I had two warranty tanks due to expansion. Current one has now swelled to the point where lifting the tank takes tools, but it's off, fuel pump is out and it's bone dry after putting a fan through it all night. I've heard that the tanks will eventually shrink back to their regular size if dry. How long does this take and are there known methods to accelerate the process? Given the mass of the material and the fact that it takes a couple years to swell up, this has go to take a while, right?
BK
My house has heating vents in the floor. After it has dried enough that the fumes are minimal (thank you EPA) I set it near a vent so warm air blows through it over the winter months. I don't know exactly how long it takes but after a couple of months it seems normal - it never has gotten as bad as yours to start with though. Warm dry air speeds up the process. I think a month or two of just regular drying would do it.
That's genius using your forced air heating. I don't have that option, but I strung the tank up in the garage with a fan blowing into it. I've also taken measurements, so I'll see how it goes, and if it shrinks enough before I get impatient I'll coat the interior.
BK
I have no experience with the plastic tanks so bear with me if I ask a stupid question.
What is the determining factor as to when a "dried" tank is ready for coating?
Measurements, as mentioned by the OP seem logical, but who would have starting dimensions to refer to? Or do you keep measuring until the dimensions stay the same? Or, maybe stop the drying when the tank fits properly? Or when the snow melts? :)
The plastic (nylon) tanks swell over time when used with ethanol containing fuel.
Some reports indicate that when stored dry (no fuel, on the shelf) they will shrink back to their former dimensions on the ~months timescale.
Ducati used to warranty these swollen tanks, but that ended a few years ago with a class action lawsuit. Some owners apply internal coatings to new or cleaned/non-swollen tanks to avoid the shape change.
Swelling/expansion can cause poor fit on the frame and interference with the ignition cylinder and a bloated look. I'd say up to ~0.5" increase in all directions. I simply defined some reference points on my own tank and will try to monitor dimensional changes over time. When it fits well I will coat the interior, unless I get impatient and just decide to reinstall again. Probably the latter!
BK
I have seen a M695 tank in UK stretch 1'' in all directions and take up ll the space to the ignition switch .
I was able to buy a new plastic tank off of eBay. I measured across the tank to the screw holes where the rubber mounts are attached.
New tank: from center line to center line of screw holes, it measured 11 3/8"
Swollen tank: from center line to center line of screw holes, it measured 11 3/4"
after three months, the old tank had not shrunk to match the measurements of the new tank. i stopped checking after that and put the tank in storage about 6 months ago. when and if it shrinks back, i will apply the caswell coating
i coated the new tank with caswell and hasn't expanded at all. The only con to the coating was losing a bit of fuel capacity.
if you plan on coating, i recommend using one of the colored coatings so it will be easy to see what has and hasn't been coated.
if the tank is dry, remove the fuel pump plate and stick a small hair dryer inside it on cool and let it sit.
this time of year is a good time to do it because houses are dry from the heating.
i would rinse the tank out first -- use water based marine clean. rinse rinse rinse. you need to get the gasoline out. you'll need to rinse it again later with xylene. some people have used acetone but it does attack the nylon. xylene is compatible with nylon and can be used to cut the coating.
That's great info mr. dragon. I'll pull my frame bumpers off and compare the distance.
I take it your unproductive 3 months were static on a shelf? I washed out my fuel residue with dish soap + water and then rigged up a "vornado" fan on full power blowing into the fuel pump opening and exiting the fuel fill hole with quite a force. I'm hoping that over time the constant air flow accelerates the shrinkage, though I'm not expecting miracles!
BK
soap probably works ok, but i would use a stronger solvent like marine clean or purple (diluted).
it takes 2-3 months in a dry place for it to dry out and shrink. it is water and some alcohol that you're venting out.
I used marine clean to wash out my old tank. For first three months of drying, the tank was out in the open on the floor where it was exposed to daylight during summer months. the air is typically dry out here in California. I did not attempt to accelerate the drying process with fans etc. Basically, I was not in a rush since I had a brand new coated tank to install and figured a slow gradual shrinking process for the old one would be better than the accelerated route. I have since placed the old tank in the original ducati box the new tank came in and put it in storage. So this current storage set up might not help the shrinking process.
I should have noted that during the three months the tank was out in the open, it did shrink but not to the 11 3/8" to match the new tank. It seemed to stay a little over 11 1/2" from center to center screw holes for a long time.
Also, when my second tank expanded the ducati dealer swapped out the original rubber mounts with some larger rubber mounts that can be adjusted because there are some slots. I can tell the new tank hasn't expanded because they are where I initially placed them.
Aprilia never replaced their affected tanks. Their instructions were to remove the tank and let it sit for 4-6 months to allow it to come back to shape, I would assume a similar time frame for ours.
Wish i'd thought of doing this over the winter months. I've ordered an ally tank from Beater in japan at massive cost! Doh!
Wish I'd thought of this before taking basically 2yrs off of riding! :-\
BK
Quote from: itsamonster on February 26, 2015, 06:10:32 PM
Wish i'd thought of doing this over the winter months. I've ordered an ally tank from Beater in japan at massive cost! Doh!
Doh! Now you've gone and done it... I searched Beater Japan and found they make an alloy tank for the S4Rs - oval fuel pump and all. More stuff to spend my money on [bang]
http://japan.webike.net/products/21788539.html (http://japan.webike.net/products/21788539.html)
No dimensional changes yet (not surprised) but my hole-to-hole measurement with bumpers removed is exactly the same as OrangeDragon reported for his swollen tank = 11 3/4".
I could easily live with the extra width, but the extra length and corresponding interference with the ignition cylinder is the nuisance.
Will do the Marine Clean thing to get more possible surface contamination off. Maybe that'll speed everything up, and it's reported to be a healthy prep for Caswells anyway, in case I decide to go that route later.
BK
Quote from: itsamonster on February 26, 2015, 06:10:32 PM
Wish i'd thought of doing this over the winter months. I've ordered an ally tank from Beater in japan at massive cost! Doh!
wait.. what??? they posted a while back they had stopped making tanks!!
I recently acquired an ally tank for my bike, it is over 3 pounds lighter than the plastic, butt it does transmit more mechanical noise from the engine! Just be aware of that if it makes any difference to you!
Maybe my search skills are rusty, but I can't seem to find reference to the fuel pump flange o-ring standardized number.
Viton is obviously the material of choice. Round o-ring is typical, but I understand that Ducati retrofit the x-ring type under warranty if pump flanges leaked.
Measurements off my original o-ring are 5mm width x 119mm OD. This would cross to a AS568A Dash Number 347 o-ring. Can anyone verify that is correct and an odd metric size isn't required?
BK
886.4.049.1A O-ring
This is the number I get from the parts diagram(monster 695) that i downloaded from www.proitalia.com (//http://)
Quote from: ducatiz on February 27, 2015, 12:01:40 PM
wait.. what??? they posted a while back they had stopped making tanks!!
Wasn't that just that they weren't allowed to ship them?
Quote from: OrangeDragon on March 01, 2015, 02:55:56 PM
886.4.049.1A O-ring
This is the number I get from the parts diagram(monster 695) that i downloaded from www.proitalia.com (//http://) (//http://) (//http://)
Sorry, not ducati p/n, but standardized o-ring number. O-rings are a bit like fasteners, with standard dimensions corresponding to a "dash" number, but because they're squishy it can be tricky to nail it. Markup is 10-20x for something like this! With a dash number you can choose your material and durometer and hit up McMaster or similar.
BK
Quote from: stopintime on March 01, 2015, 04:01:23 PM
Wasn't that just that they weren't allowed to ship them?
no clue.
I ordered it in December from www.samurider.com (//http://) who handle posting them out.
They said the wait was going to be up to 4 months........ not long now [Dolph]
Three weeks with a strong fan blowing air through the tank 24/7, initially washed with dish detergent, moved indoors next to a large window so it gets warmed up each day. No measurable change yet in the distance between the bumper attachment holes. My POR15 Marine Clean shipment leaked and UPS discarded it before delivery - replacement order is on the way again.
Rigged up a seal for the fuel pump opening to help with the next steps. 1/4" plastic cut to 6" diameter with a router jig, tapped in the center for 1/4-18 NPT elbow, oring from bulk pack I keep for my 749s fuel pump. Looks like it'll work well. I have extra materials if anyone is interested.
BK
(http://i62.tinypic.com/ilg6e0.jpg)
Nice work on that plastic cover!! My plexi cover cracked and leaked a little. luckily the paint didn't get messed up. there are some good tips on how to coat a tank on DMF, but if you want to avoid some of the mistakes I made here is link to my coating experience: http://www.ducatimonsterforum.org/index.php?topic=67331.msg1246833#msg1246833 (http://www.ducatimonsterforum.org/index.php?topic=67331.msg1246833#msg1246833) Although I didn't execute the coating all that well, the tank isn't expanding so I consider it a success so far.
That is a pretty cool seal for the pump. I am wondering if it might be possible seal the entire tank and pull a vacuum? Maybe put moisture absorbing silica packs in the tank and pull a couple pounds of vacuum? It would be interesting to know if it could speed up the drying/shrinking process.
I was thinking the same thing. Put it under a gentle vacuum, load it up with desiccant and keep it warm with a contraption I use to maintain fermentation temps. Passive shrink-back is sloooooooow. I'm also hoping the Marine Clean might help remove any thin film of aliphatic contaminates that could inhibit desorption of the water. Damn plastic tanks.
BK
that's a beautiful plug there. i made one that is two pieces of lucite sandwiched for rigidity but that one looks far more purpose built.
I drilled a hole and used a size 10 stopper in mine. about 2" in diameter and much easier to pour in and just big enough for my shop hair dryer's nozzle.
I used a stopper for the filler from the outside. there is a vent that you have to plug as well next to the filler hole, but that's no big deal.
The next experiment involved adding a couple pounds of freshly activated desiccant, using the beautiful plug to seal the pump opening, in order to achieve very low internal RH. Let's see what that does for a while. My POR15 Marine Clean arrived today, so I'll queue that up next. On particularly warm sunny days (this is northern California) I put the tank outside in direct sun where it gets hot to the touch for hours. My goal is to get this b*tch shrunk down by ~May.
BK
Finally seeing some measurable shrinkage! Lost nearly 1/8" between the bumper mounting holes.
Did the Marine Clean treatment today. Diluted 1:2 (cleaner/water) and sloshed 1.5gal in the tank for 15min. Temps were ~75F and tank was warming in the sun most of the day. Then I rinsed with 5 tanks of water which took another 30min. The drain valve was awesome. Wiped dry and put under the fan. After it fully dries I'll add back the desiccant and seal it up for more storage.
The cleaner definitely took off some yellow on the fill neck area. Cool. I had previously washed with dish detergent.
What's the recommended contact time for the Marine Clean? The instructions suggest overnight for varnished fuel tanks, but that's presumably for metal tanks and not nylon. I didn't want to overdo it. Curious what others have done.
BK
Quote from: BK_856er on March 20, 2015, 12:24:40 AM
The next experiment involved adding a couple pounds of freshly activated desiccant, using the beautiful plug to seal the pump opening, in order to achieve very low internal RH. Let's see what that does for a while. My POR15 Marine Clean arrived today, so I'll queue that up next. On particularly warm sunny days (this is northern California) I put the tank outside in direct sun where it gets hot to the touch for hours. My goal is to get this b*tch shrunk down by ~May.
BK
Marine clean needs to be reduced with water to about 5:1 or more.
Hair dryer is really your quick drying method. Desicant will likely work but slow And it might be a test of the plastic vs desicant. Best bet is something to move air Into and out of the tank.
You may find the PA6 is a stronger desiccant than the silica.
Quote from: BK_856er on March 21, 2015, 06:58:06 PM
Finally seeing some measurable shrinkage! Lost nearly 1/8" between the bumper mounting holes.
Did the Marine Clean treatment today. Diluted 1:2 (cleaner/water) and sloshed 1.5gal in the tank for 15min. Temps were ~75F and tank was warming in the sun most of the day. Then I rinsed with 5 tanks of water which took another 30min. The drain valve was awesome. Wiped dry and put under the fan. After it fully dries I'll add back the desiccant and seal it up for more storage.
The cleaner definitely took off some yellow on the fill neck area. Cool. I had previously washed with dish detergent.
What's the recommended contact time for the Marine Clean? The instructions suggest overnight for varnished fuel tanks, but that's presumably for metal tanks and not nylon. I didn't want to overdo it. Curious what others have done.
BK
I would not leave the marine clean in for more than a few minutes at a time. The tank will just absorb it too. The point Is to flush the petrochemicals out.
2:1 is way too much. 5:1 Should be the max. You're dealing with a tiny remnant of gas, not clumps of grease so you should go very light.
You don't want the tank absorbing the marine clean.
I'm experimenting with a few different techniques. As an experienced research chemist I'll navigate this a little differently.
Not too worried about the Marine Clean absorbing into the tank in the short term. The product comes as 90% water plus <5% KOH and <7% EGMBE + some nonionic surfactant. Diluting it 1:2 or 1:10 for brief contact won't matter. My interest was in removing any potential surface deposit (gum/varnish/aliphatic/hydrophobic/etc.) that could inhibit desorption of the water from the solid phase.
Nylon will not compete with a real desiccant. I'm not using silica, but something similar. The purpose is to decrease the internal relative humidity to a very low level to help drive the equilibrium. I already tried continuous forced airflow for several weeks.
Passive shrinkage takes a lot of time. Just playing with various techniques to try and accelerate that shrinkage. It'll never be "fast" due to the mass of the material and the physical processes, but maybe I can make more happen in the window of time I have. I wish I had forced air heating in my house - placing the fuel pump opening over a floor vent for the winter would be just the ticket!
BK
I wish I had had you around when I was figuring out all of this 2 years ago.
I was very reluctant to use anything stronger than 10:1 Marine Clean because I was concerned it would get carried into the PA6 by the water.
I didn't try desiccants because I had a feeling the pa6 would "compete" but I couldn't be sure. I knew that something needs to "push/pull" the moisture out of the material and heat/low humidity is a sure fire way of doing it.
The main things I found were that you have to get rid of any old gas, which you're clearly doing, but you also should try to scuff the interior surface. I actually used a dremel on a right angle with a 1/16" bit and a mandrel to make small divots in the material and key points. You only need about a 2mm divot and with the very-liquid reduced caswells it will fill the divot immediately. The divot gives the caswell's something to "hang" from and strengthens adhesion.
There is a good paper from the U. of Minnesota on PA6 and other materials absorption of water/ethanol/etc which is a little mind blowing. THey don't talk much about removing it but the figures they saw were a little disturbing in light of this material being used in a fuel tank.
Thanks, I'll look into those papers to help educate myself.
I offered to help in the early days, but there was a lot of drama at the time. [laugh]
Some interesting pieces of information below, assuming water absorption is the main event. "Reconditioning" at low relative humidity (single digit) should facilitate shrinkage if equilibrium can be achieved. Elevating the temperature will help. Kinetics will be slow regardless. The painted exterior surface should render that surface inert and therefore the room relative humidity irrelevant if the tank openings are sealed. Most of the literature is concerned with rates of absorption, not desorption, and the focus is usually on water and not fuel components. At room temperature the rates are very slow, so brief water treatments are safe. I don't think I'm showing anything new here, just capturing some concepts.
BK
The relationship between relative humidity and PA6 absorbed water:
(http://i58.tinypic.com/jv3zow.jpg)
The relationship between absorbed water and dimension:
(http://i60.tinypic.com/2n6rp1s.jpg)
The kinetics of water absorption under various conditions (governed by Flicks law):
(http://i60.tinypic.com/2r73fcn.jpg)
An automotive trade group comparison of various materials vs. conditions:
(http://i61.tinypic.com/23h0xl3.jpg)
6 month update. I've had my tank in storage, sealed up with some desiccant inside. The dimension between the bumper mounting points stabilized at a bit over 11.5" long ago, just like OrangeDragon reported. I don't believe I learned any tricks for speeding up shrinkage. Time for Caswells and some riding.
BK
Quote from: BK_856er on September 06, 2015, 05:11:19 PM
6 month update. I've had my tank in storage, sealed up with some desiccant inside. The dimension between the bumper mounting points stabilized at a bit over 11.5" long ago, just like OrangeDragon reported. I don't believe I learned any tricks for speeding up shrinkage. Time for Caswells and some riding.
BK
best trick is to move air, as you implied above. i have a small hair dryer that fits right into the filler. dries the tank out pretty well on no heat.
Quote from: BK_856er on February 22, 2015, 11:23:46 AM
I had two warranty tanks due to expansion. Current one has now swelled to the point where lifting the tank takes tools, but it's off, fuel pump is out and it's bone dry after putting a fan through it all night. I've heard that the tanks will eventually shrink back to their regular size if dry. How long does this take and are there known methods to accelerate the process? Given the mass of the material and the fact that it takes a couple years to swell up, this has go to take a while, right?
BK
This is an interesting and useful thread. After I purchased my 2006 S2R1K about 3 months ago, I noticed the usual symptoms of gas tank swelling. The previous owner was very likely using ethanol added gas and had left the tank full over the winter.
At first I was quite concerned the problem would get worse and that I'd have to go through the drying process, etc. However, after going through a few tanks of good, non-ethanol gas, oddly enough, the tank shrank down noticeably. For example, before, the clutch side button panel was touching the tank when handlebars were turned all the way left; now there's a few mm clearance.
This, I realize, is probably unusual ... but I suppose it could happen to others.
I also used Seafoam a few time in the gas to clean out the system, but I doubt this had any relevance to the tank swelling/shrinking issue.
so the measuring point is center to center of the holes ?
If so the tank I just got is 11.25" outside to outside hole is almost 11.5"
Would you advise caswelling now or wait till start of next season . And for drying how about in the garage over winter average temp -10c ...freeze the moisture out ...lol
Sounds like you're all shrunk up at least in that dimension (yes, center of the holes is the place to measure).
How about clearance to the ignition cylinder?
Clean/dry/shrunk I'd say coat at your convenience and when environmental conditions are optimal.
BK
Dry fit switch looks good ...ok will line next spring. I will keep it in basement with furnace heat blowing through it.
Thanks
So does the Caswell smell ? can i do it in the house , in the basement ?
Or will Mrs ute take a fit because of the smell ............lol
Quote from: ute on October 16, 2015, 03:01:54 PM
So does the Caswell smell ? can i do it in the house , in the basement ?
Or will Mrs ute take a fit because of the smell ............lol
Yup...
and you know how she reacts to stink better than I do.
Lol ..not good
it's not overpowering. open a window, you're good.
the bad part is the xylene or acetone. xylene is sweeter smelling.. mmmm.
Quote from: ducatiz on October 23, 2015, 05:33:58 PM
it's not overpowering. open a window, you're good.
the bad part is the xylene or acetone. xylene is sweeter smelling.. mmmm.
You're channeling your inner chemist!
BK
so rinse with xylene or acetone ....screws......rinse again let dry
seal tank up ( saran wrap )
Cut down caswell with xylene or acetone ( by how much ??? )
pour in ...reseal opening ......swish around ( alot )( 10 -15 minutes )
pour out excess
let dry
does this sound correct ? any other tips or advice ?
Thanks guys
Quote from: ute on October 24, 2015, 04:09:21 PM
does this sound correct ? any other tips or advice ?
You look here yet? --> http://www.ducatimonsterforum.org/index.php?topic=64897.0 (http://www.ducatimonsterforum.org/index.php?topic=64897.0)
BK
Perfect thanks ...don't know how I missed that in a search ......( Brain Cloud ...lol )
Quote from: OrangeDragon on February 25, 2015, 08:29:24 PM
I was able to buy a new plastic tank off of eBay. I measured across the tank to the screw holes where the rubber mounts are attached.
New tank: from center line to center line of screw holes, it measured 11 3/8"
Swollen tank: from center line to center line of screw holes, it measured 11 3/4"
after three months, the old tank had not shrunk to match the measurements of the new tank. i stopped checking after that and put the tank in storage about 6 months ago. when and if it shrinks back, i will apply the caswell coating
i coated the new tank with caswell and hasn't expanded at all. The only con to the coating was losing a bit of fuel capacity.
if you plan on coating, i recommend using one of the colored coatings so it will be easy to see what has and hasn't been coated.
well, it has been close to 2 1/2 years and I pulled my old expanded tank out of storage. It did shrink to match the brand new tank, so i decided to coat it.
This time I used the caswell dragon's blood color instead of the clear. I followed the same coating procedures as last time but the dragon's blood color performed different compared to the clear.
The dragon's blood color did not get as hot as the clear mix and thus it did not swirl around the tank as easy like the previous experience. The red color performed like thick and slow like molasses.
I had to put more of the blood color mix in compared to the clear mix as I feared the slow swirl and lack of heat wasn't moving the coating around like the clear did.
While I did not end up with missed spots like last time, there is a much thicker red coat in the tank compared to the clear coat, which equals lower fuel capacity.
IMO, I would recommend using the clear caswell coating instead of the red. YMMV
Bringing back my old thread!
My tank has been in storage (clean/dry/sealed/desiccant inside) for 2+ yrs. Stopped shrinking long ago. Finally motivated to do the Caswell treatment.
Turns out xylene is no longer available in California through normal retail channels.
Is there a known suitable replacement thinner that's easily obtained?
BK
So what is the measurement screw hole CL to CL now after 2+ years?
Quote from: booger on August 14, 2017, 09:52:03 AM
So what is the measurement screw hole CL to CL now after 2+ years?
In my case, 293mm.
BK
As far as I can tell, the screw-hole diameter method is always going to result in different measures. The tank is constantly shifting some depending on humidity and the manufacturing isn't that precise. That's why the bumpers have about a 1cm shift built in.
Quote from: ducatiz on August 14, 2017, 03:53:19 PM
As far as I can tell, the screw-hole diameter method is always going to result in different measures. The tank is constantly shifting some depending on humidity and the manufacturing isn't that precise. That's why the bumpers have about a 1cm shift built in.
Agreed. The tank is not a precision part. In my case it went from 299 to 293mm = 6mm shrinkage L/R with long term storage. Most of that change occurred within the first 2-3 months. What really annoyed me was the other dimension, front to back, making it impossible unlatch and lift the tank. I didn't record that dimensional change vs. time. Been off the monster for ~4yrs now, so looking forward to the reunion!
BK
Quote from: BK_856er on August 14, 2017, 07:09:15 PM
Agreed. The tank is not a precision part. In my case it went from 299 to 293mm = 6mm shrinkage L/R with long term storage. Most of that change occurred within the first 2-3 months. What really annoyed me was the other dimension, front to back, making it impossible unlatch and lift the tank. I didn't record that dimensional change vs. time. Been off the monster for ~4yrs now, so looking forward to the reunion!
BK
Same situation with the front/rear dims. The tank hinge has about 1cm of adjustment. But it should close without effort even with the hinge all the way to the front.
Play some Barry White when you put the tank on..
Procured some nice xylene from Amazon (thanks ducatiz!). Tank was previously cleaned out and stored with desiccant for an eternity. Spent a couple hours today scuffing up the interior surfaces with a stainless scouring pad and stainless detail brush. Finally my small and thin arms come to the rescue. Nitrile gloves and long-sleeve shirt so the surfaces wouldn't get contaminated. Rinsed/agitated thoroughly with ~8oz xylene and removed. Will air out tonight and do the actual coating tomorrow - planning to use the entire contents of the "motorcycle" kit cut with ~0.5 oz. xylene.
BK
Something went awry. What did Tyson say? Everyone's got a plan until they get punched in the face?
I added 30mL (1oz) xylene to part A and mixed it in well, then I added part B (colored, Dragon's Blood, more orange than red) and mixed for a continuous 10min. Basically following ducatiz's excellent tutorial that describes what are effectively two coats. Poured in half, then saw things were moving kinda slow for my taste after 15min and it didn't look like I was going to get complete 1st coat coverage with that quantity, so I went ahead and added most of the rest, which I had covered with aluminum foil after the initial mixing. A few minutes later I thought I should "paint" the hoses and edge of the shelf ahead of schedule due to how things were behaving. Damn the remainder in my container was suddenly super hot and already solidified! Material in the tank was still flowing, but barely. After about 3hrs the inside of the tank would leave a fingernail poke, but not a fingerprint, so basically done.
Although the xylene made the mixture much thinner as planned, it didn't seem to retard the cure rate much. In this case I would have been much better off adding the entire portion initially and treating it like a single coat.
It's a perfect 75F day per the instructions. I was super careful to scrape the sides and bottom to get good initial mixing (I'm a chemist, so I appreciate how important it is to homogenize the mixture when the components have different densities, etc.). I don't know how to explain what happened and why the stuff in the tank kept flowing, but the portion in the mixing beaker took off like a rocket and hardened. Hopefully the coating behaves and it got everywhere it needs to go. My experience sounds a bit like OrangeDragon's from March of this year.
I have pics, but my hosting site is acting up, so I'll post later.
I usually like to do all my own work, but for the massive effort/anxiety/uncertainty involved, I'd happily pay a pro do this job!
BK
My personal opinion is that the reduction rate generally accepted for the Caswell coating is too low for what we're trying to accomplish with the PA-6 Ducati tanks. We're looking for 100% coverage, not the properties of the Caswell to repair perforated steel tanks, which is what it was designed to do.
From experience, the film thickness/volume greatly affects the cure. What is left in the mixing container will cure very quickly, while the material in the tank will seem to flow...forever.\
Thin it enough to get complete coverage in one coat, drain what you can, plan on where the excess will 'live' in the tank, and be done.
Ducpainter, after my one experience I'm with you. However, I'm reluctant to deviate from the Caswell max 5% thinner instruction in order to get better flow.
Good to hear that it's normal for the Caswell "leftovers" to cure rapidly/differently than what's in the tank.
For anyone planning this in the future, be prepared to improvise and expect the unexpected + don't take the tutorial too literally.
I removed the silicone stopper (from the inside) and finally had a chance to inspect with a mirror and light. Actually from what I can see I'm very impressed with the coverage uniformity and leveling! I did fully clear the overflow holes of the partially cured epoxy - the pic is how they looked after I peeled the tape off.
Using a different image server and hope the attachments work...
BK
(https://preview.ibb.co/dRo8xQ/1_IMG_3244.jpg) (https://ibb.co/c1vXP5)
(https://preview.ibb.co/d0egHQ/2_IMG_3245.jpg) (https://ibb.co/kKTacQ)
(https://preview.ibb.co/mfJacQ/3_IMG_3247.jpg) (https://ibb.co/nDt8xQ)
(https://preview.ibb.co/dX38xQ/4_IMG_3249.jpg) (https://ibb.co/b5SqBk)
Yeah, my setup isn't two coats separated by hours, it is an inital pour and then fill up to paint the innards with a chipping brush.
It starts to gel pretty fast.
ducatiz, by my math your tutorial spaces out the two additions by 40min, and your General area last summary post describes two coats allowing the first one to get tacky. My recent experience was that the second portion gelled in about 20min. Granted I used a ROUND container to mix, not a square Tupperware with more surface area - should have followed more closely!
With a mirror I found some spots near the pump attachment that didn't get coated. That location will always be submerged in fluid and is the lowest point of the tank. My OCD won't let it be, so I have another Caswells kit on hand for touchup!
(A) I only need an ounce or so and hate to waste a whole kit. If anyone local (94303) is ready to coat let me know ASAP and I'll share what I have. I also have Marine Clean, Xylene, stoppers, fuel pump opening plate, 1x recent experience, etc.
(B) What fun science experiment can I do with 1.5 pints of Caswells?
BK
All buttoned up! The black rubber bumpers (original type pn 86610401A) are asymmetrical and have a tall and short side. Does the tall side go on the inside of the frame? Seems this way from the parts diagram. I looked at old pics of my bike and Ducati installed each side differently. [roll]
BK
Yes...tall side inside the frame.
Quote from: BK_856er on August 29, 2017, 08:22:34 PM
ducatiz, by my math your tutorial spaces out the two additions by 40min, and your General area last summary post describes two coats allowing the first one to get tacky. My recent experience was that the second portion gelled in about 20min. Granted I used a ROUND container to mix, not a square Tupperware with more surface area - should have followed more closely!
With a mirror I found some spots near the pump attachment that didn't get coated. That location will always be submerged in fluid and is the lowest point of the tank. My OCD won't let it be, so I have another Caswells kit on hand for touchup!
(A) I only need an ounce or so and hate to waste a whole kit. If anyone local (94303) is ready to coat let me know ASAP and I'll share what I have. I also have Marine Clean, Xylene, stoppers, fuel pump opening plate, 1x recent experience, etc.
(B) What fun science experiment can I do with 1.5 pints of Caswells?
BK
I try to let it get tacky, but it's really a play-by-ear.
I have found that after adding the first batch to splash a bit more xylene in the remaining batch keeps it from getting too thick before use.
I used a chipping brush to move stuff around inside to make sure areas were coated. For the opening, I covered it with the lucite and sealed it with an oring, then inverted the tank to make sure the bottom is covered.
I never put a mirror in to inspect that area, but I have look in thru the filler hole with a FO camera and found it was covered well.
Tank is on and bike is restored to proper running condition after several years hibernation. I elongated the slots in the undertank bracket to give a few more mm clearance to the ignition cylinder. Bumpers seemed to fit best with the long part on the outside. Primed the pump with a bunch of key cycles - obvious by ear when all is good. Fired right up.
First ride today over the hills to the coast and back. Everything works perfectly - just need to regain all my riding skills!
BK
(https://preview.ibb.co/jNnJ65/Full_Size_Render1.jpg) (https://ibb.co/cmXUDk)
Quote from: BK_856er on August 20, 2017, 04:22:11 PM
I don't know how to explain what happened and why the stuff in the tank kept flowing, but the portion in the mixing beaker took off like a rocket and hardened.
I think that this is pretty common for epoxy and for polyester resins - they cure faster with heat, and the curing process is exothermic AND they're thermal insulators. When they're spread out thin, they can reject the heat associated with the curing process, so they cure more slowly. The stuff in the mixing bowl can't reject heat as efficiently - in a tall, thin, round mixer it will cure faster/hotter than in something like a square cake pan. The shape of the container definitely matters. I once had a mixing container of epoxy resin start hissing, popping, and smoking - on the verge of spontaneous combustion - while the same batch applied to my mold was able to flow and be manipulated with a brush. I put on welding gloves and dropped it in a bucket of water outside and ordered more resin.
More info here (http://www.epotek.com/site/files/Techtips/pdfs/techtips_26_7.pdf).
Quote from: Syscrush on September 27, 2017, 10:55:07 AM
I think that this is pretty common for epoxy and for polyester resins - they cure faster with heat, and the curing process is exothermic AND they're thermal insulators. When they're spread out thin, they can reject the heat associated with the curing process, so they cure more slowly. The stuff in the mixing bowl can't reject heat as efficiently - in a tall, thin, round mixer it will cure faster/hotter than in something like a square cake pan. The shape of the container definitely matters. I once had a mixing container of epoxy resin start hissing, popping, and smoking - on the verge of spontaneous combustion - while the same batch applied to my mold was able to flow and be manipulated with a brush. I put on welding gloves and dropped it in a bucket of water outside and ordered more resin.
More info here (http://www.epotek.com/site/files/Techtips/pdfs/techtips_26_7.pdf).
You are 100% correct. I came to the same conclusion after thinking it through. My flawed expectation was that the "stuff left in the container" would be representative of what was going on in the tank and a gauge of the cure status. Your technical description is spot on.
BK
One year and 2 sets of tires later: the treated tank has held its shape and the coating is still intact as far as I can tell. [beer]
BK
Well done, glad everything is AOK!
So glad my tank is metal.
Great to hear its holding up.