Replace metal or will phosphorus work?

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PostPosted: Thu Aug 28, 2014 2:28 pm
Cutting out the rust in the samurai. This is the back floor, drivers side. Where the floor was spot welded to the rear boxed section, the metal was 3 layers thick. The box section made up 2 of the layers and the floor was the 3rd. In this pic, I have removed the floor and you can see the two layers of box section exposed. The upper layer of the box section is rusty, and I'll remove it and replace it with new metal, as well as the floor metal.

Image


In the underside of the same panel, there is a gap, about 2mm where the floor and box section lap. This gap was never sealed at the factory.......and thus the rust. Not wanting to cut out the whole width of the floor [ as on the 1st pic ] will a rust inhibitor like Rust Mort work to kill this rust in this gap? It doesn't look too bad from the underside, but i know that middle layer of sheet metal will have rust in it. Will the rust mort plus seam sealer work ok? or will I be redoing this repair in 5 years time. This original zuk is 28 years old. Rain and water gets pushed right into this seam, in the direction of the arrows. Why Suzuki didn't seal it???
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There is another spot where this middle layer has rusted and buckled. I will cut out and weld new metal in here.
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PostPosted: Sun Aug 31, 2014 10:05 am
You can put what ever you want on it its not gonna help.

Things that work on rust? 1. Blasting till 110% then clean and metal treat with phosphoric acid type cleaner sealer, try 5717 & 5718 by Dupont seal with Acid etch primer preferred or epoxy primer if you can clean the metal good enough after treating with phosphoric acid epoxy will not want to bond unless metal is clean clean clean, epoxy and acid don't get along.
Dennis B.
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.



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PostPosted: Sun Aug 31, 2014 3:45 pm
Doright wrote:You can put what ever you want on it its not gonna help.

Things that work on rust? 1. Blasting till 110% then clean and metal treat with phosphoric acid type cleaner sealer, try 5717 & 5718 by Dupont seal with Acid etch primer preferred or epoxy primer if you can clean the metal good enough after treating with phosphoric acid epoxy will not want to bond unless metal is clean clean clean, epoxy and acid don't get along.


Thanks for the reply, Doright.
I have a sandblaster, and will be media blasting it with crushed glass. I was also planning on using Nason Epoxy Primer.
I didn't know that epoxy and acid did not get along. I read the PDF's on Dupont 5717 and 5718. Looks like they get used one right after the other, correct? 17 first then the 18.

What is the correct order to do this? Media blast with glass first, then the 5717 and 5718 treatment, then right to epoxy or do I need to prime with an acid etch primer before the epoxy?
Thank you.



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Posts: 6213
Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
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PostPosted: Sun Aug 31, 2014 10:08 pm
If it were me I would do the blasting & Acid etch primer, easier faster cheaper.
Crushed glass will work good wear a good face mask. Dont kill your self all you can do is slow rust down you cant stop it.
Dennis B.
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

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