I'd like to fill the stock mounts on my 91 crx hf. All of the threads I've found that have identified good materials to use end up referencing stuff that's not manufactured anymore. Window weld is way too much for what it is. Is anyone familiar with something coming out of a caulk gun that is 50a durometer? I could probably go as high as 60a, but this is a daily driver and noise and comfort are a priority.

right now I have a traction bar which eliminates the front mount, and a poly insert for the rear. Nvh is pretty gnarly right now and I've been getting headaches recently from the noise because of all this sinus pressure from a cold I have right now. With this insert, it seems noise is not RPM dependent, only throttle dependent. The more power I give it at lower RPMs, the more the whole car shakes like an industrial shaker. Any power application under 2K is absolutely insane

 

Any deviation from the stock durometer is going to introduce NVH.

You cant have it both ways. It either comfort or engine stiffness.


***I used Window weld on my old H22 CB7. It doesn't hold up well to heat(underhood temperatures) and eventually breaks down.

 

I've used the "POWR BOND" from CRL. they don't list a durometer spec but 60a is my best guess. it's holding up well. I filled my mounts 5 or 6 years ago I think.

it's about half the price of 3M window-weld. I recall buying on amazon at the time. interestingly they show other similar products on their website i linked above. there may be one better suited than what i used.

 

I used 3m window adhesive and it was great for the rear mount but I don't have any long term experience. I would use it again as soon as I can find some locally.

 

It looks like a silicone based caulk or a flexible epoxy will get you the results you need. I think the flexible epoxy might have the longevity required.

 

Woah, 35 shore D is insanely stiff. I'll see if i can find a super stiff silicon or check out that power bond.

Window weld seemed like a petrolium based product so i'm not surprised it broke down under heat.

 

Goes to show how much I understand about the harness scale, I didn't know the difference between Shore A and Shore D.

Good to know, thanks.

 

If you search Google Images for "shore hardness scale", there's some good visual comparisons showing the overlap of the A and D scales.

I used Window Weld in the past, and have a tube of it to use again on my current build in the two torque mounts.

 

 

 

Thanks for sharing. Sounds like a good option for someone who doesn't mind the stiffness. Ended up purchasing the power bond stuff mentioned above. I'll post back results. The good news is that if it is too stiff, i can always drill a couple holes to smooth it out. But as i understand that has limited effectiveness.

 

Though I haven’t tried it for this purpose, based on working with it in industrial/commercial construction settings, I’d recommend NP1 sealant. NP1 is a caulk/sealant that firms up very nicely, but doesn’t get ‘hard’; it also has a 50yr warranty. Be warned, NP1 isn’t some run of the mill off the shelf at Home Depot product and is extremely “sticky” (if it gets on your clothes it’s never coming off again) and can be tricky to work with, but it stays put forever and is very durable while remaining moderately flexible. Pecora industrial window sealants are another option and somewhat similar to NP1 but more silicone like in nature; they come with at least a 20 year or better warranty. They would probably be a little easier to work with, but may be harder to find, making NP1 a more viable option. If anyone decides to go this route, PM me and let me know how it worked out, as I have no doubt some degree of success will be realized.

 

NP1 is a high-performance, one-part polyurethane like 3M "WindowWeld" or the CRL "Powr Bond." it would probably work just as well and the warranty is always nice.

 

I ended up using the PL construction adhesive as well, I ended up getting the pro strength 3x thinking it was the 7x. I am glad I ended up getting the less stiff urethane, the 3x is plenty stiff for street use. I filled a brand new cheap rear mount and the lower trans torque mount. I'm hesitant to fill the a/c bracket mount when I replace it. It ended up being a tan color but the package said it's easily painted.

 

3M Window Weld is what I always use. I've tried many other things, and nothing has ever worked as well as the window weld. And yes, it does hold up just fine to heat. the only trick is you need to make sure you clean the mount VERY throroughly before filling it to ensure a good bond. If you don't clean it well enough, it will eventually separate.