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jenkinov

Triumph tank - removal of old tank liner...An experiment.

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Gents ..

 

Thought I would share a problem ...and idea .. and experiment

 

I recently purchased a triumph 3SW ..and whilst I am extremely pleased with the bike it became apparent there was a problem with the petrol tank ..

 

The bike ran ok but as soon as I turned the petrol tap off it became blocked . a Quick examination revealed that the petrol tank had been lined at some previous point and the liner had failed and the entire lining was cracked and peeling , the New ethanol in the petrol was making the situation worse as it dissolved the lining,,hence a daily sludge .

 

 

I eas aware that the petrol tank had been repaired on a bottom seam so was cautious of the alternatives available ..

Whilst considering options i left petrol in the tank interested to see how severe the ethanol affected the lining but examination after a few days showed that whilst it dissolved enough per day to cause the daily sludge ..it mighttake years to clear .

 

 

At this point i decided to drain the tank let it dry and review options ... I thought i would ask a professional for help and contacted a loca petrol tank specialist ..interestingly they were not interested in taking the job on but suggested I use Nitromors Varnish remover (in the Yellow Tin) they also told me that if it touched the outside of the tank it would remove the paint ,,,

 

 

I therefore decided to use Clingfilm to cover the exterior of the tank ..I left the petrol tap. Pipes and tank lid on but covered the airhole in the petrol cap with a heavy gapper tape ....I burnt my hands with Nitromors paintstripper restoring my first bike at 15 ..So donned Heavy Gauntlets , goggles , extra layers of clothing and poured half a litre on Nitromors varnish remover into the tank ..

 

 

after checking for no leaks i started to turn the tank ..and kept doing so for 30 minutes ..initially i could feel the liquid moving in the tank but over the 30 minutes heard the liquid noise turn to one where i could hear debris in the tank ...eventually i could just hear the continual clatter of debris and opened the cap ....(dont breath in) to see what looked like brown rubber leaves ..I turned the tank upside down and using pliers pulled out a mass of the ..old lining

 

 

I could see that the process was working but lining remained so I added 9 class marbles and the last 1/2 litre of Nitromors Varnish remover .. I repeated the process and had a washbasin full of lining that resembled dirty brown leaves

 

I then washed the tank clean with water ....Examination revealed 98% of the lining was out and that the old lining had failed ,,It appears the lining had been put onto rust and that and leaving the tank dry had caused the initial failure ..

 

At this stage I decided to Kurust the tank ..So after allowing a week for the tank to dry .. I repeated the protest adding a full 200ml pot of Kurust ..

 

 

Again the tank was turned for 30 mins ,,examined and turned for another 10 ,,,, The excess Kurust was drained and the tank left to dry for 2 days ..

 

Thats the stage I have reached .....My Gut feel is that if i re apply a lining it may simply cover corrosion and I want to avoid a repetition of the issues I have faced so I intend to wash the tank and then see if i can run it just as it is ...

 

 

Jenkinov

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I have tried several different tank lining products and they have all failed.

I followed the instructions to the letter and removed corrosion, roughed up the insides using gravel and dried them thoroughly, but they all still peel off. Some of them were brand new tanks with zero rust.

I've now decided that it's better to weld up any weak areas in the tank and leave the insides uncoated.

Pressure testing is good for finding pin holes or poor welds, then just weld up and dress those areas.

Obviously the tank will need to be repainted, but the inside shouldn't need touching after that.

 

Pre-mix two stroke bikes have the benefit of oil in the petrol to help prevent the tank rusting inside, but there may be issues on a four stroke.

With ethanol in fuel (which is hydroscopic), many people now recommend draining the tank and storing the fuel in an airtight container if the bike isn't going to be used regularly to help prevent tank rusting.

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A lot of fuel tanks in the past (not so much vehicle ones but more rather bulk fuel tanks that were buried in the ground.... (especially on airfields where the fuel obviously has to be scrupiously clean) ...were often lined with an epoxy paint that was more or less indestructable...

..Over the years I've taken out tanks especially on airfields...that were put in during the war when the airbase was built .....and over 40 years later ...the inside of the tank has been absolutely immaculate.............like standing inside a giant enamelled bath..:-)

.......I really don't know who made such paints in those days or if such a coating would stand up to modern fuels?...but .....any current big tank manufacturer could probably point somone in the right direction as they may well still use a modern equivalent of the paint....???

PS: I used to sell these tanks on usually for holding silage effluent which believe it or not, is extremely corrosive and it shrugged that off no problems...

Edited by RattlesnakeBob

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There has been a lot of correspondence in the classic bike mags about the effect of ethanol on tank lining products. Softening the coating as you have described it also has a severe effect on the Glass fibre tanks of the 60s and 70s. There appear to be products now being marketed which have originated in the US where ethanol has been used in fuel for some time.

 

You could try one of these or wait until there is some feedback to see if they are as good as claimed. But the only definite wayto fix it is to weld it. If you dont fancy doing this yourself there are tank repair specialists but I suspect that the cost could be high which is why the liquid liners became so poular in the first place.

 

Good luck with it either way

 

Regards

Centurion

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The tank seam that I was concerned about has withstood the removal of the tank lining and at this stage I am comfortable that the tank is watertight....

 

I intend to avoid putting in a new liner unless I have no alternative ...I have been quite amazed at the ability of the new fuel to dissolve tarmac ...a hole in my drive where my son left the petrol tank tap on .......plus paint removed from both the jeep and triumph bike ..plus the propensity to dissolve tank liners .

 

When the bike came it had a been fitted with a modern 6v replica lucas horn ...sprayed black ..we spilt some petrol on it and it removed all the paint in a few minutes ...its currently a shiny silver

 

anyway enough ranting about ethanol ...............................

 

 

The tank is a nice blue/black on the inside ..what will be interesting is the effect of the new petrol on the kurust surface ...?

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Well the good news is the Process has worked ..Flushed the Tank out with some old petrol and inspected the tank ...No visible liner and no active rust ...Soo good news ,

 

Filled the tank with fresh petrol and the cleared the tap and the bike fired up no issues .....

 

 

I think I can consider the process a success ...

 

 

Now onto replacing the tyres ...I have ordered some Dunlop Unigrips

 

 

Update to follow

 

 

Jenkinov

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Well the good news is the Process has worked ..Flushed the Tank out with some old petrol and inspected the tank ...No visible liner and no active rust ...Soo good news ,

 

Filled the tank with fresh petrol and the cleared the tap and the bike fired up no issues .....

 

 

I think I can consider the process a success ...

 

 

Now onto replacing the tyres ...I have ordered some Dunlop Unigrips

 

 

Update to follow

 

 

Jenkinov

 

 

So what's the current forecast for getting it on the road ? :)

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Waiting for 2 x Dunlop Unigrips plus inner tubes ....I need to check a rear wheel bearing whilst the wheel is off ...but if its OK Its Tyres on .....

 

Bikes will be ready before me ...... I need to do my bike tests .

 

 

Jenkinov

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Waiting for 2 x Dunlop Unigrips plus inner tubes ....I need to check a rear wheel bearing whilst the wheel is off ...but if its OK Its Tyres on .....

 

Bikes will be ready before me ...... I need to do my bike tests .

 

 

Jenkinov

 

When do you start with the lessons ? :nut: :-)

 

Vulture

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when the bike is fettled .....

 

Jenkinov

 

If your ready for War In Peace next year we could take it along in the CCKW :cool2:

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Thought an update was appropriate on the petrol tank ...The kurust was very succesfull but there were still a few bits of active rust ...I used the nice weather this weekend to get the tank off and re visit the liner and rust issue ..I had basically ran the tank dry whilst running the engine so no real issue in draining the tank ..

 

I went back to basics on the cleaning and flushed the tank with water and then added 8 glass marbles a few litres of water and started turning the tank gentl ...every 10 minutes I drained the tank counted the marbles ...refilled and added the marcles and water ...

 

Must admit that I was suprised at the level of debris the Marbles dislodged ..when i empied it I used an empty light coloured plastic bucket and each discharge produced a nit of floating debris (the old tank lining) a small collection of rust/metal debris that sat at the bottom of the bucket.

 

 

The bike has been running fine so I.. was suprised at just how much debris the Marbles were knocking of the inner wall of the tank

 

5 or 6 washes I was happy with the lining and left the tank to dry ..in the sun

 

Next day I added the kurust and repeatedly turned the tank to give it a good coating ...

 

After draining the excess I left the tank 2 days to dry with the cap off and taps etc removed ..

 

 

Tank is a nice black colour inside ...this weekend I will rinse it with some old fuel to remove any excess kurust and then recharge the petrol tank with Fuel.

 

The tank was a real state inside when I got it and I envisage i will need to keep an eye on it ..but So far so good

 

Jenkinov

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As I hope this thread will help others thought I would post an update on my fight with a heavily corrodedpetrol tank...I thought I had the issue resolved but riding the bike ....particularly off road resulted in petrol slap and debris from the tank soon fouled the carb.

 

The rust reappeared and became active and I believe my decision to not add a yet? Bank liner was correct as I feel I simply would have had a worse problem in a few years time.

 

The tank has been a major barrier and reduced my usage of the bike.....I found a petrol tank specialist in hartlepool and have put the tank into their hands......I will report shortly on the results

R

 

Jenkinov

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As I hope this thread will help others thought I would post an update on my fight with a heavily corroded petrol tank...I thought I had the issue resolved but riding the bike ....particularly off road resulted in petrol slap and debris from the tank soon fouled the carb.

 

The rust reappeared and became active and I believe my decision to not add a yet? Bank liner was correct as I feel I simply would have had a worse problem in a few years time.

 

The tank has been a major barrier and reduced my usage of the bike.....I found a petrol tank specialist in Hartlepool and have put the tank into their hands......I will report shortly on the results

R

 

Jenkinov

 

 

Fingers crossed :)

 

Ian

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Fill the tank with molasses and water mix leave for a couple of weeks . all the rust will be gone .

 

5 to 1 mix will passivate the inside about 10 to 1 is acceptable. Drop a fish tank heater in to help.

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Low-fat ...thank you for the input ...I have used hydrochloric acid in solution to remove rust from a tank which has a similar impact to molasses but found that the flash rust which formed immediately afterwards was a big issue...I have tried most techniques to clean my tank over 3 years ..for tanks with light rust home techniques work but this tank is th e worst I have ever had and I feel that this is the best course of action.....

 

I will post some picks when I get the tank back

 

Jenkinov

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The petrol tank has been returned and pleasingly looks very good ....in summary the tank was found to be in a very poor state with a failed seam ....that seam has been replaced a number of dents removed and the rust removed ..a tank liner has been applied and the tank painted in primer ....I have been very impressed the tank looks much better and the interior is excellent. I know need to 're install the bike with new petrol tap..unsure whether to get Coat of paint on the tank now...or wait.....?

 

I won't star a new thread but the amal carb is flooding ....at this stage unclear if the float is sticking or if the various seals have failed with age......is this a clean.....rebuild .....or replace ..jenkinov

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Most likely some of that debris has got under the float needle. It wont cost a bean to strip and thoroughly clean everything. Remove the jet block while your at it and poke out the tiny hole that is in the throat of the carb. I can explain more fully if you want me to.

 

Ron

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Ron...A full description would help..Carbs are one of those jobs that make me pause...I have had great success and great failures....so any guidance would be appreciated..

 

Jenkinov

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Jenk. It's all fairly simple. After removing the banjo nut and float bowl. Undo the big union nut on the bottom of your carb body No36.

Easier to slacken it while it is still bolted to the bike, but otherwise I hold them (NOT CLAMP) in a soft jaw vice between the flange and bell-mouth. With the nut off, you need to remove the jet block No34 through the bottom of the carb. These are sometimes a tight fit and soaking the carb in boiling water for 30 seconds will help. By holding the carb and a wooden drift with one gloved hand, you can gently drift out the block. I use a hammer shaft or piece of broom handle. Now you can clean everything in thinners. If you peer down the carb throat from the flange end, you will see a tiny hole. This quite often gets blocked with white verdigris. Poke it out with a thin piece of wire (bristle from a wire brush) Also the corresponding hole in the jet block. Blow the jets and drillings out with air and reassemble the block in the body by heating the body again. You will see a pimple on the block which you must line up with the cut-out in the body.

 

Remove the float and drop the needle out the bottom for a thorough clean and blow job! When you replace the needle, hold it up on its seat with a small screwdriver whilst you click the float into its groove.

 

Best to buy a gasket set before you start. I find Hitchcock's are by far the best firm to deal with and they sell genuine Amal parts.

 

Let me know if you need more help.

 

Ron

 

PS Nut No36 needs to be quite tight and easiest to do it on the bike before you tighten the float banjo.

PPS I alway check the flange for flatness by rubbing in a circular motion on W&D paper on a surface plate.....A bit of plate glass is fine. It's amazing how easily they become distorted.

 

Ron

Scan-140503-0001.jpg

Edited by Ron

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