Fuel tap woes

[ssevy]

My factory tap was leaking, so I bought a Pingel as a replacement. It has an adapter block that needs to be mounted for the tap itself to screw into. Per instructions, I made sure the mounting area was flat with a file, then applied some Blue Hylomar to both sides of the gasket and mounted the adapter block. Instructions said 8 - 10 foot pounds, which on a plastic tank with threaded inserts concerned me. In any case, I gradually snugged them up until they felt snug, but they weren't tripping the clicker of the torque wrench. I then installed the tap, which was a beast to screw into the block.
Adding a splash of fuel and turning the tank right side up, I saw the adapter block was leaking. Okay, so off with the tap, more careful snugging up until the wrench clicked 8 ft. pounds. Tap back in, and now it really leaks.
Okay, tap back out, adapter block off, and I notice both inserts are about 1/16" above level now, having drawn up and out when I applied the torque.
Since I had to cut the opening a bit larger to accommodate the Pingel, I don't see a stock tap as being an option again without leaking.
So...I am thinking pull the two inserts right out, JB Weld them back in, and then remount and torque the adapter plate to 8 foot pounds, etc.? Any other creative thoughts out there?

[ssevy]

Good news and bad. The good news is that I was a dumb ass, and had the damned adapter plate flipped over, thus explaining the tapered threads being a bitch to turn, and the countersunk spots for the tap and the screws letting the gasket draw right up and out.
Good news is I think I can just JB Weld the inserts back in place, and then install it correctly. With the flat side of the plate against the tank side, there should be no way the inserts can pull up and out.
I hate doing dumbass stuff, but that is what happens when you move too fast before looking carefully at something you haven't done before.

[rf9rider]

Tried a Pingel tap on mine, couldn`t get it to seal properly.

Now left with a tank with an enlarged hole that`s completely useless.

[nickjtc]

We feel your pain! 

[ssevy]

I got some JB Weld for plastic at Advanced Auto, as the package says it has a higher specified finished strength than the original formula. It still sets up similar to the quick version, but has better fully cured strength. We'll see how it holds.
Since I am using the Pingel tap (with the adapter right side up this time ), I used the adapter itself as a template to be sure the spacing of the inserts would be correct with no undue side load. Using a large nut as a washer allowed me to be sure the inserts did not stick up above the plastic and kept any extra epoxy off the threads. Once it set up for an hour, I unscrewed the bolts and then finished the gaps around the top by dribbling in some additional epoxy until everything looked good and level. Any extra can be filed off tomorrow if need be.
Since the Pingel tap is a separate item from the adapter plate, I am tempted to just epoxy the adapter in place when I bolt it on for a permanent seal. I did buy a sheet of gasket material to make a new gasket if I decide to attach it normally. A bit of Blue Hylomar on each side should seal it just fine if this is what I do. Still thinking of any possible negatives of a permanent attachment.
Here are some pictures of the steps mentioned, in case anyone has to do this themselves at some point:

Cutting the inserts out:


Carefully and slowly enlarging the hole:


The insert itself:


The adapter plate with the inserts attached for proper spacing:


Mixing the JB Weld:


The inserts held in place by the adapter anchored in the wet epoxy:


The finished product:

[Sin_Tiger]

Good write up man  and interesting comment on teh JB Weld.

Ease up on the caffeine intact before working on the Steamer 

[ssevy]

I wish I could chalk it up to caffeine, but it is just me rushing to get this bike back together for a rally next weekend. Invariably when I rush something, I end up doing it twice, the first time to bodge it up, and the second time to repair whatever I did the first time. Slow and steady is a great theory, but one which I don't always find easy to follow when I am on a schedule.
I guess it's a good thing I didn't choose air traffic controller or working at a nitro glycerin factory as my first career choice :icon_wink:

[London_Phil]

Interesting info, but the drill picture scares me.
Just so you know what amount of material your working with under the tap assy..
Not a good picture, but I think you can see what could happen

[ssevy]

I, too, was cautious about this, but with a variable speed drill and a sharp bit, you are just barely turning the bit to round out the section where the lands lie. All I wanted to create was some additional room around the top part of the insert to provide space for the epoxy and lands to join.
Again, for anyone trying this, it has to be a drill with a slow speed that is barely turning, and the bit cannot be dull, or it will "walk" and not stay centered.

Thanks for the extra word of caution Phil. Sometimes what seems obvious may not be.

[ssevy]

Update:  The JB Weld for plastic is no good for this repair. I decided to mount the adapter with a gasket as intended, and the two inserts pulled right on out again. The epoxy stuck to the inserts themselves well enough, but just slid out of the tank material once I began to tighten the bolts.
I'm going to use regular JB Weld, and set up the bolts in the adapter plate and just epoxy the whole thing into place so that there is no stress on the inserts. Hopefully, this will seal it once and for all.
There is always a challenge to engineer a connection between two different materials, and anytime plastic is one of them, you have the potential flex and warpage to deal with. I think the fuel was actually leaking from around the junction rather than the original tap itself, as the paint is all lifted. I'm thinking a gentle pass with a sander might level the mounting point on the tank and scuff it a bit, providing better purchase for the epoxy. We'll see how it goes...

[Sin_Tiger]

The tank material is actually a nylon rather than a thermo plastic. So the bond between the epoxy and the nylon will be purely mechanical rather than some chemical interaction that happens with some combinations of thermoplastic and epoxy.

It's possible your nicely drilled hole was too nice. A good physical key will be what you need I think. A trick I've used before, not on a nylon tank, is to use a thread tap that's on the small side for the hole so that you get just the tips of the tap cutting. e.g. using a 6mm tap in a 5.8mm hole.

[rf9rider]

I tried JB weld when trying to repair my tap hole, it lasted a couple of months, then turned to goo.

Also tried Permatex 2, that lasted a week.

Still searching for something petrol resistant.

Let us know how you get on.

[threepot]

I used a 2pack epoxy glue  bought from one of those £ shops to repair 2 leaking tank threads. Said petrol and oil resistant..still holding for 18months.  So this has now put the 'kiss of death on it'

[ssevy]

Here's the install. I'm thinking of getting some of the Caswell sealer I used on my Legend, and mixing a small batch to pour just down in where the petcock is located. It might close off part of the pickup screen, but I'm thinking a solid block of this, maybe 1/8" thick over the exposed areas of the plate and pickup tube on the inside would keep the gasoline from contacting the JB Weld. I know the Caswell is fuel proof. Any thoughts?

[Sin_Tiger]

Belt, braces and a few rivets for good measure  were you a Land Rover owner in a previous life