Structural Polyester Bonding Putty - Marine Grade, Fiber Reinforced Filler, Smooth Spreading & Sag Resistant - Ideal for Boat & Automotive Repair on Fiberglass, Wood - Gallon Kit

Used it to bond in stringers and knees and make the nice fillet before laminating in a mini speed boat. Worked perfectly.

I found this a little difficult to use because the MEKP is clear and the putty doesn't change color when catalyzed. Because the putty is not a liquid, it is difficult to tell what volume of putty you are mixing up. I had no problem measuring the MEKP, but was guessing on the quantity I needed. Old fashioned Bondo for cars comes with a paste hardener that is colored. That lets you achieve a uniform color to know when it is mixed well enough. This putty is white and the MEKP is clear and runny, so it was a blind guess to know if it was properly mixed and if the ratio of 1% MEKP was achieved. It seemed to work well.

I used this for fixing some structural cracks and dings in a fiberglass canoe. Works very well. Dries crazy hard. Don't overfill because it is quite hard to sand. Not a fairing compound.

I had some structural repairs to do on a boat hull project that needed to be done before laying glass.It's thick & can be cut with polyester resin,to flo out smoother if need be. The longer it cures,the harder it is to sand. Overall, the gallon came with a lid retainer & nicely wrapped in bubble wrap. Product works great & I'm definitely happy with this purchase & would recommend

This is what it says it is, good for structural repairs, not for fine or finishing work but strong if you need to repair a Crack or hole, have used it on fiberglass fertilizer tanks and semi hoods with success