Rust Converter Recommendations

[Dat73z]

I'm preparing my car for a new windshield and seal. Unfortunately I found one spot of rust above the cowl right at the bottom on the windshield. Fortunately the metal is solid and fully covered by the seal. 

 

I was planning to just wire wheel, prime and paint but realistically I probably won't be pulling the windshield again for many years. I'm worried if I miss some specs of rust in the pores it will start again. 

 

Does anyone have recommendations on a rust converter that works well? 

[AydinZ71]

4 hours ago, Dat73z said:

I'm preparing my car for a new windshield and seal. Unfortunately I found one spot of rust above the cowl right at the bottom on the windshield. Fortunately the metal is solid and fully covered by the seal. 

 

I was planning to just wire wheel, prime and paint but realistically I probably won't be pulling the windshield again for many years. I'm worried if I miss some specs of rust in the pores it will start again. 

 

Does anyone have recommendations on a rust converter that works well? 

 

As a topical application I use rust-mort. It is phosphoric acid. It must be removed after it has done its thing.

The metal in the windshield sill is pretty thin (20-gauge?) so I would wire-wheel the rust and make sure the remaining metal is not too thin. If it is, you could add some metal with a MIG and grind flush, or use a fiberglass filler. 

Rust needs exposed metal, oxygen, and water/moisture to propagate. If you eliminate the existing rust, seal the exposed metal with epoxy (por-15 or 2-component sealer/paint) then make sure your windshield seal works 100% so you don't get moisture trapped between the windshield/seal and the window sill. Adding a really thin filet bead of sealant between the rubber seal and the metal may help prevent moisture from getting trapped back there again. I suspect the moisture is being wicked (capillary action) into the gap. 

[Dat73z]

Thanks Aydin. It looks like my local O'Reilly's has SEM Rust-Mort so I'll give that a shot.

 

Good tips info on the sill thickness, didn't realize it was so thin. If I find any pinholes I'll hit it with the tig and some filler. Worst case I could always weld in a patch and refinish the area. 

 

This was supposed to be a quick R&R but better to do it right I suppose. Never an easy project, oh well 😅

[AydinZ71]

29 minutes ago, Dat73z said:

Thanks Aydin. It looks like my local O'Reilly's has SEM Rust-Mort so I'll give that a shot.

 

Good tips info on the sill thickness, didn't realize it was so thin. If I find any pinholes I'll hit it with the tig and some filler. Worst case I could always weld in a patch and refinish the area. 

 

This was supposed to be a quick R&R but better to do it right I suppose. Never an easy project, oh well 😅

No worries! Yeah rust on a Datsun rarely becomes an easy fix LOL! I’m a year into rust repair…

 

if you TIG, then you are ahead of me friend! Once you hit that spot with a wire wheel, I suspect the metal will peel back like an orange but if you get a solid surface, more power to you!! 
 

since it’s a tiny spot, you could also save a few bucks and get a rust converting spray can. Most manufacturers sell one for 5-8 bucks. Although to be honest, if you wire-wheel it you won’t need any converter at all. Just something to seal the metal. 
 

good luck! 

[ETI2K]

I agree with @AydinZ71, and if I may add, if you decide to apply the small fillet bead, it'd have to a 100% effective seal.  If there is any void that would allow moisture into the space behind the windshield, it might exacerbate the problem by ensuring it stays wet.  Don't forget too that air carries water vapor and when it cools, that vapor will condense.  Airborne water vapor movement is tough to stop, so treat it like it will always be wet.