Which JB weld to repair fuel cell?

[Bill Manofsky]

I have seen other posts where it has mentione to use JB Weld to make minor repairs to fuel cells. Which JB weld? I assume it is either Black Silicone or Ultimate Black Silicone....

http://www.jbweld.com/collections/rubber

Bill

[Dietmar]

Not sure a silicone based product will work on a fuel cell.

Years ago I used something called PLIOBOND- sold (still) at Aircraft Spruce. Held my leaking cell together for a couple of weekends until a new one arrived.
Unfortunately, it can not be sold in CA in case you chose to drink it.
Dietmar
www.quixoteracing.com

[Bill Manofsky]

Not sure a silicone based product will work on a fuel cell.

Years ago I used something called PLIOBOND- sold (still) at Aircraft Spruce. Held my leaking cell together for a couple of weekends until a new one arrived.
Unfortunately, it can not be sold in CA in case you chose to drink it.
Dietmar
www.quixoteracing.com

Some of the guys said that they used JB Weld and it worked pretty well. Any two part epoxy should work. I just want to make sure I get one that does not delaminate or is not compatible with gasoline. The JB welds in the link I posted are for rubber, so they should work. I just want to make sure they are the correct ones. I am essentially going to use a rubber patch over a small blister I have on one of the lower corners of my cell.....like a tire patch.

[jchracer]

Depends on the material of the cell. Is your cell a black rubber type material or the yellowish urethane material? Those are the two types most common to formula cars and each has a preferred repair material.

[Charlie Schmidt]

How about a urethane glue, like they use for windshield installs?

[teamwisconsin]

I would send the cell in for service to see about a patch. http://www.aerotechservicesinc.com these guys are in your neck of the woods and they do really good work. And if it's not patchable, maybe it's better to just replace it anyway?

[J Leonard]

Hardman urethane D-50. I think it was Fuel Safe that recommends it. Available at McMaster, P/N ?

[Bill Manofsky]

Depends on the material of the cell. Is your cell a black rubber type material or the yellowish urethane material? Those are the two types most common to formula cars and each has a preferred repair material.

It's black rubber. The one on the right in the photo below....

[Bill Manofsky]

I would send the cell in for service to see about a patch. http://www.aerotechservicesinc.com these guys are in your neck of the woods and they do really good work. And if it's not patchable, maybe it's better to just replace it anyway?

I want to try it myself before sending it out to anyone. It is a very small blister the size of a pea that is not leaking. I just want to reinforce it with a patch. I just want to use the right glue that will not dry up and delaminate.

[Supersmile]

Just went through this on a car I purchased with a leaky cell. (The cell was made in 1990 so it did pretty well in the long run). I just used the plain jane original JB Weld, bought the large size tubes (Amazon Prime) and troweled it on over the cracked areas in a thin layer. Let it dry 24 hours, filled the bladder while it sat on newspapers, looked for staining, emptied bladderl, repeated. Took about 4 applications but I made it through the first weekend with the car without it leaking. New bladder is in there now, but I think the repaired bladder is still fuel tight. The original JB Weld is pretty flexible in a thin layer.

My bladder was an old ATL one, the yellow material they use.

I can post up a photo of the repairs if you want.

[Bill Manofsky]

Just went through this on a car I purchased with a leaky cell. (The cell was made in 1990 so it did pretty well in the long run). I just used the plain jane original JB Weld, bought the large size tubes (Amazon Prime) and troweled it on over the cracked areas in a thin layer. Let it dry 24 hours, filled the bladder while it sat on newspapers, looked for staining, emptied bladderl, repeated. Took about 4 applications but I made it through the first weekend with the car without it leaking. New bladder is in there now, but I think the repaired bladder is still fuel tight. The original JB Weld is pretty flexible in a thin layer.

My bladder was an old ATL one, the yellow material they use.

I can post up a photo of the repairs if you want.

Yeah, lets see some pics. Thanks. Bill

[Supersmile]

Ain't pretty, but it worked.
Not that I felt all that comfortable racing like that, but I wanted to make sure the rest of the car was OK before investing in a new bladder.

[Bill Manofsky]

Ain't pretty, but it worked.
Not that I felt all that comfortable racing like that, but I wanted to make sure the rest of the car was OK before investing in a new bladder.

I suggest next time using thin rubber on top of the glue. This is essentially how they make the bags anyway. They are layers of rubber glues together.

The rubber would significantly increase the shear strength of the patch...much like a tire patch on an inner tube. An inner tube would more likely still leak if only the glue is applied to the hole.

[bhamfal]

I've used proseal (aircraft spruce has it) in the aviation world on both composite and aluminum tanks with great results. On the composite tank it sealed the aluminum fill plate to the vinyl ester tank. I wonder how well it'd stick to bladder material....it stuck to everything else with gusto and it is fuel proof.

[Bill Manofsky]

I've used proseal (aircraft spruce has it) in the aviation world on both composite and aluminum tanks with great results. On the composite tank it sealed the aluminum fill plate to the vinyl ester tank. I wonder how well it'd stick to bladder material....it stuck to everything else with gusto and it is fuel proof.

My concern is that those are rigid surfaces where the bladder is flexible.

I called Aerotech Services who makes and repairs fuel cells. They use EC776 Epoxy by 3M on their cells. It is a one part epoxy. I called 3M and it only comes in a quart or larger. I have a call into one of their sales reps to see if I can get a small sample pint. This is what I am going to use.

[RussMcB]

Kind of on-topic, and maybe food for thought...

I have my cell out and planned to take it to a local airport shop to have them test it, even made an appointment. Then I realized I could just hold it under water (in my back yard swimming pool), kind of like looking for a leak in a tire. It wasn't easy holding it under water (probably funny to watch), but it tested well - no leaks.

I called the airport shop to let them know I wasn't coming by, and they mentioned that if I ever did have a leak, they could sell me the stuff to repair it myself. If you'd like, I can call them again to learn more about what it is they have to offer.

[problemchild]

I have bought fuel resistant epoxy from McMaster carr and used with good results. Unfortunately, I don't have that info with me.

[HayesCages]

Try this:
http://www.rematiptop.com/technical/...dures-Rev4.pdf

We got it from these guys:
NEVADA:

4665 Manzanita Ln.
Elko, NV 89801
Phone: (775) 778-0640
Fax: (775) 778-0642
Trinidad Garcia

Western Zone Manager

Martin Goehner

Shop Manager

[Bill Manofsky]

Kind of on-topic, and maybe food for thought...

I have my cell out and planned to take it to a local airport shop to have them test it, even made an appointment. Then I realized I could just hold it under water (in my back yard swimming pool), kind of like looking for a leak in a tire. It wasn't easy holding it under water (probably funny to watch), but it tested well - no leaks.

I called the airport shop to let them know I wasn't coming by, and they mentioned that if I ever did have a leak, they could sell me the stuff to repair it myself. If you'd like, I can call them again to learn more about what it is they have to offer.

o I assume you pressurized it for this test. I would be concerned with water getting into the cell, then getting it out.

Yes, I would be curious as to what your airport shop has.

[Bill Manofsky]

Try this:
http://www.rematiptop.com/technical/...dures-Rev4.pdf

We got it from these guys:
NEVADA:

4665 Manzanita Ln.
Elko, NV 89801
Phone: (775) 778-0640
Fax: (775) 778-0642
Trinidad Garcia

Western Zone Manager

Martin Goehner

Shop Manager

Thanks, If I don't hear back from the 3M rep, i will give these guys a call.

[Hardingfv32]

I have done a lot of product research on adhesives that are impervious to gasoline. I would say there are none. You will find 'resistant' but that is not same as 'proof' or impervious. This goes for some of the special acrylic paints like Imron.

Gasoline seems to be a very special blend of chemicals that is hard to deal with.

Brian

[Bill Manofsky]

I have done a lot of product research on adhesives that are impervious to gasoline. I would say there are none. You will find 'resistant' but that is not same as 'proof' or impervious. This goes for some of the special acrylic paints like Imron.

Gasoline seems to be a very special blend of chemicals that is hard to deal with.

Brian

That is somewhat contradictory since they glue fuel cells together. There are cells in race cars made in the early 80's that are still not leaking.

I just called Aero Tech Services to confirm. They bond the seams with epoxy and use an autoclave for the final cure. They use the EC776 epoxy made by 3M in the manufacture and repair of their fuel cells. I am just having difficulty locating a small sample of this stuff since the smallest I can find is by the quart. If I can find a pint sample size, this is what I am using.

[Joe Henslee]

"AC-236 Class B is a two-component, manganese dioxide cured, liquid polysulfide polymer system providing excellent fuel tank and fuselage seals. It has outstanding resistance to aviation gasoline and jet fuel, as well as resistance to chemicals and petroleum products common to the aircraft industry. AC-236 Class B maintains its flexibility and bond strength on most metal substrates like aluminum, stainless steel, steel, and many coatings under extremes of temperature, weathering and stress. The mixed compound is a thixotropic paste easily applied by extrusion, injection gun or spatula. It has excellent tooling properties. Application uses include sealing integral fuel tanks, repairing integral fuel tanks and sealing fuselages."

The above description is a 3M product sold by Aircraft Spruce. I spent the majority of my engineering career in aircraft manufacturing environment, and this same type material is used in wet wing boxes and wings to contain fuel and anything exposed, on both aluminum and CFRP aircraft. HTH.

[Bill Manofsky]

I was in aerospace for some time too and am quite familiar with structural and sealing adhesives. AC-236 may be great on metals, but we are talking rubber. Apples and oranges.

ATS is using EC776 successfully on their rubber fuel cells. This is what I will use.

Thanks for your input,

Bill

[Rick Kirchner]

I've used two items with great success: aerolife fuel tank sealant from aircraft Spruce and a dow flourosilicone that's about 90 bucks a tube that you can also get at spruce. I seal every seam just to keep seepage through the cloth layers to a minimum.

for testing for leaks:
1) clean the cell with mineral spirits and then with a detergent like simple green and a brush until it's as clean as you can get it.
2) rub a heavy coat of talcum power over everything.
3) cap the outlet and any vents
4) put the cell in a black garbage bag and tape it around the fill neck.
5) insert the fill pipe and fill with gas, cap it off
6) sit the bag in the sun for a few hours
7) cut the bag off and inspect for damp spots in the powder

I've done this at least a half dozen times and it finds the smallest leaks and works flawlessly.

You can test the cell with water in Ridgecrest if you take the foam out. the heat and lack of humidity will dry it out sufficiently, but the foam is much harder. If you have to ship a cell you pretty much have to fill it with water and dump it a few times to get the hydrocarbon out and make it shippable.

Whenever I take the cell apart to work on the pickup or replace the foam I always run this test before putting the cell back in.

I did a ton of testing in 2003 to see what adhesives work with fuel. I tried most of the common silicones, shoo goo, contact cements, etc. JB Weld was the only item completely unfazed by weeks in AVGAS. The rest either swelled and lost adhesion or disappeared into solution completely. At the time I did not have access to the two products above that I've used since.

While you have the bag out take a couple hours to re-engineer the container to keep rocks out (they bounce off your suit and have an annoying habit of getting into the container and wearing little holes in the cell) and also make it so that you can remove the outer cover without drilling out a bunch of rivits, and make parts out of ensolite that will protect the neck and outlet from chafing, as well as make a gasket to keep dirt and water out.

[Bill Manofsky]

I've used two items with great success: aerolife fuel tank sealant from aircraft Spruce and a dow flourosilicone that's about 90 bucks a tube that you can also get at spruce. I seal every seam just to keep seepage through the cloth layers to a minimum.

for testing for leaks:
1) clean the cell with mineral spirits and then with a detergent like simple green and a brush until it's as clean as you can get it.
2) rub a heavy coat of talcum power over everything.
3) cap the outlet and any vents
4) put the cell in a black garbage bag and tape it around the fill neck.
5) insert the fill pipe and fill with gas, cap it off
6) sit the bag in the sun for a few hours
7) cut the bag off and inspect for damp spots in the powder

I've done this at least a half dozen times and it finds the smallest leaks and works flawlessly.

You can test the cell with water in Ridgecrest if you take the foam out. the heat and lack of humidity will dry it out sufficiently, but the foam is much harder. If you have to ship a cell you pretty much have to fill it with water and dump it a few times to get the hydrocarbon out and make it shippable.

Whenever I take the cell apart to work on the pickup or replace the foam I always run this test before putting the cell back in.

I did a ton of testing in 2003 to see what adhesives work with fuel. I tried most of the common silicones, shoo goo, contact cements, etc. JB Weld was the only item completely unfazed by weeks in AVGAS. The rest either swelled and lost adhesion or disappeared into solution completely. At the time I did not have access to the two products above that I've used since.

While you have the bag out take a couple hours to re-engineer the container to keep rocks out (they bounce off your suit and have an annoying habit of getting into the container and wearing little holes in the cell) and also make it so that you can remove the outer cover without drilling out a bunch of rivits, and make parts out of ensolite that will protect the neck and outlet from chafing, as well as make a gasket to keep dirt and water out.

Rick,

Thanks for chiming in...good stuff. I am at the point where I can do an engine build on the Lola. Bill