Comparing 3M and Permatex Windshield Repair Kits

I uploaded this video awhile ago but never got to writing the post about it. I had so much going on with the holidays and family that it got postponed. 

I had two of our cars have windshield cracks. Oddly enough, both cars came from other family members with exactly the same crack in the center of the windshield in almost the same spot. One from my dad, click here for that post.

The first one, I had a chance to get fixed at our local oil lube place but figured I was in a hurry and it was cold out and I had heard it was better to do it when it was warm so I didn't do it and the little crack with several off-shoots spread out in both directions one night and when I came out in the morning, it was beyond hope. 


Because of that, I figured it couldn't hurt to try and see if one of these kits would work on it. 

With the other car, we got it a few months ago and I wanted to fix the crack BEFORE it cracked into something that wouldn't be fixable. I had watched a youtube video on buying a kit and using a syringe to fix the small crack.


I stopped at a store and the people at the store raved about the 3M kit saying a customer came in saying it worked great. I purchased that kit on the comments of the workers. It was also a few dollars cheaper than the other kit. The only other kit they sell is a Permatex kit which is more like the one I saw on the youtube video. 


I opened the kit and was frustrated to find that I needed a screwdriver to "assemble" the kit. I was frustrated that it also really doesn't have anyway to evacuate the air from the crack, it uses force to push the liquid into the glass. It also has a "screw" in center to force the fluid in and after the first try, the washers in the kit got stuck inside and made it quite useless in getting any fluid into the crack. The screw in center also got "stuck" due to the liquid and I needed pliers to be able to unscrew it but like I said, the washer got stuck inside it. 


The BIGGEST frustration that I had with the 3M kit was that you had to screw it down against the windshield right at the crack and it warns you that if you screw it to much, you can crack your windshield more. Well, since I had to do it several times, it actually did crack my windshield more. You have to have someone on the inside of the car basically to tell you if you are placing it in the right spot and you have to look at it with your face laying on the windshield as you screw the little pressure things down to make sure they are touching the window but not over-touching the window to cause too much pressure. 

I did like that the 3M kit gives you a big bottle of the repair fluid with a lid and a squeeze dropper so you can move the suction cup plastic thing and then screw down the center screw applicator and put more fluid in but it is such a crappy design getting stuck and putting so much pressure that I think they could use something similar to the other kit but just give you more sticky round things. 

You can see in the picture there is a black bottle with lid that has plenty of the repair fluid in it. The other kit, Permatex only has the little white squeeze thing filled and mine didn't have enough fluid so I actually was glad I had the 3M extra resin so I could use it with the other kit.

You can see in the outside picture and one from the inside of the car that the kit did "repair" the center of the crack but you can also see little veins where it caused the crack to split more due to the pressure of the repair plastic kit. 
 
The last thing the both kits have you do, is to put a few drops of the repair fluid on the outside of the windshield and put a small square of plastic over it and put it in the sun. It is supposed to fill in any chip or hole left on the outside of the car. Then, you peel off the plastic and use a razor (which both kits provide) to scrape any residue off the window and and then clean it. 
 
The Permatex kit comes with ONE round double sided sticky guide and a plastic molded thing which allows you to put the plunger into it and make suction on the crack and then put pressure into it to allow the repair resin into the glass. 
 
In my opinion, this one was better all around to use as you can see the crack clearly with the round sticky guide and you don't have to put pressure on the window to fix the windshield. The issue I have with this one is that if your crack extends beyond the small hole it allows, you can't move it or reuse it so if you put it on and then realize you needed it over a bit, tough, you need to purchase another kit. 
 
They also only give you that little bottle of resin and it wasn't enough as mine was mostly air. Once you put the sticky round guide over the hole, you then put on the plastic mold which allows you to put the plunger in. The first step is to suck the air out with the plunger for a few minutes. 
 
The next step is to insert the resin and use the plunger to force air into the cracks that you just pulled air out of. It seems like as soon as you take the plunger off, the air would go right back into the glass but what do I know.   

I did this on the cracked windshield I was going to replace just to see if it would work and would fix a crack. At this point, I was so disgusted with the 3M one that I bought the other to see if it would work in the future. You will see that the entire windshield has cracks but I wanted to know if this kit would work better than the other and I really think it did perform better even though it didn't give as much fluid but I was frustrated you couldn't reuse it and move it if the crack extended longer than the small round dot the sticky thing covers. 

You can see the air bubble from the inside of the car when you are pulling the air out and you can see the bubbling fluid when you are pushing the fluid into the crack. If I didn't have the extra fluid from the other kit, I may have been more upset as the tube I had didn't have enough to even fill up the little cup thing and perhaps, it didn't need more but I couldn't tell that any actually came out so I think that is a flaw in the Permatex system. Maybe if the squeeze container was clear, it would be better. 

I was impressed as you can see, there is a small area around the center that actually looks repaired but I think more was repaired due to the extra fluid I had to insert and push in with the plunger. 

After all this, when I had the glass guy come to the house to replace the windshield anyway, (check out my post on how I got a huge discount on the new window) he told me they fix cracks for $25 and use the electric machine that evacuates the air and keeps it out as the repair resin is inserted! After spending about $14 each on the kits and having the frustration of having to figure the kits out and causing more damage etc. if it is more than a ding in the future, I will for sure be calling the repair guy! I think they actually will guarantee their work as well as I know the quick lube place will give you a year guarantee on their repairs as well. 


My advice, get someone else to fix it. If not, use the Permatex kit but buy two in case one doesn't have enough fluid.  Or, buy one of each kit so you have extra fluid and can use the 3M kit if there are spots where the Permatex kit doesn't fix, you can move the 3M kit around and reuse it so both are the best option. 

I hope this helps you in the process of fixing your car and windshild!