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Gasket or proseal

R

Rivethead

Well Known Member
I'm about to button up my tanks and I'm torn between using the cork gasket and possibly some sealant or just using proseal and being done with it. I've noticed on a few threads that touch on the subject that some people go the proseal route, in fact it seems to be the norm, I just want to get some input before I do something that is so permanent. Well, I know that proseal isn't permanent but for my prefered effort levels it might as well be.
 
I vote proseal only. The gasket will eventually leak. Don't let anyone fool you, the proseal only panel can be opened up without too much headach. I've done it a couple of times.
 
I had a cork gasket shrink and then leak after I put the plane away for a couple of weeks. The tank was nearly dry so the gasket was not getting bathed in gas. Don't worry Safety Police; I was easily FAA compliant when I landed.

On another note: You have such limited access with the wings attached, I would not (and didn't) use then phillips screws to attach the plate. I used hex head but bolts will work as well. Good luck.
 
I used Proseal only and tested the tank with the baloon method. Five days later the baloon was still inflated as the first moment.
 
cork gasket and fuel lube (ezturn)

When I first built my tanks, I used proseal to seal the access hole. I've had those tanks off and open several times now, so you likely WILL have to open them at some point. It wasn't too hard to remove the cover even with the proseal.

However, the next couple of times I've used the cork gasket BUT I've slathered it on both sides with fuel-lube first (also known as EZturn) and they stay in good shape that way. Don't reuse the gasket.. order new ones.

No leaks either way.
 
I vote proseal. I had to go into one tank before I installed the wing, because I did a bonehead on the vent line. Still the cover come right off and cleaned up nice with a razor blade, scraped sideways with MEK. I vote proseal, no worries.
 
An important data point that should be included when provide information on this type of subject (I did such and such and has hasn't leaked) is to provide informatyion about how long it has actually been in service with no leaks.

I install all covers exclusively with tank sealant. Just about guaranteed to not leak.
Install them with gaskets...just about guaranteed to (eventually) leak.

One important detail to keep in mind so that the cover is easily removable if using tank sealant to install access covers and fuel level sensors is to not fully tighten the screws. You need to tighten just enough to get squeezout around the full perimeter and leave an approx. 1/32" thick gasket of sealant between the cover and the tank. This will make it easy to tap a putty knife, etc., between the cover and the tank to pop it off.
 
Ditto

mototopo said:
I used Proseal only and tested the tank with the baloon method. Five days later the baloon was still inflated as the first moment.
Click to expand...

I did the same thing but only my balloon stayed inflated over two weeks until I vented it.:D Sure gives you a warm fuzzy feeling.:rolleyes:
 
I'll take the contrary position here and recommend the cork gaskets, BUT they need to be slathered up in Permatex Aviation Form-a-Gasket first. Not a hint of a leak in 5+ years, and much easier to get apart then prosealed components. I do agree with using something other than phillips head screws. Socket cap screws, or my favorite, torx.
 
I've personally done a lot of RV tanks. Cork gaskets, with or without sealant, almost always leak in 3-5 years. With pro-seal only, I've never seen a leak.
 
Mel said:
I've personally done a lot of RV tanks. Cork gaskets, with or without sealant, almost always leak in 3-5 years. With pro-seal only, I've never seen a leak.
Click to expand...

That's why I am going to open my tanks this summer and remove the cork gaskets. Will proseal instead.
 
based on the above mentioned I plan to use proseal instead of the gasket and pray for no leaks...there or any where else. I am currently 1/2 done prosealing/riveting tank number 1...
 
Using "proseal" to seal up access ports on fuel tanks is fine....but is it possible that builders are using the wrong type of "proseal".

For instance in the PRC-DeSoto range their equivalent of the 2 hour "proseal" as supplied by Vans is PR-1440 B2. However their recommendation for access ports on fuel tanks is PR-1428. This product is described as an "Access door sealant"......"a low adhesion product widely used for removeable fuel tank inspection ports".

This product would seem to offer the best of both worlds....the positive sealing of "proseal"....plus the ability for easy removal.

Maybe all manufacturers of "proseal type products" also have a lower adhesion product specifically for removeable fuel tank inspection ports.

Many RV builders are not that tuned into sealants/adhesives generally and so when they get a tub of "proseal" with their kit they tend to want to use the same product for everything.

Has anyone out there used a more specialised product, such as PR-1428, for this application.
 
Yes...

Captain Avgas said:
Has anyone out there used a more specialised product, such as PR-1428, for this application.
Click to expand...

...I've used it, but not on a RV - this is the recommended sealant for the four access panels on the lower surface the wet wing fuel tanks on my Grumman Tiger. They give access directly into the fuel tank.

Correctly used, the seals seem to have a long life span, but are removeable if needed.

The material is "FlameMaster CS3330B or Desoto/PRC PR1428B."

FlameMaster even calls it an "Access Door Sealant" and it's red, not the dark grey of the usual fuel tank stuff.

http://www.aviationproductsinc.com/Publications/TDS_PDF/CS3330B.pdf
 
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did a Google search for Pr1428...only found I could buy it in the UK. Anyone know where to buy in the US>
 
ah...found it on their catalog...part F524, 6 oz. Sem kit, low adhesion sealant
For inspection plates....no price listed though. ph numb 830-995-5900 if anyone else is interested.
 
F554

F524 6 oz. Sem kit, low adhesion sealant $38.56 For inspection plates ( ...
Mike H 9A/8A SOLD
 
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McFly said:
I had a cork gasket shrink and then leak after I put the plane away for a couple of weeks. The tank was nearly dry so the gasket was not getting bathed in gas. Don't worry Safety Police; I was easily FAA compliant when I landed.

On another note: You have such limited access with the wings attached, I would not (and didn't) use then phillips screws to attach the plate. I used hex head but bolts will work as well. Good luck.
Click to expand...

Hey Mcfly, check your private messages.
 
ProSeal PR-1826

I'm an Air Force Aircraft Fuel System Specialist. The Technical Order (TO) that deals with Fuel Systems is 1-1-3. It is available online if you google "TO 1-1-3" under the Robins AFB site. I say that to say this. I have used PR-1826 on just about everything, including access panels. It is fast curing around 30 minutes (B 1/2), has adhesion promoter in the bag, can easily be removed if it pops a leak, and is pretty much the only sealant we use in my shop.

If you have any questions on fuel systems, feel free to ask because I am about to start building a RV-7A so I will have alot of questions coming to y'all.
 
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