Author Topic: 3M 90 - okay to use in engine compartment..or no?  (Read 2012 times)

Stan Simpson

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3M 90 - okay to use in engine compartment..or no?
« on: September 21, 2020, 09:45:10 PM »
I've ready many suggestions here from owners suggesting 3M90 as a preferred adhesive. Is it okay to use it to replace the insulation that is on the ceiling of my engine compartment? The can says highly flammable and vapors are also combustible. I certainly don't want to start a fire.

Tried Gorilla Glue the last time the insulation came loose. Worthless.

If not the 3M90, then what?

Thanks,
Stan
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Jim Nichols

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Re: 3M 90 - okay to use in engine compartment..or no?
« Reply #1 on: September 21, 2020, 10:53:34 PM »
You could use self tapping screws with fender washers or 3M black super weatherstrip adhesive. Maybe both. Very fast tack time. It may cost between 12-15 dollars per tube. Napa Auto Parts carry’s it.
Jim/Natasha Nichols
05 Monterey 36'
400 Cat C9
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Steve Huber Co-Admin

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Re: 3M 90 - okay to use in engine compartment..or no?
« Reply #2 on: September 21, 2020, 11:12:54 PM »
Stan,
It should be OK as once it dries completely there should be no outgassing or vapors. Be sure that you cover all the adhesive with the insulation and let it dry completely before driving. I think most if not all spray adhesives are flammable prior to drying. I used it on my coach to insulate the rear areas of the engine compartment. The factory insulation above and in front of the engine was OK so I didn't mess with it. If you are concerned reuse and add more of the large fender washers. to hold the material in place. You probably should use them or an equivalent in any case to ensure the insulation stays in place over the years.
Steve
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Fred Brooks

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Re: 3M 90 - okay to use in engine compartment..or no?
« Reply #3 on: September 22, 2020, 12:38:16 AM »
   3M-90 spray is the very best, You only get one chance to line stuff up. Only flammable when spraying. I have been using it for over 20 years and never fails. Fred
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