Insulating and sound deadening

[ryans69chevy]

I'm trying to come up with a safe way to insulate and deaden the sound of my cab, specifically the roof. I have the outer skin removed and found GM used a fiberous material in the center.

I've searched the site, but haven't found an answer. I'm wondering what product I can use between the panels that can withstand welding. I have to spot weld the edges all the way around as well as weld the back seam.

I've heard of lizard skin, not sure if that stuff could withstand the welding process. I'm sure any of the peel and stick products would just burn up. I might call lizard skin and see what they say. Do any of you have any ideas or first hand experience? A lot of the threads I've read are of people glueing the panel back on which I'm going the welding route.

Thanks

[SeanB242]

I have not done this but when installing something like Dynamat. It does not have to cover every inch of the panel, so you could install within several inches of the edge which would give you room to weld.

[sick472]

Sean makes a good point. Dynamat will perform well without full coverage for sound abatement, but will do very little for temperature insulation. I would consider using a dynamat product along with rock wool insulation for your project. I have NOT done this, but if you check into rock wool, stone wool, or mineral wool you will find temperature ratings upward of 1832 degrees F (1000 deg C). Welding temps get a lot hotter than that, but if your spot welding in your pieces and allowing the proper time for cooling in between spots...your damage to the insulation will be minimal and, I don't think the rock wool will burn, just melt some near the extreme heat. You can get this rock wool from common box stores. Owens Corning makes some, I know. It is actually made out of melted and spun rock. It will resemble regular fiberglass insulation, but more dense and stiff.

[ryans69chevy]

I'm just worried about a spark flying between panels and starting a fire. If I used a peel and stick material I wouldn't cover the whole thing. I would install about the same amount as GM did. That's why I was wondering if anyone has used or knows of anything else that can handle the heat of welding and not start a fire. Just trying to get more coverage that so called "stock".

[binford]

I just posted about the lizard skin stuff in another post. You can buy the ceramic beads and mix it yourself. If you paint to the edge it will burn back a little. Leave 3/4" and you would be fine. Or paint, burn, sand and repaint what gets charred. I used some of the peel N stick, then insulation. I used a foiled micro bubble insulation. I find the foil works great. Take a piece of tin foil and hold it 3" inches from you face, you can feel the heat reflect back.

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