Rubberized undercoating under cargo area carpet

[clunk]

I just pulled my rear carpet and caught the rust demon before it could destroy my jeep. I repaired a bit of through rust with some sheetmetal, pro-seal and sheet metal screws. I also completely sealed off the drain plugs with sheet metal because they seemed to be part of the problem, and seemed to be more harmful then they where good. This is my DD, so I don't plan on swamping it. There was alot of surface rust, which wire-wheeled, coated in rust converter and painted with rust-oleum (i'm too cheap to pay for POR-15)!

Anyways, the repairs are done and I'm happy with it and will be putting in the carpet again (without the underlay, though). I'd like to put down some rubberized undercoating to give a little sound deadening. I'm not too concerned if it stays a bit tacky because the carpet will be over it.
Has anyone done this? How was the noise before/after removing the stock underlay and applying the undercoating.
Oh, and heres a few pictures of the minimal rust I found. I definately caught it just in time, since I could see it causing big problems if I had left it for another year. You can also see a few pictures of the quick job I did with the 20g sheet metal, self tappers and pro-seal.

and after the repair

 

[Char-Broil]

that's nasty! i hate rust. what year is your jeep? i have my whole floor herculined. you could really do the whole thing with probably 2 quarts of herculiner (available at autozone for ~$30) or just the cargo area with 1 quart. i am REALLY impressed with how tough it is and it deadens sound as good or better than rubberized undercoating, and especially the spray on stuff which is disappointingly thin. i do use my carpet over top of the herc without underlayment unless i am doing some real wet/muddy offroading, then i pull it out. i use a 3/8" rubber mat in the cargo area and noise inside is not bad. i have a borla exhaust and 32" bfg all terrain tires and with the carpet in and the mat in the back it is reasonably quiet on the highway. without the carpet and the mats though it is a bit loud just because it is like a drum inside

 

[clunk]

Mines a 1990. I pulled the front carpet last year when I was worried about rust, luckily didn't have there. I'm going to pull the front carpet again and make sure it's really sealed this time around since I think I still get a little water under there.

I thought about herculining it, but I'm a cheap SOB and I have several cans of undercoating on the shelf already from a while ago, so I'll probably just use those.

Hoping these repairs hold out for some time to come, although I'll probably flog this one in a few years time..and of course, buy another XJ

 

[LiamN]

See that gunnel, on the inside, behind your wheel well?
i still get water in there, no idea how.

if you wanna have some fun look into vortex/herculiner or something like those for the flooring of your truck. got it on mine, now muds no biggie on the floor.

 

[bcmaxx]

I just pulled my rear carpet and caught the rust demon before it could destroy my jeep. I repaired a bit of through rust with some sheetmetal, pro-seal and sheet metal screws. I also completely sealed off the drain plugs with sheet metal because they seemed to be part of the problem, and seemed to be more harmful then they where good. This is my DD, so I don't plan on swamping it. There was alot of surface rust, which wire-wheeled, coated in rust converter and painted with rust-oleum (i'm too cheap to pay for POR-15)!

Anyways, the repairs are done and I'm happy with it and will be putting in the carpet again (without the underlay, though). I'd like to put down some rubberized undercoating to give a little sound deadening. I'm not too concerned if it stays a bit tacky because the carpet will be over it.
Has anyone done this? How was the noise before/after removing the stock underlay and applying the undercoating.
Oh, and heres a few pictures of the minimal rust I found. I definately caught it just in time, since I could see it causing big problems if I had left it for another year. You can also see a few pictures of the quick job I did with the 20g sheet metal, self tappers and pro-seal.

and after the repair

They must be prone to rust in the areas you repaired! We just finished welding some patches into my bros 92 xj in the same places!!!

 

[bcmaxx]

See that gunnel, on the inside, behind your wheel well?
i still get water in there, no idea how.

if you wanna have some fun look into vortex/herculiner or something like those for the flooring of your truck. got it on mine, now muds no biggie on the floor.

While patching my brothers rear floor we had the carpet and inner quarter plastics off and noticed both rear pockets were almost full of water, drilled a couple holes and drained it, a few rainy days later swish swish around corners, filled up again, I checked my 89 and the rh pocket was full of water too, wtf?? We did the water hose test and found the water was leaking in from small cracks in factory seam sealer at the very end of the drip rails, very small cracks but it would really pour in after a rain. Just cleaned it up and put fast cure urethane on both the jeeps drip rail ends. dry at last!!!!
we coated the floor with black rubberized rockercoating, dries nice and doesnt make a mess or stain crap black

 

[clunk]

While patching my brothers rear floor we had the carpet and inner quarter plastics off and noticed both rear pockets were almost full of water, drilled a couple holes and drained it, a few rainy days later swish swish around corners, filled up again, I checked my 89 and the rh pocket was full of water too, wtf?? We did the water hose test and found the water was leaking in from small cracks in factory seam sealer at the very end of the drip rails, very small cracks but it would really pour in after a rain. Just cleaned it up and put fast cure urethane on both the jeeps drip rail ends. dry at last!!!!
we coated the floor with black rubberized rockercoating, dries nice and doesnt make a mess or stain crap black

thanks for the heads up man, mine was also leaking some water into those back compartments. Looked at some similiar cracks as you mentioned but thought...nahh! Do you mean the cracks that are only visible when the back hatch is open? didn't do the hose test yet, but I'll fix them tommorow. Oh, and when you say rubberized rockercoating do you mean something like rhino-liner or the cheaper stuff for doing undercoating?

 

[bcmaxx]

yes with the hatch open where the drip rail ends (looks like two seams are kinda mitered together where it meets the drip rail)

I meant rubberized rockerguard I used it on my flares and below the lower body line

, and the cargo area of my brothers jeep, comes in a aeresol can and you can coat is as thick as you want , get it at lordco (Its in a tall blue can - available in black or white)

 

[jmeti000]

i just did the same thing... pulled the carpet and floor mat, cleaned up all the rust and patched the small holes.. however im a broke student so i just went to home depot, bought some tubes of black silicone and spread it all over everywhere as thick or thin as i wanted it. obviously not what the stuff was meant for...but it definatly works and was alot cheaper.

 

[Blaine B.]

The best thing is to get rid of the insulation material below the carpet. The carpet can be completely dry, while the insulation is sopping wet! The damned thing alone destroyed my hatch/trunk space floor metal in a year and a half. Damned!

 

[clunk]

yeah, I removed the sopping wet underlay underneath the carpet. I plan on putting the carpet back in, minus the underlay. I also decided to remove the carpet that is under the rear seat completely (the stuff with the seat belts around it), so that it's easier to just pull the carpet completely and clean under there. I think when I re-do the front, I'm just going to cut it into sections so that it's easier to remove for cleaning. For example, one panel will be for behind the seats, one panel for the trans tunnel, one panel for drivers side, one panel for passenger side.
Sure, it won't look as nice as the factory carpet, but it's a jeep--I don't really care.

 

[Blaine B.]

It would be nice if there was a mat or something for the entire floor...like the "carpet delete" option some of the heavy duty trucks have available.

 

[Jeepm@n]

Anyone know of a good sound reducing mat that won't absorb the water under the carpeting? I too have the famous rust disease on both my Heeps floors and I like a quiet interior. I can't do a thing to them though till spring thanks to the balmy -8F temps this time of year.

 

[Lowrange2]

Dynamat - requires a deep pocket tho.

 

[bcmaxx]

What about a cheap truck bed mat cut to shape?? That should kill the sound a bit!

 

[clunk]

Just laid down a first coat of the rubberized undercoating, waiting for it to dry..I think it'll take a few coats before it's thick enough for my liking.

 

[bcmaxx]

we used four cans,and did just to the rear of the back seat

 

[cracked-butt]

ok now i know where to pay special attention to when its warm enough to work on it again. (just way too cold to do any kind of "real" work on it now).
when i tear all that crap out of the back, i dont want to re-install all that crappy plastic, (i see storage spaces!!!)
oh, how long it take you guys to do all this? just to get an idea of how much time im lookin to not have any carpet in.

 

[clunk]

ok now i know where to pay special attention to when its warm enough to work on it again. (just way too cold to do any kind of "real" work on it now).
when i tear all that crap out of the back, i dont want to re-install all that crappy plastic, (i see storage spaces!!!)
oh, how long it take you guys to do all this? just to get an idea of how much time im lookin to not have any carpet in.

to pull the carpet and side panels? probably 30 minutes at the most. Theres only a few screws holding the interior molding down. Once you pull that off, the carpet just pulls right out.
To sand it, do the rust treatment, prime it and do the patches took a while longer. I'm on layoff for a while so I have more than enough time on my hands at the moment, though

 

[Plays For Jeeps]

$3 at local junkyard will buy a rubber truck bed liner. I had enough to cut a trunk mat and 4 new BEEFY mud flaps.