Reply to Mike Meyer:
Found It!! From Caterpillar Service Letter dated September 27, 1977, "SERIAL NUMBERS GROUND OFF OF STEEL CAN BE MADE LEGIBLE"
make a etching solution of
15 grams copper chloride
15 grams ferric chloride
35ml water
60ml hydrochloric acid
They warn only mix the acid to the water, not water to the acid
Then polish the surface with fine emery cloth or a polishing wheel in a electric drill.
Then with a swab apply the solution for 5-10 minutes till the numbers appear, longer time might be needed in cold temperatures, but too much swabbing makes the numbers less distinct.
After wash the area with ethyl or methyl alcohol, do not initially wash off the etch with water as this causes a film of copper to form.
Finally wash the area with water.
[quote="Mike Meyer"]Found It!! From Caterpillar Service Letter dated September 27, 1977, "SERIAL NUMBERS GROUND OFF OF STEEL CAN BE MADE LEGIBLE"
make a etching solution of
15 grams copper chloride
15 grams ferric chloride
35ml water
60ml hydrochloric acid
They warn only mix the acid to the water, not water to the acid
Then polish the surface with fine emery cloth or a polishing wheel in a electric drill.
Then with a swab apply the solution for 5-10 minutes till the numbers appear, longer time might be needed in cold temperatures, but too much swabbing makes the numbers less distinct.
After wash the area with ethyl or methyl alcohol, do not initially wash off the etch with water as this causes a film of copper to form.
Finally wash the area with water.[/quote]
Thanks Mike, will try to get hold of the chemicals and give it a go, might have to wait till lock down gets eased a bit more first. There is no sign of a fire no blackening of any surfaces, I believe it has been left out in the open for many years. Looks like #2 big end failed and then got left in the bush.