Expanding foam?

[Travis05Rubi]

Long story short, I pulled my tank and discovered what seems to be expanding foam in the rear frame cross member.

Anyone else have that? If its factory its a poor decision if rust avoidance matters. If its from the PO im not sure why it was used. Not hiding damage, not for sound deadening, not for any reason I can fathom.

Thoughts?

 

[freedom_in_4low]

I never had the tank out of my 99 TJ to see back there, but my 06 definitely did not have that. If a TJ came that way from factory i'm pretty sure I'd have seen posts about how dumb of an idea that is.

As to why...I find it is usually a fruitless endeavor trying to figure out why people do some things.

I have an 89 Grand Wagoneer with a floor that can tell us about the results of holding water against a steel surface and I don't think it would favor foam.

 

[Unique Username]

As @freedom_in_4low said, it’s an endless endeavor trying to figure out what POs do. Could have had a noise they couldn’t track down and they hit it with foam to try and make it go away. No telling.

 

[MountaineerTom]

Maybe trying to get it to float better?

 

[Feralkid]

Are there holes rusted through that he was trying to fill in with the foam to hide it?

 

[TheBoogieman]

Some things just don't make sense.

 

[Mitchrb1]

There is a piece of metal under my 2004 Chevy Suburban that vibrates/rattles when in drive with the brakes on. Goes away in Park. Really annoying ordering at drive throughs. I am wondering why I didn't think of this brilliant idea. Probably the heat shield on the exhaust. Is spray foam flammable? Hmmm lol

 

[Travis05Rubi]

There is a piece of metal under my 2004 Chevy Suburban that vibrates/rattles when in drive with the brakes on. Goes away in Park. Really annoying ordering at drive throughs. I am wondering why I didn't think of this brilliant idea. Probably the heat shield on the exhaust. Is spray foam flammable? Hmmm lol

Use fire block foam. Sold.at any hardware store.

 

[Travis05Rubi]

Are there holes rusted through that he was trying to fill in with the foam to hide it?

No rust. Just an oddity I guess.

 

[Hamfists]

Jeep definitely used expanding foam on the newer jeeps , I’ve found it in multiple places on my 2012 jk that I bought new,

I haven’t seen it on my tj , that looks like the po tried to Jerry rig something

 

[B1Toad]

Use fire block foam. Sold.at any hardware store.

You probably mean fire stop foam. Fire block foam only prevents air drafts in non-fire rated area. Fire stop seals openings in fire rated assemblies. Both are combustible but fire stop has a rating of 1 to 2 hours. The orange color is for inspectors to readily identify it.

 

[Travis05Rubi]

You probably mean fire stop foam. Fire block foam only prevents air drafts in non-fire rated area. Fire stop seals openings in fire rated assemblies. Both are combustible but fire stop has a rating of 1 to 2 hours. The orange color is for inspectors to readily identify it.

That's some good knowledge right there. They oughta call it "fire slow" foam instead for dummies like myself.

 

[macleanflood]

That's some good knowledge right there. They oughta call it "fire slow" foam instead for dummies like myself.

If your fire burns for more than 1-2 hours you've lost the house or building. Soda ash glass windows fail quickly in wildfire heat. Lots of other things will go before you lose that foam.

-Mac

 

[B1Toad]

Yep, the whole purpose of fire ratings are to give more time for evacuation, although in some cases they can prevent a fire, for instance the ratings of plastic electrical boxes. When the box contains the allowable number of conductors (or less), the fire rating time exceeds the time it takes for the available fuel in the box to be consumed, containing the fire. That is one reason why there are cubic inches marked on every box and why there are calculations to tell you how many of each size conductor you are allowed to put in there. Another reason to use a licensed professional.

 

[Travis05Rubi]

For those that have been unable to sleep at night wondering what the expanding foam was for I sluethed it out.

Finished installing the Barnes4wd tank skid. Which also included such surprises as a new fuel pump, housing, radiator, t stat, fan clutch... all a chapter of "while its apart i might as well" The skid is CHOICE. Good business, good product. I might go for their link kit over metalcloak arms in the future. I need to learn to weld and just might take a night class to do so first.

Back to the foam. The carriage bolts that the skid mounts run a little loose in their seat. I knew the PO changed the pump and housing because it wasn't Mopar. Adding the foam stopped the carriage bolts from unseating upon reinstall. One popped free from the forward most mounts and getting it back in place about gave me arthritis. That was all the A-HA! I needed to conclude my belief.

So, rest easy all. Mystery solved.

 

[macleanflood]

I think your PO wins the Red Green award for that one. Actually it's pretty brilliant. I replaced mine with nutserts...

-Mac