Jeepwalker
I'm Awesome
Here's what I would do ....and in fact, I had a few windshield rust areas similar to yours, but not as bad. You can eat all that rust away and completely stop and fix the rust situation. And for now put on a protective coat on it. It's going to take a little time, but trust me, it'll eat all the rust away.
1) Take a grinder or wheel on a drill. Grind down the heavy rust and grind back to clean metal around each rust bloom. A grinder on a drill rotates somewhat slow and won't cause sparks that'll pit the glass. Grind down to mostly metal.
2) Get some Rust Dissolver (HERE) and brush or daub some on the rust spots with like a small brush, spoon or end of big screwdriver. It will eat the rust away. Get plenty on there. The goal is to keep applying it and it'll eventually eat away all the rust, even in deep pits. Do this on a warm day this fall. A warm day will increase the chemical activity. Try to work some under the gasket. If your windshield is cracked, pitted real bad, etc and you plan to replace it, maybe consider cutting a little bit of the gasket away with a razor and eat that rust out that's in the gasket area. You can fill the cut-away part later with black RTV so it won't be very visible.
3) Let it sit and do it's work. Periodically, re-brush the rust dissolver...disturb it and move it around. Gas bubbles are produced due to the chemical reaction of dissolving the rust away. That's normal. But eventually there won't be as much chemical in contact with the rust. So periodically work the Dissolver around to ensure its in contact with the rust, every 15 minutes or so. Apply a little more Dissolver if you need to. Don't let it dry out.
4) Every once in a while, maybe after 45 minutes, take a little stainless steel brush (those little ones that look like a big toothbrush) and brush the surface and work the dissolver in. The goal here is to disturb the rust even more to let the chemical continue to work on hard-to-get-to deep rust pits. You might wipe some Dissolver away with a paper towel, and then apply a fresh batch. Hit it again with your SS brush again a bit later.
5) Keep doing this until ALL the rust is gone. Even the *smallest* pinhead of rust in a deep pit. get it all out. Once it's completely cleaned out 100% (not 95%....but 100%), then clean it off with a damp sponge...and neutralize it with water and a nylon brush. If you need to, clean the area, with a scuff pad and water. Then quickly dry and blow clean with compressed air. Dry it off quick so it doesn't flash-rust.
6) Like Hipster indicated, you might be left with a hole or two rusted all the way through. If you have a hole in the metal, then you need to figure out what do to with the hole. If you want to come back later, then skip to #7 and once the primer cures (the next day) apply a daub of RTV over the primer. If you want to deal with it now, then cut a square hole with a cut-off tool and cut out the rust area. I'm guessing you'll have a 1/2" x 1/2" hole by the time you cut it out. Cut & fit a new piece of metal that fits into the hole. You can weld on a stiff piece of wire or thin rod to your patch to hold it while you tack it in place, then cut if off. Anyway, then *carefully* weld it in place. Obviously tent off your windshield with a welding blanket or piece of sheet metal, whatever you have. Finish grind as needed.
7) Brush ...with a small modeler's paint brush, some Self-Etching primer (HERE) onto the de-rusted area. Make sure you work the self-etching primer into the pits. Let it sit a few minutes. Then come back and spray 3-coats of self-etching primer over the rust pit area. Self-etching primer really treats the metal and it won't rust.
8) If you're not going to paint for a year then maybe apply some paint ...but you really don't need to. I've let metal treated with self etching primer outside for years and it didn't rust.
It's a little bit of work, but you will have completely removed & arrested the rust alltogether. You can't say that about rust converters. And sand blasting won't get into the deepest pits (plus it's real messy). But you could hit the rust areas with a hand blaster too and some ultra-fine silica sand HERE.
1) Take a grinder or wheel on a drill. Grind down the heavy rust and grind back to clean metal around each rust bloom. A grinder on a drill rotates somewhat slow and won't cause sparks that'll pit the glass. Grind down to mostly metal.
2) Get some Rust Dissolver (HERE) and brush or daub some on the rust spots with like a small brush, spoon or end of big screwdriver. It will eat the rust away. Get plenty on there. The goal is to keep applying it and it'll eventually eat away all the rust, even in deep pits. Do this on a warm day this fall. A warm day will increase the chemical activity. Try to work some under the gasket. If your windshield is cracked, pitted real bad, etc and you plan to replace it, maybe consider cutting a little bit of the gasket away with a razor and eat that rust out that's in the gasket area. You can fill the cut-away part later with black RTV so it won't be very visible.
3) Let it sit and do it's work. Periodically, re-brush the rust dissolver...disturb it and move it around. Gas bubbles are produced due to the chemical reaction of dissolving the rust away. That's normal. But eventually there won't be as much chemical in contact with the rust. So periodically work the Dissolver around to ensure its in contact with the rust, every 15 minutes or so. Apply a little more Dissolver if you need to. Don't let it dry out.
4) Every once in a while, maybe after 45 minutes, take a little stainless steel brush (those little ones that look like a big toothbrush) and brush the surface and work the dissolver in. The goal here is to disturb the rust even more to let the chemical continue to work on hard-to-get-to deep rust pits. You might wipe some Dissolver away with a paper towel, and then apply a fresh batch. Hit it again with your SS brush again a bit later.
5) Keep doing this until ALL the rust is gone. Even the *smallest* pinhead of rust in a deep pit. get it all out. Once it's completely cleaned out 100% (not 95%....but 100%), then clean it off with a damp sponge...and neutralize it with water and a nylon brush. If you need to, clean the area, with a scuff pad and water. Then quickly dry and blow clean with compressed air. Dry it off quick so it doesn't flash-rust.
6) Like Hipster indicated, you might be left with a hole or two rusted all the way through. If you have a hole in the metal, then you need to figure out what do to with the hole. If you want to come back later, then skip to #7 and once the primer cures (the next day) apply a daub of RTV over the primer. If you want to deal with it now, then cut a square hole with a cut-off tool and cut out the rust area. I'm guessing you'll have a 1/2" x 1/2" hole by the time you cut it out. Cut & fit a new piece of metal that fits into the hole. You can weld on a stiff piece of wire or thin rod to your patch to hold it while you tack it in place, then cut if off. Anyway, then *carefully* weld it in place. Obviously tent off your windshield with a welding blanket or piece of sheet metal, whatever you have. Finish grind as needed.
7) Brush ...with a small modeler's paint brush, some Self-Etching primer (HERE) onto the de-rusted area. Make sure you work the self-etching primer into the pits. Let it sit a few minutes. Then come back and spray 3-coats of self-etching primer over the rust pit area. Self-etching primer really treats the metal and it won't rust.
8) If you're not going to paint for a year then maybe apply some paint ...but you really don't need to. I've let metal treated with self etching primer outside for years and it didn't rust.
It's a little bit of work, but you will have completely removed & arrested the rust alltogether. You can't say that about rust converters. And sand blasting won't get into the deepest pits (plus it's real messy). But you could hit the rust areas with a hand blaster too and some ultra-fine silica sand HERE.
