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Discussion Starter · #1 ·
Help Please!

On a CB450 K1, I am trying to clean the fuel tank.

The bike has sat for years with fuel in the tank and this has turned to varninsh. I have cleaned out the insides with acetone and now just have to get rid of the rust. However, the two pipes at the back/bottom that are joined by a flexible pipe are gummed up also.

I have tried poking a piece of wire through to no avail and then injected some acetone into the pipe, leaving it for some hours in the hope that it will dissolve the varnish. This does not seem to be working either.

Has anyone got any bright ideas as to how to do this better? I'd be ever so grateful to hear them.

Cheers

Sean
 

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Flatten the end of the wire (keep it short) put it in a drill,you may need a extra hand to do this.
 

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Flatten the end of the wire (keep it short) put it in a drill,you may need a extra hand to do this.
Make sure it is not long enough to pierce the tubing at the bend, or mark it with tape so you know where to stop. Getting past the bend can be a problem, if that doesn't clear it. As long as you get some flow through each, it will be good enough, as they are there to balance the sides of the tank that are blocked by the tunnel.
 

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Sean, I've used old fashion pipe cleaners (if you can find them) and worked them back and forth until they broke through the goop. Dipped in acetone, they should be able to clean out varnish and rust deposits, with patience!
 

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Sean, I've used old fashion pipe cleaners (if you can find them) and worked them back and forth until they broke through the goop. Dipped in acetone, they should be able to clean out varnish and rust deposits, with patience!
You want the ones from a tobacco store, not from an arts and crafts store; tobacco store cleaners are made with cotton, the others from plastic.
 

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Got an old brake, clutch, or throttle cable? Cut a short piece of the inner cable and put it in your electric drill. Spin that into the tubes gently. The cable will go around the bend. Try it at a low speed and be careful. The tubes may be rotten enough that you could go through the wall.
 

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Discussion Starter · #8 ·
Well I tried the brake cable a twisted wire +/- drill and some more acetone. Finally I picked up a cable/zip tie and tried that. It went through on one side but not the other.

Another piece of thin wire followed, then I injected some water using a syringe and "happiness and joy, :)" it shot through. Did the same syringe trick on teh other side and I'm now ready to proceed with the derusting electrolysis.

Thanks all for your ideas.

Sean
 
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Gun cleaner. for automotive paint. also household paint stripper. it removes paint and varnish. try not to let it sit too long. try it on a piece of painted surface and see how it works. if you're not going to wear gloves be careful it'll burn ya. don't let it sit on rubber or plastics. if it does do not leave it. wipe it immediately. i have used a needled syringe. don't freakin poke yourself
 

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Discussion Starter · #10 ·
:-:)cry::cry:
So here's the full story. The inside of the tank as I started looked something like this:

Fuel Tank Before.jpg Petcock Before.jpg

The petcock, I cleaned with thinners and a wire brush - turned out quite well. I set up an electrolysis circuit using a shaped piece of sheet metal, suitably insulated:

Anode Before.jpg Electrolysis Setup.jpg

This wasn't the only anode; I used differently shaped ones to get at front and sides. But you get the picture - haha!

After several rounds of cooking - fill tank with solution (25 grammes baking soda in 1 litre of water); connect it all up and leave for some time; drain and flush the tank, then replace the solution (I had two lots and let the crud sediment after use, befoer re-using); clean the electrode, connect it all up and start again – things seemed to be going well:

Electrolysis in Action.jpg

After a week or so, progress seemed to have stalled, so I decided to finish off by using some acid. I used swimming pool acid (Muriatic or HCl) diluted somewhat, and left it in teh tank for about 10-15 minutes max - I was only trying to put icing on the cake as it were. I rinsed it out then with some baking soda solution and copious amounts of water. I let the tank sit in the sun for a bit, poured in some acetone, blew it out with air after pouring out the acetone and then added some ATF since I thought there might be a bit of delay befoer filling. The inside after all this was a joy to behold. Below is a pic of the anode after the event and the tank after about a week / 10 days:

Anode After.jpg Fuel Tank After 10 Days.jpg

All well and good. Sadly, when I moved the tank a week later, I noticed that some ATF had leaked out! Closer inspection revealed two points, one on either side of the bottom of the tank, which were leaking. Also noted were several bubbles in the paint which I am guessing are other holes waiting to happen - any thoughts on this?

Pin Holes 1.jpg Pin Holes 2.jpg

I am assuming that the acid caused the problem and since that it was dilute and only in the tank for a short while, that the rust was almost through in the first place. Better to find this out now, than have fuel start leaking all over me and the engine at some remote spot?? Gotta find something positive! :)

Any advice on how to fix things would be appreciated. I guess I need to remove the paint to see just how bad the problem is. Is braising/welding an option? I have read mixed reviews about linings, and these are not available locally anyway.

Somewhat deflatedly,

Sean
 

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Old school radiator repair shop, they have soldering skills, brazing and welding is too harsh for the thin metal.
 

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Discussion Starter · #12 ·
"My mama told me there'd be days like this!"

The trick to life is never to get completely disheartened!!

After the saga above, I pressed on; I had been trying to start-up the last day or two with no success. Not even a hint of a start. So today I rigged up a "proper fuel supply (tin can with two bits of brake pipe through the bottom, one hooked up to each carb). Still nothing :(

Then having noticed that one spark seemed a bit weak, I thought to try new ones. I then noticed than one gap was practically nil. Regapped it, inserted it, topped up the tin can and .....

If I could upload a video, you'd see/hear a bike that had sat for 15 years fire up and run remarkably smoothly!!!:D:D:D

Of course a few adjustments were required, but whatever; success!!

Life is good!!

Sean
 
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That's great Sean, congrats on bringing this bike back to life!

As for the fuel tank pinholes, there is a product out there (well, out here i suppose) called Redkote. It's a red liquid (that can be thinned with acetone) that is poured in and sloshed around until it cures, many thin coatings are recommended, as it will build thickness. Petcock is removed and its hole plugged during coating and I'm not sure what one would do with the balance tubes, maybe plug them with a length of insulated wire as the coating wont bond to plastic, steel only.

I've seen it on the web in liquid form in paint cans, but I've also seen it a few times in dry powder form, activated by adding acetone. This would probably be best for international shipping. I'll have a look and post back.

that was quick, https://ftrs.com.au/redkote/dry.php they have a dealer in South Africa if that helps.

and these folks on ebay Aus will ship to your location.

it may be easier to find a different tank though.

Alan
 

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Discussion Starter · #14 ·
Thanks guys.

I'll follow up on that SA dealer Alan; I am told - by what I think is quite a reliable informant - that only 2 of these bikes were imported into Zim, so a replacement tank may be hard to come by.

Old school is definitely required here Barry; too many new schoolers got their papers in an unbelievably short time.

Sean
 
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Sean, if you can upload to Youtube post the link, I would love to hear it fire up. About the pin holes, exactly the same thing happened to my K5. My tank was fairly clean, but I wanted it spotless. I used pure vinegar thinking it was a mild acid. After a couple of days the paint started to bubble and I had leaks. I used Caswell tank liner. Caswell is available world wide. It is a two part phenol novolac epoxy gas tank sealer. Using it is very process sensitive, temperatures are critical. It solved my problem, provided a perfectly clean tank interior and has been 100% reliable even with the oxygenated, ethanol based garbage the call gasoline in this country. I am a believer in it and have used it to line the tank for my GL1200. This tank was in very bad shape and I took it to a radiator shop to be hot tanked. The bike has one season on it now and is holding up fine. I have also lined the tank for my GL1100 which will be on the road this summer. You will hear more about tank liners on this forum Many of us use them and have our favorite products. Good luck and keep us posted.
 

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Discussion Starter · #16 ·
Good suggestions.

I've looked into both products. Red-Kote is available in South Africa - at $134 per can for the powder!! The Caswell liner is available in UK, but getting it to Zim would present problems as it is designated a hazardous material and therefore cannot travel by air. So I will go with the Red-Kote I think.

I did contact a radiator man locally and he's willing to have a look, but isn't at this stage offering any guarantees; he is worried that once we take a closer look there may be more holes than currently apparent. Since the red-kote claims to fill holes up to 1mm diameter only, I think the safest thing is to strip the paint and inspect the tank more closely. Any biggish holes could then be soldered, leaving the smaller ones for the liner. I'd hate to pour $134 worth of liner in only to find I have to waste it all by having to solder holes afterwards.

Jim, I have never tried to upload to Youtube; don't think I can. I put it on facebook, if you want to look there.

Sean
 

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I agree that Caswell is a good system as well, but Redkote has something Caswell doesn't that sets it apart. It's elastic and flexible enough that it will remain intact after a coated tank is dented rather than crack and become useless like systems that cure into a solid layer.
 

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Discussion Starter · #18 ·
Hi all,

Got my tank back today. All holes fixed adn pressure tested. They even sprayed a bit of paint on the underside of the tank where I had cleaned all the paint off. Either a nice touch, or they're trying to hide something. :/

Anyway, anyone ever in Harare and need a tank soldered, I can heartily recommend Mike's Radiators.

Now I haev another problem, but that's a different story, so a new post - Racing engine/sticking carb slide?

Sean
 
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