Originally Posted by Len
this is a really good post Len- what I've noticed is this- it's easier to master painting and buffing skills, but it's very difficult to master body filler sanding/blocking/board skills. I've seen bodymen with 30 years experience struggle with sanding filler- the problem is, every surface on each car is a different slope and shape to sand. Very few if any, are perfectly flat or round. Featheredging and blending filler into the sheetmetal, is a difficult job and hard to accomplish. The bodyman is way ahead, if he can bolt on/weld on a new panel, and just paint it- both in cost and time and materials. Often times it's MUCH cheaper, to just replace the panel.
basically I've grown to hate bondo/filler work, it's a real PITA
the main problem I've noticed is, body fillers are too hard for the job
of sanding. They have to be hard and tough when cured, to last in an outdoor vehicle body environment against the elements- but the same quality that makes them last, makes them a mother to sand and feather
what someone needs to invent, is a body filler that sands just like DRYWALL SPACKLING. Ever do some sheet rock repairs, and notice how easy that stuff sands and feathers ? I find myself thinking, "I wish bondo sanded this easy on the car". Just wipe spackling over a hole in a wall, when it dries, it sands easily flat with a small hand block- paint it with a brush- presto- the hole is fixed. Multiple layers can be applied with ease. It's almost "too easy" to sand.
that's what needs to be invented for auto body- a filler that requires no hardener, air dries, that sands EASILY. Body fillers tend to be hard as concrete after one day of curing- and if they are sanded/filed when still soft, yes it's easier to shape them, but the file or sandpaper clogs right up- the filler cures further and then shrinks later on- showing the bodywork.
I've done large areas of sheetrock with spackling compound and it's lasted 10+ years and still can't see it. Yet any body repair on a car, I can pick out with my eye after a few years- no matter how "good" the work, eventually it shinks and you can see sandscratches, feather edges, etc.
this is going to sound wacky and funny, but to be honest I'm actually tempted to try some spackling on a fender- just because it would be so much easier to sand ! No doubt it would not work, due to absorbing moisture outside soaking into it. I did repair a large area in my bathroom with spackling, and actually used my autobody airboard and block to sand/finish it-after being painted with water resistant bathroom paint and a roller, it still has not come through- even though it is hit with water and steam almost daily- it's a wall in the shower area, above the tub- and I did that repair back in 1994.
another issue is, the paints have become too toxic for auto body repair. Len, you mentioned the supplied air and having to act quick to save your life without one. A person who was not a bodyman, would think that's simply ridiculous, to work with that stuff. When we have to paint cars in space suits similar to germ warfare suits, there's obviously a problem there. They need to come out with less toxic paints that a charcoal mask can handle, and do away with these toxic urethanes and polyurethanes already. These toxic paints are not "modern technology"- they are 60 year old German technology, invented when they didn't know any better. In 2008 it just seems dumb having to spray toxic paint on a car, and risk your life- unless we buy a $500 air supply.
the hardeners are the nasty stuff- I sprayed some sythetic enamel w/hardener last week, then cleaned the gun with lacquer thinner thoroughly- just having the spray gun in my trunk after it was cleaned, it gave off fumes into the interior of my car and was making me dizzy and my breathing got funny- when I picked up my son from school nearly 2 hours later, he smelled it and said "what is that smell, it's giving me a headache" after about 5 seconds in the car. That's how nasty that stuff is- just the RESIDUE in the gun, in an enclosed area, does a number on a human being. We had to drive home with the windows down- that doesn't happen with straight lacquer or straight enamel- I've had spray guns recently used in the trunk, after using non-ISO paints, and driving in the car I can't smell anything.
it's the ISO hardeners, they have to go, and be replaced by a more user-friendly system- to be honest I would not care if they outlawed the ISO stuff. Deadly chemicals in spray paints just seem dumb to me- by definition the paints become aerosols, and create a deadly gas chamber wherever they are used. The paradox is, they outlawed lead based paints, to go to ISO paints- when in fact the lead paints were not as deadly as the ISO paints.