Corrosion Proofing a Crystalyte Motor for Rainy Weather

[calinb]

I've been riding my 5304 equipped ebike through some very wet weather that's plagued NW Oregon over the last month. Although I've read that rust on the magnets can eventually become a problem, I've not had any trouble with my motor whatsoever. Nonetheless, I got a scare in an email from my vendor--Mike of ElectricRider.com. Mike cautioned me strongly against riding in wet weather and said that some people have even experienced failures after only a single ride in the rain!

Despite Mike's interest in keeping a customer happy rather than selling replacement motors, I remained unconcerned because I've had very good results corrosion proofing all kinds ferrous and non-ferrous metals with two products common in the aviation industry--Corrosion-X and ACF-50. I've also had fantastic results treating electronic equipment with the stuff. (It quiets old and noisy pots very well) and using it as a penetrating oil. I know of no electrical device that's ever been harmed by it. In one impressive trade show demo, the vendor filled a fish tank half-full with the fluid and placed an operating CRT television into the tank. Half the screen was submerged with the televised picture on the screen.

http://www.acf-50.co.uk/
http://corrosionxproducts.com/dealerpage.htm

In the U.S., I've used two suppliers--Aircraft Spruce and Chief Aircraft. I've used both products and can't really say that I've found either one to be superior to the other.
http://www.aircraftspruce.com/catalog/appages/acf50.php
http://www.aircraftspruce.com/catalog/appages/corrosionx.php
http://www.aircraftspruce.com/catalog/appages/acf50.php

I figured that, if I could get the cover off the motor, I could treat the inside and probably keep my motor protected from corrosion for many months, if not years to come. Unfortunately, removing the cover turned out to be somewhat challenging--hence this post and my hope it may prove useful to others. I wish I'd had a camera on hand, but I had not expected the removal of the cover to be such a big deal.

Before attempting the procedure on your own motor, please realize that your results may vary from mine. You may damage your motor resulting in financial loss or even the crash of your bike! You might smash your finger or even die--hard for me to say. Okay--enough of the forum disclaimers! How I got that cover off....

Mike mentioned that I could just pry evenly around the perimeter of the cover until the cover bearing disengaged from the axle. Haha--that's easy to say but very hard to do without damaging the cover or hub housing or perhaps modifying the housing to implement some pry points. You see--there's nothing to pry against or grab! The gap between the cover and the hub housing is too thin to permit the insertion of any effective prying tools without damaging the cover or the cover flange of the hub housing.

After removing the cover screws, I first ground down and smoothed a hacksaw blade using a grinding wheel in an effort to concoct a usable pry tool. Although I could force the blade into the gap between the cover and the housing with gentle tapping from a hammer, I could not budge the cover before my tool bent. I also tried to pry the cover loose with pin punches inserted into the cover screw holes with no success--not enough leverage or mechanical engagement of the tool was available. Tapping the punches against the holes did not rotate or loosen the cover either.

I finally found a solution in a 3x14 pan head sheet metal screw. After grinding off some of the sharp and pointy tip of the screw with my grinding wheel, the screw could be "self-tapped" into the cover holes without interfering with the underlying threaded screw hole of the motor housing. By slowly working the screw back and forth with a screwdriver (tighten/loosen...tighten/loosen..etc.), I was able to engage the screw into the cover over the distance of a couple of threads. Of course I could have used a tap to cut threads in the cover for a machine screw too, but probably not successfully while the cover was mated up against the hub housing because it would probably be impossible to use a tap without damaging the underlying hub motor housing screw hole threads.

Once I found that I could cut threads to tightly engage the machine screw into the cover only (but not the underlying motor housing of course, I placed the screw into the threaded tip of my Harbor Freight slide hammer (body work dent puller) and screwed it back into the cover with the slide hammer tip held captive by the screw head. Then I screwed the slide hammer shaft onto the tip, took a deep breath and started working the slide in an effort to dislodge the cover. The screw can only handle axial loads--pulling the cover straight off--so it's important to keep the screw straight while pulling and not impart a side load on the screw, possibly dislodging it from the hole. I started with soft taps but found it required a couple of moderately strong "hits' before the cover moved outward a very small amount. Once I saw movement, I removed the slide hammer and screw and re-installed the apparatus into the next cover screw hole to loosen my way around the perimeter of the cover. After the 3rd or 4th hole, the cover popped free of the motor housing flange, leaving a gap sufficient to insert a proper pry bar (or screwdriver ) and easily free the bearing from the axle with the cover.

Phew--the hard part was done and I hadn't sacked my cover or motor yet! I pulled another el-cheapo Harbor Freight "special" off the shelf--a paint spray gun--and placed a few thimble-fulls of ACF-50 into the paint hopper. (Just spray some into the paint sprayer hopper, if you have the ACF-50 or Corrsion-X aerosol can rather than the bulk product.) I cranked up the air pressure on my air compressor, closed down the fluid valve on the gun to a very low setting, and opened up the air valve. The idea is to set up the sprayer to over atomize (at least compared to a proper paint spray pattern) the ACF-50 or Corrosion-X. Ideally, you want to transport the fluid to the internals of the motor with a heavy "fog." Make sure to blow a bunch of the fog back behind the stator and drive it into the magnets too. Leave no surface uncoated with a thin coat of material. The insides don't need to be dripping heavily--they just need to be coated.

After coating the inside of the motor, replace the cover by gradually tightening the cover screws in a cross-wise sequence. As always, I used RTV silicone sealant around my wires where they exit the axle, but I don't think it's a good idea to attempt to completely seal the motor elsewhere. It appears that water could get into this motor but, hopefully, it can also get out! Interestingly, I found no signs of moisture or corrosion in my 2-month old motor, despite many rides in light to very heavy rain.

I now ride in wet weather without worry of corrosion or corrosion induced failure because I've never seen ANY corrosion on any object that I've treated with these products in the past!

I hope this helps others to realize the enhanced utility (and even fun) of a rainy weather capable ebike and Crystalyte hub motor. Rain is likely 3/4 of the year where I live. I ride with an Aerostich Roadcrafter motorcycle suit and I've been riding motorcycles in the rain (and worse) for many years. I don't own vehicles that must be parked due to rain!

-Cal

 

[fechter]

It seems the covers are stuck on by the paint. Once the screws are out, I used the edge of a hefty pocket knive blade and tapped it into the crack with a hammer. I had to try on a few spots before it finally popped. Once it opened up enough to get a flat screwdriver in the crack, it came off pretty easy.

Water has a tendency to get in at the wires, so if the wires exit the axle on the bottom, there is less chance it will follow the wires in.

I agree it is not a good idea to totally seal the motor. There should be a vent somewhere to let moisture escape. Heat from the motor will help drive moisture out.

The controller is much more prone to destruction by water than the motor.

 

[monster]

are there any maintenance tips for crystalyte owners?

should we oil th motor?

 

[calinb]

I noticed that the bearing in the cover was a sealed bearing. I assume the bearing on the other side of the hub is also sealed so, apart from my corrosion proofing treatment every couple of years or so, I can't think of anything on my brushless 5304 that would require maintenance. Corrosion-X and ACF-50 are also light oil lubricants but, even though they penetrate and worm their way into the smallest of clearances, I doubt much gets past the bearing seals, which is probably a good thing because the factory grease stays inside the bearing and doesn't get diluted by the light oil--though it would be a very small amount.

I keep my controller in a waterproof Ortlieb pannier bag. I've never had any overheating problems but, when the weather drys out and warms up, I can leave the top of the pannier bag open to permit some air circulation across the controller or I could just strap the controller on the top of the bag under the pannier closure strap .

-Cal

 

[mvadventure]

The first time I got caught in a heavy rain with my 5304 the motor locked in a wide open position and the throttle and cruise control became ineffective. This was not fun. Fortunately I was only a couple of miles from my destination and after almost six hours under cover everything dried out sufficiently to operate normally.

Feedback from the forum had me putting silicone on everything, which I have done yet it is impossible to coat the thumb throttle. I have siliconed all the entry and exit points for the wires, especially on the motor itself. Since that initial dramatic experience, in addition to the silicone I have covered the throttle, cruise and controller with zip loc bags when it rains but have found it time consuming to cover the controller due to the fact it's not all that accessible when it's raining. By the time I get my rain suit on and cover the throttle and cruise the controller is wet.

So now, and it may not work when summer comes back, I have it in a doubled Wal-Mart bag tied at the top and turned upside down in one of the saddlebag baskets. It ain't getting wet from the rain. I keep a few rubber bands handy to secure the zip loc bags over the handlebars and have reasonable confidence everything will function properly. It ain't pretty and it's not 100% but so far so good. I have not experienced one of our famous Florida solid rains however and hopefully will be able to avoid one. (fat chance)

Mike

 

[calinb]

The first time I got caught in a heavy rain with my 5304 the motor locked in a wide open position and the throttle and cruise control became ineffective. This was not fun.

Mike, Yikes--no doubt!

Feedback from the forum had me putting silicone on everything, which I have done yet it is impossible to coat the thumb throttle.

Hmm--I'd come to the conclusion I'd never mess with a grip throttle again because it's very difficult to position everything in ergonomic locations without interference between something on the handlebars (throttle with LED indicators, Shimano Rapidfire shifters, brake levers, cruise control, handlebar extensions etc.) I must've pulled everything off and on four or five times before I found a setup I could live with and I'd just about come to the conclusion that a grip shifter and thumb throttle would be better. But the Oregon rains have fallen heavily on my grip throttle and cruise control with no mishaps. Hmm...

-Cal

 

[rkosiorek]

<snip>

Feedback from the forum had me putting silicone on everything, which I have done yet it is impossible to coat the thumb throttle. I have siliconed all the entry and exit points for the wires, especially on the motor itself. Since that initial dramatic experience, in addition to the silicone I have covered the throttle, cruise and controller with zip loc bags when it rains but have found it time consuming to cover the controller due to the fact it's not all that accessible when it's raining. By the time I get my rain suit on and cover the throttle and cruise the controller is wet.

<snip>

Mike

with the throttles the secret with the dielectric grease is to TAKE THE THROTTLE APART!!!!! the parts you need to waterproof are on the INSIDE. the same is true for the Cruise Control. use a small artists paint brush to coat the guts with the dielectric grease.

okay so its a little more work than siliconing the openings. but it works.

rick

 

[monster]

i live in england where it rains all the time and i've had no problems with my X5. i haven't treated it at all. i cycle every day and get caught out many times. maybe its luck of the draw?

 

[rkosiorek]

i have lived in the Netherlands. not sure which is worse for wet weather. i had problems once. then i switched to dielectric grease. no more issues.

 

[calinb]

i have lived in the Netherlands. not sure which is worse for wet weather. i had problems once. then i switched to dielectric grease. no more issues.

The U.S. pacific northwest (Portland, Seattle) receives rain 9 months of the year. The Netherlands is worse. It receives rain 12 months of the year.

 

[rkosiorek]

oh come on now. there are some nice summer days in the Netherlands.

it is not a big thing to take any of these throttles apart or to reassemble them. the grease really does work to water proof the connectors and the guts of the throttle. that is why the automotive, marine and aerospace industries use it.

rick

 

[Rassy]

calinb said:

Mike mentioned that I could just pry evenly around the perimeter of the cover until the cover bearing disengaged from the axle

In other threads, it was suggested that a three arm gear puller could be used to remove the cover from a hub motor, and to replace it, since the strong magnets will try to snap it back into place. The gear puller would engage on the spoke flange, and push against the axel. I haven't tried it yet.

 

[calinb]

since the strong magnets will try to snap it back into place.

My Cruiser cover is cast aluminum, as I recall, so that's not a problem.

The gear puller would engage on the spoke flange, and push against the axel. I haven't tried it yet.

Interesting! So the idea is to engage the arms on the spoke flange and use the center "screw tip" against the axle to push the bearing and cover out on the other side. I have a few gear pullers (it'll probably need a big one to span the spoke flange) but I guess I wasn't thinking "outside the box" (or from the other side of the hub). [/quote]

oh come on now. there are some nice summer days in the Netherlands.

Yes--I was exaggerting and joking. I've visited The Netherlands during the summer but I actually prefer the winter with fewer tourists (like myself ). Actually, the weather is very similar to the weather at home, but with more rain in the summer. You can nearly count on three beautiful months each year here in the Portland/Seattle area with virtually no rain. It may be August - October or it may be June-August, but we get three sunny months. Of course that's all changing. Climate models show the weather becoming wetter here.

 

[monster]

i've used lots of vasaline (petroleum jelly) on my motor to keep the water out. would this be good for the throttle too?

 

[fechter]

i've used lots of vasaline (petroleum jelly) on my motor to keep the water out. would this be good for the throttle too?

I don't think it would hurt.

Inside a hall throttle, the wires connect to the hall sensor, which is a little plastic transistor-looking thing. If you take the throttle apart and seal the wires between the cable jacket and the actual sensor, it should work underwater. Silicone would be best for this, but hot melt would also work. Likewise, you could pack the area with Vaseline to keep water out.

 

[Julez]

Hi!

Thanks for this thread!

I am about to get a Crystalyte too, and as I live in a city "famous for rainy weather", waterproofing it is rather important for me.
After some internet research, I found out that ordinary "penetrating oil" has the same properties as the "ACF 50" stuff. So I bought some cans on eBay.
I also found out that a cool stuff called "butyl rubber" exists. Its called "Bärenkacke" (bear's poo) in Germany.
I got a good deal from an insolvency on eBay, and boy, the stuff must be 20 years old judging from the metal tube and the simple printings on the boxes.
Its a smelly, tar-like black goo which becomes a little harder over time, but never solidifies completely. Thus, sealed parts can be disassembled again, and small relative movements of the parts do not cause problems. This stuff is supposed to be great for sealing car windows...

Well, my plan is to give the stator a really good dash with that oil, and after that, reassemble the housing with the butyl rubber sealing the flange.

I'm not yet sure what to do with the cables, but I have access to quite thin teflon tubes. I could try to fasten one at the side of the stator, so that one end goes to the deepest part of the housing, and the other end exiting with the cables. Then I could seal everything, and after heavy rain, take a syringe and suck on the free end of the tube. Any water that could have entered the motor would be sucked out then.

Cheers,

Julez

 

[spinningmagnets]

from julez:

I think I have figured it out how to make Crystalytes waterproof. First thing, apply a drip loop to the cables.
http://freshaquarium.about.com/od/equip ... iploop.htm
This means, if possible, install the axle in a way that the cable slot faces downwards. Otherwise, the water that trickles down the cable will be lead directly into the slot, thus entering the motor.
Second, get anti corrosion wax like the one used for cars. I did a lot of research, and found out this is the best:
http://mike.british-cars.de/
Open the motor case, and put an awful lot of it in. As times go by, it will melt and be distributed around the motor. It will not evaporate like sprays, and yet creep into the smallest gaps over time.

Third, seal the side caps with isopropyl caoutchouc. This is a black messy substance sometimes used to seal car windows. It has a consistency of tar. It gets a little harder over time, but still stays flexible so thet the removal of the parts is no problem. Apply it to the flanges, then tighten the screws.

I have my crystalyte 408 in use since early 2009, and my city has a lot of rain, it is called the capitol of rain actually. I do not have the slightest problems whatsoever.

and also Jeremy Harris
Any motor, whether in a hub or mounted externally, will be susceptible to damage from water, grit, dust etc. If you want a good reliable bike that needs minimum maintenance and will cope with bad weather then you need to pay attention to keeping water and dust/grit out whilst still allowing adequate cooling.

One, often overlooked, problem is that motors 'breathe', drawing in cool, damp air when they cool down and driving it back out again when they warm up. Some have suggested that this is one of the biggest causes of hub motor corrosion, which seems to make sense. The same would apply to any other motor equally, though, unless it's very well ventilated.

The approach I've taken with my boat motors (modified RC outrunners) is to replace the bearings with stainless steel ones (not good for high loads, but OK for my application) and seal the motor windings, Hall sensors etc in epoxy. I also coat the magnets and inside of the rotor with epoxy, and add a coat of paint to the magnets (they can corrode quite badly if they get wet). The exposed bits of the shaft are greased, but could be made from ground stainless bar if I was fanatical about preventing corrosion.

It would be harder to prevent a hub motor suffering from water damage, especially one with gears. It is quite easy to improve the waterproofing of a direct drive hub motor though, just by spraying the stator with silicone conformal coating and then heat curing it. This will do a very good job of keeping the elements at bay, although water damage to the bearings is still a possibility.