I have a truck with heavy surface rust on the cab roof and hood. None of this rust is all the way through the metal (yet) and I need to do something right away. I am not concerned with looks and need suggestions on the cheapest fix possible.

I was thinking hit it with a sander down to bare metal and use one of those spray can primers? I know nothing about this stuff so I may be way off. If my idea won't work please let me know what to do.

Thanks
Stab

 

Sand...sand...sand your hood. Cheapest is auto primer with filler then coat with spray paint. Primer from a rattle can alone will still rust.

Bob

 

Before you paint, use some phosphoric acid-based product on it (naval jelly, metalprep). That will help remove or at least neutralize the rust. I've had decent results with spray can primer, as long as it got a good finishing coat of enamel to seal it.

 

Stab
Don't leave out the phosporic acid step that Angus talked about. If you just sand and reprimer then paint, you'll STIL have rust. I'd do it just like Angus said.

 

>I have a truck with heavy surface rust on the cab roof and
>hood. None of this rust is all the way through the metal
>(yet) and I need to do something right away. I am not
>concerned with looks and need suggestions on the cheapest
>fix possible.
>
>I was thinking hit it with a sander down to bare metal and
>use one of those spray can primers? I know nothing about
>this stuff so I may be way off. If my idea won't work
>please let me know what to do.

On the cheep.

Wirebrush/sandblast is a touch superior to sandpaper in terms of time involved, but on the cheep, you can obtain decent results with a pack of sand paper. Harbor freight tools has 10,000+ rpm angle grinders for the $30.00 range, a decent wirebrush runs for these runs $10-$20 or so. Those $6.00 wire brushes will disigrate even when the surface area is as small as the the roof. Sand paper plus a small drill wirebrush, these I fetch at Schucks at $1.00 a pice, would probally be adquate

Navel Jelly runs about $5.00 a cup or so, vs ospho/jasco at about $6.00 a quart. Navel jelly much faster, jasco/ospho has good penitrating power. You probally want to use the slower stuff for the etching process, and the thick goo for the stubern spots, though in theory you can use the ospho/jasco to convert the rust into a thick black paint like shield.

Duplicolor self etching primer runs about $4.00 a can or so depending where you shop. two cans is probally enough for a roof. Plus two cans of primer sealer, and you will want an enamal layer, as primer along will yield rust in time. I'm not sure of the hood requirements, will concept estimate just the roof portion. I'm not sure how long primer alone would protect a roof... I did notice surface rust on honda tin after 1 year of a single primer layer.


So let's see.

80 grit sand paper 25 sheets. About $10.00
5 small cheep wire brushes About $5.00
Quart of ospho/jasco about $6.00
a cup of navel jelly about $4.00
---------------------------------------------
Prep materials about $25.00


3 cans of primer about $12.00
3 cans of primer sealer about $12.00
3 cans of enamal ($5.00) about $15.00
---------------------------------------------
about $39.00

about $64.00

This would be doing good job, but not worrying about the finner grits of sandpaper for a smooth finish, which would add to the cost. So the enamal layer would look a touch rough, but hey, protected in the event you want to finish up. There are cheeper primers and paint on the market, which would lower costs of corse, which would probally decrease the lifespan of the paint job. You have the onsale $1.00 a can enamal paints which would probally provide adquate protection for like a year before faiding / pealing / cracking, and I know there is a bargon primer at $2.00 also at schucks, this stuff drys very rough and needs to be wet sanded, but if you are not worried about the look of it, it's up to you. Actually a rough roof depending how it was done might even look good, in that sorta vinyl top sorta way.