Monday, September 27, 2010

Bondo Basics

Where would the world be today without the luxury of Bondo. Ever since I can remember, well 20 years or so, it has been all the hype. You have yourself a nice looking muscle car or any car for that matter and the first thing everyone wants to know, even if they don't say it is " how much bondo, looks really nice, hmm how much bondo, bondo bucket?" Well I'm here to say that bondo is an absolute necessity if you are going to have a nice looking, straight paneled ride.

Let's get one thing straight about the use of body fillers (bondo). It is not, and I repeat not for cars that have rust. It is not for cars that have holes in them. That is what you have a welder and patch panels for. If you think bondo will hold or last over a hole of any size you'll be assuredly let down. All those hopes and dreams of having that ugly hole patched will certainly come back and haunt you. If not today, which is sometimes all the longer it takes, give it a year. Moisture will have a field day pushing out the plastic filler and leave you again worse off with a rusty, bubbling, bondo'd up sick looking disgusting scabby eye sore! - geez London "take that bondo" :)

Bondo, or plastic filler, body filler, call it what you want is great stuff, but it is made to smooth out panels. It's a filler in the sense that it fills waves and imperfections in metal. It doesn't take the place of it. It is a cheap and easy replacement for the use of lead. If you have holes you really need metal to patch them, and truthfully it's much quicker to simply cut a piece of metal and tack it in there. It will last if done right for years, especially if you keep it dry and clean. If you live where I do near the great lakes "keep it out of the salt".

All body fillers are basically the same. Some claim to be better than others, but seeing as we're not patching holes anymore with it, I go for the one that sands the easiest. These are known as the light weight body fillers. They usually sand quite easy, and they won't clog up the sand paper nearly as bad as the heavy weight (gold) fillers. I personally stay away from the 'bondo' brand, don't know why really, maybe it's the nightmarish name from my past, but that's neither here nor there, I go with the Evercoat brand. I have had great success over the years and see no need to change. They haven't been able to improve too much on it over the past 15 years.

I have experimented with most brands and weights over the years and one thing they have in common is how to mix it. The single most greatest factor in mixing bondo is the temperature where you're using it. If it is 60 degrees in the shop it will take 15-20 minutes or longer to set up, if it's 80-85 degrees where you are, you have just enough time to mix it fast and run to get it spread. Mixing is the standard 1 inch ribbon of hardener / golf ball size filler. If it's hot, cut back a tad. If it's cold, DON' T add more for it won't help. That can and usually will create pinholes and gummy bondo that will not sand well. You are forced to let it harden on it's own or put some heat on it. Heat the panel first a little if you can, it will help at least to get it to start setting up. Have patience, if you get on it right away it may let go, or flake off the panel and you'll be starting over. Let it bond to the panel thoroughly. Take your nail or a pocket knife and scratch on it. I usually nurse it awhile till it sets up just enough where I can carve any mess I made out of it spreading it , off. It saves time when it comes to sanding.

They make a plethora of tools to work with bondo, most of them will be trial and error for you, you'll find a system that works for you and have all the confidence you'll ever need in working with body fillers. I'll have to save the sanding techniques for a upcoming article, they need explanations, for they all are good for some things and not so well for others. Stay in touch!

By: London Vande Zande
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