Underbody primer

[2footbraker]

Anybody know a part # or make-up of the thick coating used on the underbody of later model VW's? I'm thinking specifically of the layer under the finish coat that appears to be "brushed" on. Thanks for any info.

 

[bbarbulo]

http://3mcollision.com/products/coa...-paintable-rubberized-undercoating-00544.html

like this?

 

[Rembrant]

I used this stuff in grey when I replaced the rockers and patched the floor on my TDI Beetle. I did brush it on, sort of, with a small putty knife. I also bought the same stuff in black, but in tube that fit in a caulking gun for doing joints that I had to paint over (because the car was dark blue). It is similar to the factory coating.

https://postimage.org/

 

[oilhammer]

Seam sealer is often brushed on and is paintable. Any body shop should be able to point you to a source for that.

 

[bbarbulo]

seam sealer is NOT brushed and hasn't been since the early 90s. seam sealer is applied robotically and remains untouched after assembly, whereas on old cars they used to brush it after application.

so when he said 'brushed' on, I think he meant the textured undercoating of the entire floor.

 

[Rembrant]

so when he said 'brushed' on, I think he meant the textured undercoating of the entire floor.

The stuff I pictured above was recommended to me by two body shops, and in the grey color was almost an exact match in color and texture as OEM stuff on the underside of my 2000 Beetle. After I welded in a patch in the floor, I scuffed up the surrounding coating, and the seam sealer blended right in and seemed to adhere well to the 16 year old original coating. FWIW.

Seam sealer is also used on the rocker panels on the Beetle as they're a bit of a different animal than the Golf's and sedans. It has to be smoothed out and painted afterwards. I welded new rockers on both sides, so I had to re-seal the standing seam underneath and the underside of the rockers.

I guess I'm not 100% sure what the OP is looking for, but the seam sealer I used is very close to the original coating on the underside.

 

[oilhammer]

seam sealer is NOT brushed and hasn't been since the early 90s. seam sealer is applied robotically and remains untouched after assembly, whereas on old cars they used to brush it after application.

so when he said 'brushed' on, I think he meant the textured undercoating of the entire floor.

My brand new Mercedes Sprinter has seem sealer clearly applied by a brush by hand in various places. It is most certainly not the work of a robot.

 

[bbarbulo]

that's possible, guess if you can't get a tight panel fit, you fill it with seam sealer. Most companies have moved away from hand brushing seams since no two cars came out the same, robot applies SS, panels sqeeze together, and that's it. Working in auto production I get to see this stuff first hand.

OP, you need undercoating or seam sealer? What are you trying to do?

 

[2footbraker]

I'm looking for the rippled coating over the rockers. I want to repaint a couple spots on the pinch welds that were damaged by a jack before rust sets in. I appreciate all the responses. Would they use seam sealer on such a large area?

 

[2footbraker]

Rembrandt, where did you buy that stuff?

 

[bbarbulo]

Canadian tire has dominion products. So should all body supply houses.

 

[Rembrant]

I'm looking for the rippled coating over the rockers. I want to repaint a couple spots on the pinch welds that were damaged by a jack before rust sets in. I appreciate all the responses. Would they use seam sealer on such a large area?

The textured coating on the rockers is a different product again...that is gravel guard, and it is sprayed on.
As for the seam sealer, forget the that the word "seam" is in the title of the product, it's just a sealer that can be used for sealing/coating anything you want. Autobody shops use it all the time. On the pinch weld, it is applied really thick in spots.

When I replaced the rocker panels on my Beetle, I had to remove all of the old seam sealer from the pinch weld. I re-coated the whole pinch weld with grey seam sealer using a putty knife about 1" wide, and then I sprayed the textured rock guard on it afterwards, from the pinch weld part ways up the side of the rocker.

Rembrandt, where did you buy that stuff?

I got the seam sealer at CarQuest and the Gravel Guard was on sale as Napa (The professional quick dry stuff that's paintable). Just go to the autobody section of one of the big auto parts shops and they'll have everything.

Edit: It's called gravel guard, but I just checked and the stuff I used has a different name FYI, see below. (PS: I just used this stuff to coat a rear brake dust shield before install, it's great for stuff like that too). Just be careful...Canadian Tire sells a version of this stuff that doesn't dry completely...don't use that.

Just go to an autobody supply shop, or the autobody department of the large auto parts stores, and they should be able to help you with this stuff too.

https://postimage.org/

 

[oilhammer]

that's possible, guess if you can't get a tight panel fit, you fill it with seam sealer. Most companies have moved away from hand brushing seams since no two cars came out the same, robot applies SS, panels sqeeze together, and that's it. Working in auto production I get to see this stuff first hand.

OP, you need undercoating or seam sealer? What are you trying to do?

VAG products still have some hand applied spots on them, too. I looked all over this 2008 PT Cruiser I have here on a lift (72k miles, needs an engine ) and it has NO seam sealer ANYWHERE underneath or under the hood, which is probably why it is already rusting pretty bad everywhere. This 2004 Jetta right next to it (with 273k miles and does most certainly NOT need an engine ) has hand applied (or at least touched up) seam sealer all over it, under the hood in the inner fenders at the strut towers most notably that is obviously not a robot's work.

Maybe you work at Chrysler?