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weeping fuel around rivet and syringe

A5555

Well Known Member
I have one weeping fuel rivet on the top of my left wing about 10 inches from inboard edge on the aft most row. I see a faint stain after a couple weeks of flying. The wing is unpainted but I'm getting ready for paint so I need to fix the rivet. I'm posting this because of the surprising result in application of the proseal. On a whim I decided to try a syringe to force proseal from the outside inwards around the rivet. I cut the end tip from the syringe and left the thin wall in place. I thinned the proseal with acetone. Here's the surprising part, I was able to apply all the force I could muster onto the syringe to force the proseal in to the rivet without the proseal squiring out and making a mess. I was amazed. I know I had at least 50 lb on the syringe, syringe area ~ 0.5 sq inch, so pressure on the proseal = 100 psi. The end area of the syringe thin wall created a much better seal than expected. The pressure inside the syringe is transferred thru the thin wall of the syringe and makes the seal. I don't know if this will fix the weeping rivet but I know if this pressure could not force the proseal in that nothing will. In the picture the proseal has been cleaned from the end of the syringe to view the size of the hole. Note, I tried the loctite fix previously but that did not work.

IMG_20150919_114819.jpg
 
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Something I know will work when you have one or two weeping/leaking rivets.
You can drill out the rivet and clean the hole very well with MEK/MPK. Get the proper Cherry Lock or Max rivet and cover it in proseal and also put a dab of pro seal in the hole before pulling the rivet. Let the proseal fully cure before filling tank with fuel.

This should fix the leak and I guarantee that one rivet butt in your tank will not cause you any issues as long as you installed a finger screen on your pickup tube. The shop head of a 3/32" rivet is too big to fit thru the screen and will not block off the fuel flow thru the screen. I know that a loose rivet butt in the tank may be very controversial and may not be for the faint at heart, but I personally know that it works and it sure beats pulling and opening a tank for one or two pesky rivets.

Now if you have leaking rivets all over your tank, this procedure is not the fix. You should pull the tank, open it up, clean and seal the leaks from the inside.
 
Something I know will work when you have one or two weeping/leaking rivets.
You can drill out the rivet and clean the hole very well with MEK/MPK. Get the proper Cherry Lock or Max rivet and cover it in proseal and also put a dab of pro seal in the hole before pulling the rivet. Let the proseal fully cure before filling tank with fuel.

This should fix the leak and I guarantee that one rivet butt in your tank will not cause you any issues as long as you installed a finger screen on your pickup tube. The shop head of a 3/32" rivet is too big to fit thru the screen and will not block off the fuel flow thru the screen. I know that a loose rivet butt in the tank may be very controversial and may not be for the faint at heart, but I personally know that it works and it sure beats pulling and opening a tank for one or two pesky rivets.

Now if you have leaking rivets all over your tank, this procedure is not the fix. You should pull the tank, open it up, clean and seal the leaks from the inside.

agree, that is plan B if I need it.
 
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the tank has been full for the past several days both sitting and flying. the syringe method seems to have stopped the leak on this rivet.
 
Also...

The shop head of a 3/32" rivet is too big to fit thru the screen and will not block off the fuel flow thru the screen. I know that a loose rivet butt in the tank may be very controversial and may not be for the faint at heart, but I personally know that it works

If swag in the tank is really bothersome, you can pull the tank, inject plenty of sealant in the hole, install the rivet, the shake the rattler around until it hits the sealant. This also makes it possible to inject more effective sealant, as you can make gravity work for you.
 
seems safer

to apply pressure (as Steve is doing with his ProSeal syringe) to force Loctite into the rivet area than to pull a vacuum and try to suck it in. The tank will withstand far more pressure differential with local external pressure than what can be generated by pulling a vacuum on the entire tank without deformation. Maybe a syringe with tip ground-off and an O-ring on the end to make an air seal around the rivet factory head we're trying to force the Loctite under?

-Stormy

contemplating this fix for years but never seem to get around to it.
 
Good to know Steve... thanks. Pictures?

well, not much to see but here is the offending rivet. it's been several days with a full tank (to the brim) and no weeping as was before. who knows how long it will last but I'm going to paint it and take my chances right after I finish sanding these freek'in wheel pants.

IMG_20151009_143656.jpg


IMG_20151009_143638.jpg


IMG_20151009_143629.jpg


n-l0PHKqYxPrBali5M6uVoGPYlGK6s0VVbk-w1hZr-KEiqeh9nSeZbTFMkguwTPw0_jZfc70vNIkkhgtOxfxr-n-eMC7bOgFeUmeVSSCLVd1QIcaCFTlkWzNtVzZOmUUoP3DpkvoKK_qM-EA8I6fn9uAh7UcjvbDfimFtwLJ-ib61cEqnNG6PMM9zQhF_79i3Wru838U2PhFFpgI10oEfWnUTwDMGfZAmNyPx1P-hLuYP1qGURaWx_wnJIvfstREQxq3Y7cplbG17-23Ot0Zy8JF-eRchS3WnmeRrH09oZ2RszqvTZ9PiCy0puP0C1PQdc2E0CLJsbABmoxj-qOyuJU9IXcKKl14Vj5-Wlvtp81uVZi1bwBTq7qWXUlv-meMMPMppIfRZvcbRGinLpt8FCNtvumoNw5C2mm6Jz4671CptEbVYYZNPl5nsSnA8GKa7nNKb0O7eu_rkyf9kB0AEx8WO9Y_CnDpxHSS-ojEqI1egKiz77JxXFAFbVd6yk-yUdAJ3Z58j0K7w_Tz6FL9_x-z39oZdvxg3X-sswuYZ_w=w558-h744-no
 
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I posted my syringe process a few years ago on a weeper I had on the bottom of my tank. I used pliobond with a modified syringe with a rubber bushing to seal around the rivet. Make sure you leave the fuel cap off to allow the pressure to inject & seal around the offender. It's been more than 2 years without any weeping.
 
I posted my syringe process a few years ago on a weeper I had on the bottom of my tank. I used pliobond with a modified syringe with a rubber bushing to seal around the rivet. Make sure you leave the fuel cap off to allow the pressure to inject & seal around the offender. It's been more than 2 years without any weeping.

The vent should cover that..
 
about one year later. weeping rivet is still sealed. August 2016. no need to pull a vacuum on the tank with this method.
 
Just to add to the data on this technique, I developed a weeping rivet near the leading edge of one of my tanks that was very successfully dealt with using the syringe technique.

This happened after flying my 900h, 13y old RV8 through some pretty heavy rain. Some paint must have peeled back from the top of a rivet, exposing a leak which made itself apparent the next time I went flying (big blue halo around it etc). While bracing for having to remove the tank and cut a hole to fix from the inside I decided to try this technique as there appears to be no downside.

I did not thin the proseal at all, but I did use a 5cc syringe instead of a 10cc syringe (you can exert more pressure at the tip as the plunger is about half the surface area of a 10cc syringe).

Its been 6 weeks and another 20h of flying (at least) and the repair has held up nicely.

Jon Weiswasser
N898JW
 
Just to add to the data on this technique, I developed a weeping rivet near the leading edge of one of my tanks that was very successfully dealt with using the syringe technique.

This happened after flying my 900h, 13y old RV8 through some pretty heavy rain. Some paint must have peeled back from the top of a rivet, exposing a leak which made itself apparent the next time I went flying (big blue halo around it etc). While bracing for having to remove the tank and cut a hole to fix from the inside I decided to try this technique as there appears to be no downside.

I did not thin the proseal at all, but I did use a 5cc syringe instead of a 10cc syringe (you can exert more pressure at the tip as the plunger is about half the surface area of a 10cc syringe).

Its been 6 weeks and another 20h of flying (at least) and the repair has held up nicely.

Jon Weiswasser
N898JW

that's good news. you may have reached close to 200 psi pressure at the tip. did you have much squirt out at the tip with the non thinned proseal?

and BTW, my repair with this method is still holding fine after a couple of years and 200 hrs.
 
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Years ago I had an Aerostar. They are known for fuel leaks. I used to carry something called a "click patch" with me (I think that is what they are called). Had to use these patches a few times and each time they worked as advertised. Very simple and inexpensive. I cannot remember where i got them or who gave them to me.
 
Almost 4 years now still not leaking.

Going on 5 years since build and recently have several weeping rivets left tank at bottom aft flange. Not serious, just enough to make blue ring around rivets.

Have feeling this will require tank removal and aft baffle surgery to repair. It would be hard to get tank dry and push sealant uphill successfully, but considering it.

Install of aft baffle is tricky, probably pushed too much sealant down to get adequate seal. Right tank is ok - so far.
 
Going on 5 years since build and recently have several weeping rivets left tank at bottom aft flange. Not serious, just enough to make blue ring around rivets.

Have feeling this will require tank removal and aft baffle surgery to repair. It would be hard to get tank dry and push sealant uphill successfully, but considering it.

Install of aft baffle is tricky, probably pushed too much sealant down to get adequate seal. Right tank is ok - so far.

Hi David,
My post was related to my previous ones in which I've gone 4 years with the syringe fixed weeper and it's still not leaking.
I've now been flying my RV 11 years now.
 
Syringe method

Due to a bee plugging the vent to my left tank and pullng almost full vacuum, I ended up with two weeping rivets, likely lifted a thin spot on the sealant. Dam glad the tank did not collapse!

Anyway, I had read this thread and thought of a bit of a modification to the syringe and loktite method. My weep was very small on each of the two rivets only getting a little blue after a week or so.

I took a 1/2? syringe and cut the tip down to about 1/16? and then stacked 3 - 1/4? o-rings glued to the syringe and together. This configuration allowed me to squeeze the loktite as hard as I could push on the syringe and the o-rings squeezed down and sealed very well.

For what it is worth I used red loktite as I only had red and blue in the tool box and red seemed a little thinner. Repeated 3 times with a day or more between to allow for the loktite to cure. Seems to have solved the problem.
 
I took a 1/2? syringe and cut the tip down to about 1/16? and then stacked 3 - 1/4? o-rings glued to the syringe and together. This configuration allowed me to squeeze the loktite as hard as I could push on the syringe and the o-rings squeezed down and sealed very well.

.

what glue did you use> What were the O-rings made of?

thanks!
 
well, not much to see but here is the offending rivet. it's been several days with a full tank (to the brim) and no weeping as was before. who knows how long it will last but I'm going to paint it and take my chances right after I finish sanding these freek'in wheel pants.

IMG_20151009_143656.jpg


IMG_20151009_143638.jpg


IMG_20151009_143629.jpg


n-l0PHKqYxPrBali5M6uVoGPYlGK6s0VVbk-w1hZr-KEiqeh9nSeZbTFMkguwTPw0_jZfc70vNIkkhgtOxfxr-n-eMC7bOgFeUmeVSSCLVd1QIcaCFTlkWzNtVzZOmUUoP3DpkvoKK_qM-EA8I6fn9uAh7UcjvbDfimFtwLJ-ib61cEqnNG6PMM9zQhF_79i3Wru838U2PhFFpgI10oEfWnUTwDMGfZAmNyPx1P-hLuYP1qGURaWx_wnJIvfstREQxq3Y7cplbG17-23Ot0Zy8JF-eRchS3WnmeRrH09oZ2RszqvTZ9PiCy0puP0C1PQdc2E0CLJsbABmoxj-qOyuJU9IXcKKl14Vj5-Wlvtp81uVZi1bwBTq7qWXUlv-meMMPMppIfRZvcbRGinLpt8FCNtvumoNw5C2mm6Jz4671CptEbVYYZNPl5nsSnA8GKa7nNKb0O7eu_rkyf9kB0AEx8WO9Y_CnDpxHSS-ojEqI1egKiz77JxXFAFbVd6yk-yUdAJ3Z58j0K7w_Tz6FL9_x-z39oZdvxg3X-sswuYZ_w=w558-h744-no

Steve, any chance you still have these pictures? I have a weeping rivet on the bottom of my left tank. Also, will this procedure work on a bottom rivet?

Thanks, Jim
 
Steve, any chance you still have these pictures? I have a weeping rivet on the bottom of my left tank. Also, will this procedure work on a bottom rivet?

Thanks, Jim

Yes. It will work on a bottom rivet. Mine has been leak free for almost 6 years now.
 
weeping fual tank rivet

I had a couple leaking rivets . I didn't use Loctite I used thick CA glue. I pressured it in with air pressure from the outside. My rv7a n838wt was finished in 2005 tanks still not leaking. Although I think using the proseal
should work I didn't think I could thin it enough.
 
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