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It’s The Pits

Author Photo
By Frank Taylor | Sep 1, 1992

Rt. 2, Tamarack Road, Whitewater, Wisconsin 53190

Co you’ve succumbed to the disease and purchased a ‘rust
bucket.’ You’ve cleaned, scraped, washed, blasted, honed,
polished and rebuilt the chassis to like-new condition. You
can’t put it off any longer, you must now work on the sheet
metal. Maybe some of you like this part best? Let me explain.

I’m a farmer, not a body man. I paint because I’m too
cheap to pay someone else to paint for me. But how do you get a
like-new finish on that rusty sheet metal? You’ve seen those
tractors at shows, the ones with the mirror finishes, and you
think, ‘Did this tractor ever sit outside?’ Most likely
yes, it probably didn’t look any better than yours when he
started on it. So how did he get that shine? Here’s one way.
Now remember, I’m a farmer, not a body man; if someone who
should know tells you different, listen to them.

First, sandblast the sheet metal, if possible; be careful with a
large capacity blaster, you can warp the metal beyond use in a very
short time. Back off with the nozzle and keep moving. A wire wheel
is your next best option. Once you’re down to bare metal, take
the dings out with a flat body hammer and a bucking dolly and some
heat. If you want to stretch the metal, heat a spot about the size
of a quarter and place the dolly behind and pound the sheet
between. If you want to shrink the metal, heat a spot the size of a
quarter and then pound all around the spot, without the dolly. You
will eventually end up with less metal than you started with.

Once you’ve got it flat, prime it with zinc-chromate primer.
This primer should be applied very thin, and please, buy a good
paint spray respirator and use it, for this and all your painting;
these paints can kill you.

Now it’s time to fill the pits. There is a product called
Poly-Prime, made by the Marson Co., 130 Crescent Ave., Chelsea, MA
02150. They call it a ‘sprayable polyester
primer-surfacer-filler.’ I call it liquid Bondo. The product is
sprayed as is in a heavy cream consistency and is activated with
MEK (included). It sprays best at low air pressures with a pressure
pot type gun. It dries very fast and will ‘dust’ easily
with too much air. Three coats will fill very deep pits. When this
dries, the surface will be very ‘orange peeled.’ Sand this
flat with a DA orbital air sander with 180 grit paper. If you sand
down to bare metal before it’s flat, just spray another coat.
Once it’s flat, spray three coats of lacquer primer surfacer,
then wet sand that with 400 grit by hand. This will fill all the
scratches in the poly-prime left by the DA sander. Now you’re
ready for the top coats. I use DuPont Centari with a catalyst. It
shines well and is much more forgiving than Imron.

It sounds like lots of work, but the results are worth it. And
remember, paint is very soft for several days after spraying;
you’ll probably put the first scratch in the hood while bolting
it on!

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