Rust

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Anyone have any suggestions on how best to remove all this roof rust? Thank you for your assistance.

[73EStroker]

Media blast then get a good coat of epoxy primer on within hours after doing that. Do not sand blast! Use soda or walnut shell or you will stretch the metal.

[72cudamaan]

Is it just surface rust? Or is there rot? If there is pitting or rot you may be farther ahead replacing the whole skin.
If you don't sandblast properly, yes you can damage the panel. Maybe ice blasting? I still suggest you start by removing the glass
and seeing what shape the glass jambs are in. Your earlier picture didn't look so good.

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Thanks for all the ideas. I appreciate that. No, there is no rot. It is just heavy surface rust. I am going to take that windshield out and see what the rest is like. I know that lower part isn't looking good. I did go out to princess auto and purchased a siphon sand blaster and some walnut shell. I don't know if there is not enough pressure from the compressor or if the walnut shell is just not a good media for it but it wont even hardly touch the paint. I have a 90-125 psi compressor so that should be enough.

[jimynick]

You could look up blasters in your area and ask who does media or soda blasting. Most any home compressor won't keep up with the volume as opposed to the pressure req'd to run a blaster. You may be surprised what blasting will expose, so don't forego the roof skin just yet. Good luck with it. 

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You could look up blasters in your area and ask who does media or soda blasting. Most any home compressor won't keep up with the volume as opposed to the pressure req'd to run a blaster. You may be surprised what blasting will expose, so don't forego the roof skin just yet. Good luck with it. 

Yeah, that's what I was thinking about the comp[ressor too. Probably not quite enough power. I bought a DA sander so will see how that works first. You may be right though, I won't hold my breath that it will come out unscaved lol.

[jimynick]

The DA, with 40 grit paper will knock the surface rust down, but it won't touch the pits unless you sand through the roof skin. You could try something like Naval Jelly in the pits, but remember, the pits are below the surface for a reason- they've eaten deeper into the metal and you may end up with  bunch of pin holes that'll drive you crazy trying to get rid of them. The only cure would be to fill them and your choices are bondo, fibreglass or solder and none of them are a walk in the park to get right. If the pits prove to be deep and numerous, you may want to consider AMD's new roof skin as it won't be ALL that much more work than screwing with the old one. Take an awl and without using insane pressure, press in the big pits. A good roof will come through unscathed and a rotten one will puncture. 

[Topcat]

Take the rear glass out. The corners are notorous for rotting out.

If it has pitting in those areas, your dutchman panel will need replacing as well.

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Yeah, that's what I was thinking about the comp[ressor too. Probably not quite enough power. I bought a DA sander so will see how that works first. You may be right though, I won't hold my breath that it will come out unscaved lol.
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The DA, with 40 grit paper will knock the surface rust down, but it won't touch the pits unless you sand through the roof skin. You could try something like Naval Jelly in the pits, but remember, the pits are below the surface for a reason- they've eaten deeper into the metal and you may end up with  bunch of pin holes that'll drive you crazy trying to get rid of them. The only cure would be to fill them and your choices are bondo, fibreglass or solder and none of them are a walk in the park to get right. If the pits prove to be deep and numerous, you may want to consider AMD's new roof skin as it won't be ALL that much more work than screwing with the old one. Take an awl and without using insane pressure, press in the big pits. A good roof will come through unscathed and a rotten one will puncture. 

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Great point. I will take of the surface rust and see what I'm left with.

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Take the rear glass out. The corners are notorous for rotting out.

If it has pitting in those areas, your dutchman panel will need replacing as well.

Thanks for that tip as well Topcat. I really appreciate everyones help. This is my first project so I have a lot to learn.

[torredcuda]

Three ways to take care of rust-sandblast,chemically treat it or cover it.Blasting with an aggressive media like coal slag or aluminum oxide needs to be done carefully or will warp the metal,dipping it in or spraying it with a rust converter or acid type product works good but can be pricy or messy,covering it using a paint like POR 15 or Rust Bullet is also OK but I don`t use it for exterior surfaces only interior or undercarriage.

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Three ways to take care of rust-sandblast,chemically treat it or cover it.Blasting with an aggressive media like coal slag or aluminum oxide needs to be done carefully or will warp the metal,dipping it in or spraying it with a rust converter or acid type product works good but can be pricy or messy,covering it using a paint like POR 15 or Rust Bullet is also OK but I don`t use it for exterior surfaces only interior or undercarriage.

I did try the sandblasting route with walnut shells but I don't think my compressor was big enough to handle it. It hardley wanted to remove paint let alone rust. As such I thought to give a DA sander a shot and some 60-80 grit paper and it seems to be taking it off nicely. I only have a patch about 1ft x 1ft done and down to bare metal. So far so good. I did contemplate a chemical remover but like you say, would be expensive and messy.

[Topcat]

Three ways to take care of rust-sandblast,chemically treat it or cover it.Blasting with an aggressive media like coal slag or aluminum oxide needs to be done carefully or will warp the metal.

I agree.

After getting familiar with the pressure pot, I turned down the PSI using Alumiinum Oxide.
I got it to a point where the PSI wasn't a threat of warpage occuring yet still strip paint.
The stripping process was slowed down signifacantly but it did work without harming the metal.
Distance to surface is important along with constant movement.

I wouldn't do complete panels this way of course. Just small areas.

[73EStroker]

By saying you went to Princess Auto tells me you live in Canada. Trust me the least expensive way to do this properly and permanently is to find a professional to do what myself and others have said here - IE media blast it. It is a one time fee and sometimes you can spend more goofing around trying to buy useless parts and equipment that allows you to do a not so good job if you know what I mean. You only have to do this once if you do it right. Also take heed that it has been suggested to replace the roof if the original is too pitted. Panel replacement is by far the least expensive way to do good reliable bodywork and puts you in the situation of a lot of body shop choices as opposed to filling as has already been said. Especially with rust you can bleed money as a body shop won't quote rust repairs but they will quote panel replacement. Better to know your costs when the car goes in! Not get that oh so familiar phone call " well we found some more rust deeper and it looks like it will be another 20 hours". Hope this is inspirational.

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By saying you went to Princess Auto tells me you live in Canada. Trust me the least expensive way to do this properly and permanently is to find a professional to do what myself and others have said here - IE media blast it. It is a one time fee and sometimes you can spend more goofing around trying to buy useless parts and equipment that allows you to do a not so good job if you know what I mean. You only have to do this once if you do it right. Also take heed that it has been suggested to replace the roof if the original is too pitted. Panel replacement is by far the least expensive way to do good reliable bodywork and puts you in the situation of a lot of body shop choices as opposed to filling as has already been said. Especially with rust you can bleed money as a body shop won't quote rust repairs but they will quote panel replacement. Better to know your costs when the car goes in! Not get that oh so familiar phone call " well we found some more rust deeper and it looks like it will be another 20 hours". Hope this is inspirational.

You are absolutely correct 73Estroker, I do live in Alberta Canada. You make some very good points and I haven't ruled out doing as you and others have suggested. However, having said that, I started doing some DA sanding on it with some 60-80grit and the small spot I did thus far is looking really good and smooth with no pitting yet but that's not to say I won't find any yet. It does look worse in the picture than it really is as well. It looks quite solid but again, who knows. I did consider purchasing a whole new roof skin but no one will ship to Canada from the states and if they do its an arm and a leg. Was talking to a guy in my area who bought just  a fender and whoever he got it from whacked him 350 for shippping so that isn't a very cost effective route either. I will know more as I get into it I guess. Thanks again for your suggestions. Appreciate any and all suggestions always.