How to FIX spinning tank nuts

[Mustang]

it is best to not drill the tank plastic .................better to grind the captive nut down so it fits back in the hole and use jb weld to hold it in .
less chance of creating a leak that way .

[Colonel Nikolai]

So this is my question, do I drill this out so the captive nut fits back in, then epoxy it all up and put the captive nut in the expoxy?

Don't remove any more of the nylon tank material if you can avoid it. Ideally you want the opening to be smaller than the cavity. I would replace the captive nut with a new stainless acorn nut of equal size, M6.

In an ideal situation you'd machine your own nut so it has grooves around the outside or hourglass shaped so the epoxy has more to hold onto when you seat it. I didn't do this and so far solution has held for over a year.

[Bob Tosi]

We are a resourceful bunch aren't we?  

[Sin_Tiger]

You can get serrated nuts, resembling a cylindrical pine cone for a few cents, that will push / screw in and give a good key. That's what I was intending to use before my mechanic decided to do it his way.

We shall see  



Number 5 in the picture

[Colonel Nikolai]

Sin_Tiger, I like the thinking. #5 would get a good purchase in the JB Weld / Metal Epoxy.

[Bob Tosi]

[/quote]Posted: Sun Feb 12, 2012 1:32 pm    Post subject:
Sin_Tiger, I like the thinking. #5 would get a good purchase in the JB Weld / Metal Epoxy.

I repeat myself

We are a resourceful bunch aren't we?  

[Bob Tosi]

The ground down captive nut



Epoxy all ready to go


The cleaned out hole


Filling the hole


All done

[tauzero]

I had this problem a while back and used a flanged nut to sort it out:

http://www.tauzero.co.uk/bikes/tiggers.html#turningbolt

[Colonel Nikolai]

I had this problem a while back and used a flanged nut to sort it out:

http://www.tauzero.co.uk/bikes/tiggers.html#turningbolt

Something like so, with the flange (bottom) facing inward sounds great because the resin now has something to hold onto assuming the flange is buried in the resin. The only problem is how do you keep the resin from getting in the threads? I would almost think you'd end up gluing the screw into it if you used one. Maybe use wax in the threads?

[tauzero]

I just took care to apply the epoxy only where it was needed, after I'd put the nut in place. I'd have had problems if I'd put the epoxy in the hole first.

[RJS]

Most of my screws were spinning when I bought my Tiger. I have only had to resort to drilling the head off one.

The others were removed by pushing the screws down by an angle of about 20 deg, which tightens the insert in its hole. I achieved this by various means - a couple with a loop of wire twisted until screw was angled; a couple with a strip of ply cut like a 12" rule and with a vee cut in the end. This will slip between tank and side panel and can be pushed down to angle the shaft of the screw. Pulling the rubber washer from behind the screw gives you more room to do this.

The cordless drill with allen bit kicked the screws loose once they were held at an angle. Only one screw failed to respond to this treatment and needed the butchery described in the main text.... but try this method before creating major holes in your tank !

I made new rubber washers from thin slices of rubber tube which are harder than the originals and stop the screws from 'bottoming out' on the inserts, which I think is a factor in them seizing. I now tighten the screws with my cordless drill set to no3 or the shorter handle of an allen key.

Hope my experience will help someone and avoid major surgery !

[Geoff W]

I had a couple of spinning nuts. I just ignored them for a while. The next time I tried to remove them they came out with no problem. The only difference was that I did this on very cold frosty day. Differential contraction or something similar I would guess. Once I had the bolt out I ran a drop of liquid super glue behind the captive nut and I have had no problem since. A year or so later another one started spinning, so I awaited Winter and repeated the procedure, again the nut came out with no problem. It works if you have the time and patience to wait for cold weather. If not then perhaps a pipe freezing kit as used for emergency plumbing repairs may work.
It seems odd, I would expect metal to contract more than the plastic tank, but it has worked for me.

[Sin_Tiger]

You will rarely have to wait very long for cold weather in the UK    That its a bit puff a surprise though and another alternative method to add to the list.

[Geoff W]

Ah yes , cold weather in Singapore. Hell freezing over etc, etc , etc.

[Sin_Tiger]

Ah yes , cold weather in Singapore. Hell freezing over etc, etc , etc.

Oh yes, about as likely as a horse free burger in the UK