I've been mixing my own filler for years, but a rookie in the shop made me question my whole method.

For the last decade, I always added the hardener first, then the filler, mixing for about 45 seconds. This new kid, Jake, does it the other way around and his sets up perfectly every time. He said his teacher at the trade school in Fresno drilled that into them. I tried his way on a quarter panel last week and got way fewer air pockets. Is the order really that big a deal, or did I just get lucky? What's your mixing routine?

3 comments

3 Comments

gray69d ago

Wait, you're adding hardener to an empty cup? That's backwards. You always put the filler in first so you can see the ratio as you add the hardener. Doing it your old way makes it way too easy to mess up the mix.

oscarb779d ago

Look, my old way has worked for fifteen years without a single bad batch. I pour the hardener first because it's the smaller amount, then I fill the cup with filler until the line matches. It's foolproof. Your method, @gray6, sounds like a great way to accidentally add a whole tube of hardener to a thimble of filler and end up with a smoking hockey puck in thirty seconds.

rowanellis8d ago

My first ever batch of filler set in about 90 seconds because I did the hardener first. I had to agree with gray6 after that, filler first lets you see what you're doing. I guess my old way was just my way to make a mess fast.