Came across an old friend today, its called Plastic Padding Chemical Metal and i have not seen it for a few years and thought it had been discontinued in favour of more modern products such as epoxy based, so what is it?
Chemical metal is what it says it is, and is a useful accessory to carry in any expedition or off road vehicle, basically it can be used to bond almost anything, metal included, and is resistant to oil and water, so can be used for a multitude of repairs quickly. Unlike modern epoxy based alternatives it is actually a polyester based product, much like body filler, and is used in much the same way, mix a little with hardener and quickly apply, it can be applied thickly or thinly, it can be sanded, but at 20 degrees it goes off in 10 minutes, so it is quick and easy for a multitude of repairs.
Modern epoxies suffer many problems, many are not resistant to oil or water and claim to be off in minutes, but in reality take a full 24 hours to fully cure, and many epoxies do not adhere well for emergency repairs to 4X4's, and many epoxies are too rigid and do not flex as steel does, so often crack and the problem reoccurs.
Todays little problem was a Mitsubishi Shogun of a mate, he had a slight leak on his diesel tank and asked if i could repair it, his problem was a previous owner who had not cleaned the underside and abrasive dirt had built up and the movement of the fuel tank and its guard had abraded part of his tank and worn the metal thin. Pulling off the tank meant removing the guard, crossmember, and packing the gearbox into position and dropping the tank and guard together, so a lot of work. In addition a new tank was £900 from Mitsubishi.
After dropping the guard, and finding it would not come out unless it was dropped with the tank, i resorted to plan B, move the guard to one side and access the bottom of the tank i let him clean out all the trapped dirt, inspecting the tank found the metal was very thin at the rear, and after scabbling it with a grinder with wire brush the problem became clear.
It actually had 7 pin holes in it, so the tank was drained, and out with the trade catalogues, Cromwell Tools listed my old faithful chemical metal so off to get a large tub (£12.73 inc vat) so was a good price, some was ordered and duly delivered, the bottom of the tank was sanded once it was scabbled and all the rust removed. The chemical metal was mixed and a thin layer applied to the rear half of the tank, it had a usable time of about 2 minutes in this weather, and was certainly set in 10 minutes, this was repeated twice to thicken up the layers to the recommended 4mm thickness and allowed to harden.
Once hard the fuel was put back into the tank and hey presto no leaks, it was sanded gently to remove any ridges or marks and painted, there was no sign of any repairs.
Over the years i have used this on many things, vehicles, industrial gearboxes, cracked engine blocks, and many more things, its more flexible and much quicker to harden then modern epoxies unless you buy the very expensive industrial epoxies , and is great in the toolbox for off roaders. It comes in tubes, or in the bulk tin, and will stick almost anything as long as it is cleaned propery and abraded, and you can have a repair in minutes instead of hours.
As an aside, one cracked engine block i repaired nearly 30 years ago with it is still running and in service.