yachtflame

To use undercoating inside or not

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I’m redoing the inside of a 1948 Jaguar MK V saloon. I’ve stripped it down to bare metal. Wire brushed it and acid bathed with ospho. Once dry, I wire brushed it again the painted with rust converting spray paint. I’m thinking of now spraying undercoating to seal it all but I’m worried that the smell of tar might stay with it. Has anyone done this that can advise on lingering smell? I’d hate to drive the wife around hearing about an awful smell!

 

Wayne Elsworth

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36 minutes ago, yachtflame said:

I’m redoing the inside of a 1948 Jaguar MK V saloon. I’ve stripped it down to bare metal. Wire brushed it and acid bathed with ospho. Once dry, I wire brushed it again the painted with rust converting spray paint. I’m thinking of now spraying undercoating to seal it all but I’m worried that the smell of tar might stay with it. Has anyone done this that can advise on lingering smell? I’d hate to drive the wife around hearing about an awful smell!

 

Wayne Elsworth

 

Really, really bad idea. The eau du asphalt will stick around for quite a while.

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Inside the doors, roof etc. it was used to reduce  noise levels. Some areas had paper pads stuck onto the wet coating and had a second coat applied.

There are newer products that stay flexible and don't off gas as long  as the old tar base products.

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My thought is that it would quite down noise and vibration with minimal added weight. The car has some kind of tar based coating in the doors and roof top now. Just trying to stay semi original.

 

wayne

Edited by yachtflame (see edit history)

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There are several sound deadening products on the market, that are less messy to use and don't have a lingering tar like smell. Dynamat and 3M, 08840 sheets are two that come to mind.

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Wayne.......paint two or three coats, and use the dyna mat......great stuff......Ed

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Make sure the inside of the doors is super clean and new paint to apply DynaMat.... 

Otherwise if it does not stick well inside the roof or door area it will peel away..

If it happens in the doors it gets jammed up in the window mechanism...seen that a few times!

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For the exposed area where asphalt was originally used, go with spray-on truck box liner.  It is available in the exact same texture of the original undercoat, and will always retain that brand new appearance when washed, unlike real asphalt which always appears dirty once it picks up dust and road grime.   Think of how nice and black freshly laid asphalt pavement looks, but it never stays that way.

 

Craig

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I'm  rewiring my '54 Ford, so I have the front seat out and some of the carpet pulled back a bit. This gives me a chance to see how the POR-15 I treated the interior with about 10 years ago is holding up. The "por" mean "paint over rust,", so it's designed to go on without extensive rust removal, IF you follow instructions. The floor had surface rust on the top back then - extensive in spots - but no rust through and the underside of the floor was pretty good because the car had been undercoated when new.

 

I'm happy to say that the POR-15 is still looking good and the rust has not come through anywhere I can see...even after 10 years. Sound deadening used was just the standard carpet underlay, and it seems to work pretty good.

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I need to deaden the insides of the doors and floor in my '36 Dodge. I was thinking of using the bed liner but without multiple coats it's rather thin. Spray undercoating,as mentioned , is also not a good idea. I thought of the Dynamat, but the windows on this vehicle are not sealed to the weather originally, and the old paper mat lip held the water causing rusting. I'm afraid that the Dynamat might do the same thing. I was considering something like Flex-seal since it's rubber based and can be built up.

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Flex-seal is silicone. I’ve had problems with its ability to adhere to things. It’s not as good as the TV ads say! If you plan to use something like silicone, dilute regular RTV silicone with naphtha, this makes it water thin and can then be brushed or sprayed. Depending on the amount of naphtha used, you have 10 to 15 minutes working time with it before it evaporates off and is normal silicone again. I’ve used this method on molds when building boats. Clean, smooth and nothing sticks to it!

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Thanks for the advice. I really didn't want to use anything that has a silicone base as silicone is difficult to remove. Interesting idea for mold making too!

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 I have a convertible that I primed and painted the inside floor.

 I then applied a thick layer of a rust preventive that is made to spray on the underside of commercial trailers.

 It does not fully dry and heals itself if scratched.

 I then cut appropriate pieces of house roll roofing and laid it down stone side first into the wet material, covering it and another light layer and then thick paper.

 This gives a "mass deadner" to the sheet metal and quiet's it.

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I have used a product called Lizard Skin for sound/heat insulation and liked it. If you are just looking to seal, then paint would do the job nicely.

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