Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Fuel Tank Leaks

Matronics Email Lists Forum Index -> RV10-List

View previous topic :: View next topic

Author Message

rv10builder(at)4sythe.com
Guest

Posted: Fri Mar 02, 2007 9:53 am Post subject: Fuel Tank Leaks

I have completed my tanks and during testing have noticed some leaks

along the rear baffle and the tank skins.  No doubt I did not get

enough or good placement of the tank sealant.  Does anyone have any

tricks for getting into the tank to get more sealant along that those

edges?  I thought about taking the fuel senders out so that I could get

in through that hole.  On the outer edges, I can get in through the fuel

cap area.  I am having trouble getting to the middle of the tanks

though.   Is it acceptable to seal on the outside of the tank where the

baffle meets the skins?



Thanks,



Kent



Kent Forsythe

40338 - Wings

Slow Build All The Way!

jesse(at)saintaviation.co
Guest

Posted: Fri Mar 02, 2007 11:28 am Post subject: Fuel Tank Leaks

Kent,



I think the biggest issue would be the size of the leak.  Ideally, you want

a good seal of Proseal on the inside of the tank so the pressure would be

wanting to make it seal more, rather than push it out, which is what you

would get if you put it on the outside.  It might not make a huge

difference, so with the tank already sealed up, you could probably try a

little along the outside of that area.  Van's, I believe, has mentioned

using some kind of locktite that will wick into the hole to seal little

holes, especially around a rivet or something like that.  Van's also has a

kit that you can get to put an access panel in the rear bulkhead, which

would allow you to get your hand inside, but that puts that much bigger hole

in your tank which could allow other leaks.  Again, it comes down to how bad

the leak is.  If it is leaking along that whole joint, you might even

consider drilling it out and redoing the bulkhead.  Use plenty of proseal

when you do that part.



Hope this helps.



Jesse Saint

Saint Aviation, Inc.

jesse(at)saintaviation.com

www.saintaviation.com

Cell: 352-427-0285

Fax: 815-377-3694

--

pitts_pilot(at)bellsouth.
Guest

Posted: Fri Mar 02, 2007 11:54 am Post subject: Fuel Tank Leaks

I really can't answer your question ... but acceptable to whom???  My 

knowledge about pro-sealed Grumman AA-5 series tanks says ...... no.  On 

those tanks you have to remove all the sealant near the leak and re-seal 

... from the inside.  I have heard of some leaks being stopped with 

Loctite (green, I think) which will wick into a crack, and it expands as 

it 'cures'.  You can stick a vacuum cleaner hose into the filler and 

seal the vents to get a little negative pressure to help the locktite 

along.  Don't seal the hose in the opening .... some good shop-vacs will 

deform the skins.

Linn

do not archive



Kent Forsythe wrote:



 	  Quote: 	
		  



I have completed my tanks and during testing have noticed some leaks

along the rear baffle and the tank skins.  No doubt I did not get

enough or good placement of the tank sealant.  Does anyone have any

tricks for getting into the tank to get more sealant along that those

edges?  I thought about taking the fuel senders out so that I could get

in through that hole.  On the outer edges, I can get in through the fuel

cap area.  I am having trouble getting to the middle of the tanks

though.   Is it acceptable to seal on the outside of the tank where the

baffle meets the skins?



Thanks,



Kent



Kent Forsythe

40338 - Wings

Slow Build All The Way!

james.k.hovis(at)gmail.co
Guest

Posted: Fri Mar 02, 2007 12:04 pm Post subject: Fuel Tank Leaks

Kent & Jesse,



In the production world, we've used thinned sealer (I'm not sure how

similar the sealer we use is to Proseal) and apply a slight vacuum to

the tank. This helps get the sealer wicked into the gap. Will Proseal

thin with MEK or Acetone?



Kevin H.



On 3/2/07, Jesse Saint <jesse(at)saintaviation.com> wrote:

[quote] 



 Kent,



 I think the biggest issue would be the size of the leak.  Ideally, you want

 a good seal of Proseal on the inside of the tank so the pressure would be

 wanting to make it seal more, rather than push it out, which is what you

 would get if you put it on the outside.  It might not make a huge

 difference, so with the tank already sealed up, you could probably try a

 little along the outside of that area.  Van's, I believe, has mentioned

 using some kind of locktite that will wick into the hole to seal little

 holes, especially around a rivet or something like that.  Van's also has a

 kit that you can get to put an access panel in the rear bulkhead, which

 would allow you to get your hand inside, but that puts that much bigger hole

 in your tank which could allow other leaks.  Again, it comes down to how bad

 the leak is.  If it is leaking along that whole joint, you might even

 consider drilling it out and redoing the bulkhead.  Use plenty of proseal

 when you do that part.



 Hope this helps.



 Jesse Saint

 Saint Aviation, Inc.

 jesse(at)saintaviation.com

 www.saintaviation.com

 Cell: 352-427-0285

 Fax: 815-377-3694

 --

drfred(at)suddenlinkmail.
Guest

Posted: Fri Mar 02, 2007 2:44 pm Post subject: Fuel tank leaks

Pro seal will dissolve in MEK. 



Fred Williams  40515

rvbuilder(at)sausen.net
Guest

Posted: Fri Mar 02, 2007 3:22 pm Post subject: Fuel tank leaks

True, however Toluene is the correct solvent to carry Proseal.



Not beating the archive drum here but it's been discussed several times

before.  There is a wealth of information in dem dar archives.  Heh



Michael

Do not archive



--

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Fri Mar 02, 2007 7:05 pm Post subject: Fuel tank leaks

You guys are killing me with your butchered description of my Beloved

ProSeal.  ProSeal is a high quality PolySulfite Thixotrophic (Sticky

Shit) made exclusively by DeSoto, a division of PPG (and unfortunately

for my cloths a staple of the Air Carrier Industry - part 121).  Van and

their Flame Master Product though a "Knock off" form of such a quality

product is not and will never be my ProSeal.  Like Charleston (Ben Hur

and Moses) said "you will have to pry it from my dead hand".



There are four distinct reasons for failure in application. 

1. Expired product.

2. Improper mix procedure... John G. you can chime in here.

3. Improper atmospherics like humidity or extreme temperatures.

4. Operator error in the installation/application.



This is the glue that holds airliners together.



The product you are using, (which I would venture to say is not my

beloved Proseal) comes in paintable "A" (like syrup) and extrudable "B"

(like old toothpaste).  Properly applied I can create a convex 1/4

fillet as small as 3/32" of an inch, and then apply a fillet spoon to

convert it to a near flawless concave seam of beauty.  In bead sizes

larger than 3/8" in the hands of an epileptic (no offence intended) I

can take a disgusting irregular "sloppy" bead, Mist it with Isopropyl

Alcohol and while using a cheap latex glove convert it into a smooth

final product.  The alcohol evaporates without altering the catalyzed

bead.



Within minutes it can be cleaned with alcohol.  Within hours it requires

MEK (which you better know what you are doing).  We NEVER ever use

Toluene although we have it cause it alters and adulterates the final

chemical, cured composition.  My beloved Proseal is paintable, it is

removable (but a real BITCH) and sticks to any and everything that is

clean.



Now as to pulling a vacuum, nothing could be further from proper

technique. A vacuum (negative pressure) causes atmospherics to enter

from outside of a tank.  It leads to bead failure.  I guess a slight

positive pressure could help wick Polysulphite into a fayed seam from

within the tank but using correct procedure is always recommended. The

slightest excess in either Negative or Positive is going to reform your

pristine tank into a new beast. Proseal can be laid over clean,

previously applied and cured substrate.  The secret is getting it to the

specific area of the leak.



This is Experimental Aircraft Manufacture so you boys and girls have fun

playing with chemicals and toys of dubious result from your chemistry

cabinet.

John Cox

the Turbanator #40600

--

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Fri Mar 02, 2007 7:15 pm Post subject: Fuel tank leaks

http://corporate.ppg.com/ppg/aerospace/default.htm



http://www.ppg.com/prc-desoto/pdf/sglssary.pdf



Simply the facts.  Flame-Master is not "ProSeal".  It is a knockoff copy

of the product spec.  Think of facial tissue and "Kleenex". Cellophane

tape and 3M "Scotchtape".



Every good Sheetmetal Instructor can give you a complete lesson in 10

minutes.  Mediocre ones never do. Now installing Wet Rivets (those with

rivets coated in this damn stuff) takes a little longer. Every good

riveter can do wet rivets. Great riveters do it faster and cleaner.



John Cox

rvbuilder(at)sausen.net
Guest

Posted: Fri Mar 02, 2007 7:42 pm Post subject: Fuel tank leaks

You say polysulfide, I say tomato.  Seriously though, my Toluene comment

comes from many past rounds of this and doing some of my own looking.

But of course I always bow to a properly trained A&P who likes his

polysulfide's a bit too much.    My reference point is this:



http://www.vansairforce.net/articles/tank_sealant.pdf



Fortunately our little airplanes aren't held together with this stuff,

just end up with a PITA messy leak. Personally I wouldn't thin it but I

would rather see people at least use the proper solvents if they feel

the need.  Seems that the article above was well written with a fair

amount of research.  But as the old saying goes, I'm no expert and

always do your own due diligence when it comes to information "heard" on

an Internet mailing list.



Michael

Do not archive



--

flysrv10(at)gmail.com
Guest

Posted: Sat Mar 03, 2007 10:51 am Post subject: Fuel Tank Leaks

I also had a couple of fuel leaks and tried working from the outside.  Of course I had no luck and had to cut the tank and fix it from the inside.

 

 I got an Access Panel plate from van along with pop rivets that had closed ends.  You need to cut a circular hole on the aft side of the tank and reach inside and reseal along the suspected joint in X, Y and Z directions.  This repair sounds a lot more complicated and drastic than you it really is.  It took me a lot of time admiring my problem that it took to fix it.

 

 You may need more than one opening in your case to fix everything.  Good luck.

 

 Contact me offline if you additional info.

 

 Do not archive



On 3/2/07, Kent Forsythe <rv10builder(at)4sythe.com (rv10builder(at)4sythe.com)> wrote:[quote] --> RV10-List message posted by: Kent Forsythe <rv10builder(at)4sythe.com (rv10builder(at)4sythe.com)>



I have completed my tanks and during testing have noticed some leaks

along the rear baffle and the tank skins.  No doubt I did not get 

enough or good placement of the tank sealant.  Does anyone have any

tricks for getting into the tank to get more sealant along that those

edges?  I thought about taking the fuel senders out so that I could get

 in through that hole.  On the outer edges, I can get in through the fuel

cap area.  I am having trouble getting to the middle of the tanks

though.   Is it acceptable to seal on the outside of the tank where the

baffle meets the skins?  [quote][b]

evmeg(at)snowcrest.net
Guest

Posted: Sun Mar 04, 2007 7:23 am Post subject: Fuel Tank Leaks

Before you cut your tank up you can try to run some thinned down sealant

along the inside edge. I do this on all of my tanks as a matter of

practice. Just mix up some sealant and thin it down with MEK....about 1

part mixed sealant to 1 part MEK. Then you can dump it into the lower

outboard corner of the tank through the fuel cap....I use a paper funnel

to keep it where I want it. Now just tip the tank up and run the mixture

down the seam to the other end. Turn it over and run it back and just keep

it moving until it is all used up. If that does no good then go ahead and

cut the holes in the back. Good luck and feel free to contact me with

questions.

Cheers.

Evan Johnson (400+ sets of RV tanks)

(530)351-1776

 	  Quote: 	
		   I also had a couple of fuel leaks and tried working from the outside.  Of

 course I had no luck and had to cut the tank and fix it from the inside.

 I got an Access Panel plate from van along with pop rivets that had closed

 ends.  You need to cut a circular hole on the aft side of the tank and

 reach

 inside and reseal along the suspected joint in X, Y and Z directions.

 This

 repair sounds a lot more complicated and drastic than you it really is.

 It

 took me a lot of time admiring my problem that it took to fix it.

 You may need more than one opening in your case to fix everything.  Good

 luck.

 Contact me offline if you additional info.

 Do not archive

 On 3/2/07, Kent Forsythe <rv10builder(at)4sythe.com> wrote:

>

> 

>

> I have completed my tanks and during testing have noticed some leaks

> along the rear baffle and the tank skins.  No doubt I did not get

> enough or good placement of the tank sealant.  Does anyone have any

> tricks for getting into the tank to get more sealant along that those

> edges?  I thought about taking the fuel senders out so that I could get

> in through that hole.  On the outer edges, I can get in through the fuel

> cap area.  I am having trouble getting to the middle of the tanks

> though.   Is it acceptable to seal on the outside of the tank where the

> baffle meets the skins?

>

> Thanks,

>

> Kent

>

> Kent Forsythe

> 40338 - Wings

> Slow Build All The Way!

 --

 Rob Kermanj

---------------------------------------------

This message was sent using SnowCrest WebMail.

http://www.snowcrest.net

n8vim(at)arrl.net
Guest

Posted: Sun Mar 04, 2007 7:31 am Post subject: Fuel Tank Leaks

Be careful thinning!



 From the info in a PDF previously posted:

"There has been much discussion regarding thinning tank sealant in order 

to get it to flow into small cracks or voids. While the manufacturers do 

not recommend doing so, as they must maintain compliance with the Mil 

spec., tank sealant can be thinned using Toluene. *Sealant can be 

thinned with up to 15% Toluene, by weight*, without affecting the 

properties of the sealant. While other solvents, such as *MEK, may thin 

tank sealant, they may also affect its properties* with potential 

adverse results, so it is recommended to use Toluene if you must thin 

the sealant. *An alternative to thinning the sealant is to use a Class A 

sealant whenever a lower viscosity is needed"*



-Jim 40384, Finished putting in fuel return lines... All sealed up!



evmeg(at)snowcrest.net wrote:



 	  Quote: 	
		  

Before you cut your tank up you can try to run some thinned down sealant

along the inside edge. I do this on all of my tanks as a matter of

practice. Just mix up some sealant and thin it down with MEK....about 1

part mixed sealant to 1 part MEK. Then you can dump it into the lower

outboard corner of the tank through the fuel cap....I use a paper funnel

to keep it where I want it. Now just tip the tank up and run the mixture

down the seam to the other end. Turn it over and run it back and just keep

it moving until it is all used up. If that does no good then go ahead and

cut the holes in the back. Good luck and feel free to contact me with

questions.

Cheers.

Evan Johnson (400+ sets of RV tanks)

(530)351-1776

  



>I also had a couple of fuel leaks and tried working from the outside.  Of

>course I had no luck and had to cut the tank and fix it from the inside.

>

>I got an Access Panel plate from van along with pop rivets that had closed

>ends.  You need to cut a circular hole on the aft side of the tank and

>reach

>inside and reseal along the suspected joint in X, Y and Z directions.

>This

>repair sounds a lot more complicated and drastic than you it really is.

>It

>took me a lot of time admiring my problem that it took to fix it.

>

>You may need more than one opening in your case to fix everything.  Good

>luck.

>

>Contact me offline if you additional info.

>

>Do not archive

>

>On 3/2/07, Kent Forsythe <rv10builder(at)4sythe.com> wrote:

>    

>

>>

>>

>>I have completed my tanks and during testing have noticed some leaks

>>along the rear baffle and the tank skins.  No doubt I did not get

>>enough or good placement of the tank sealant.  Does anyone have any

>>tricks for getting into the tank to get more sealant along that those

>>edges?  I thought about taking the fuel senders out so that I could get

>>in through that hole.  On the outer edges, I can get in through the fuel

>>cap area.  I am having trouble getting to the middle of the tanks

>>though.   Is it acceptable to seal on the outside of the tank where the

>>baffle meets the skins?

>>

>>Thanks,

>>

>>Kent

>>

>>Kent Forsythe

>>40338 - Wings

>>Slow Build All The Way!

>>

>>

>>

>>

>>

>>

>>      

>>

>--

>Rob Kermanj

>

>    

>



---------------------------------------------

This message was sent using SnowCrest WebMail.

http://www.snowcrest.net

Rick S.

Joined: 12 Feb 2006
Posts: 347
Location: Las Vegas

Posted: Sun Mar 04, 2007 8:47 pm Post subject: Fuel Tank Leaks

Yeah but he has made 400+ sets of tanks  



He might have a bit is experience fixing leaks!!  



Rick S.

40185



do not archive

_________________
Rick S.
RV-10
40185

Display posts from previous:

	Matronics Email Lists Forum Index -> RV10-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum