New Under-Hood Insulation - Page 2 - PeachParts Mercedes-Benz Forum

ykobayashi · #16 03-03-2020, 10:03 PM

I’ve used that stuff for years on my cars. It has not broken down for ten years. I’m way too cheap to buy a real hoodliner.

I wish I used a better glue than 3m spray on adhesive though. It falls down once a year and I have to spray on more glue.

On my w123 I didn’t have too much laying around the garage so I just put a 1’x2’ piece right above the turbo. That seems to be the spot that gets really hot. The guy who owned the car before me had no hoodliner and I can see the clear is a little messed up in that area. But it was a cheap paint job so the entire car looks dingy up close.

Ahhh...Lowe’s. You know, I bought mine by the foot on a 4’ wide roll at OSH. RIP OSH. It was a really good deal.

Skid Row Joe · #17 03-03-2020, 11:51 PM

Quote:

Originally Posted by SD Blue

I would like to know how well this holds up. My concern, due to the heat locally, was the underlying hexcell construction was made of plastic. However, it the mylar sufficiently reflects the heat, this may not be an issue.

I agree, the foam pad has to be replaced about every 2-3 years around here and much less if it ever absorbs diesel fuel.

A long time ago.....no, a very long time ago, 25+ years...….. I scraped off the OEM grey foam insulation from the inside of my '83 300SD's bonnet. I drove the car several hundreds of thousands of miles, post foam removal, and never had a paint issue on the bonnet, or anywhere else on the car for that matter.

I drove the SD in the Deep Southern States to Texas for many years in this condition. Dead of Summer included. I must conclude that engine heat doesn't bother the bonnet's top paint.

spock505 · #18 03-06-2020, 05:56 PM

Check the bulk head rubber seals with hood, otherwise it can lead to engine fumes entering via heater scoop on otherside.

This is for a 124 when I drive mine without hood insulation, if stationary with blower on it really wafts in.

It creates an indentation into the foam:

optimusprime · #19 03-07-2020, 07:42 AM

Gregory nice job there my friend .Something i need to address in the up coming weeks .But its hard to find the material over in uk in that size to do it all in one piece .

Skid Row Joe · #20 03-08-2020, 02:29 PM

Quote:

Originally Posted by spock505

Check the bulk head rubber seals with hood, otherwise it can lead to engine fumes entering via heater scoop on otherside.

This is for a 124 when I drive mine without hood insulation, if stationary with blower on it really wafts in.

It creates an indentation into the foam:

That's good to know. I didn't notice any fumes of any type though. Thanks!

dlssmith · #21 03-12-2020, 12:40 AM

The OEM hood pad like the one in a pic posted by Spock505 has a decent sound deadening effect. I really noticed the difference there after driving mine with the pad scraped off for a few days before I could install the new one.

Clemson88 · #22 08-23-2024, 10:02 AM

I'm painting all my sheet metal now and have the hood on a bench with two coats epoxy primer/sealer and 2 coats of high build primer all sanded a slick so it's time (finally) to flip in on the table and install a new hood pad.

Will you show me how your replacement pad weathered a decade of age by posting a photo, please?

Thank you kindly, Sir.

leathermang · #23 09-06-2024, 12:51 PM

A long time ago there was this discussion about glue to use for under the hood insulation.
3M has a product which is used in upholstery work regularly... 8088

But 3M has another spray contact cement LISTED FOR HIGH HEAT applications like UNDER A CAR HOOD.
'''Part No. 08090
Warranty Details (30 DAY REPLACEMENT IF DEFECTIVE)
Aerosol contact adhesive designed for bonding vinyl tops, heavyweight liners and hood silencer pads where high strength and heat resistance are needed.''''

Graham · #24 09-12-2024, 04:59 PM

Refectix no doubt has a number of products. In contrast with some comments earlier in this thread, the plastic interior of the sandwich is said to be polyethylene (it melts at about 230F)

The Refectix site says:

Note: Not for use in direct contact on surface temperatures that are 180 F or greater.

and

Description:
Reflectix® Indoor Duct Insulation consists of two layers of highly reflective film (96% reflectivity) that are bonded to two tough layers of polyethylene. Two inner layers of insulating bubbles resist conductive heat flow while a center layer of polyethylene gives Reflectix® high reliability and strength.

Reflectix® Outdoor Duct Insulation consists of two outer layers of aluminum foil that reflect 97% of radiant heat. The outside layer of foil is made of heavier foil. Each layer of foil is bonded to a tough layer of polyethylene for strength. Two inner layers of insulating bubbles resist conductive heat flow while a center layer of polyethylene gives Reflectix® high reliability and strength.

The Reflectix® Double Reflective Insulation is the most versatile, widely-distributed, energy-efficient product that we manufacture.
The product consists of two 96% reflective layers of film bonded to two internal layers of heavy gauge polyethylene bubbles (total thickness 5/16”).

Clemson88 · #25 09-16-2024, 03:19 AM

I have my hood off, along with all 4 doors, the sunroof and trunk lid, for painting and the hood insulation is something I need to do before I get to final prep for base and clear.

Clemson88 · #26 09-26-2024, 12:18 PM

Quote:

Originally Posted by Marshall Welch

Also interested in how that will hold up. My story- I installed a sheet of aluminum-mylar coated thick foam I bought from a marine supply company. It has a mineral-loaded barrier layer sandwiched in between two layers of foam.

It works well, but it's heavy. After a few months, it started to come loose, so I removed it, and re-applied adhesive. The second time, I used 3M Super Trim adhesive to hold it on, and that works better than the 3M Super 77 Adhesive did. I've had it on for about 5-6 years now- it's holding up well.

Is that Super trim adhesive the Super Trim 90?

JHZR2 · #27 09-26-2024, 08:05 PM

Quote:

Originally Posted by Clemson88

Is that Super trim adhesive the Super Trim 90?

I always use the 90. It’s “high temp” and available from the Home Depot. Lasts as long as the foam in those panels.

Marshall Welch · #28 10-08-2024, 12:08 AM

Quote:

Originally Posted by Clemson88

Is that Super trim adhesive the Super Trim 90?

"3M Super Trim Adhesive", "#08090". The can is probably 10 years or more older. I also fabricated about 6-8 retaining screws using nylon screws and nylon capped nuts; speed nuts, and 4-6 inch long strips of galvanized steel (sheet metal), which were slid into the holes in the steel reinforcements running along the inside of the hood. I punched corresponding holes in the sound deadener material.

The adhesive is starting to come apart along the outer edges, and in the center, but not yet to a degree to warrant removal of the material and re-applying adhesive. If I recall correctly, I used about 1-1/2 or more spray cans of the adhesive. After I installed the insulation, I compressed it by first laying a sheet of corrugated cardboard over the engine, then putting lots of wads of crumpled paper all over on top of that, and then closing the hood for several hours or longer; overnight probably wouldn't be a bad idea. I might have done it for overnight, but haven't looked back at any service records I might have recorded. I would do the same thing in the future if I needed to do it again.

I recommend getting two cans of the stuff- I would apply copious amounts -- follow the instructions. It's not cheap, but neither is your time to re-do the job. I hope this helps.

Edit: I also used fender washers on each of the retaining screws, to help distribute the weight of the insulation sheet. I believe that the fender washers are stainless steel- they were significantly thinner and lighter weight than any galvanized steel washers I had access to at the time. Either would probably work, though.

Edit2: Regarding the 3M Super Trim Adhesive- the can I still have says: "Net wt 19 oz (539g)".

JHZR2 · #29 10-14-2024, 08:50 AM

Quote:

Originally Posted by Marshall Welch

"3M Super Trim Adhesive", "#08090". The can is probably 10 years or more older. I also fabricated about 6-8 retaining screws using nylon screws and nylon capped nuts; speed nuts, and 4-6 inch long strips of galvanized steel (sheet metal), which were slid into the holes in the steel reinforcements running along the inside of the hood. I punched corresponding holes in the sound deadener material.

The adhesive is starting to come apart along the outer edges, and in the center, but not yet to a degree to warrant removal of the material and re-applying adhesive. If I recall correctly, I used about 1-1/2 or more spray cans of the adhesive. After I installed the insulation, I compressed it by first laying a sheet of corrugated cardboard over the engine, then putting lots of wads of crumpled paper all over on top of that, and then closing the hood for several hours or longer; overnight probably wouldn't be a bad idea. I might have done it for overnight, but haven't looked back at any service records I might have recorded. I would do the same thing in the future if I needed to do it again.

I recommend getting two cans of the stuff- I would apply copious amounts -- follow the instructions. It's not cheap, but neither is your time to re-do the job. I hope this helps.

Edit: I also used fender washers on each of the retaining screws, to help distribute the weight of the insulation sheet. I believe that the fender washers are stainless steel- they were significantly thinner and lighter weight than any galvanized steel washers I had access to at the time. Either would probably work, though.

Edit2: Regarding the 3M Super Trim Adhesive- the can I still have says: "Net wt 19 oz (539g)".

That many cans seems excessive. Ive always used about half to 3/4 can and it has stuck for years. Eventually the foam covers start to decompose.

On occasion I’ve had a small area come loose, but an injection there has fixed it. Again, never needing multiple cans. I have to wonder if you actually use too much???

Marshall Welch · #30 11-07-2024, 10:02 PM

Quote:

Originally Posted by JHZR2

That many cans seems excessive. Ive always used about half to 3/4 can and it has stuck for years. Eventually the foam covers start to decompose.

On occasion I’ve had a small area come loose, but an injection there has fixed it. Again, never needing multiple cans. I have to wonder if you actually use too much???

Thanks for sharing your experience; maybe “less is more.” I’ll consider this in the future. The price of this product has certainly increased since my last purchase, so there’s some incentive.

Edit to add: The nylon nuts I referred to as “capped nuts” in my previous post are acorn nuts. I had forgotten the correct name.