Do you think sand- or other media- blasting would be a possible way of getting dynamat off?

Just outta curiosity, why? If I had the means, I'd love to "dynamat" my ride!

yeah, what on your 4runner has Dynamat on it??

Well I had a small leak that went unnoticed for a large amount of time, and it has presented some serious rust issues that need to be addressed before it gets worse. The problem is, the rust continues under the dynamat, and I can't tell where it finally stops, so all the dynamat on the floor must be removed, just to make sure. Dynamat is replacable, the floor of my truck...not so easy haha.

Everything. Doors, back wall, floor, roof, most of the firewall.

Heat it with a hair dryer or heat gun (carefully) and pull it off. Get a corner started with a putty knife, grab the foil layer and the tar layer and slowly pull it off the body so it has time to stretch and release. It's a huge pain in the ass.

By the way, if you try to blast it you will just end up with a layer of tar with a nice "sand and perforated foil inlay" and it will make proper removal all the more difficult.

I've heard dry ice helps to chip it off (after you have removed the top foil layer). I thought heating it would make it sticker and more viscous? I could be wrong. I'm trying to avoid the whole scrape with a putty knife thing at all costs, because it's probably going to be the whole floor of my truck. I hope it doesn't come down to this.

Haha ya I more meant after the foil layer was pulled off, and a putty knife was scraped over the remaining gunk. You still think the sand will just stick to it? I feel like it would be hitting it pretty hard, maybe it would take the remainder off? Thoughts?

I have taken off dynamat before as well as heavy duty 3M automotive adhesive tape, and heat has always been the way to go.

Have you every scraped linoleum off a sub-floor? That's basically what it will be like if you get it cold, and there will be all kinds of little spots left behind.

Usually, if you take your time, and heat it while pulling and giving it time to separate from the surface it comes up like it went down and you don't need to scrape. This requires patience and the right touch so you don't tear the sheet. The other nice thing about doing it this way, is you can pull it back as far as you need to, cover the sticky side of the dynamat, do your rust cleanup, and hopefully just lay it back down (apply with heat as well).

That's really great info. No one anywhere else on the internet (that I have looked) has mentioned using heat. You think it will come off that clean even if the surface it was/is adhered to is rusted? Either way, I will definitely try to bring the heat first

The rust is going to add some excitement to the job and if you find it's not coming up very well around the rust it may be better to use a utility knife and cut around it. Or just pull up what you can from the rust and deal with the cleanup of that spot later.

There is also the possibility that the rusted area may have created a "bubble" where all the adhesive is no longer stuck to the body and instead the underside is coated with dust. If you find a bubble like that, I would cut around it with a utility knife and pull up that section. This would certainly make the job waaaaaay easier, and if you find it that way I would buy a Powerball ticket soon.

Good luck!

Got it.

Haha I'll definitely look into a lotto ticket if that's the case. Anyway, this probably won't happen until the end of summer, thanksgiving, or christmas. If I remember by then, I will post up results. If I don't remember this thread, I'm sure I'll make another one just to document the job. Thanks a lot for your information!