Using Body Filler

Last update: Dec. 25, 2000

©By: Charles Christ
Formatted for the Morgan Web page by John T. Blair

Ok gang some simple instructions to filling area's with auto body filler.

#1. Any where you are going to have an exposed surface to moisture I strongly recomend a fiberglass based filler. Something like what is refered to as "Tiger hair", "Duraglass", or "gorilla snot?" This type of filler is water proof and does not attract moisture to the repair site after being finished.

#2. Bondo is extremly pourous and will absorb an amazing amount of moisture(and retain moisture like a sponge in a zip lock plastic bag)! " mud", "bondo", "putty" is best reserved for an overlay finish material after the duraglass filler has been used to fill and in some cases seal some irregular seams in a repair.

#3. Spot putty or "glaze" is strictly a finish thin layer for covering any minute imperfections (small scratches and pin holes - tiny air pockets) there are 2 types on the market:

  1. laquer based: shrinks like the dickens but works
  2. acrylic: shrinks less and seems a bit more stable.
Be carefull after priming acrylic since it swells up with thinner from the primer and if you sand it too soon when job is about a month old it will shrink back and reveal depressions you were trying to fill with the putty.

#4. Seam sealer. If you are enjoying good luck in panel replacement and evrything lines up and fits exactly where you wanted it, this stuff when brushed (use an acid brush here) over the seam looks just like the factory assembled your car. Good for back sides of panel partial replacement to deter moisture from geting into a seam and promoting rust to start again. Also used in floor pan and under hood areas, sometimes under body areas too.

#5. Primer is not a product to be considered as "finished". Primer is a pourous finish to promote adhesion of a finish coat(paint). By no means shoot primer as a finish coat so you can go out for a drive! Once you get it wet, rust is going to start under the primer.

I hope that this very simplified list describes what filler goes where, when working with metal. Fiberglass is a whole new horizon and it requires a person who is imune to the itching and scratching the fiberglas dust promotes! Glass work should be left to someone with a good amount of experience. It is not fun scratching and itching for a day or two if you do not posess the protective clothing.

Chuck (good luck out there fixing what mother nature is trying to reclaim!)

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