West System 407-5 Low Density Filler 4 oz

West Systems make the best epoxy products for my outdoor wood projects. This filler makes it much easier to sand. I have used West Systems products for years.

This fairing compound mixes well with epoxy to thicken the epoxy to a orange-red colored goo, the viscosity of which depends on how much you mix in -- from a soup to a peanut butter type of consistency. It is easy to trowel on to shape whatever it is you are forming. Sands much easier than fiberglass, but still strong. The only improvement would be if they could make it into a lighter color, or better yet, white. The red-orange color is bold and takes several coats to completely cover over with white gelcoat.

I had to do some fairing and filling of a keel and rudder. It worked great for filling. Not great for fairing. Very good product, be sure to use whichever product (403, 405, 407, 410, etc) is recommended for your use, it makes a big difference in finishing! I definitely prefer West system products, too quality stuff for boat work!

This is more of an advisory than a review, for people who have not purchased one or the other of these fairing compounds. I mixed one pump of 105 WS resin with each product. They both filled a two ounce cup with peanut butter consistency epoxy putty. All though the Microlight container is about 4 times the size of the Low Density, it may come out to approximately the same number of 2 OZ batches per container, although I haven't counted. 1. The 407 is purple. This is basically microballoons that we've been using forever. They say it's wood toned, but unless you're using purpleheart, I don't think so. The 410 is light tan and much easier to hide, if you're painting. 2. The 407 applied easier than the 410 in the first 5 minutes, but as the epoxy started to go off, it became immediately unusable. Much shorter working time with the 407. The 410 doesn't go on as smoothly, but you can work with it right to the max set time of 20 minutes. Both leave a nice feathered filet with few if any air bubbles. 3. The 410 is much easier to sand. WS says the 407 has a higher structural strength, but it's still poor. I wouldn't use it for bonding. I think I'll use the 407 for repairing blown out corners on paint grade projects as it probably has a better impact resistance than the 410. If you're fairing something that isn't going to receive heavy impacts, I would recommend the 410. Side note: If I'm filling checks on varnished projects and I want a high structural bond, I use polyester milled fiber, or milled fiberglass powder. It hardens to a translucent finish, which I prefere, because let's face it, you're not hiding anything, it's a check, a natural occurrence with wood. You can also add colorants to it and get pretty damn close to the wood grain (remember, the wood changes color in time, epoxy doesn't).

Very high quality like any of the West System's products I've had the pleasure to use. You can mix it in any amount to get the consistency you need (from honey to peanut butter), and it will cure into an easily sandable mass. I used it with G-flex 650 to "spackle" some exterior painted woodwork that had developed a rough surface due to weathering. Sanding was easy with an electric handheld random orbit sander-can't see the repair after painting. I followed the directions that came with the epoxy and it worked well.

Used this product with epoxy and wood dust, to fill cracks and knotholes in a canoe I was building. It set nice and slow, easy to work with. Sanded great. Very satisfied with the process and results.

Another great west system product

I mixed up 20oz of epoxy and it took nearly the whole bottle to get to the "peanut butter" thickness. I thought it would perform better than the less expensive powders but it doesn't.

Great filler. Don't open in high winds . You'll be sorry. I didn't do this. No really, I didn't.