406-2 Colloidal Silica Filler, 2 oz | Epoxy Thickening Additive | Control epoxy viscosity for strong, reliable structural bonds and precise application with this thickening additive.

This stuff works great. My first epoxy fiberglass repair has gone well. The 406 silica allows you to create an epoxy filler of almost any consistency. My repair was a small home on a vertical side of a boat. Getting a couple layers thick enough to not sag was key. I found it easy to sand down with 80 grit paper and am very happy with the results.

I’ve dealt with a couple of epoxy brands over the years and West System’s is by far the best all around system that includes both epoxy and fillers. These fillers are a bit pricy when you factor in the weight or volume but they work just like fillers should. I have yet to encounter any negative issues with these fillers, and they all appear to be packaged in a professional environment. The fillers come bone dry and don’t have any impurities in them.

This is the best and easiest product & system I have used so far.

Great stuff!! This unbelievably powdery mess mixes extremely well with resin epoxy to form a thick gel that dries into an opaque white plastic. Don't inhale this stuff, it's like powdered glass and definitely not a good thing to inhale. Eye and Ear protection required, no doubt. Wear a hockey mask and breathe through a sock.

I mixed some of this colloidal silica with a 2 part epoxy glue to thicken it up. The more you add the thicker the glue mixture gets. The powder is super light, and floats everywhere, so a mask is not a bad idea. Handle it slowly and carefully.

Used it to add to gelcoat during a crack repair on our boat and it is amazing. ALWAYS USE A RESPIRATOR!!! This is a very fine dust and it will damage your lungs.

Here in Hawaii, even Ace Hardware doesn't have this. Thank you for Amazon to sell this.

Similar to other brand products and delivered very quickly. No complaints.

Lo compraría nuevamente. Buen producto.