Warning on hood pad job
 

I do not recomend using 3m Super Weatherstrip Advisive tube glue (yellow death), part number 051135-08001. I spent six hours prepping my hood; spraying, chiseling, spraying, chiseling, spraying, chiseling and finally cleaning. That was the worst job I've done yet on my 300sd. Worse than the expansion valve change that I did. After all that work it turns out that I made a very bad choice for adhesive. I emptied the tube evenly over the hood pad and then tried to spread it into a light layer as per the directions. The glue began to get firm and I was not able to spread it only several minutes after it was first applied. I worked as fast as I could to get full coverage around the edge. I then applied the pad with the help of another person. It did not stick worth a damn. I worked for 20 minutes trying to hold the pad to the hood. There just wasn't any holding power in the glue. I'd guess that about 30% of the pad is loose.

It seems to me the glue just dries too fast for this job. If you can get the glue on the surface and the hood pad up within a couple of minutes you might be ok. Also the foam is too porous for this type of glue. I don't think it's designed for use on foam. Please save yourself this frustration and use the proper part for this job, 3m Super Weather Advisive Spray. You can get it at Napa for around 14 or 15 dollars. Don't be a cheap ass like me and try to save 10 dollars. Spend the money and do the job right the first time. Wish me luck with my floppy hood pad.

One of the 3M products with a name like you mention looks and smells like contact adhesive. I don't know if contact adhesive is well suited for underhood application. If it is then I would take the pad to someone who installs headliners, they spray contact adhesive from a sprayer like a paint sprayer and could make quick work of the hood insulation.

First, on Contact Cements.... they are supposed to dry before putting the parts together...and you must coat each part which is to be put together...
I guess you did not have the benifit of the seach before you started this job...
This has been discussed..... even to the extent of me posting the picture of the PROPER 3M Contact SPRAY to use.... as a lightweight is also available which looks almost identical... BUT which is not made for the higher heat and weight of a hood pad...

I've had luck at times and no luck at times. All of this is with the same spray.

I don't know if its a combo of humidity, surface prep, etc, but every now and then I get one to work. I've probably done this job 6 times with about 50% success. The truth comes out about six months down the road. I have 2 of them falling off again, while several others are there for life....

Don

Check out this...

http://www.peachparts.com/shopforum/diesel-discussion/69400-hood-pad-wont-stick.html?highlight=hood+pad

I used 3M High Strength 90 (the spray in a green accented can) for both of my hood pads and had no problems what so ever. Used blue painters tape for a clean edge and probably could not do it alone- and I didn't; so it came out great, and no sagging at all. Two years on one, one year on the other.
:) :) :)

Several years ago, on my 190E, I replaced the hood pad. My Indy advised me to use some sort of 3M black weatherstrip adhesive, in a tube. I do not remember the exact numbers at this time.

I decided not to take his advice, and used a spray adhesive instead. Wrong!

I did very good prep work, but the spray adhesive just did not hold. It was sort of like a "post it" note. You could stick it up, but it would fall back down. Finally, I gingerly pulled the hood pad back, and liberally applied the black weatherstrip adhesive, behind the hood pad, and it sticks like a champ to this day, (Except one little spot, where I did not get the weatherstrip adhesive. It's a small spot, about the size of a pie pan, and til this day, I can press it up, and it will stick, for a day or two.)

Just another experience.


george d

BTW- 3M spray adhesive comes in more than a few strengths- 90 is the highest and you would be unwise to use any weaker version.

Wow, cool use of the search function there to find exactly what you needed to find...

by the way, you and Randy sound like an old married couple....especially after one of the couple tooted in bed! ! ! :D

After replacing hundreds of sound pads on Porsches and Mercedes, this is what works best for me... every time.

Spread a cheapo plastic drop cloth across the engine bay to collect the old crap you must scrape off. Cleaning is the key to a long lasting job. Then I spread a layer of high quality contact cement, the flamable kind, on the hood and over most of the sound pad, especially all of the perimeter. Now toss the drop cloth. Use a cheapo paint brush and toss it when finished.

Get someone to help you and start at the edge nearest the windshield. Smooth it out from the center to the edges working your way toward the front bumper. Go slow, be accurate. It's hard to remove even at this stage and nearly impossible once it's set for thirty minutes. The new composition sound pads last a long time :D

Where do you get a hood pad? I need to replace the one on my 84 300td wagon. Thanks.

Just what exactly are you getting at?

"I CALL THAT BOLD TALK FOR A ONE-EYED FAT MAN!"---John Wayne in True Grit-- 1969

Fuzzball, We know where you live... and it is VERY close to both of us....

My friend Hans has the following suggestions for replacing a hood pad (since I just bought one for the 300d -- big hunks falling out, crappy replacment job).

Get the new pad and lay it out flat for a day or so. This will let it "uncurl" and fit properly.

Scrape all the old hood pad off with a fairly sharp scraper (don't scratch the paint). Remove all the loose crap for sure, else it will just separate some more under the new cement.

Clean the entire area with carb cleaner and rags. You can leave some cement, but anything that softens must come of. Plan on an hour or more.

Install the pad minus adhesive, using a broom between the radiator support and the hood to hold it up in the center. This allows you to get it properly centered and so forth. The factory pad tucks behind things all the way round, so it will stay up with the broom in place (I suspect this is a floor broom, not a straw one).

Fold the top half down, spray hood and pad with cement (3M Super high temp, anything else will fall down when it gets hot). Wait until it is just tacky and re-install the top half. Will stick permanently at once, so be carefull!

Once the top is set (30 min or so), fold the bottom half up and cement it in the same way.

Allow to stand 30 min or so before closing the hood, should stay up until the foam crumbles.

The job on my current pad (what's left of it) is pretty spotty, wasn't glued in all that well and has failed over the rear of the engine. I feel bad pulling off almost good foam, but I can't see trying to glue the bad part back up, either.

Oh well, I love to spend money!!!

Peter

Call Phil here at fastlane (http://catalog.peachparts.com/) and he should be able to get you one: 1-888-333-4642