Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Best Tank Sealer

Hey Guys....need to derust my T140ES tank....going to use Evapo-Rust to remove rust......
but need a good sealer... any suggestions on tank sealers ? Red Kote ?

Thanks....
Pete
Hudson Valley , NY
81 T140ES
76 TR7
71 T100R

...is a common knowledge that after a while, the stuff will be worst than if you did not used it and almost impossible to remove it completely.

When a tank has serious problems, better to cut it from the bottom seams, fix it and re weld it.

Interestingly...the weld lines are where my tank started rusting!!!

I used POR15 some 15 years ago and its still doing fine.

edit...the weld lines were from a dent repair. They removed a section of tank from the base, worked on dent from both sides, re welded the cut out section then painted. after approx. 18-24 months I noticed rust in my fuel at the carbie filter.

I've done six tanks so far with POR-15. The oldest one I did was back in 2010. It still looks like brand new metal inside, after eight years of ethanol fuel.

Most sealers will fail sooner or later, lots of info on this subject on Britbike, good preparation seems to be the key, but personally I would use a tank sealer only as a last resort.

I recently wrote a thread on how to de rust and seal a Norton Commando tank, see This Link

In summary I used 500 grams of citric acid dissolved in about 1 gallon of boiling water. With the solution in the tank, I let it stand for a day or two moving the tank around so that every area was covered.

Next I used Phosphoric acid rinsed around inside the tank, this removes any remaining rust and leaves a phosphate finish on the steel.

After rinsing with water, I sloshed Isopropyl Alcohol to remove any remaining moisture.

Then the tank needs to be dried using a hairdrier or similar. This can take a while but the tank must be bone dry inside if using POR 15. Some flash rust may appear but according to the POR 15 instructions this is OK.

With the tank bone dry you add POR 15 and rinse around for 30 mins. Then any excess should be drained. Avoid letting the POR 15 pool in one place.

Takes about 4 days to cure and works well

POR15 gets my vote.. I've used it on maybe 6 tanks and haven't seen any issues.

Personally i wouldn't consider using a tank sealer you hear so many horror stories,paint jobs are costly enough without having the hassle of removing broken down sealers from inside tanks are carbs etc,and then having to re-paint again
If possible proper repair job at this stage, only my opinion guys.

Dave

Sealer is for sealing holes. No holes, no sealer.

I fill my tanks with vinegar and leave them for a week or two. Then rinse with baking soda, water and some odd hardware to scrub what's left. It's bare metal for me these days, or fix leaks and repaint.

Cheers,
Bill

Hi GTSRider, Rust is a huge issue on fuel tanks. Many ways to remove it. I don't know what way is best or if it matters. Just get the rust out.

Regarding liners/sealers I think you'll find they are pretty much a must to prevent future rust & rust holes.

It seems the original tanks did pretty well at not rusting too bad, but once rust started it changes things. After cleaning rust they rust much more readily for some reason. I've observed this on several tanks. If you just clean, it will rust again & will perforate. It just will.

Ethanol fuel tends to promote rust also. Under the fuel level is not much a problem, but the upper inner surfaces exposed to air is very prone to rust & rust perforation.

After a derusting using Kreem my tank perforated on the upper surface after only 4 years. I did not use a liner or sealer.

I checked tank upper with mirror often & could see rust getting worse as time went by. One day I was getting gas seeping out a pin hole a few inches to rear of gas cap. Again down low was ok. I always parked bike with full tank, but that doesn't help the top.

I had really nice original paint. There was only the tiniest pin hole. Hardly noticeable on paint. I was committed to save paint & wanted to do it myself to save money.

Kreem liner is not durable at all, so don't use it. However Kreem paint mask works very well & you can protect paint from acetone & the sealer you want to use. Use 3 coats of paint mask. Put glad wrap over paint mask while doing the sealer as paint mask is very fragile. Paint mask is water soluble, even 1 drop of sweat will compromise it.

After much research I narrowed my choices to POR15 or Caswell tank sealer. Both can be applied over some rust, or so the instructions say. So some remaining rust in seams seems to be ok.

I decided on Caswell after reading up on both the above. I knew I had leak & could see more rust perforation was soon to follow. I felt Caswell was a really good sealer & it also stops further rusting according to Caswell.

I really do not know which sealer is best, so you research & decide. Whichever, follow instructions very closely.

With confidence I can say if you do not seal tank it will rust & fairly quickly. If your paint is good, you can remove rust, seal & save paint.

The liners can be removed by various companies that do this, plus clean & reseal. Often the paint is lost in that case. These companies can save paint in rusty tanks in many cases similar to how I did. You can remove liners with certain chemicals at home also. Not easy, but possible.

I could not find a good used tank. All the used tanks I saw were damaged fairly badly or rusty. Most had much worse rust than mine. New tanks I don't know, how are they? Looking at the forums some don't fit right, leak, rust. They may or may not come painted. No easy answers. New tank + paint is very costly.

At your stage I feel you cleaning & lining yourself would be the best solution.

If you decide on Caswell get at least the 1 pint can. The little 3 gal. size can is not quite enough to cover easily. Also get a 1/4-19 BSP straight pipe tap to clean any sealant from tap threads. I got an Ebay $4 one from China. It actually came in a few weeks & worked good. Get a large black rubber "stopper" from Ace Hardware to block off fuel filler neck. That worked good. I made plugs for tap bungs. Old fuel taps with screen cut off would be good. I found it impossible to keep all traces of sealer from threads. The China made tap cleaned sealer from threads perfectly, but pull plugs & wipe threads to remove sealer as you can before it cures.

I don't know about POR15, but with Caswell, let it cure at least 1.5 weeks. Do not short cut the cure time. Let it cure much longer than instructions say. That seems to be a key factor it long life.

All this was a lot of work, but paid off. Also I get no more rust flakes in fuel filters. So the sealer actually does keep rust at bay, at least until it deteriorates. As the testimonials say, the good sealants last many years.

Paint some sealer right up to very top of filler neck. This seals the crimp of the filler neck & prevents leaks there also. Not on outside of neck, but inside. Gas pump nozzles have not damaged the Caswell sealer in neck. It's quite tough material. But I'm careful to not try to chip it.

Good luck on your tank, take your time & you will be good.
Don

Hi GTS
I used kreem in two different tanks with great results since 1999 never had a problem!
But the tanks wasn't too rusty had a few very small holes who filled with bronze welding!

Phosphoric acid rinse followed by Caswells and it will last for years. Well, ... over 10 on my tank. The Caswell kit back then said good for 2 tanks ... Maybe two peanut sized Hardley Ablesons but not a T140 tank or any other with decent gallonage.
Good luck.
Don

I'll nominate 'gallonage' as word of the day

Thanks guys for all your input......I think POR-15 sounds like the right product for my situation.

Hi GTSRider, Good. Let us know how it goes. What size did you buy? How did you do it? Did it tend to cover easily, even on the center support tube?

I found I needed to turn tank slowly to get the Caswell to spread evenly. Turning too quickly didn't allow time for it to flow & spread. The sealer had a good affinity for metal & wanted to spread well when turned slowly, even on center tube. I used a small mirror & flash light to check coverage looking through filler neck. I would expect similar with POR15.

I also found it not so simple to pour all the sealant out. Practice with some fuel or solvent or the like. Sounds simple, but I found it not. I had some 1/4" plastic tubing from Ace Hardware on hand. Ended up siphoning some sealant out from right saddle as it wanted to pool there. I tried to roll tank such to collect on right saddle as you can't access left saddle. I don't know what others did. Mine is '73 Tiger with US tank.

Since Caswell is 2 part like epoxy it has a short working time. That made you work quickly & a short drain time. I expect the 1/2hr. drain time of POR15 would be much more forgiving, but I would still practice 1st. Full cure time is 4 days. I would do at least twice that. That is what several vintage car guys I know do.

Are you trying to save the paint?
Don

Some simple POR15 advise. I'm sure TR6Ray could add and improve on. First of do not shake the tin, if it's been sloshed around then leave it to settle for a few days to allow any bubbles to come out. Stir the tin in an up and down movement from the bottom up, stir slowly until you have a uniform colour. Once added do not shake the tank. Coating the centre tube will be the hardest part so get that out of the way first. I found letting the sealant pool at the top of the tank and then turning right way up allowed me to coat one side of the tube at a time. Then roll, prop, wait, roll, prop, wait etc until you are happy you have a decent coating. I do not tend to worry to much about it being really thick just well coated.

Draining the tank is just as laborious. Remember there is a raised boss around the fuel tap holes so draining this way will tend to promote pooling. Instead I drain from the filler, if I'm going to have any pooling I would rather it be on the top of the tank.

I have successfully sealed a few tanks around the filler neck using just a sealer. However the last two tanks I have done both required work in this area and using POR15 alone has failed and the paint is lifting. I do not think it is possible do properly prepare this area once the crimp has been disturbed. Personally I will go back to soldering each one.

I'm also a fan of pre prepping the tanks I do. They get washed with a de greasing agent and pressure washed before being rinsed with phosphoric acid to remove the worst of any corrosion and general crap. I then use a small cheap endoscope connected to the lap top to inspect all the seams and crevices. Once I'm happy I start the process using whats provided in the POR15 kit.

Rod

How do you dry tank after internal wash ?

For the first washes I rinse the tank with some acetone. That gets it nice and dry and keeps the surface rust at bay. When drying before applying sealer I use a hot air gun but I understand a hair drier can work as well. It's a frustrating process, just as you think you are done you roll the tank and more water appears! You also get to watch your nice clean rust free tank flash rust in front of your eyes. It does need to be bone dry though so do not rush this stage and if the tank is hot to touch when done let it cool some before adding the sealer.

I questioned POR15 about using using acetone or MEK to dry the tank (Kream do just that) and was told it would ruin the etch left by the de rusting process and cause the sealer to fail. So don't do that!

Rod

If the external paintwork is in good condition and you're not planning on respraying, I would caution against using Acetone or MEK. These are strong solvents and will ruin any paintwork.

The following chemicals are paintwork safe and wont damage the exterior finish:-
- For initial degreasing and general cleaning I would use a detergent based solution rinsed around with hot water several times.
- Rust removal can be achieved using 500g (0.5 lbs) of citric acid mixed with hot water up to near the filler cap and left in the tank for up to a couple of days. Use a cork or rubber bung to seal the filler hole and position the tank to ensure complete coverage including the top area as mentioned. Use a hose and cold water to rinse out the citric acid.
- Following use of citric acid, swill the inside of the tank with approx 500cc of phosphoric acid to remove any remaining rust and to etch the surface ready for the sealant
- Isopropyl Alcohol can then be swilled around inside the tank to remove moisture and any remaining chemicals, do this twice using approx 500cc each time.

After using the above chemicals, the tank interior should be clean enough and ready for sealing. The only remaining step is to ensure the tank is bone dry internally. This can take many hours if not days as moisture tends to accumulate in the metal seams. Use a hair dryer, hot air gun, airing cupboard or sunny position etc. to assist drying Then inspect the interior using a torch, mirror, endoscope checking every possible area for moisture especially the seams. Some flash rust will appear during this stage but certainly POR15 (Paint over Rust) can cope with this.

Hi, Gunner is correct about paint damage with strong solvents. My instructions recommended acetone as a final rinse. Acetone will dissolve old Triumph paint instantaneously. Faster than brake fluid. I know that from personal experience. My understanding is paint was cellulose lacquer.

I can say with personal experience Kreem paint mask will stop damage from acetone. I used 3 heavy coats & let dry well between coats. It peels easily & readily dissolves with water. So you must be gentle with it. Covering parts of tank with Glad wrap or the like can be helpful. But don't let acetone get between Glad wrap & paint mask.

If you use other solvents I recommend testing. Kreem paint mask is often no sold locally. I had to use Ebay. I tested with acetone & verified it protects paint.
However if you have a hole in tank, acetone can/will come though hole & damage paint under the mask... I blew mask into the pin hole which was on top of tank so very visible. Let it dry over night. Then after 3 coats Kreen did final cleaning with acetone & sheet rock screws. Not a trace of paint damage.

Acetone tends to remove any trace water remaining. Acetone evaporates very easily from tank. However I did tank in summer with hot days. 100f. I found just setting tank in sun & turning it occasionally dried water in 1 day. Acetone dried in less than 1 hr in sun. My problem was finding day cool enough to use Caswell without too fast of cure.

Always learning, interesting that acetone rinse can remove a coating that can promote rusting. Hmmm. That's serious food for thought.

At the shop on cars we quit cleaning tanks as 100% rusted soon. They were sent to radiator shop that had fuel tank cleaning service. No idea what the cleaning solution was.
Don

Hot tanks are heated alkaline solution, ie. mix lye with water and heat. Removes everything. Quickly.

Very dangerous, by the way. My dad use to own a radiator shop and the smell of the stuff was pretty bad.

I did a number of tanks in Kreem, then found Continental radiator shop in Buena Vista. The had a service where they basically created a fuel bladder inside your tank then baked it on. It cost 100$ but you got back a tank that was otherwise bare, clean metal.

Then you paint.

It wasn't cost effective for them and they stopped doing it. It added about 5 pounds to the tank. Guaranteed never to leak, though. I think it was mandatory for some classic racing clubs....

Cheers,
Bill

The cure for rust in cars was the extensive use of zinc plated steel on the underbody and critical panels, wonder if a tank could be zinc plated or glavanized.

I've wondered the same thing. Or maybe tinned internally? Sounds expensive but some of these lining jobs are expensive.

There is a barrel zinc plating plant nearby, the issue will be the drainage of solutions between each step as I doubt one or two petrol tap holes and a filler hole will be enough as the barrel moves automatically.

Auto fuel tanks in the USA were galvanized inside and out until plastic tanks took over...And they do often rust from inside after maybe 30 years.. ....These bike tanks are 50 years old...