im thinking about buying a 2000 f150 heavy half and the only concern i have is it has some rust on the bottom of the doors inside and out and was wondering if they can sand blast the rust and spray linex over it , also will that help stop the rust or will it come back just under the liner , and if anyone would know what it might cost about any help would b appreciated

 

Personal opinion - sand blasting drives the rust particles into the metal and hides it, short term. You really need to neutralize it with a conversion coating - POR-15 is one, but there are others. I live in Wisconsin (rust belt, salt the roads) and we have some practice with the orange monster.

Once conversion coated, proper prep and prime will be required before any coating. Anything short of this and it's only a matter of time.

 

If it's surface rust, then no problem, it can be easily removed and the dealer can take care of it with little effort.

If it's deeper than just some surface rust, the the following steps are necessary:

1. Clean rusted area with methanol or acetone. (A phosphoric wash will not de-oil the area.)
2. Apply a phosphoric wash. Typically, these products are 85% phosphoric acid and can be diluted with water in a 20:1 ratio. After the rust converts, wash off with methanol or acetone, do NOT use water.
3. Sandblast using a non-oily blasting media. Sandblasting is necessary in order for future coats to achieve a mechanical bond. Sandblasting is preferred over sanding with a pad, but if sandblasting is not prossible, use a sanding pad. Blow clean with air only.
4. Apply a primer if you are not going to immediately coat the surface. Otherwise, skip this step and go to #5.
5. Apply LINE-X or whatever.