Just how bad can the inside of a 'sound tank' actually be?

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JonW
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Just how bad can the inside of a 'sound tank' actually be?

#1 Post by JonW » Mon Aug 24, 2015 12:14 am

Sometimes you can’t catch a break, others you wonder what you did to garner such favour from the gods... This week was one of the forumer, sadly.

I recently picked up another LC, I had in my mind that I would restore it, but Im just not sure I can do yet another yammy 2T twin and I need some of the parts for my resto LC. The bike was a bit rough... That’s probably the understatement of the year. I mentioned to the seller when I saw it that, while I would like to have said ‘Ive seen worse...’, I actually hadn’t.

Anyway, enough of my issues with what I may or may not do with the thing, or when... I thought I would show you one of the most horrible tanks you will ever see. The seller proudly claimed the bike ran when they got it, and said, “see it even has fuel in it!”, vaguely shaking the tank. Which did indeed sound ‘fluidy’. The bottom edges of the tank felt sound, I was hopeful...

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...I wasn’t born yesterday tho, the rust on the top and the locked cap with no key all sounded like a recipe for disaster and I didn’t expect much, but it would have been nice to catch a break, its been a while...

‘Scabby’ isnt the word... Its just not descriptive enough!

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First job was to take the petcock off as it was seized and since nothing came out when I undid the bowl, I figured by now that I was dealing with rusty water not fuel and it had clogged the in tank filter. One of the screws broke off, of course.

While it was upside down I noticed rusty water on the bench, I thought it might be leaking from the cap, but no it was coming out of pin holes on the top surface! Ive never seen that happen.

I wasted an hour or two trying to free off the tumblers in the cap with some WD as they were seized (of course!). I got one side loose and even got the cap to turn a few degrees, so I had loosened the seal. But I realised it wasn’t going to all free up so no chance to hone those picking skills, and out came my largest set of waterpump pliers. 2mins later the cap was destroyed, but off...

Eeek... The cap was totally rusted, it was just a bunch of rusted debris, some had to be pulled from the filler neck where it was stuck in place.

With that out I saw this... Its like some kind of moonscape from a world hidden from civilcastion for many years... Which I guess it is!

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I scraped around a bit, found it had some kind of liner with rust under that skin. Sigh... I felt a bit down to be honest....

So... I decided on a little experiment. The new plan would be to cut the top off and try and clean up the bottom in the blaster with a view that if it was good enough I could either I find a tank that had a good top and rotted bottom or just build my own tank on the top. I decided to save the filler as well for this reason. Who says Im not adventurous? Haha!

I started by cutting the top away and getting two parts...

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The lower half looks good still at this point... Yeah... Get ready for more bad news...

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‘Smallish’ hole on one side... I can fix that...

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My plan was to blast this and it didn’t fit in my blaster, but it will fit in one of my mate’s units... But I needed to strip the paint, liner and rust off first as its not the done thing to leave all that crap in someone else’s unit. So I hit it with Aircraft stripper and then after a scrape I used the wire wheel on a drill, the some rust converter to stop it rusting more.

As you can see, I now have a sieve... The light flecks are light showing through!

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I didn’t even wire wheel it that hard and blasting would be much harsher.

So, a cautionary tale... What looked like a decent and sound underside was actually holed in very many places. Something to think about next time you see a tank on ebay for a good price LOL!
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L.B
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Re: Just how bad can the inside of a 'sound tank' actually b

#2 Post by L.B » Mon Aug 24, 2015 12:32 am

Oh gutted for you Jon,thought this would've worked out nicely.
Im still sure a black plastic fuel safe container can be blown for these tanks,LC & RZ.
Oh well hang it from the rafters now....

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Re: Just how bad can the inside of a 'sound tank' actually b

#3 Post by JonW » Mon Aug 24, 2015 12:34 am

yeah, I will find some white duct tape and hang it, people who come round will try and buy it, always fun :)
80 XT500 Supermoto!
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Re: Just how bad can the inside of a 'sound tank' actually b

#4 Post by evan_calgary » Mon Aug 24, 2015 1:46 pm

I have one in the garage that we discovered the same issues with after blasting. Little tiny holes everywhere and some bigger ones. The highest point behind the fuel filler seems to be a bad spot as well. It has become a welding project.

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Re: Just how bad can the inside of a 'sound tank' actually b

#5 Post by silverstrom » Mon Aug 24, 2015 2:55 pm

Man, that's ugly.

Since it's obviously never going to be used you should have a little fun with it. Try an electrolysis experiment. I bet that within 2 days there is absolutely nothing left. The electrolysis process should only remove rust and paint, and as far as I can tell that's all you actually have. I don't see a lot of what could be considered metal.

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Re: Just how bad can the inside of a 'sound tank' actually b

#6 Post by JonW » Mon Aug 24, 2015 7:09 pm

I agree Evan, its like this tank was upside down when you look from the outside, but I guess condensation was the key to the holes here. The pics I didnt show have stalactites of rust hanging from the roof of the tank!

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I agree John, it wouldnt take much to see this tank just return to nature, its quite scary really...
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
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84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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Re: Just how bad can the inside of a 'sound tank' actually b

#7 Post by evan_calgary » Tue Aug 25, 2015 3:49 pm

I think this should be taken as a warning that really ANY pinholes in a tank likely is a good indication there are more hiding. That upper part of the tank that sits higher than the filler neck is a bad place for holes thanks to condensation. Have seen it a few times. As for electrolysis, you would need to first clean some of the gunk or your electrified bit (anode? cathode?) will just get covered very fast. Tried that with a 200 tank. Evaporust is much more effective IMO.

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Re: Just how bad can the inside of a 'sound tank' actually b

#8 Post by hondaror » Thu Aug 27, 2015 11:01 pm

It just goes to show how one of us needs to start making aluminum repro tanks. I may make a go of it in due time. Have to convert my storage garage into a viable shop.
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Re: Just how bad can the inside of a 'sound tank' actually b

#9 Post by evan_calgary » Sat Aug 29, 2015 2:20 am

Rory, how is that even done? Is it a steel frame that you press blank sheets into then weld together? Have always been curious about that

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Re: Just how bad can the inside of a 'sound tank' actually b

#10 Post by L.B » Sat Aug 29, 2015 4:59 am

I think youd be better off approaching a tank producer like acerbis after market tanks.
Get them to make a tank thats "blown" into the shape of an rz tank.
So many tanks are rusted out on the bottom. So cut bottom off & use top shell of tank
Over the plastic tank.....if that makes sense. Im at work banging this out lol.

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Re: Just how bad can the inside of a 'sound tank' actually b

#11 Post by two-stroke-brit » Sat Aug 29, 2015 1:00 pm

i saw a guy build an ali tank from scratch for a norton (i think) on u-tube.
no special tools( apart from a welder) just a ton of hands on skill and untold hours of sweat.
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Re: Just how bad can the inside of a 'sound tank' actually b

#12 Post by JonW » Sat Aug 29, 2015 8:14 pm

you can get ali tanks from India/asia and they are not the right shape, better than the steel tho lol. There si a uk mob who will do an alloy one, for GBP 2k! The only steel tank that is right is OEM, the others are all badly mis-shaped.

I like Jason's idea, hide another fuel cell under your old painted steel 'top sheet'.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
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85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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Re: Just how bad can the inside of a 'sound tank' actually b

#13 Post by hondaror » Mon Aug 31, 2015 10:26 pm

evan_calgary wrote:Rory, how is that even done? Is it a steel frame that you press blank sheets into then weld together? Have always been curious about that
You have to make a plug out of wood to bang your aluminum over. Weld baffles in and weld the bottom to the tank. It takes loads of skill. I'm going to try one day. The toughest part is the filler. What style?, and how to incorporate that.
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Re: Just how bad can the inside of a 'sound tank' actually b

#14 Post by evan_calgary » Tue Sep 01, 2015 1:11 am

That is a lot more labor intensive than I had pictured in my head. If you try it I would like to see this go down. Would you be able to do the same with glass? Maybe not given the amount of banging the mold would take...

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Re: Just how bad can the inside of a 'sound tank' actually b

#15 Post by wolfman » Sat Sep 05, 2015 7:46 pm

evan_calgary wrote:That is a lot more labor intensive than I had pictured in my head. If you try it I would like to see this go down. Would you be able to do the same with glass? Maybe not given the amount of banging the mold would take...
These tanks were stamped at the factory, top and bottom, then joined.
Wood or sandbag forming would be tough because the knee reliefs are a compound line that cannot be formed by hand. Once I get the shop built I was considering pressing some aluminum tanks but I had better get my tig skills back.
Blow, ( vacuum forming ) plastic would be nice too and I have the setup.
Just need to build the shop.
Big question is cost ?
What would you be willing to pay for a blow molded factory looking tank ?
What would you pay for an aluminum factory looking tank ?
What would you pay for a modern, ( helmet relief, modern filler ) tank that would bolt up ?
$700-$800 U.S. ?
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