It's been a dozen or so years since new, but whatever glue I used on the rear hatch weatherstrip of my 240 is failing. Looks like I didn't miss any areas, but the rubber is just coming a adrift. The original stuff on my '78 Mercedes and day-to-day 2006 GMC are still looking good. Any recommendations as to which adhesives to use, and which to avoid?

Thanks, as always

3M has always worked well for me.

Thanks for the tip.

That's the one I'll go with.

Richard McDonel

On 8/22/2025 at 1:59 PM, mayolives said:

3M has always worked well for me.

Does it last for 20 years?

Good question. I 've used it several times over the past decades and used it again on my 79 last year but I doubt that I'll be around in 20 years to confirm.

Pretty sure I know the answer, but for confirmation's sake, I'll ask. First, the set-up.

Just got a new Precision complete weatherstrip kit for my 1972 240Z. The door strips in the kit are quite a bit different from the OEM ones in that they have a "gripper" channel (see Photo 1) whereas the OEM strips have but a thin U-channel (see Photo 2). I believe this was a design change made for the 280Z.

Both of these are meant to attach to the metal weld and quarter window flanges around the door openings. The OEM strip's grip on the flanges is then reinforced with a stiff U-channel (Photo 3) that covers all but a small section of flange along the bottom of the door opening where the inner scuff plate does the job

In his book "How to Restore Your Datsun Z-car", author Wick Humble said (page 135) that the factory's 280Z-style weatherstrip comes preloaded with a "non-hardening adhesive/sealant in the "U" of the weld flange trim that was not previously specified." Clearly, the strips I got from Precision do not have such a preloaded material

So, my question to you fine folks is this:

• Should I apply some kind of adhesive/sealant in the U-channel and, if so, what would you recommend?

I'm already using 3M Yellow Super Weatherstrip and Gasket Adhesive on the rest of the car that needs such a material.

I think that adhesive is the only way forward. However, you could always try it first without glue and see whether it can adopt to all of the door contours and then stay in position... especially in the areas of tightest bends. I'm pretty sure that it won't.

So, I bought a cartridge of 3M Windo-Weld Super Fast Urethane adhesive to use when I set my windshield. It's $44 at my local NAPA store but I see it for $32 on Amazon.

Do you who have done weatherstrip replacements think this will be good for the door weatherstrip as well? It sure seemed as though the OEM weatherstrip had a "permanent" adhesive used on it.

I’m not sure about the “super fast” part of it. You should only need sealant on the corners of the wind shield IMO.

That's 3M's marketing terminology and being a chemist who has worked with one-component urethanes, I know the many variables involved.

BTW, I spoke today with a local auto service shop owner who has many collectible cars and has installed several windshields over the years. He advised that the 3M product is what should be used but not to bother with using it in the channel where the glass goes unless the car will be parked outside or driven in the rain regularly. Wick Humble's restoration book also does not advise using any adhesive in this channel during glass insertion.

He also advised to place the windshield on the car without first applying the urethane to the weld flange and then to "backfill" the inner part of the weld flange channel with urethane. Humble advises putting adhesive into the weatherstrip's channel before installation and then backfill both the exterior of the weld flange AND glass channels with adhesive once you're satisfied with the placement. Makes sense to do that on the exterior portions so I'll see what things are like when I get to that point.

Finally,as for the door weatherstrip, my local guy says to put it in "dry" and only use some 3M Yellow Super Weatherstrip and Gasket Adhesive at the point where the two ends meet up on the door sill.

3 hours ago, Seppi72 said:

good for the door weatherstrip

I think it depends on the weatherstrip. I have a vague memory of metal clips in the Kia Sportage weatherstrip. No adhesive was needed.

Really though, just put it on and if it's loose put some glue on it.

Handling time 10 - 20 minutes, full cure 24 hours for the Windo-Weld (Amazon can't spell). Sometimes marketing converts a problem in to a supposed benefit. They don't actually say that "super fast" is a good thing. Work super fast and you shouldn't have any problems.

Forgot to say, cure time probably depends on relative humidity. It's a moisture cure. I remember using a moisture cure construction adhesive on a hot dry day in summer and it took forever to set up.

Full Cure Time 24 hr

Handling Time 10 min - 20 min

https://www.3m.com/3M/en_US/p/d/v000074326/

Edited 1 hour ago1 hr by Zed Head

Right you are, Zed Head, as temperature, humidity and the area actually exposed to atmosphere are the critical variables.

And, don't blame Amazon for that spelling. It's what is on the cartridge itself. Ah,marketers... Many's the time I've had fascinating discussions with the ones I worked with. Always looking for that "hook" to drive customer recognition and product uniqueness. Sometimes a few weren't securely tethered to reality. I remember one asking if I could replace air with something less expensive. 🙄