Seam Sealer

crazyboutwagons · Sep 16, 2017

We took the wagon out today to a all Mopar car cruise Gene's 13th Annual Mopar BBQ and Cruise in Myersdale's,Pa . was our first time there was a great day and lot of nice cars.

On our way home we ran into a large thunderstorm with heavy downpour. When we got home I parked the car in the driveway to cool off before putting it in the garage. I just went to put it away and saw a large wet spot under the car under the right rear quarter panel.

I got out a flashlight and crawled under to look .there was water dripping from the spare tire well. I removed the spare and there was 2 inches of water in the bottom of it. I assume it is either being sprayed up from the road or the side window is leaking as there is some rust along the bottom glass.

The factory seam sealer around the inside of the well is really brittle and I am thinking of removing all of it and resealing . where can I buy a good replacement. also I took some of it off seam of the quarter panel to the rear taillight panel and there is a white foam in the seam under the seam sealer should I try to remove this also or just the sealer and reseal with new. I was also thinking of coating the bottom of the well with spray undercoating after resealing all the seams. looking for guidance here.

challenger · Sep 16, 2017

I used some 3M 08300 in a regular calk gun tube. It is a tan colored like the original. I dispensed it and then sort of troweled it out like the factory did. I used a 1" putty knife I think. The old stuff just crumbles away. It also gets loose and comes away from the panels and traps moisture for a very long time so, if the car sees wet roads, moisture will pretty much stay trapped until it makes its own drain hole aka rust.

crazyboutwagons · Sep 16, 2017

thanks for the info. were did you purchase it. does it require a special gun or will a standard Home Improvement store one do.

1978 NYB · Sep 16, 2017

3M is the best.

AAP, Carquest and other automotive stores all carry it. Look in the glues and sealers section.

crazyboutwagons · Sep 16, 2017

should I try to remove the foam filler and replace or just remove old sealer and recoat with a generous amount of new sealer

Wonderwagon · Sep 16, 2017

Not sure of your wagon model year, but on the fusalge style wagons, there is a trim piece above the rear quarter window. It is secured at the rear by a clip that has a bolt that goes through the window rubber, and is secured by a nut inside the car. The sealant may have dried out allowing water in and channeled down to the spare well. Might consider a water test to see if it is the culprit, dried out sealant under the window seal may also be the gully party.

crazyboutwagons · Sep 16, 2017

Wonderwagon : wagon is a 68 I was going to do a water test tomarrow. My guess is that today was just the right set of circumstances with all the rain on the road being thrown up by the tire was just hitting a unsealed seam spot on the underside and entering the spare tire well because I have never seen water leak out whenever I wash the car. will try the test to be sure .will post the results tomarrow

Wonderwagon · Sep 16, 2017

this was where my 69 took water in cheers

CBODY67 · Sep 16, 2017

In the spare tire well, and also in the depression on either side of the main floorpan of the luggage compartment in the sedans, is a flat plastic pop-in plug. Take that plug OUT, carefully to re-use it, so that the residual liquid can drain out that way. That hole is where the factory rust preventative "wash" and the later metal primer "wash" drained out of after "the dip". If you might deform or mutilate it, you can use some tape to temporarily seal the hole as you search the Mopar restoration vendors for a new plug.

Put the car on secure jackstands and methodically look at all body seams and undercoating (if equipped) for sealer that is missing or degraded. 3M is the premier sealer, as noted. The "foam" might be from a flat piece of foam that was put there in production of the body or at an attachment point of some component (for sealing and sound deadening purposes).

If you can find a Chrysler parts book for the general model year, you can see the illustrations of how the sheet metal is configured and goes together. There might also be a section in the Chrysler service manual's "Body" section that details where sealer should be applied and how, on the body seams.

Please keep us advised of how it goes.
CBODY67

crazyboutwagons · Sep 17, 2017

I used some towels last night and soaked up all the water out of spare tire well. The area is completely dry today. I took a better look today and noticed some rust along the bottom channel of the side window on the inside of the tire well. I also noticed some watermarks on the inside glass from top to bottom. I am thinking the rain was coming down hard and the window seal must be suspect. I got to figure how to remove the outside trim and get a look at the gasket. looks like the same scenario as described Wonderwagon above. going to check the FSM if no luck ill take it to Bodyman that repaired the rust. don't want to eff up the trim. will let you guys know. I am leaning towards the 3M brushable sealer as it seams to be the easiest to get into the nooks and cranny's of the spare tire well

crazyboutwagons · Sep 21, 2017

Update :
spent better part of a afternoon removing all the seam sealer in the spare tire well. I found 3 holes that the factory sealer had shrunk and exposed along with the seam along the bottom of the tire well and the 3rd seat foot well. I got some brushable seam sealer and will seal all the holes then check the side glass for water intrusion. I sanded all the areas to bare metal then coated with self etching primer. took pictures but the digital camera will not download to computer working on getting a newer one and will post when I can make the download.

CBODY67 · Sep 21, 2017

Sounds like a good plan! Those spare tire wells have always been very exposed to perils that normal quarter panels are not. Following the seam sealer application with some paint and then spray-on undercoat might help, too.

CBODY67

crazyboutwagons · Sep 23, 2017

Update: I resealed all the suspect seams in the tire well today when I got home from work. I used a product called Transtar Seam Sealer. The Auto Body supply house was out of the 3M product they said they sell equal amounts of both products. I asked the body guy who repaired the rust on the wagon and he said product is good and easy to use but he uses the 2 part type or a single stage that both require as special applicator and for my application he recommended it. it was easy took me about 45 minutes to doo the whole job. I think it looks great. will let dry overnight then paint. directions say it can be painted in a hour. I put it on heavy in a couple spots so wont hurt to wait. here are some pics of before and after