Petrol tank question........

Johno23

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I’m about to get my 1979 triumph bonnie up and running again. Most of the work is done now but I’ve just noticed the inside of the tank is ............well, a bit shit really. Not sure what it is, but I’m pretty sure it shouldn’t look like it does.
So, what do you do to flush it out properly, I’m guessing some kind of acid or caustic substance :nenau I’ve really no idea. So naturally I came to the GS fountain of knowledge for any advice.............:thumb
 
I think the traditional way (and therefore appropriate for a Triumph) is a load of nuts and bolts, a good shake around and a flush with petrol :D

Alternatively you could do it properly....... ‘ang on, I’ll be back....,,

Andres
 
Be careful not to damage the coating inside the tank,if not already.
 
Clean out the basic gunge and loose bits( shaking loose nuts and bolts around in it etc). wash out and degrease, etch with phosphoric acid.
Tankcare do a complete kit for cleaning and sealing but I prefer Bill Hirsh sealant as its not a two pack and is very simple to use.
 
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also look at silmid its used in the aircraft and marine industry to seal tranks that have to be done in situ
 
I have done a few over the years, as someone else said here be careful..

I put a load of nuts and bolts in a thin sock, tie up the end, drop it in and fill the tank with coca cola or sprite, leave for a couple of hours, then drain half out and shake the tank vigorously. Drain, repeat a few times, then dry out. Then add a litre or 2 of white spirit, and do the same a few times. it worked for me.
 
Frost automotive do a reclining kit .....
 
I did my R90 tank with white vinegar, I bought 25 Ltrs on eBay ,around £25.00 including delivery. Did a great job on my tank, I left it in for about a week.
 
Some good ideas, but we really need to know a bit more about what you are looking at. Have you had a good look around inside with a scope?

Has the tank been lined previously? People who just seal a tank, without dealing with rust first are commonplace sadly My neighbour's Super Rocket was a classic case & a right bastard to fix after the sealant kept falling away & blocking taps & filters. I won't go there now, but hopefully we are just dealing with rust.

The way forward really depends on the severity of the problem. Light rust will usually clear with the vinegar solution above, but severe cases will probably need a full acid treatment. Punture holes in the base may well need opening up & whole areas plated by an expert.

So .......... tell us more.
 
I’m actually not sure if this has been treated previously. The frame tunnel just below the filler seems to have something on it .see pic. Inside however the rest just seems to be rust.My scope isn’t great but have a look at pics..........
 

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Has the tank been lined previously? If so you need to find out what with and get the appropriate solvent to remove it and start afresh. If it's just rusty, without actually being holed, then there are various ways to clean it up as mentioned above. If the resulting bare metal is sound then I wouldn't line it, just don't leave any unleaded fuel in it for extended periods.

I've used Caswell sealer on a couple of tanks with good results.

https://www.caswelleurope.co.uk/

I haven't used the Frost products but the metal prep stuff looks like it could be what you need to start with if your tank hasn't got sealer in it.

https://www.frost.co.uk/auto-maintenance/automotive-tanks-products/fuel-tank-repair.html
 
I’m actually not sure if this has been treated previously. The frame tunnel just below the filler seems to have something on it .see pic. Inside however the rest just seems to be rust.My scope isn’t great but have a look at pics..........

Not the best of views. No6 gives a few further ideas for DIY.

Personally, I would be probably be looking to send the whole thing for a nice acid dip & start again with a repair if needed, a good sealer & repaint, but I appreciate it's all down to budget when running a practical classic. Indeed, aggresive treatments can sometimes blow the whole thing away; but then again there are usually tell-tale signs to guide you, like petrol vapours & witness from leaking areas/seams. For instance, I had one that leaked through the steel behind the tank badge - sadly the whole tank was a danger area & it was only a bit of crude leading & sealer holding the fuel in; yet some cheeky b'stard had seen fit to bodge the job for fiscal gain back down the line.
 
Thanks for the advice:thumb
The tank seems pretty good. As a starter I’m going to use the vinegar method as this won’t do any harm either way, I’m hoping it should clean it enough to be useable, if not, I’ll have to go a bit more extreme. The paintwork on the tank is good, so we’ll see what a week of vinegar does:blast new thread coming ..............Lockheed calipers.........:rolleyes:..........getting the feckin pistons out!
 
new thread coming ..............Lockheed calipers.........:rolleyes:..........getting the feckin pistons out!

Wrap the caliper in a heavy towel and apply an airline to the hole where the flare nut goes . . . Expect a loud bang (DAMHIK) :thumb.

Bob.
 
Wrap the caliper in a heavy towel and apply an airline to the hole where the flare nut goes . . . Expect a loud bang (DAMHIK) :thumb.

Bob.

I've done that a few times but it's fraught with danger.

Far better and safer to remove the pads and to pump the pistons out just using brake hydraulic pressure......or a grease gun.
 


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