3M Bondo Short Strand Fiberglass Reinforced Filler 21 oz (595.34 g) with Bondo Cream Hardener 0.5 oz (14g), Repair Holes Up To 0.5 IN, Waterproof (SS-PT-ES)

The media could not be loaded. EXTREMELY IMPORTANT DISCLAIMER AT THE BOTTOM‼️‼️Here's review though, specifically for auto repairs, but also some general bondo advice.I used 3M Bondo Short Strand Fiberglass Reinforced Filler to fix a large rust spot on my car, and let me tell you, if you do it right, this stuff is ridiculously strong. Once it’s cured, it’s as solid as, if not stronger than, the original sheet metal. My goal was to create a structurally sound, paintable surface after getting rid of the rust, and this filler absolutely delivered.But here’s the deal: if you don’t mix it right, you’re in for a frustrating time. Let me save you some trouble.Step 1: The Strength is No JokeOnce this sets, it’s like welding new metal onto your car. It doesn’t crack, doesn’t shrink, and it bonds extremely well. I was working in cold weather, and it still dried in 15-30 minutes, ready to sand. That’s impressive, considering most fillers struggle in lower temps.If you’re patching a rust hole like I was, get rid of ALL the weak metal (smack with hammer, sand, and again, sand some more). This filler is strong, but it’s not magic, if you slap it on top of rust, the problem will come back. Prep and treat the rust surface properly, and this stuff will hold like a champ. (I used POR-15 and a rubberized undercoating, which I also have under reviewed under my profile if you want the best of the best like I did lol. Cheaper spray rust neutralizers and preventers are available though, you don't need this necessarily.)Step 2: The Hardener Ratio is Where Most People Mess UpThis is the part you NEED to get right. The included cream hardener is a little stingy for the amount of filler in the can, and if you don’t use the right amount, things get annoying fast:• Too little? It takes forever to cure, and you’ll be stuck waiting hours instead of minutes.• Too much? It’ll set before you can spread it properly, and you’ll be fighting against a rock-hard mess. This is really bad if you put it on whatever you're working on but can't work with it and it's stuck on your surface.Here’s What Actually Works:• Use slightly more hardener than the directions say. Not a crazy amount, just a small increase.• Mix FAST until the color is completely uniform. No streaks, no swirls, just one consistent shade.• Once mixed, IMMEDIATELY spread it out into a thin layer on your mixing surface (I used cardboard).Why? It cures through an exothermic reaction, basically, heat makes it set. If you leave it in a thick pile, it heats up too quickly and hardens before you can work with it. By spreading it thin, it cures more evenly and gives you time to apply it. (Even if you're not using this for cars, this is still a good practice with any fillers).Step 3: Sanding & Making It Paint-ReadyAfter curing, this filler sands beautifully, assuming you applied it evenly. If you messed up the mix, you’ll either have rock-hard clumps or a weird gummy texture that won’t sand properly. Get the ratio right, and it smooths out great.That said, this is a structural filler, so don’t expect a perfectly smooth surface right away. To get it paint-ready, you’ll need:✅ A lightweight filler – This smooths out any imperfections and evens out the surface.✅ Spot putty – This is the finishing touch for getting it perfectly smooth and one last high grit sand paper sand, before priming and painting.I actually reviewed the lightweight filler and spot putty I used, and they worked perfectly as the top layer on top of the strong foundation this fiberglass filler provided. (again under my profile if you want liked my result and want what I used) If you’re doing bodywork, this combo is the way to go, fiberglass for strength, lightweight filler for smoothness, and spot putty for perfection.What I’d Change? Just Give Us More Hardener.Seriously, for the amount of filler in the can, they should include more cream hardener. If you don’t ration it right, you’ll run out before using all the filler, which is annoying. Just something to be aware of. Honestly just buy yourself a tube of cream hardener, unless you think you're only going to use a little bit of bondo.Final Verdict: Absolutely Worth It- If You Follow These Steps! You be the judge though, I've never done anything like this project, just have some good knowledge and have used bondo before. I think it turned out okay!• Strength: 10/10 – Feels like actual metal when cured.• Drying Time: 9/10 – Fast, even in cold weather.• Ease of Use: 7/10 – There’s a learning curve with the hardener ratio.• Paint Prep: 8/10 – Needs lightweight filler and spot putty for a flawless finish.• Value: 8/10 – Great, but they should include more hardener.If you’re fixing rust, follow these steps, and this filler will hold up like a champ. If you wing it, you’re gonna have a bad time. Save yourself the hassle and get the mix right from the start, as well as everything else you'll need for a repair like this! I reviewed everything else I used because I spent way too long researching everything I would need, and didn't find many reviews that gave me assurance or helpful info about each, I was kind of on my own. I'm still working on the reviews, but pretty soon they'll all be there if you click on my account.‼️DISCLAIMER: This stuff releases an ungodly amount of fumes for a LONG time. If you are working in an indoor area, even with decent ventilation, you absolutely NEED to wear a respirator. I know I hyped this stuff up, but you can seriously damage your body messing around with this stuff without the proper gear. Even if you are outside, it's still best practice to wear one. Since Bondo is applied in thicker coats, it can release 3-5x more VOC content (deadly fumes) than spray paint does, this is like serious stuff. Not only that it releases fumes for a LOT longer. Wear a respirator, no joke.‼️

Worked great

Used this product to repair some damaged plastic car body panels. Used it with cloth to form the rocker panel where a 6” piece was missing. The other side was crushed and used it to rebuild it. Easy to work with. Drys quickly so you have to work fast!! I’d 100% recommend this product!

Cool product. Works as described and easy to use.

As a last resort, I needed to repair a large metal turning composter, which was rusting after many years of use. (Alternative was an expensive purchase to replace. Bondo 764 was the proper choice for me.To use, you must measure out an approximate amount of hardener from a "toothpaste" tube, and thoroughly mix the hardener into the resin. This is not completely trivial, since the resin is highly viscous because of the fiberglass filler. By the time the hardener and resin are properly mixed, you have, at summer temperatures, only 2-3 minutes to apply the resin to your project. Thus, you mix only a little at a time.The fiberglass filler makes the resin quite strong. I had pressure-washed my composter before applying the resin to the outside. The pressure washing (from the inside) removed the thinnest of the rusted metal, showing where the weakest areas were. I applied the resin to these areas (about 5 square feet, keeping it about 1/4" thick, spreading with a small spatula-like board (about 1" wide). The metal door to the composter had a serious crack, so I used some fiberglass cloth under the resin. I was concerned that the door, which must flex slightly, would be too stiff, but it flexes sufficiently and works perfectly.There were a few places where I might have had slightly less hardener than preferred. These were slightly sticky for a day -- not enough to coat your hand or glove, but enough to notice that it wasn't perfectly hard. After a day, it hardened perfectly. This is a symptom, I believe, of insufficient hardener. (I didn't measure -- just estimated.)I have since filled the composter with considerable heavy bulk, and the resin is holding perfectly (about 2 months). It bonded primarily to oxidized paint, and is a firm bond. It's a composter, so I didn't sand and finish the resin. Maybe someday if I'm ever bored...Bottom line, the resin is strong, and hardens well. The color is ugly, but it's meant to be painted. I will use this again if I have repairs to make to sheet metal.

The product works great just wish it came with more hardener , good price for the product size , smoothness came out pretty even , dries quickly , no leakage so far , fast cleaning

I had a problem with my bathtub and shower, I had a crack, the cost to replace the whole bathtub and shower unit was close to 1800 period.I bought Bondo glass short Strand,Bondo Fiberglass ResinBondo All-Purpose Putty, andBondo Fiberglass ClothBondo Glass, Short Strand Reinforced Fiberglass Filler.I followed the instructions that’s available on YouTube and I applied to each one of them in the proper sequence Then I applied the primer paint and final paint.I was able to fix the defect.The total cost is $126 for everything.They saved me more than $1400.The only small problem that I had at the final coat of paint does not match the rest of the bathtub color.I highly recommend these products.If you use them try to follow the instructions that’s written on the item from outside exactly.Try to be patient with sanding. Make sure that each layer is sanded properly before you move to the next coat.I also had a ceramic tile that was broke.Instead of replacing it, I applied the same materials and got good resultPlease see the attached pictures.Thank you.