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Ospho and Cold Galv

9K views 12 replies 6 participants last post by  swvalcon 
#1 ·
My rear window channel is a constant source of rework. It’s always rusting and I am forever stripping it down, treating it with one thing or another and repainting. I was thinking about doing ospho and then cold galvanizing it this time. Has anyone tried this? I’ve used them separately but never together. Any side effects (i.e. cracking up, poor adhesion…)? Thanks
 
#2 ·
I use Ospho but epoxy primer seams to work best to seal it all up...Have you tried using an epoxy? I'd have to say it sounds like your not getting all the rust out ,use the Ospho to remove rust NOT convert it...Some stiff wire wheels will help a lot..or a recirculating spot blaster...You are taking the glass out , right??????
 
#4 ·
Years ago the bottom of the rear window channel disintegrated with rust. I removed the rusty metal and rebuilt it with fiberglass. The problem now comes in from the bottom of the window channel going down about 4 inches. This area is vinyl covered and the metal underneath is heavily pitted and has many holes. For striping I typically use a 4" wire wheel on a side grinder, a D/A with some rough grit, and then a Dremel in the pitted areas with a cut off blade (trying to scale but not remove the metal). I've used epoxy primer in the past but honestly I didn't think much of it, probably a mistake from what I'm hearing. I'll give it another shot, along with Ospho. This is a tuff area because of the vinyl keeping moisture against the finish. Thanks for the replies, I’ll post some pictures.
 
#5 ·
some pics would be nice...just remember that after cleaning up the rust and then applying the ospho it must be epoxied THEN fiberglassed.otherwise the glass wont stick very well to the metal and although fiberglass isnt near as good a repair as some new metal, a glass repair should last 2-3 yrs
 
#6 ·
I hit it with a wire wheel and put one coat of Ospho on. Keep in mind some of the areas showing filler are fiberglass backed and have no metal behind them. I'm trying not to dig too deep in these filled spots, not to take out the existing fiberglass backing. Next, I plan on hitting it with a Dremel with a cutoff wheel and conservatively, removing more metal around bad pits. Ideally I’d like to redo the metal but I don't have the equipment of the $ so I'll be working with this.
 

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#8 ·
Heres a couple things I noticed right off;
Thats going to be a hard piece of glass to find so if your not going to remove it then cut up some cardboard and duct tape it down so you protect it better,and your paint finish looks pretty good so cover that too...
bondo will soak up just about anything and you'll have problems getting anything to stick so clean out that old bondo...
Thats a very good wire wheel ,its one I use a lot,after the ospho drys wire wheel it again and reapply the ospho...something I do is wire wheel it while its wet....when your ready ,scuff it up good ,clean it with a wax & grease remover and prime with epoxy BEFORE using any fillers,fillers dont like to stick to ospho treated metal but epoxies stick well and fillers stick to epoxies well ...when your all done sanding, seal it all up with epoxy again...
As long as you know,those panels are wasted and need to be repaired with metal for a long lasting repair and this is just a temporary fix, its probably the best way to get the longest lasting repair you can but anything more than two years is a gift....
 
#9 ·
I'm having second thoughts on the metal replacement. I'm a little hesitant though the last guy I used to fix an old deck lid warped it badly. Mig welded it instead of tiging it and used 1/4" plate. $350 and 2 gallons of bondo later I had a mediocre lid that weighed about as much as an engine block. I ended up getting another lid. Thanks for looking close. I thought someone would say something about the window if they did. But yup, I got a replacement to put in. Junkyards are a powerful place in the South. Thanks you’re a big help. I'll post again when I decide how I want to go.
 
#11 ·
I've decided to go with what I have. I put on ospho, grinded and wire wheeled times 5. Finally I epoxy primed. I waited for activation and sprayed it but it was still very watery going on. When in hardened it created what's like a plastic shell. Thanks for the heads up on this, an eye opener. I think years ago I used laquer primer or something else, it was thick put it didn't look like this.
 

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#12 ·
One thing I thought of is a good seal. There has to be moisture and /or rust existing after the repair has been made. Check for water leaks after the job is done, also check the under side of the rusted metal for more rust, wire brush it down, ospho and seal with epoxy primer.
 
#13 ·
If your trying to fiberglass that mess it will come back to bite you. At best it will be a temporary repair. What you use for primer wont make that big of a difference. You really need to cut it out and rebuild with new metal then finish it off with epoxy and body filler and paint from there. I know a lot of work but only way to get any time out of your repair.
 
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