what is best way to clean up the rust in these little finicky areas before I treat with POR 15. The only thing I have come up with is a diamond tip dremel bit.

A wire brush at most. POR 15 needs the rust for it to do what it does...

Hate to say it, but the only way to correctly and successfully get rid of that rust is to remove the screen and rubber seal and repair it with a weld and treat it from inside so the rust doesn't come back.

Removing metal, treating and filling with body filler and POR15 still won't cure the surface rust that's on the other side of that panel.

I have an 89 VW Caravelle, I do what you're doing on an annual basis, because I can't be bothered removing the glass and fixing it properly. Some of my work lasts for more than 12 months, some less, and there's always a new one that appears not long after you've fixed the rest. I remove all the flaky rust, apply the metal ready, then the POR15, then a tie coat before filling the hole with whatever filler I have to hand. I then apply another POR15 over the finished fill, then prime and colour as required. The rust still comes back..... I don't have that much time to spend on it until I slow down my work week. Otherwise I'd be doing it once, and properly.

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MichaelR said..
Hate to say it, but the only way to correctly and successfully get rid of that rust is to remove the screen and rubber seal and repair it with a weld and treat it from inside so the rust doesn't come back.

Removing metal, treating and filling with body filler and POR15 still won't cure the surface rust that's on the other side of that panel.

I have an 89 VW Caravelle, I do what you're doing on an annual basis, because I can't be bothered removing the glass and fixing it properly. Some of my work lasts for more than 12 months, some less, and there's always a new one that appears not long after you've fixed the rest. I remove all the flaky rust, apply the metal ready, then the POR15, then a tie coat before filling the hole with whatever filler I have to hand. I then apply another POR15 over the finished fill, then prime and colour as required. The rust still comes back..... I don't have that much time to spend on it until I slow down my work week. Otherwise I'd be doing it once, and properly.

yep, I think you are dead right. This is a campervan as well, so don't want to just sell it after all the work I have put into to it.
What tie coat do you use after the POR 15 and before the filler?
cheers

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keensailor said..

MichaelR said..
Hate to say it, but the only way to correctly and successfully get rid of that rust is to remove the screen and rubber seal and repair it with a weld and treat it from inside so the rust doesn't come back.

Removing metal, treating and filling with body filler and POR15 still won't cure the surface rust that's on the other side of that panel.

I have an 89 VW Caravelle, I do what you're doing on an annual basis, because I can't be bothered removing the glass and fixing it properly. Some of my work lasts for more than 12 months, some less, and there's always a new one that appears not long after you've fixed the rest. I remove all the flaky rust, apply the metal ready, then the POR15, then a tie coat before filling the hole with whatever filler I have to hand. I then apply another POR15 over the finished fill, then prime and colour as required. The rust still comes back..... I don't have that much time to spend on it until I slow down my work week. Otherwise I'd be doing it once, and properly.

yep, I think you are dead right. This is a campervan as well, so don't want to just sell it after all the work I have put into to it.
What tie coat do you use after the POR 15 and before the filler?
cheers

Anything really. Paint doesn't readily stick to POR15 and you need to wait for it to cure properly too. If you have a chat to the blokes at Warriewood, they'll set you straight.

If that's the front screen, get it removed by a pro, do the work, and have him come back and re-fit it with a new seal. It's not that expensive when it comes down to it.

If you don't want to remove the glass and do a proper job then Penetrol would make a good choice. Clean up the area as good as you can then keep brushing Penetrol to make sure it soaks under the glass all the way inside.
If you have a hotmelt gun you can build a small dam out of glue around the rusted area then drop some Penetrol into it an let it soak through for 10-15 minutes so it wets the rusted metal around the rubber seal and all the way through to other side of the glass. Then remove the dam and let it cure for 1-2 days before painting over it or else fill the hole with Shelleys Blockade and then paint it with oil based paint.
I did this to my 4x4 windscreen after it started leaking water down the inside of the glass when raining, was only going to be a temporary patch until I changed the chipped windscreen. I used some glass superglue to fill the chips and stop the glass cracking also as a temporary fix but 13-14 years later still using the same windscreen and rust patch still not leaking so I left it like that.

Just to add a couple of notes.
rust converters and por 15 etc. only work on the first layer of rust. They wont work on bubbly pitted scaly rust.
penetrol is great stuff if used as mentioned above and a have a used a small masonry bit on hammer quite successfully to remove stubborn scale from tight spots.

Without side tracking the original post, what's the best way to remove the rust stains/tears on otherwise intact paint?

I was going to try high strength vinegar and then rinse well with water. Am I on the right track? Any other suggestions?

Thanks

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GoneDiving said..
Without side tracking the original post, what's the best way to remove the rust stains/tears on otherwise intact paint?

I was going to try high strength vinegar and then rinse well with water. Am I on the right track? Any other suggestions?

Thanks

"Metal Gleam" it's a mixture of acids but mostly phosphoric. Mix 1:5 and slop it on with a soft broom. Leave a couple of minutes and hose off.

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GoneDiving said..
Without side tracking the original post, what's the best way to remove the rust stains/tears on otherwise intact paint?

I was going to try high strength vinegar and then rinse well with water. Am I on the right track? Any other suggestions?

Thanks

Jif.

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GoneDiving said..
Without side tracking the original post, what's the best way to remove the rust stains/tears on otherwise intact paint?

I was going to try high strength vinegar and then rinse well with water. Am I on the right track? Any other suggestions?

Thanks

I have had good results using Diggers Rust & Stain Cleaner from the Green Shed!!

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GoneDiving said..
Without side tracking the original post, what's the best way to remove the rust stains/tears on otherwise intact paint?

I was going to try high strength vinegar and then rinse well with water. Am I on the right track? Any other suggestions?

Thanks

I used Ranex Rust converter , just paint it on and wipe it off before it dries. Or else cut & polish compound if you don't mind doing the whole car.
Also used Oxalic acid on the sails and it removed all the rust stains successfully so can't see why it wouldn't work on car paint as well .