3M Bondo Fiberglass Resin Repair Kit, 00422, 0.9 Quart

This works awesome just what I need

It worked just like the instructions and the multiple online reviews said it would. It was actually fun to use. A few recommendations: (1) If this is a first time for using fiberglass, read others' reviews of this kit plus some online guides on the hazards of fiberglass lay-up and then watch at least several videos on fiberglassing techniques on YouTube. Be aware that some of the videos contain errors. (2) If used as directed, this kit is safe. However, there are multiple fire and health hazards involved in using this kit if you are careless. Wear a face mask filter designed for working with fiberglass and a pair of eye protectors. Exercise caution with what chemicals you are mixing, and prevent the spread of fibers from the cloth and/or dust from sanding dried fiberglass. Before laundering clothes that may have fiberglass in them read articles on laundering clothes after working with fiberglass insulation. (3) To make sure I had the right amount of resin in each batch for my small job I went to a Bed, Bath, and Beyond and bought a glass drink-mixing jigger glass and a small glass measuring cup. I never needed more than eight ounces of resin, and the cup was usually perfect. To measure the hardener for small jobs your only option is to patiently squeeze and count the drops one by one. It doesn't take that long. I mixed the two parts in old jelly jars I had cleaned and dried. Some plastic cups (including the red Solo cups I tried) will dissolve if you mix the fiberglass in them, but real glass won't. (4) Use very sharp scissors to cut the cloth; give yourself a large clear work surface; and ensure adequate ventilation. (5) If you want to buy more of the cloth in the kit, remember to order fiberglass cloth and not fiberglass mat, which is different and harder to work with. (6) Acetone is a superior clean-up material for this job, but it is very flammable, and it can react badly with some other chemicals. (7) Clean up very carefully, especially the fibers. I used a vacuum with a HEPA filtration system. It takes a little preparation to do it right, but it was fun, and the object I repaired is now stronger and much more rust resistant.

3M Bondo 422 Fiberglass Resin Repair Kit - 422C

I bought this to repair a fiberglass-composite garden planter that fell over and cracked. The cracks were getting larger every winter, so it was time to repair them. Overall, I think this will do the trick, but it was a messy job. The resin is like thick maple syrup, and when you paint it over the fiberglass it pulls it up in sticky threads. Since the repairs were on the inside, I didn't care what it looked like, but it would be hard to get a smooth finish on a large area unless you applied many coats. Also, the dinky little plastic dish they include is pretty lame, unless you only need to mix a tiny bit of resin. Better to use a plastic takeout soup or yogurt container: you can wipe the brush on it, and it's much less likely to spill. And they only give you one lone wooden stirrer. Plan to dig out plastic knives from your junk drawer if you need to do extra coats or use the product again in the future. Oh, did I mention the kit doesn't include a brush? You should get cheap ones, and several. Overall, you could order the resin and fiberglass material separately and end up with the same "kit." (I actually didn't need this much, but I didn't see that there was a smaller kit available. Now I have to store this really toxic material. Oh well.)

I am not an expert when it comes to rust repairs but I found working with this fiberglass kit pretty easy. Used to patch two nasty rust holes behind and underneath the battery tray, the fiberglass hardened beautifully and was easy to paint afterward. No more water leaking into the vehicle's cabin and I believe this fix will last for a long time, probably outliving the car.