Fuel tank captive fixing issue

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Stainless or leather strap over the tank would look very cool indeed and may be functional of course! Would protect the rear of the tank also. Not sure how it would be secured or how it would interface with the modern central petrol cap, as opposed to an offset Monza/vintage cap.
The alloy tanks have an offset petrol cap, so might work.... but then again you would hope that the front mounts were unlikely to work loose on an alloy tank.
 

Voodooo

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Stainless or leather strap over the tank would look very cool indeed and may be functional of course! Would protect the rear of the tank also. Not sure how it would be secured or how it would interface with the modern central petrol cap, as opposed to an offset Monza/vintage cap.
The front of the tank strap could be secured by the battery / coil box bolts. And the rear strap by the rear tank bolt. This would be only use as visual aesthetics only and not for tank mounting.
 

Fast Eddie

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The front of the tank strap could be secured by the battery / coil box bolts. And the rear strap by the rear tank bolt. This would be only use as visual aesthetics only and not for tank mounting.

NO!

Make a tank strap by all means... but please, no false tanks straps.

Where does that end... fuel injector bodies (badly) styled to look like monoblocks ?!
 

cliffa

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Stainless or leather strap over the tank would look very cool indeed and may be functional of course! Would protect the rear of the tank also. Not sure how it would be secured or how it would interface with the modern central petrol cap, as opposed to an offset Monza/vintage cap.
It would need to be wide enough to have a hole for the filler cap at that point, but the rest of only needs to be circa. 25 - 35mm wide I guess.
 

Voodooo

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NO!

Make a tank strap by all means... but please, no false tanks straps.

Where does that end... fuel injector bodies (badly) styled to look like monoblocks ?!
lol. Where else you going to secure the tank strap without welding or drilling into the frame?
 
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Well I have now (hopefully.!) sorted the captive fixing issue by using stainless steel prong T nuts. These are primarily designed for providing a threaded insert into wood, but they worked fine on the plastic fuel tank by heating them first and pushing the prongs into the tank. This was after the paint was carefully removed around the fixings and the prongs on the T nuts were shortened a bit due to me not being sure how thick the plastic was on the tank.! Once done, these were then bonded into place with Araldite. They provide a lot of resistance to turning and a good surface area for the adhesive to provide a strong bond. As a final precaution against a repeat episode, I will fit stainless steel studs with an insert hex in the end and use nyloc nuts with washers instead of using the original screws. That way, I can at least hold the stud in situ whilst undoing the nut.

Thanks again to all for the suggestions & comments, much appreciated. :)
 

Stephen_Spencer

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Well done Deano. Sounds like a well thought out and permanent solution. Did you take any pics of the fixings/application that you can post? Always useful to those that experience this problem and go looking for the thread.
 

MAK

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Well done Deano. Sounds like a well thought out and permanent solution. Did you take any pics of the fixings/application that you can post? Always useful to those that experience this problem and go looking for the thread.
Maybe for future reference..
Clarendon metric series Keensert.
Metric thread inserts.
Once in position you tap down carefully the three pegs.
 
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The JB Weld let go on my rigged tank and frankly I'm getting tired of taking it off, grinding, cleaning reapplying epoxy. I'd like to get a new aluminum tank or get one fabricated. I know we've been down this road before. Ya think Norton would have spares or anybody stateside know of a custom fabrication shop? Bikes running good. Did a few hundred miles past 2 weeks.
 

BritTwit

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The JB Weld let go on my rigged tank and frankly I'm getting tired of taking it off, grinding, cleaning reapplying epoxy. I'd like to get a new aluminum tank or get one fabricated. I know we've been down this road before. Ya think Norton would have spares or anybody stateside know of a custom fabrication shop? Bikes running good. Did a few hundred miles past 2 weeks.
Isn't MxMartin selling an alloy tank?
 

Clive

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As you found I think once it lets go it is very difficult to make something anchor. So can you bite the bullet and bolt through into the tank itself? I haven't had a close look but an inner circular flange tapped and appropriate gaskets? Anyone with a lathe should be able to create something like this. The real game is getting the inner piece into position but a cheap ebay inspection camera would help.

The other thing I was wondering - I have spent quite a bit of time trying to scrape number plate double sided tape off my car bumpers so as big a plate as possible with captive nut/ countersunk bolt through etc with decent double sided tape onto underside of tank? Has to be worth a go as the easiest option and least obtrusive.
## that is - bolt through plate not tank - perhaps a plate that curves round the inside of the tank and double sided taped on? ##

1622096811283.png
 
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Fast Eddie

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Someone on here fixed theirs by putting a course threaded stud into the tank. relying on studs and nuts to secure it to the frame rather than screwing bolts into the tank each time. But I can’t recall if they used some kind of thread insert? I’ve tried to search but failed to find the thread. Might be worth a more tenacious search...
 
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Thinking on glassing in a .....helicoil is it called? Jagged edged disc to keep it from spinning and a threaded stud? Have to search.
 

cliffa

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Various options if you look through this thread, but I think I’d use what FE posted, (studs welded to circular plates, which are available with plates up to 2” diameter I think) and bond them on with one of the rubbery adhesives that come in mastic gun tubes. Some of those are super strong.

these are they..


And I have used this with great results..


see a Demo..


Cheers,

cliffa.
 
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Various options if you look through this thread, but I think I’d use what FE posted, (studs welded to circular plates, which are available with plates up to 2” diameter I think) and bond them on with one of the rubbery adhesives that come in mastic gun tubes. Some of those are super strong.

these are they..


And I have used this with great results..


see a Demo..


Cheers,

cliffa.
I've already JB WELD epoxied a disc and stud (the standard base stud you posted). Held well for about 3K miles and let go. Cleaned it, reapplied, got another grand out of it. Now it just keeps letting go. Have to start from scratch. Grind, prep, reapply. Getting tiresome. I'd pop for a new tank if I could. I wish the tank came with a stud design. Drops in to the battery box slots nicely and fit a larger diameter washer under that crappy velcro held matt. Could be the constant vibes at 4800, road grime, bouncing over road seams.
 
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Clive

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I've already JB WELD epoxied a disc and stud (the standard base stud you posted). Held well for about 3K miles and let go. Cleaned it, reapplied, got another grand out of it. Now it just keeps letting go. Have to start from scratch. Grind, prep, reapply. Getting tiresome. I'd pop for a new tank if I could. I wish the tank came with a stud design. Drops in to the battery box slots nicely and fit a larger diameter washer under that crappy velcro held matt. Could be the constant vibes at 4800, road grime, bouncing over road seams.
Sounds like you've reached the point where you need to consider getting a mechanical solution with a flange inside the tank bolting through the tank to an outside flange with a stud attached. If the inside one has, say four studs silver soldered into the flange then it should seal well enough with an appropriate gasket. Could be made easily with a lathe and use an inspection camera to see where it fits inside the tank.
 

Fast Eddie

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I still reckon that a thread insert into the tank, with a stud locticed into it, would be best.

The question of course is; is the tank meaty enough to take an insert. But someone on here already dun it Guv, so the answer is yes.
 
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