3M Perfect-It Gelcoat Heavy Cutting Compound, 1 Quart – Fast Cutting Marine Oxidation Remover for Boat & RV Gelcoat Surfaces

Should you use this 3M Heavy? Here's some parameters for fiberglass gel coat: This is the stuff for boats/RVs that are a few years old but don't leave a white dust on your shirt or hand if you brush it (after a good pressure wash, of course). If you're getting significant dust, you should probably dry-sand first, use this second, use a lighter compound third, then rinse or vacuum or blow off fourth and then wax. Compounding leaves significant abrasive dust behind on the boat that needs removed before waxing. The whole process takes several days to over a week for a 25-ft boat.. Sorry, but it does. I use this if wet-sanding is not quite necessary but somewhat close. It's a little more aggressive than Presta Gel Coat Compound, but not by much, making the Presto a very good second-rounder or for lighter work. (Presta also provides more shine at that stage but not as much efficiency at oxy-cutting.) 3M Heavy shines somewhat when done on glitter gel coat, but mostly provides a flat, polished consistency to the finished product when viewing askance to the light. It's unlike some with polish in them, which create a false impression that early in the process. 3M Heavy is indeed for cutting old oxy and must be used with a good rotary, not a DA. If you want oscillation, set your rotary's velcro pad off-center one or two millimeters. But muscle is required and consistent RPM rotary polishers provide this, along with the 3M Heavy. In hot weather, dot the surface being polished rather than applying it all to the rotary pad. Do a picking-up action as you rotate and as you keep moving. This keeps the compound from drying too fast upon use, because it's in a droplet and already placed, rather than smeared on thinly, as we're taught. This stuff is expensive, but when you're into working on something with a lot of value, it's best to spend the money and be sure you're making good progress safely. Never linger in one spot too long, as it can burn, but this is not likely if you keep moving and feel the surface frequently against your cheek.

This compound cuts very well, it did a great job removing the oxidation from my fiberglass boat. I buffed with a wool pad and had no complaints. This is not meant to be a final product though, you'll notice swirl marks etc after use. Recommend going from the 3M Heavy to 3M Medium and/or 3M light depending on how the finish is looking in between and finishing up with a wax. I buffed the rubbing compounds in with a wool pad but the wax I moved to a foam pad to finish. I really like the 3M products and with time and quite a bit of work it made my 20 year old boat look like new when I was questioning if I was going to be able to revive the gel coat.

Great product that's well worth the price. It removed years of chalking on my boats gel coat with ease. I'm going to do a second pass on the scratches

I restored a couple of jetskis over the winter and when it came time to clean up the fiberglass I thought I had a good recipe. The bottoms of these skis are black and were heavily oxidized. I spent hours and hours and blasted through a lot of heavy cutting pads using Mequiars 49 heavy oxidation remover. I struggled through one ski and then decided to try this stuff for the second ski. WHAT A DIFFERENCE!! This stuff was a 1 and done for oxidation! Unbelievable!! I used a heavy cutting foam pad on a DA polisher and followed the basic instructions and it was a night and day change from the Meguiars.

Does a great job of removing oxidation and surface imperfections on my old boat.

I own a marine services company and the product does a great job and happy customers

Best product i have ever used to remove heavy oxidation from my boat. Restored my 25 year old boat gel coat to like new.

This product did wonders on my 2004 Cobalt boat. I used a Rupes polisher with wool pad along with this polishing compound and was able to very effectively and efficiently cut through the oxidation o. The gel coat, revealing a high polish surface. When done correctly, this product can produce mirror finish results. Highly recommend.

Great product Highly recommend it if you have heavy oxidation issues

Work as advertised

Es un excelente producto muy bueno

Nutze nun schon die 2. Buddel von dieser Politur. Hiermit 3 Boote aufbereitet und zu neuem Glanz verholfen. Bietet sich an bei stark verwittertem GFK, hat sehr gute Schleif- und Poliereigenschaften.

Delivered as promised. Using it on a 15+ yr Larson bow rider (white) and it’s restoring the original glossy finish very well… using a 7" power buffer w/ wool pads