Tank rost und sealer

[Shadowfax]

Hallo, entschuldige im Voraus mein schlechtes Deutsch – ich habe Google Translate verwendet.

Der Tank meiner BMW R27 hat außen keinen Rost und ist hinter den Knieschonern in Ordnung. Soweit ich weiß, leckt er nicht.

Das Innere ist nicht so gut. Da ist Rost und da ist Tankversiegelung. Ich weiß nicht, ob das die Originalversiegelung ist. Was wäre die beste Behandlung:

1. Rost entfernen und belassen
2. Rost entfernen und neu versiegeln
3. Rost und Versiegelung entfernen und nicht versiegeln, wenn nichts leckt

Ich würde den Lack gerne behalten, da er original aussieht.

Vielen Dank.

[Shadowfax]

[Taz]

Hello Martin.

That seems to be the original sealer...with some corrosion.

The original sealer is the real thing, in my experience only removable with brute mechanical force...but that might not be necessary. The relaxed approach would be take the tank off, empty it and use handfull of small wood screws (1/2" long) and gently moving around to remove loose rust, then clean thoroughly and put back in place. Make sure to use E5 (the less ethanol, the better) only, and stabilise the petrol during months of storage. Occasionally adding a drop of oil won't hurt.

Or you can hand over the tank to a professional tank sealing companz and have it cleaned and relined properly...

All the best, Taz

[RTwenty7]

In my opinion there is 2 ways to move.

- if there is no leakage go on and drive until it becomes leaking. don´t try to remove anything, just new gasoline and go on.

- professional tank restoration with blasting out the old seal and if its still solid after that, new seal and be happy (in Germany from 250-400 eurodollar)

any other ideas are junk, believe me

[Shadowfax]

Two replies in English. Google translate must be worse than I thought  I don't know what the etiquette is regarding English/German.

Thanks for the replies. The bike has stood still for a good few months, so there it's old fuel, with debris. It probably does need cleaning, otherwise the newly-cleaned carb will just clog up again, despite the fresh fuel filter. A gentle approach - possibly a combination of what Taz suggested with electrolysis - sounds good.

Then keeping it topped up with fresh fuel might do the trick.

[Heiko]

Hello Martin,

just feel free to ask in English. A lot of members here are able to understand.

[4Taktix]

Hi Martin,
in any case I'd loop a petrol filter into the fuel line, first of all. -> Paper insert.
( even if most of the guys here go nuts, hearing this recommendation )
( They worry about reduction of flow by such a filter )
But:
1. you will notice the difference at high speeds, if there is any.
(leaning the mixture = more heat, less power, less topspeed)
2. You'll rather get home with a lean mixture (carefully) than with carb-jets clogged by rust.

Concerning the Tank inside, I'd remove loose rust and sealer by e.g. putting some hands full of fish-tank-grit
(broken stone, sharp-edged ) into it and shake and turn it for a long while.
Most comfortable this can be done with a concrete-mixer, if you have access to any.
Wrap the Tank in as much thick blankets as you can find and fix it somehow inside the mixer,
then let it run several hours, change orientation of the tank inside the mixer or simply tilt the mixer from
time to time. Empty tank and rinse thoroughly several times.

After that you have less risk for loose particles drifting around and eventually clogging the petcock, carb,
or jets. I'd use a fuel filter anyway then.
Now you can leave it as it is and drive and enoy ( e.g. most of the russian bikes like Dnepr, Ish, Molotow, Ural
never saw tank sealer. Sure they have a reputation being unreliable, but this is for many reasons ... )
Else you now can derust the remaining stains in a chemical way and apply new sealer.
Afaik there were complete Sets on the market, containing everything required for a complete tank restoration.
But consider you'll have toxic/harmful waste after the first step and you probably have to dispose it of
appropriate. Nothing for the kitchen-sink.

[strichzwojan]

Hi,

my recommendation would be, to check out if the tank ist fueltight in the present condition. Dont seal before! The sealant will be an obstacle, if you have to solder some leaks. If you intend to use more than one tank filling per season, sealing might be not necessary. The alcohol in todays fuels can dissolve a good amount of water.

Jan

[Borgward]

Two replies in English. Google translate must be worse than I thought  I don't know what the etiquette is regarding English/German.

die Google Übersetzung war excellent

Hubi

[kahlo]

I see the original red paint and a thin white tank sealer on top. The rust was not removed properly, and the tank was not cleaned properly before this sealing attempt. And it looks like the rust was not stopped as new fresh rust is present.
So, not good at all.

Kahlo  .

[R26SPORT]

In my opinion there is 2 ways to move.

- if there is no leakage go on and drive until it becomes leaking. don´t try to remove anything, just new gasoline and go on.

- professional tank restoration with blasting out the old seal and if its still solid after that, new seal and be happy (in Germany from 250-400 eurodollar)

any other ideas are junk, believe me

Hello! Regarding the language, I have a similar problem. Google does not translate well from the native language (in my case Spanish) to German, it does it quite badly, but I took the advice of a forum member (I don't remember the name now) who recommended me to first translate from the native language to English, then translate from English to German, at least it seems to work well because nobody has complained lol.
Regarding your problem, I'll tell you what I did, I removed the tool tray or glove box by filing the upper weld, it comes out perfectly without damaging anything, with that huge hole you can take the tank to a specialized workshop to have it sandblasted, then remove all the dust with air and re-weld it with MIG or Laser welding again, and it is ready for the application of the paint which is 2-component epoxy, special for hydrocarbons, it is done by rotating the tank and removing the excess paint, this procedure is done twice and it is perfect. In my case, I have the tank with the original external paint and in perfect condition. I was able to do this treatment without damaging anything. The paint only burned a few millimetres on the edge of the weld (with laser the damage is minimal). The little that is burned is easy to do a touch-up of paint without it being very noticeable.

Regards

Alejandro

[Taz]

... Two replies in English. Google translate must be worse than I thought  I don't know what the etiquette is regarding English/German ...

No worries...as a number of other members have confirmed already, the translation has been spot on...however, English is well understood around here (as are several other tongues), and eventually all that translating business might cause the questions and/ or the answers to lose some precision.

And finally...there is no etiquette...if you want to be super compliant you might wish to post your questions in the English part of the forum, but to be perfectly honest there's no need for that these days

All the best, Taz

[Shadowfax]

Thanks everyone, also for the language suggestions.

There does indeed seem to be some white layer on top, as @kahlo suggests. It's good to know that the red layer is the original one. What I'll do is drain the tank and see how much loose stuff is in there. I like 4Taktix's idea of the aquarium gravel + concrete mixer. Reasonably subtle, with little physical effort involved from my part 

My main concern is not leaks - it seems OK. It's avoiding getting all the rust and other particles into the carb. I cleaned the petrol filter (it's a cleanable one) and flow is pretty good.

Will report back once done.

- Martin.

[Taz]

Hello Martin.

Sorry to interfere with 4Taktix' suggestion, I still opt for the small wood screws...they don't cause any additional dirt (like dust or gravel broken further down), can be bought at any hardware store (even B&Q will have them) and 1 to 1 1/4 pounds of them will go a long way....I had mine in use now for the third tank without any signs of them getting less effective...

The main thing with the concrete mixer is...lots of blankets, lots of straps...once the tank has come loose the rust will be a lesser problem to deal with

Have fun, Taz

[berndr253]

If the inner coating ist the original one it can be removed with caustic soda - in fact in a higher concentration. I have tested that method twice with very good results
Important is to fit the tank above a plastic tub - if there is any leakage the lye can float into that tub!

Bernd

[Shadowfax]

Hello Martin.

Sorry to interfere with 4Taktix' suggestion, I still opt for the small wood screws...they don't cause any additional dirt (like dust or gravel broken further down), can be bought at any hardware store (even B&Q will have them) and 1 to 1 1/4 pounds of them will go a long way....I had mine in use now for the third tank without any signs of them getting less effective...

The main thing with the concrete mixer is...lots of blankets, lots of straps...once the tank has come loose the rust will be a lesser problem to deal with

Have fun, Taz

Screws + concrete mixer sounds a good idea, too. But yes, there will be excessive wrapping and strapping. 

Thanks Bernd for the pictures. I'll see how things look after the initial clean. Undoubtedly not as beautifully clean as your last picture

[berndr253]

The tank I´d shown in the pictures above showed no corrosion inside. The treatment with the lye is only the first step. After that the tanks should be treated with a rust converter, then the tank is cleaned with water, then dried.
After all the inner surface was overdone with epoxy-resin.
I used epoxy-resin from Restom - but there are other products which are resistant against gasoline.

Regards

Bernd

[bullet]

professional tank restoration with blasting out the old seal and if its still solid after that, new seal and be happy

I second that.  25 years ago I did the removal of rust and old seal myself.  Loads of work, kept me busy over serveral weekends.  And distributing the new seal evenly by moving the tank around until it solidifies might take two to three hours, a real nightmare.  Thereafter my arms felt like falling off any second.

Last year I had another tank which needed a new seal, but I took it to a professional tank restorer.  They did the (sand or glass) blasting, made a pressure test to find leaks (which they would have fixed if there were any), and applied a new seal.  They provide a warranty for the seal being resistant to any fuel from E10 to diesel.  Was quite expensive and felt like burning money at first, but I could do other work in the meantime.  And I'm satisfied with the result, so the money was well-invested.

The alcohol in todays fuels can dissolve a good amount of water.

Yes.  Don't be afraid of E10 petrol.  It is not as bad as many people try to make you believe.  It even has advantages besides being more affordable.

[Taz]

... Don't be afraid of E10 petrol.  It is not as bad as many people try to make you believe.  It even has advantages besides being more affordable ...

Now you have made me curious...would you please care to enlighten me about the benefits of that stuff? Besides the slightly lower price (for a fuel that has less energy content per litre, so BMW recommended to consider a larger main jet for our wee beemers when used regularly) I cannot think of anything positive...

[Kees]

Well, for one, it reduces the CO2 output of your vehicle.

[strichzwojan]

Ich bin zwar nicht bullet, Ute, aber ich antworte mal...

Das Ethanol im Sprit hat einen guten und zugleich schlechten Effekt. Es ist wie mit der Medizin: Die Dosis macht das Gift.
Ethanol ist wasseranziehend und wasserbindend. Dem Sprit beigemischt sorgt es dafür, dass gewisse Mengen an Wasser gebunden und mit dem zerstäubten Gemisch "verbrannt" werden können.

An den Tankstellen in Norwegen gibt es für den Winterbetrieb den "kondensfjerner" zu kaufen, den man in den Tank gibt. Das ist schlicht Alkohol.
https://www.thansen.no/verktoy-forbruk/kjemi/additiver/kondensfjerner/kondensfjerner-til-bensin-1-liter-99-7-alkohol/n1413864/pn1413965

Wie gut sich Wasser und Ethanol vertragen kenne ich vom Camping. Da wird der Spiritus mit 10 Prozent Wasser verdünnt, damit die Flamme rußarm brennt und nicht die Topfböden versaut.
Zurück zum Fahrzeug...
Der Nachteil: übersteigt das Wasser im Sprit einen gewissen Prozentsatz, so entmischt es sich und steht dann als Pfütze im Tank. Dort kann sich Rost, aber im Zusammenwirken mit dem Benzin auch säurehaltiges Zeug bilden, was Beides nicht gut ist.

Wer also mit seiner Einzylinder mehr als eine Tankfüllung pro Saison verfeuert, der sollte auf der sicheren Seite sein. Deswegen würde ich bei einem frisch aufgebauten Tank heute auf eine Versiegelung verzichten.

Jan

[kahlo]

Deswegen würde ich bei einem frisch aufgebauten Tank heute auf eine Versiegelung verzichten.

Ich nicht  . In so einem Tank bildet sich Flugrost schneller, als man den Rostentferner/-umwandler ausgiessen und trocknen lassen kann. Was soll da erst langfristig passieren...

[strichzwojan]

Ich persönlich überwintere meine Motorräder alle randvoll betankt. Wie soll da eine Oxidation am Blech stattfinden. Und wer ablässt schwenkt eben mit Zweitaktgemisch aus. Das sind übrigens altbewährte Tipps aus den 40er, 50er-Jahren...

Schlecht sind immer so Sachen wie Flußmittelrückstände oder auch auch aus den Falzen kriechende Entroster wie z.B. Phosphorsäure, die gerne genommen wird. Dann hat man den Teufel mit dem Beelzebub ausgetrieben...

[cledrera]

Wie soll da eine Oxidation am Blech stattfinden

?

Der Wasseranteil im Benzin enthält genügend Sauerstoff, um eine Oxidation anzustoßen.
Viel ist das allerdings im Vergleich zum entleerten Tank nicht.
Wer aber Angst vor Rost hat, ist bei unserem Hobby sowieso schlicht falsch.

[berndr253]

Die Geschichte von Ethanolzusatz in Benzin ist alt - schon in den 20 und 30 er Jahren des letzten Jahrhunderts wurden Akohol Benzin zugemischt - mit bis zu 25% zu konventionellem Sprit.
Ich fahr E10 seit dem es das an den Tankstellen zu kaufen gibt - in allen meinen Motorrädern, angefangen von der 25/3 bis hin zur auf 800 Kubik aufgebohrten R50/5. KEIN Zylinderkopf wurde auf bleifrei umgerüstet und ich war und bin seit vielen Jahren nur noch zweirädrig unterwegs.
Auch die Horrorgeschichten mit durchgegammelten Tanks wegen des bösen Ethanols kann ich weder bestätigen noch nachvollziehen.

Mag sein, dass nicht alle Spritschläuche mit dem Ethanol klarkommen und aufquellen - dann muss man die halt mal gegen welche aus beständigem Material auswechseln.

Grusz

Bernd

[RTwenty7]

Bernd, das ist wie mit fast allem im Leben. In unserem Fall Öl, Unterbrecherkontakte, E10 Sprit, Bleifreizusatz und noch zahllose andere. Man muss nur lange genug drüber quatschen und irgendwann wächst ein Mythos, dem alle (oder die meisten)folgen und erliegen.
So funktioniert das Versicherungsbuisiness, das Pharmabuisiness, das Werkstattbuisiness und noch viele andere, Foren übrigens auch  

[Taz]

Alright...so apart from getting answers to questions I didn't ask (like the lead-free topic) I was told that E10 will reduce the CO₂ emissions of my vehicle, while at the same time due to lower energy content per litre the vehicle will have poorer fuel efficiency....this source (German) gives 0.9% less CO₂ and 1.9% more consumption.
Allegedly it will also reduce the total CO₂ emissions as the ethanol comes from plants or parts thereof...and if using sugar canes or wheat for the production this puts my wish to move freely in direct competition with others wishing to eat. I could not find any information on how the different production methods of "normal" fuel and ethanol compare CO₂ wise, though.


Also the E10 fuel can hold more water, which in my humble opinion is more a drawback than an advantage, as the fuel will get in more water from the air when it's warm, and when it is getting colder the water will fall out and will make a puddle at the bottom the tank, "helping" corrosion (which I don't love, whatever Clemens is saying ). The process will repeat with every temperature cycle, worse in humid air (like in the UK)...

Not convinced, I will continue to use E5 (less ethanol), even it is only available over here as "Super fuel" at a considerably higher price...

[bullet]

I'd always recommend sealing the tank.  Air has always humidity, which leads to condensation in the tank.  And there is lots of humidity, especially on islands with loads of liquid sunshine.   

The larger main jet is always a good idea for the older models.  In the early 1950s BMW tried to make these more fuel efficient by leaning the mixture, but this doesn't work because the rider opens the throttle further in order to compensate for the power loss.  In some cases this leads to piston seizing by overheating.  BMW corrected this during the production of the R26.  The largest main jet, which does not reduce the top speed, protects the piston and does not increase fuel consumption, because you get the same power as before by openening the throttle less.  It also makes the engine E10-safe.

@Taz: the source you cite also says that the lower price of E10 compensates the (slightly and almost unmeasurable) higher consumption.  Looking at the UK prices for E5 I'd say it is over-compensated.  Paying the higher price for E5 is burning money, literally.

The amount of water getting into the tank is a function of air humidity and temperature changes, not of the tank contents.  E10 will absorb more water than E5 before a puddle of water forms at the bottom.  E10 does the exact opposite of what you think it does.

[Alter Schrauber]

Sind wir eigentlich im Englischsprachigen Bereich? 

Die Eingangsfrage war doch hervorragend übersetzt.

Gruß Jörg

[M. Bumerang]

Jetzt sag bloß du kannst kein Englisch?
Manfred

[Alter Schrauber]

The only thing that bothers me is the anticipatory obedience. That was already the case in the company. 

Gruß Jörg