Fillers

fillers

bondo- while it is a generic term for body fillers, ie plastic epoxies
the actual product 'bondo'tends to have a higher solvent content
while this make it easer to spread, it leads to more shrink, as the solvent
evaporate and the product cures.
If you are going to use plastic fillers then buy a good quality ( we use evercoat rage,and then sparingly )
while body fillers have there place in auto resto, they are usally not used
correctly. If it is applied to thick it shrink and crack as it out gasses and cures.Thin coats of correctly mixed filler is the way ,curing then sanding between coats.
There are dif types( chem makeups) of plastic filler.
talc-
most fillers are talc based,talc being the main solid component
typically use by 90% of the industry for filling small areas and feathering repairs.
alm-
also called metal to metal filled, main solid is alm power typically used in areas of the car that have a higher vibration or shock loads
we use it primarily around doors/trunks and deck lids
kitty hair-
epoxy resin filler with short, fiberglass strands and talc for for its main solids og designed for fiberglass ,it is mostly used to pack it to bad repairs.(we see alot of this.) We use it... to make molds for shaping complex curves out of steel, or on fiber glass
out of those 3 kittyhair is the only one that is NOT hydroscopic .

lead-
to og filler, old skool, not much use today, we still do lead work for some clients, while it is a lost art, it is actually very simple to do.
non lead lead-
same as above but it is a tim based alloy with no lead in it
working temp is slightly lower than true lead
(thanks EPA)

the best way to do a repair, is to do it and not use ANY fillers and metal finish . this is unrealistic for most peeps , their check book, or skill level.
(most people do not have the patience to do this).
the final thickness on filler ( for our shop) can be no more than .075" (1/16"), I want it thiner than that

glazing putty-
talc based, but with much smaller particulate size than standard plastic filler. use primarily for pin holes, ( if you use good fillers correctly you wont have pin holes) and small repairs has a high solvent content -so it will shrink if used incorrectly .
NEVER use one part glazing compound EVER

I still HATE Bondo

the devil is in the details

In a good paint job there are many thing involved to make it look right. Any monkey can pull the trigger and squirt paint. Body work and prep are critical . If it ain't straight underneath the paint

it will look like crap, shinny crap, but still crap . While you can polish a turd, ( thank you myth busters) it is still a turd.

The Human brain is an amazing thing, the way it processes what it sees, and inputs it to the brain , The way that I understand it the eyes only pick up a certain number of things in a mental image and the mind fills in quite a bit of the picture. As a result a few small 'errors' in a car will not be picked up by the human brain, but the more 'errors' there are the more the mind will pick that up, once it reaches a certain level , or crosses a threshold, the part of the mind that does the filling in, says , " something isn't right". It isn't exclusive to cars, I learned this while I was in my last career , real estate .

The threshold is different to every single person. While I have trained my eyes and mind to have a very low error rate. by looking close and slow, using your eyes, as a secondary sense and using the skin of my finger tips as my primary sense.

We, ( 00 dub and I) well spend 16 man hrs , or more, doing this prep work on each of the sections before we shoot. The reason we do it in sections is more to do with not being overwhelmed , or overloaded with the scale of what we are working on, by breaking it down to a manageable level we are able to make a as close to perfect surface as we can.

All we are doing is eliminating the errors . you must be in the moment and in tune, if you rush it or push it, you will miss the devil because he is in the details.