluidically tight, I can't tell if there are pinholes. Pressure testing is difficult to do and there is no telling whether stresses from vibration won't open up a pinhole leak point. The other thing to consider is rust prevention. The conventional wisdom is to keep gas in the tank - the vapor displaces the oxygen which prevents rust. Having seen rust develop inside my tank because the gas cap leaked during wet sanding, I felt more comfortable sealing. Much research on the web yielded 4 candidates

  • Kreem - most opinions recommend to avoid this product. Hard to tell if this is because of sloppy application or what. I find it hard to believe that a poor product would be on the market as long as it has been. 
  • POR-15 - what I used. A lot of people swear by it but there are some negative opinions out there. As with all products, following instructions is key to successful application. Has well proven rust prevention characteristics.
  • Redkote - similar opinions to POR-15.
  • Caswell Epoxy - similar opinions to POR-15

You can Google each of these products and make up your own mind. 

If you are going to seal the tank, you should seal before you paint the outside of the tank!!!

The first two steps in preparing the tank for POR-15 are to clean and etch the insides. First an application of Marine Clean dissolves all grease and oils on the inside of tank. You can seal the ports in your tank with Duct tape. Follow the instructions - 

Next, treat the tank with Metal-Ready. Follow the instructions. The jug on the left has the dirty Marine-Clean that came out of the tank after 2 hours. Each surface needs about 20 minutes of cleaning time. I did a lot of shaking to agitate the cleaner periodically. 

Each surface within the tank needs to be exposed to the Metal-Ready for about 20 minutes so you will need to rotate the tank into a new position for each exposure - same process as for the Marine-Clean. The Duct tape did leak a bit while the tank was upside down but this was minor. After Metal-Ready is complete, the tank needs to be emptied and rinsed with hot water a number of times. They recommend no longer than 2 hours of exposure to Metal-Ready. 

All in all, roughly 4 hours of cleaning time..... fun hey!

The next step is to thoroughly dry the tank. It must be absolutely dry. Use a hair dryer or heatgun to force warm air into the tank to dry the inside. I also baked the tank in an oven at 200F for a couple of hours after this to make sure that it was absolutely dry.


Then the POR-15 gets mixed thoroughly and poured into the tank. Make sure you have all holes plugged properly. This stuff is messy and sticks like crazy to anything it touches. Lacquer Thinner will clean up small "accidents". Keep rotating the tank to make sure all surfaces get properly coated. 

My tank has a vent line. The sealer plugged the vent line so I had to keep blowing air through it to keep the pathway open. When you are sure you have everything coated, you can open one of your plugged ports and drain the excess sealer back into the can and leave it to harden for disposal. The most important thing to remember is to read the instructions!

The sealer needs at least 4 days to cure before exposure to gas. Play it safe and add a couple of days....

Saturday, June 30, 2012

Part 21 - Bodywork and Paint

It’s time to talk about bodywork. No, not the kind that involves plastic surgery. There’s a lot of bodywork preparation before you can slap the paint on. And slapping paint on is not really how it is done either.

The basic process:

  1. Eliminate all rust and old paint - sandblasting can do both. Surface should be about 80 grit and clean in order for the body filler to grip properly.
  2. Apply body filler to correct small surface defects and sand to 80 grit
  3. Clean the parts thoroughly. Use a degreaser/soapy water and follow with a cleaner like Eastwood Pre. Keep your hands off the surface - use gloves to avoid transferring oils from your fingers to the surface that will prevent paint adhesion.
  4. Apply epoxy primer (2 coats allowing for manufacturer recommended flash time between coats) and wet sand to 600 grit the day after application if needed. You can also proceed directly to paint if you laid the primer on nice and evenly.
  5. Apply top coat and wet sand starting at 1000 grit all the way to 2000 grit
  6. Use rubbing compound and then polishing compund. Use a buffer if you have one and know how to use it without causing damage to the paint.
  7. After 30 days of paint cure time, you can wax the surface.
  8. Sit back and enjoy the result (or call a pro to redo it).

What actually happens:
All rust and old paint from all the parts needs to be removed. Media blasting is an efficient way of doing this but make sure the person doing the blasting knows how to do it without distorting your sheet metal parts. I used Cost $225 to do the blasting. Block off all holes in your tanks properly or you’ll have blast media inside them which is difficult to get out. You could consider getting your parts powder coated at this point but that depends on how much bodywork you need to do. Powdercoat is recommended for the frame because of it’s durability. However, my frame had a lot of imperfections that needed fixing so I didn’t do powder coating.

After getting the parts back, I convinced myself I could still see signs of rust. Got Jasco Prep&Prime from Lowes and followed the instructions (or so I thought). What a disaster. After rinsing Jasco Prep&Prime off the tanks and frame I experienced flash rust. Things looked bad. I used a wire brush and sandpaper to clean everything up again. This was a painfully laborious process which negated the time saving benefits of having the parts blasted. I think I should re-read the instructions before using this particular product again. Rinsing with water is not the way to go. 

Flash rust

Many laborious hours of wire brushing and sanding

The gas tank had a ridge down the center with two concave depressions on either side roughly 1/8” deep.  Here's a short video showing surface prep and application of body filler.

The entire tank was covered with a thin layer of body filler and then sanded down with 80 grit wrapped around a flexible block. This generates a ton of dust so was mostly done outdoors with a sanding face mask.
First of many body filler applications

First of many sanding sessions

This process was repeated many many many times until the surface was perfect. The number of hours that went into the tank makes it most likely the most expensive tank in creation. Fortunately my garage time is free.  The rear fender required some work on the sides to cover up the weld distortion from mounting the internal struts, and to mold in the fabricated taillight extension. The front fender required some minor work too. The oil tank was in bad shape and required a complete coating of body filler and a lot of time sanding. Many hours were lost in preparing the oil tank. The handlebars needed work to mold the gauge cup and panel modifications.  

Frame molding

Rear Fender

3/8 brake line welded in place to protect wiring

Oil Tank

Sanding the oil tank 

Swingarm molding
After bodywork, it was time for paint. To protect everything from paint spray and dust, I erected an 8x8 pop-up tent inside the garage and covered this in plastic. WARNING: Vapor build up inside the tent can reach a level at which the slightest spark can cause an explosion. You have to ensure adequate ventilation and use an explosion proof fan. This is a dangerous way to paint due to the high solvent content. Do not try this at home.

Two eye bolts were screwed into the ceiling to suspend the frame inside the paint booth.  Parts were thoroughly cleaned with soapy water and then wiped down with Eastwood Pre. It is critical to keep your fingers off the parts – you do not want to transfer oils from your fingers to the metal as the oils will prevent the paint from adhering properly. Use a tack cloth to remove any last minute dust fibers that may have settled on your parts. Some tack cloths leave behind a sticky residue so be careful with product selection. If you can remove the dust fibers with an air gun, you will be better off.

In the "booth" ready for primer

The primer is a 2 part epoxy primer/sealer from I used a $15 harbor freight spray gun with a disposable moisture/particulate filter to shoot the primer. The compressor was a borrowed 25 gallon Craftsman unit. I had no prior experience spray painting with a compressor. There is plenty of painting advice on the web and you can get a good insight into the process by reading Joann Bortles book.

Disposable Inline Moisture/Particulate Filter

Harbor Freight Spray Gun

To cut a long story short, the primer came out ok. Always use a mask or respirator, disposable paint coveralls, gloves and safety glasses. There will be a lot of particulate in the air - you don't want it settling on your skin or getting into your eyes and lungs.

Primed Parts

The Eastwood Epoxy Primer was ready to sand after being left overnight and can be topcoated up to 5 days without sanding. The primer was wet sanded with 600 grit to eliminate orange peel and other imperfections. In some places I accidently sanded directly through to the metal so had to clean and reprime sections. This is painful and something you want to avoid by being very careful around the edges.

Primed and wetsanded

Final paint was a single stage automotive urethane from I figured that Single Stage Urethane would be more straightforward to apply than a 2 stage basecoat-clearcoat system for a first time painter. I screwed this up multiple times. Everything got painted at least twice and some things like the tanks.... 3 to 5 times.... Fortunately I bought a gallon of paint.
Bouelvard Black Single Stage Urethane

Painting is a very dusty and messy process.

Paint dust clings to everything
Mask - clean filter and filter after painting

After screwing up the paint application and sanding through to primer accidently a number of times, I resorted to painting outside. Setting up the tent again and managing all the paint dust inside the garage wasn't something I was terribly keen on. Airborne particulate was obviously more of a problem in the open air, and an insect or two landed on wet paint. Insects should be removed immediately so that the paint can flow around the affected site. Nothing a final wet sanding can’t take care of. I ended up with a lot of orange peel. You can probably see it in the handlebars:

A little bit of orange peel

I tried spraying a guide coat of white rattle can paint over the urethane - this allows you to make sure you sand everything down to the same level surface, eliminating high and low spots in the paint. A light misting is all you need. While wet sanding you want to wet often to remove the sanding paste that results. I kept a hose nearby for repeatedly hosing down the parts. Unfortunately I got a lot of water into the tank because the gas cap leaked. This resulted in surface rust on the inside of the tank which had to be treated.

Block wet sanding the guide coat with 1000 grit
After wet sanding down to 2000 grit (1000, 1500, 2000), rubbing compound was used to remove the fine scratches left behind by the 2000 grit paper, followed by a finer polishing compund to remove the marks left by the rubbing compound. There is nothing quick and easy about this process. It takes time and will test your patience. 

Rubbing compound and polishing compound

You should be rewarded by a glossy smooth surface if you do everything right. If you didn't, you will have to grade your work on a scale of 1 to 10 where the number is the distance from the part that the paint looks good. For example, a 10 means the part only looks good from 10 feet away, and a 1 means the part looks good from 1 ft away. My parts ended up being about 2ft parts. I eventually redid the tank completely.....

After urethane topcoat, wet sanding to 2000 grit and Turtle Polish

Frame after top coat, wet sanding, rubbing compound and polish

Some things I didn’t know that I wish I had:

  • Make sure your paint surfaces are scrupulously clean.
  • Figure out your spray gun settings on scrap material. This is trial and error - many videos on have good pointers on spraygun adjustment. I ended up spraying at about 50psi measured at the gun with about a 4 inch fan at about 8 inches away and paint control full open.  

  • Paint settles on the part you are trying to paint and overspray settles on parts in the vicinity. This overspray causes problems because the paint that settles on distant surfaces is relatively dry and causes a rough texture. On a frame this can cause problems if you add a coat to the backbone  and don’t follow through to the lower rails. Paint the backbone first and then proceed to the lower rails so that you can paint over the overspray to keep everything smooth. If you respray the top you need to respray the bottom...
  • Make sure your parts are spread far enough apart in your spray booth and be conscious of where you are directing your spray. You don't want overspray on other parts in the booth or you’ll leave the rough overspray texture on them.
  • Be careful when you spray the underside of fenders or the gas tank tunnel. The paint shoots back out at you as fast as it leaves the gun. Stand to the side or you’ll get a face full of paint. Fortunately I had safety glasses and dust mask on when this happened...
  • If you notice a paint run, leave it. You can correct this after the paint has cured. I had limited success correcting runs in wet paint.
  • Make sure you leave adequate flash time and you spray at the correct temperature specified for the activator and reducer. Failure to do so can result in solvent pops that will require the paint to be stripped and redone. Hundreds of little pinholes will suddenly open up in the paint after an hour or two. Unfortunately they go through all paint layers.
  • Do not let the paint gun run out of paint. What is left in the gun will start gelling while you are mixing a fresh batch of paint and come out in chunks when you least expect it wrecking your paint job. If you do get chunks, wait for the paint to dry and then repair.
  • Don’t stress too much trying to get perfect coverage on the first coat. Second and third coats will even coverage out. For the single stage urethane paint, a mist coat for the first layer can help to prevent runs and sags by giving the second layer something to grab on to.
  • Avoid excessive orange peel. This is hell to sand out later. Can be caused by moving the gun to fast, being too far from the surface etc. Google “paint orange peel”
  • Avoid runs and sags. Caused by excessive paint, gun too close or moving too slowly.
  • Remember it is only paint. It can be sanded off and redone. Ad infinitum.
  • Don't use a coiled air hose from the compressor to the paint gun. The coils catch on everything. Use a straight line for the spray gun and keep one hand on the line to prevent it from touching freshly painted parts.
  • Make sure your gas tank and oil tank caps don't leak. You don't want water getting into your tank and starting rust while wet sanding.
  • If you are going to seal your tank, do this BEFORE you paint - the sealer sticks like crazy to everything and will make a mess of your paint.
  • Good luck.

How to use a paint cup.

Sunday, April 29, 2012

Part 20 - Handlebar mods for Dakota Gauge Cup

Looking purely at fabrication aspects of the bike, the most time consuming fabrication effort was the handlebars. Ok, cut the laughter and read on.

The first modification to the bars consisted of making holes for the internal wiring and adjusting the ID of the right side to fit the internal throttle. This is all explained in the following blog posts

The next step was to install a gauge cup to hold the speedometer/tachometer display. The gauge cup is a good quality item from Dakota Digital. For the first round, I used the $80 mounting bracket from Dakota Digital. The result looked like a minimum effort bolt-on, which is exactly what it is – out of place and dead ugly and it leaves some wiring exposed to connect the gauge. Uggggg!

For round 2, I removed the bracket and made a hole for the wires in the handlebar and tapped a hole for mounting the gauge cup. This allows the gauge control wires to be hidden which solves one aesthetic problem and the gauge sits right on top of the handlebar partially solving the wart-like aesthetic issue with the Dakota Digital bracket.  

Mounting and wire entry holes for more integrated look

Gauge cup mounted directly to the handlebar

All of this sounds straightforward and easy enough to accomplish in 5 minutes, and I guess it should be. But, the amount of time spent staring at options, sourcing brackets, deciding where to drill the hole, deciding whether you really want to take a drill to the expensive chromed gauge cup to modify it for direct handlebar mounting, all takes time. Lots of time. Easily 8 hours of time. 7.5 hours of thinking and research and 1/2hr of actually doing the work. I lived with the results of Round 2 for weeks. Slowly but surely I went from “it’s okay”, to “it will work”, to “its half @*&$@”.  

Time for round 3. Why not invest even more time into a set of handlebars. It’s not like the bike ever needs to be finished, right? Round 3 is the ultimate (for me anyway) aesthetic mounting. I had seen this style of mounting on a Jerry Covington bike and thought that if I ever developed the skills, then that is what I wanted for my bike. Turns out, Dakota Digital make a raw steel gauge cup that can be welded in place. The only problem is that the handlebars need to be chopped, a piece big enough to accommodate the gauge cup removed, the sides coped to match the gauge cup profile (which isn’t easy), gauge cup angled correct for the rider and then everything welded in place. All this has to be done making sure the handlebars are still straight and above all safe when the job is complete since the gauge cup will now be holding the handlebars together. All the cutting and shaping was done with a dremel tool, hacksaw and hand files. 

Handlebars clamped to ensure alignment

Dakota Digital Steel Gauge Cup - hole drilled for wire entry

After  4 hours of labor the mounting was done. Aesthetically, hands down a winner. The cup was welded in place with the flux wire welder. Some of the ugliest welding you will ever see but I’m pretty handy with a grinder. Grinding and welding, or is that welding and then grinding, easily took an extra hour so we were up to 5 hours.

Gauge cup welded in place

Then I made a fatal error. I was pretty proud of the look I had accomplished and pleased that I persisted past the very basic bolt-on from Round 1, through the more integrated Round 2 and the ultimate Round 3, so I called my wife to take a look. First comment “why is the gauge pointed up at the ceiling” so I remind her that it is made for a taller person. Ok, onto comment number 2 – “something doesn’t feel right”. “Wadaja mean” I ask? “Feel right? That is not an engineering term”. “Is the gauge in the middle?” she asks. Ok now we have some more technical terminology so this is easier to deal with and I explain with great pride how often I measured and how much effort I took to ensure that the cup was perfectly centered between the risers. The response – “well something is off”. Mmm not an engineering term but maybe I’ll send the wife on back inside while I work on some more technically challenging issues. The handlebars look great – in my opinion. Maybe the welding and grinding and lack of paint are “off”. Then she says “the left looks longer than the right”. “Yes ma’m, there is a 4 inch difference to allow for the internal throttle” I say demonstrating my technical superiority and easily refuting the “its off” statement. Expecting that to be the end of it, I moved away to clean up the tools. She drops the next bomb shell – “If you look carefully you’ll notice that the bend on the right of the handlebars starts a little closer to the speedo than the bend on the left”.  Still feeling pretty sure of myself I take a look. Wham. Hits me in the head. The damn handlebars are off. Now I’m using inappropriate technical terminology but it works for this situation. Out come all manner of measuring devices and yes, the handlebars are longer on the left than the right by easily ¼” when measured from the outside of the riser to the edge of the thick bar as illustrated below.

I had been so fixated on the gauge cup centering between the risers, I never noticed the handlebars were badly manufactured. I tried as I could to look past this not wanting to lose the time investment, but hell, there was no way that this was going to fly.
Emailed the vendor and told him what had transpired. At this point he is suspicious because I had modified the handlebars and he is sure (although not coming right out and saying it!) I screwed something up so he asks for me to send them back. Easier said than done my friend. Eventually we discuss by phone and I agree to send them back but needed to recover the expensive gauge cup first. More grinding and whining and eventually after many hours of careful grinding and not so careful whining I am able to extract the cup. Ship the two halves back and get the confirmation that “yip – bars are off”. At least I now know that “off” is acceptable bike builder terminology.  He further confirms that the batch of 6 he has in stock are all “off”. Someone must have messed with the jigs used during manufacture. Eventually the replacement arrives. It is back to square one.
All the work done on the first handlebars had to be repeated. I’d like to say it went quicker the second time because I knew exactly what I wanted to do but all the modifications wound up taking 8 hours at least. The gauge cup install was as much of a bear the second time as the first time.

Fast forward about 3 months and the bike is being prepped for paint. After a lot of work with body putty molding the cup into the frame making it look a single organic piece, it is time to shoot the primer. Primer goes on and the bars look great. So why stop there? Why indeed. Here’s a great looking handlebar but the wire exits between the risers leave a small amount of the wire harness visible. And how safe is this whole business of a gauge cup keeping the 2 halves of the handlebars together? Mmmm, given that the gauge cup had to be welded and then extracted and then re-welded, what is the integrity of the metal? Mmmm. Maybe I need to add some reinforcement. Mmmm, if I add reinforcement that can double as a wire hider - that would be helpful.

Round 5 - So after a little more thought, out comes the grinder, some ¼” steel plate, a piece of old 16 gauge sheet metal. After making the new parts and grinding off all the primer I had just put on, I had another 3 hours invested into the handlebars. Then it was off to Ron’s house to use his TIG welder to weld the new parts thinking that 1 hour would be all I needed. Things went downhill fast. Having experienced all manner of metal distortion using the TIG welder, I was prepared for anything and started with the handlebars bolted to the top clamp of the triple trees to make sure everything stayed in position. After a lot of fussing, the plates are tacked in place - everything is square and beautiful. I unbolted the handlebars from the clamp and noticed that the bolts where now a little tighter but figured that the metal had moved as far as it was going to move and the tacks would hold everything in place during final welding. So I commence with final welding. 

"Final" Welding
At one point I heard a metallic “plink” sound but thought nothing of it. Had I stopped at that point and investigated, I would have discovered that one of the tack welds had broken due to the welding stress allowing the risers to move in toward each other. But I didn’t stop and inspect and completed the welds on both sides. After things had cooled a bit, I test fit the bars to the triple tree clamp and THEY NO LONGER FIT. The spacing had shrunk by a full 3/32” so it was no longer possible to bolt them up. What a mess. Ron reached over and shoved the grinder in my general direction with a “I think you’ll need this....” expression on his face.
Damn, all the work down the tubes. After another ½ hour of careful grinding and I had the one end of the front and back plates loose. Even though the risers sprang back when the final weld was released, there was still an offset between the riser spacing and the clamp. Something had bent in the process of welding everything together. At this point there was nothing else to do but grab a big crowbar and start bending things back to normal. With Ron manning the crowbar and me the welder, we managed to separate the risers enough and tack the plates back in place with heavy duty tacks this time. According to Ron, he could feel the risers pushing back on the crowbar during the first tack weld but I’m not sure that this was the beer talking. Eventually, everything was welded up and everything fit. Another 4 hour mission complete.
It would be great if the story ended here..... but it doesn’t. The wire entry hole in the top triple clamp is not centered front-to-back between the risers - the hole is slightly forward of the obvious place to put it so I had to cut a slot in the front plate and then weld a cosmetic piece over that to properly hide the hole in the triple clamp. in the middle of the bars. Another session of grinding everything smooth and some more body putty to re-create the organic just-grew-out-of-the-metal look. 

Finally, reprimer and repaint. Surely that is the end of the story but no. I got a pretty major paint run which required some serious sanding to remove. In the process I sanded right through the paint, which required more work to repair. The good news is that I think I’m finally done with the handlebars.... Seriously.