Hey,
I've got a 78 F100 that I would like to (eventually) have repainted. This truck has VERY minimal rust, all is just surface rust. A bit on the back wheel wells and the bottom of the driver side door frame. Thats about it. There are no rust holes or nothing.
I know nothing about bodywork but dont want to pay an arm and a leg just to sand off a bit of rust. How do I go about doing this? If I can't afford to get it painted right away should I wait until I can afford the paint before working with the rust? I would like to tackle the rust before it gets worse but I don't want to have bare metal exposed either as it'll just rust again. It may be a couple years before I can afford a good paint job

 

After doing some research I came across the product Ospho. Does anyone have experience with this and do you think it would work in my situation?

If I were wanting to fix up the wheel wells would I just scrape of the paint on the rust (previous owner just painted over top of everything), put some of this stuff on, let it dry then use primer?
Is primer OK exposed to the elements? I dont get much snow here but lots of rain

 

Ospho is phosphoric acid. When applied to rust it converts the iron oxide to iron phosphate. Need to remove any heavy rust. Run over the surface rust with some sandpaper, brush off the dust with a dry paint brush and paint on the Ospho with a brush. It will turn the rust to a black color as it converts to iron phosphate. Let it dry thoroughly and prime right over it. Primer will last a while but you need some type of top coat of paint to properly seal the metal from the elements.

 

primer attracts and retains moisture!!!!!! you will need a sealer over your primer or an epoxy primer. consider zero rust rather than primer. do your metal prep, then coat with zero rust, it holds up very well. under no circumstances do you wanna leave primer exposed and outdoors. Dan

 

Ok, thanks guys. There is no heavy surface rust, most is pretty light, bubbling in a few spots. So would taking a wire brush and sand paper work ok?

So let me make sure i've got the order down pat.

scrub away paint and rust flakes/debris. Make sure its clean. Paint on the Ospho, let dry.
Prime it (any primer brand recommendations?) and then Seal it (any brand recommendations for this?)
Is that about right?

 

Anyone else?

I looked closer at one of the rust spots. It's a small spot but unfortunatly it has eaten through... So how would I treat that spot? I plan on trying the rest with the ospho

 

Someone with more experience than me will have to give you tips on the spot that has rusted through, I do not know how to stop that. I am not a paint and body person, I have just used Ospho before.

 

you would probably be best off to leave well enough alone until you can do a complete job. All the rust needs to be removed and new metal welded in, patch panels are available...there is the option of using fiberglass filler but it will not last as long. there are several books available for paint and body-work..don't feel intimidated by never having done it, if you follow the step-by-step process outlined in these books you will have a satisfactory result

 

Ok... So if I spend the year (or however long till I can afford it) studying and figuring out the methods then it would make more sense to do it all in one shot.
I just dont want anything spreading like crazy so thought it may be better to tackle the spots before it got worse.

Would it be alot cheaper if I did the prep work before getting it professionally painted? What would that entail?

 

the prep work is the most important and time consuming, but like I said there is a lot of ltierature available, your local library will likely have some. This will also show you some of the tools needed.....if you have a compressor, you may want to consider painting yourself.

 

eq, get online and order a qouple of cans of zero rust, follow the directions, busting off the scaly stuff, then shoot the spots with the ZR. it will seal the rust, so as to keep it from growing. I put it on some spots on my old car this winter(in the rust belt), it performed as advertised, still looks great. then you can make your desicions as you become better informed. rust never sleeps and it gains speed once it has started. my 1st duster went from minor surface rust to cancered out in 3 years while i was waiting to build it. Dan

 

^^Exactly my fear. Heres one of the issues. Previous owner painted right over the rust instead of treating it. So I would have to actually scrape off the paint before I can Zero Rust or Ospho it. Will the rust still grow under that paint layer?

I'll attack the spots that are visable but the spots around the wheel well (they are bubbling) are the ones painted over and the biggest spots on the truck

 

Ssidney I dont have a compressor but can easily get one. I've got a fear that I'll screw up something like the paint. Thats something that I really want to look fantastic and I dont want to mess it up! I guess... whats the worse that can happen? I take it in anyways.. lol
I'll do some reading and see if its even possible for me to be able to paint it myself.

Thanks
Kim

 

Yes you will have to remove the paint to get to the rust. Like Dan said, rust never sleeps. Painting over rust does not fix anything, only temporarily hides the problem while it continues to get worse.

 

my only concern is that when you start to get rid of the rust under the bubbles you may be in for a nasty surprise, quarter panels and patch panels are dirt cheap for the fenders. What I would concentrate on first is checking out the cab mounts and floor pan and maybe catching those before things get out of hand