mototopo

mototopo

Well Known Member
Today was time to test my right tank for leaks.

The bad new is that there is a small leak in the inboard lower corner (in the joint between the most inboard rib, the skin and the tank brace),... the good one is that I can reach it "easily" through the access hole...

I sealed the cover without the cork gasket using just proseal, but it's cured so well I'm unable to remove it!!
How may I remove the cover without damaging it or the rib??? :confused:

Thanks...

P.S. I hate tanks!!!!! :mad:
 
As I recall, when Vans had the fuel pickup service bulletin, one of the recommended techniques was to use a serrated plastic knife to saw away at the proseal, followed by a putty knife to pry the cover off.

I'm just in the process of leak testing my HRII tanks, but this is being done without prosealing the access plate or fuel pickup. Once leak free, I will then proseal them on.

One thing I'm going to do is embed a loop of dental floss in the Proseal. The idea is that it will be used as a ripcord should the cover have to be removed later on. We'll see.

Vern
 
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putty knife... may even try using a hair dryer to warm it up a little... i assume you have not put fuel in it yet. Proseal is no joke once cured! good luck!
 
Ok.. thank you guys... putty knife is the way to go. I'll try also to warm it up a little.

One more information: my leftover proseal expires this month. May I still use it to re-close the tank or have I to buy more? (I just need maybe 20 grams...)
 
Pro-seal has a pretty good guard-band on time expiration. I have successfully used pro-seal that was several years old when stored in the refrigerator.
 
Warming the pro-seal with a heat gun makes the job very easy. No fuel in the tank for sure!
 
oh no.. still no fuel in the tanks :rolleyes:

thank you very much for your help... tonight back at work :)
 
The safe way

Claudio,
Use either a plastic putty knife or fabricate a wooden putty knife out of either a Popcicle stick or a medical tongue depressor. Simply sharpen one end using your belt sander. Wood or plastic will not damage the aluminum rib/access cover. A wooden stick can be re-sharpened many times, as needed.
This is how professional A&Ps do this job. Remember that all the fuselage skins on pressurized aircraft are sealed with ProSeal.
Charlie Kuss
 
chaskuss said:
Claudio,
Use either a plastic putty knife or fabricate a wooden putty knife out of either a Popcicle stick or a medical tongue depressor. Simply sharpen one end using your belt sander. Wood or plastic will not damage the aluminum rib/access cover. A wooden stick can be re-sharpened many times, as needed.
This is how professional A&Ps do this job. Remember that all the fuselage skins on pressurized aircraft are sealed with ProSeal.
Charlie Kuss
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I can endorse Charlie's comments from my own McDonnell-Douglas production shop experience. For one reason or another, I sometimes removed components attached with cured proseal. It can be a pain, nevertheless, the use of any metal tool such as a putty knife was strictly verboten. This was because it is virtually impossible to use a metal tool without scratching or possibly gouging the underlying aluminum surface. The use of heat to help soften the cured proseal was acceptable and we commonly used a plastic scraper such as the officially sanctioned one shown below. Its ends could be quickly and easily resharpened to any angle desired on a bench sander. Some guys preferred sharpened wood tongue depressors, others even used modified windshield ice scrapers they retrieved from their car out in the factory parking lot.....anything but metal.

24p9t2s.jpg
 
Mel said:
Pro-seal has a pretty good guard-band on time expiration. I have successfully used pro-seal that was several years old when stored in the refrigerator.
Click to expand...
I'm getting ready to do my tank and I have a quart that's from 07. I've heard that I could use it, but I'm too scared to do it. Leaking fuel tanks would be a nightmare and I'm willing to spend $40 with Van to sleep peacefully. Spruce wants $160 for a quart :mad:
I know the brand s they sell are different but the price difference is ridiculous; I'm glad I checked.
 
Instead of Proseal...

I have not tried it, but I've heard that instead of sealing the access cover and sender with Proseal, use fuel lube on the cork and rubber seals, then screw in place.

If someone has tried this, could you post the results?
 
I did...

Buggsy2 said:
I have not tried it, but I've heard that instead of sealing the access cover and sender with Proseal, use fuel lube on the cork and rubber seals, then screw in place.

If someone has tried this, could you post the results?
Click to expand...
I originally prosealed my cover in place, then the Vans SB to safety wire the pickup tube nut was published...
Removing the cover was not difficult. Proseal is a sealant, not an adhesive, so once you get started prying, it comes off fairly easy. But I did this when the tank was not installed! Once the plane is assembled, it wouldn't be as easy.
I reinstalled using the EZ Lube on the cork method. You have to be careful to not overtighten the screws because the 'greased up' cork will squeeze out. No leaks in 2 years of flying.
 
Still no luck...

Spend a couple hours trying to remove the cover but it's still there.. I used wood tongue depressors sharpened at about 60°.. I was able to remove the proseal around the cover, but I'm unable to let it slide between the cover and the rib. :mad:

Used an heat gun to warm up the prosealed area with no effect.. maybe I didn't heated it enough but I'm afraid that too much heat may damage the aluminium. How much heat may I use??

Any more suggestion? :confused:
 
Yep, I didn't think the tongue depressor would do much. You need something more significant. A metal (thin) putty knife will do the trick. The phenolic scraper in my earlier post also will do it. A long flexible and sharpened piece of stainless will also do the trick. More than anything a slow but patient approach will get it done. You can heat the proseal/aluminum quite a bit. You won't hurt anything.
 
Thank you Tony.. I'm going back in the shop for more frustrating attempts.... I will try with a little more heat and maybe a thin SS sheet with much attention :eek:
 
There's one trick we used back at Boeing. It was completely unauthorized and if you were found in possession of this tool you would get into big trouble. It did work well. However, it can do major damage also.

Go to a camping store and pick up an "emergency wire saw". It has two rings on the end of of long piece of wire. The wire is serrated like a saw blade and normally is used to cut wood. But works well on sealant also.
 
Also, if you have a "chip chaser". That's about the right thickness and you can use that to dig out the sealant. Much less destructive than the wire saw.
 
Thank you Tony...

The idea of the wire saw let me think I'll do a mess.. I don't have enough space to insert it between the cover and the rib due the proseal is just a thin layer and I think I'll end up destroying the cover, but you gave me some good ideas.

I'll let you know ;)

UPDATE!!
Well, after one more hour of work the cover is finally removed!!! I used a thin sheet of SS to open the way to the wood tongue depressor and more heat.. working a little at a time and finally I was able to remove the cover without damages. :)
Thanks to everyone !!
 
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mototopo said:
Thank you Tony...

The idea of the wire saw let me think I'll do a mess.. I don't have enough space to insert it between the cover and the rib due the proseal is just a thin layer and I think I'll end up destroying the cover, but you gave me some good ideas.

I'll let you know ;)

UPDATE!!
Well, after one more hour of work the cover is finally removed!!! I used a thin sheet of SS to open the way to the wood tongue depressor and more heat.. working a little at a time and finally I was able to remove the cover without damages. :)
Thanks to everyone !!
Click to expand...

Glad to hear it! Make sure it doesn't leak this time around!!!! Nothing like doing it twice huh? Im praying I get the second one right... I had to remove the entire rear baffle of my first tank!
 
I just did this job yesterday to repair a leak on my plane. I found that a scraper lubricated often with MEK cuts thrpough much better than the scraper alone. To get to the hard to reach portions of the plate I cut a 12" spackling blade and used that.
 
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