Taking care of surface rust appearing (since sandblasting) prior to epoxy priming

[squidmarks]

Although I wanted to epoxy prime everything shortly after I had my body sandblasted, things don't always work out nicely. I was able to get the chassis primed, but my fenders, and hoods did not get primed and have sat around and I have noticed a bit of surface rust appearing here and there, particularly around patches I had welded, but I also saw some in the general surfaces as well. Does anyone know of a good product to take care of this sort of surface rust prior to priming? I've heard that washing with sulfuric acid will take care of it, followed by a water rinse, but it would seem to me that that would cause another case of flash rust to appear.

Geoff

[3.2 CAB]

I would not use Sulfuric Acid on the panels. A few different products on the market will take care of just light surface rust, and not really harm the surface like Sulfuric Acid could. Some of the products can even have a very mild phosphoric acid content, and are made for this type of application, and will readily remove the surface rust with very little effort without possibly damaging or contaminating the "fresh" metal surface. PM me if you would like to discuss some of the different products. Tony.

[3.2 CAB]

Geoff, I answered your PM. Tony.

[Tim K]

This is in the sticky at the top of the Bodywork forum

Metal Conditioning And Epoxy Priming 101

Here's the link to the rest of fhernand's articles:

Links to Freddie Hernandez' 101 series

Good luck!

[squidmarks]

Tim,

I've read these before but forgot the metal prep/epoxy priming one dealt with this issue (Hey, I'm getting old). Thanks!

Geoff

Originally Posted by Tim K

This is in the sticky at the top of the Bodywork forum

Metal Conditioning And Epoxy Priming 101

Here's the link to the rest of fhernand's articles:

Links to Freddie Hernandez' 101 series

Good luck!

[rw7810]

PickleX is a good product for this. Go here for info: http://www.autobodystore.com/forum/index.php

[bandjoey]

I'm 2 week in from media blasting and waiting on sheet metal I want to weld in before I undercoat. Sprayed on Eastwood metal wash. Comes in pint can, mixes gallons with water. So far just a few spots of surface rust on the fenders from handprints. Those I sanded down and sprayed again. They advertise up to 3 weeks protection from flash rust. I'm impressed.

[squidmarks]

Originally Posted by bandjoey

I'm 2 week in from media blasting and waiting on sheet metal I want to weld in before I undercoat. Sprayed on Eastwood metal wash. Comes in pint can, mixes gallons with water. So far just a few spots of surface rust on the fenders from handprints. Those I sanded down and sprayed again. They advertise up to 3 weeks protection from flash rust. I'm impressed.

Actually, I'm about 2 months now since sandblasting and it is only areas that I have welded or, like you had original fingerprints from the sandblaster (not sure why) that are showing surface rust. The general areas are not showing rust - there may be some there that I'm not seeing, tho. I'm going to wash it down with one of these metal prep solutions (like the Eastwood one) that contain phosphoric acid before I epoxy prime.

Thanks for all your suggestions.

Geoff

[squidmarks]

Ok, I ended up using PPG DX589 and DX520 metal conditioners. I just want to check with you experts to make sure that this fender is looking like it is supposed to (pretty ugly). I expected to see the hazy zinc phosphate look, but not the rusty orange patches. I suspect that these are iron phosphate, not iron oxide, tho. I prepared it as per the PPG instructions - DX589 1st followed by a water rinse. This produced pretty much what you see. The DX520 treatment after didn't change things much. Is this what it is supposed to look like? There was very little surface rust, before this metal prep treatment, but now it looks like its all over the place. Can I assume that these orange patches are not rust but is harmless iron phosphate that can be primed over?

Thanks.

Geoff