3M Scotch-Weld Instant Adhesive Primer AC79, Clear, 2 fl oz Bottle

I repair things as a career. Like huge industrial stuff,1000ft long lake freighters, steel mills etc. I have access to so many expensive industrial chemicals and adhesives. None I had found were up to the task on a home project I was doing in my shop. I needed to bond a rubber boot to a part made from POM (Acetal)Both are difficult to adhere to. Nothing sticks to POM and anything strong does not flex with the rubber.LOTS of inter-web research and LOTS of claims and hype.I found that both materials were on an extensive list 3M had of materials P40 is comparable with.They were NOT kidding!It worked even without the primer!Like my first try I mis-located the boot a bit..... Too late! It is still stuck right where I put it.This stuff is ultra thin! Some part in the description says gel. NO!BUT! the way this stuff wicks into the gaps and stuff makes this all the better for me.I assemble the parts exactly where I want, a single drop at the joint......and it's capillary action pulls this stuff right where it needs to be!I've used it on a few more things playing around.THIS STUFF WORKS!HIGHLY RECOMMEND!The primer is a must have IMO.It gives the best chance at a successful bond, especially for difficult plastics.YOU PRETTY MUCH GET 1 SHOT AT IT!Ray the Maker

If you work with 3M tape you will love this primer. The tape has a much stronger adhesion..

This a scam just use acetone, I believed some of the other reviews that said it was improperly used or something along those lines but this stuff is literally overpriced acetone ain’t really did anything

I am gluing silicon rubber to a stainless steel washer; a very difficult task. I first used just Scotch Weld PR40, plastic and rubber adhesive. I abraded the washer and rubber with 150 grit sandpaper. After 24 hours the rubber peeled off fairly easily. I repeated the experiment but used the Scotch Weld AC70 brushed on the abraded rubber. After 24 hours the rubber stuck very well even while pulling with considerable force! The primer and abrading are essential!

I used it on some silicone sleeve tubing, it’s rolls off very quickly, it needs to be applied to the other surface like 3m tape or what ever you are trying to stick

This made it possible to bond something I was told couldn’t be done: silicone. The problem is, it accelerates the bonding process. It makes it almost impossible to get things lined up when you’re dealing with floppy silicone. I suggest using it with a formula that allows longer working times.

This is *not* just acetone like you can buy in a can or nail polish remover. Acetone is simply what is used to dissolve the ingredients that are actually important. These compounds aren't hazardous so they don't need to appear on the SDS.This stuff works. If you try using just acetone you'll find that it doesn't. 3M makes great stuff. Use this primer with their instant adhesive for plastic and rubber.

Purchased this to go alongside my Scotch-Weld. It does a good job of priming surfaces like plastic and glass and makes it set quicker so I don't have to carefully hold it in place while it dries.