Tank Inspection plate sealing ?

Captain_John · #1 12-04-2005, 06:11 PM

Tell me, All...

I spoke with a local builder (Wicked Stick) and I have arrived at a decision which I am definately, probably, likely or may do.

I plan on sandwiching the cork gasket between two fine layers of proseal for several reasons.

1) To keep the cork gasket in place
2) So I don't have to CRANK down on the screws and am still reasonably assured a good seal
3) To facilitate reasonable removal ease at a later date

What did you do? How did it work out?

CJ

robertahegy · #2 12-04-2005, 06:37 PM

That's exactly what I did, CJ. I have had no leaks and the seal was made over two years ago. I also dabbed the screws in proseal before inserting them. The senders were installed using just proseal, no rubber gasket. I also dabbed those screws. I used the senders from Van's.

Roberta

Tom McCutcheon · #3 12-04-2005, 06:57 PM

I baught an RV-4 that had a seep at the inspection cover that was installed with the cork gasket and I believe a bit of some sort of adhesive. Talked to Vans and they said to dispense with the cork and just use the Pro-Seal which I did. Also dabed a bit on each screw and no leaks. My Son's RV-4 had been put together without the cork gasket also but had developed a seep at the lower fitting which necessitated taking off the inspection cover. Actually we took the tanks completely off of the plane which showed leaks at both senders also. Anyway, we were anticipating a real problem getting the inspection cover off. However it came off fairly easily using a gasket scraper. Clean-up was also fairly easy. Our concern (and the people at Vans seemed to agree) that the cork would eventually leak. The senders had cork and they leaked. So, I would suggest that you despense with the cork. We applied a liberal amount and dabed the screws and snugged it into place without really sinching down on the screws so as to leave a liberal amount of seal between the cover and tank. Also, wiped with a finger some on the inside of the outer and inner radius of the doubler to be sure fuel would not seep between the doubler to the screws. So far - no leaks

Hope this is helpful
Tom

redbeardmark · #4 12-04-2005, 07:13 PM

I left the cork gasket out and used the goo, goo on the screws too, and used stainless steel allen head screws(hopefully less likely to strip out if removal is ever necessary). I did leave the rubber gasket on the sender, but can't remember the reasoning. No leaks so far.

Lots of folks doing it lots of different ways, with lots of success. Pick one and cross your fingers.

Ironflight · #5 12-04-2005, 08:17 PM

No cork gaskets for me - just used pro-seal, and did the screws as well. I also left the gasket off the quantity senders - just used proseal.

Paul

ptrotter · #6 12-04-2005, 10:04 PM

CJ,

Rather than ProSeal, I would use Access Plate Sealant (CS3330). It seals just like ProiSeal, but is designed to allow the access plate to be removed easier.

Bob Axsom · #7 12-05-2005, 02:41 AM

I was totally ignorant of any requirement to do anything special so I left the cork in tightened the screws and assumed everything would be OK on all four tanks. I was a pretty careful builder and spent a lot of time trying to get everthing just right (4222 hrs on a QB RV-6A). This is another area where I am thankful I did not paint the plane before flight. The first time I did the two gallon increment fuel gage calibration fill everything seemed OK. The plane was out at the hangar at Chino for final assembly so I only saw it at weekends by this time. The next time I saw it blue fuel stains were visible on the underside of the wing and fuselage. Fuel had run into the fuselage, pooled under the seat and bagage floor. It had run all the way back to the tail and was dripping out of every sheet metal seam. I tried to use an offset screwdriver left over from my F-101B pinapple terminal block inspection days to tighten the screws and liberally applied proseal on extended icecream sticks to fix the problem. All tanks continued to leak at a reduced rate. I pulled all tanks so I could get some real torque on the screws and really apply the Proseal liberally. All of the screws turned easily when I started to tighten them on this third attempt. The leaks were reduced but they were still there. I removed the tanks again figuring that the proseal was not sealing because of the presence of fuel residue on the surface from the first attempt to fix the problem without removing the tanks. I scraped of the proseal (not a trivial task) and cleaned the area (I do not remember everything I used but rubbing alcohol was certainly included) retightened the screws (I don't really remember any significant movement) and applied Proseal across the joints and the screw heads (picked up some pounds there) and I finally stopped the leaks. I have zero confidence in the permanency of the seal and I wish I had read Roberta's post several years ago - it really sounds like the way to go. This is one area that will not tolerate any mistakes.

Bob Axsom

Captain_John · #8 12-05-2005, 05:01 AM

Thank you all for your replies!

Paul, that access sealant sounds like just the ticket!

Thanks again!

CJ

LettersFromFlyoverCountry · #9 12-05-2005, 08:10 AM

I did that, however the words ProSeal and "ease" should never be used in the same sentence.

On my second tank, I used the cork gasket, ProSealed both sides, stuck in, ProSealed the outside, nd then during testing discovered a leak along the inboard baffle. Of course, by then, the ProSeal had cured. I pried off (and you can ruin a rib i a hurry doing this wrong) the plate and now I had a bunch of busted cork to pry off.

I decided, when putting it back, that it would be easier to get the ProSeal off around the ring without the cork gasket, and that given the amount of Proseal used, the gasket didn't really make removal any easier.

As far as the fuel sender goes, that rubber gasket is REALLY thick, in my opinion...TOO thick. When testing it, I didn't think the length of the bolt was suitable, so I through THAT gasket away and prosealed that.