Ospho question

[JohnMartin]

After a 24 hrs with Ospho on the metal , then neutralize by reapplying, then rise with water and dry. How long can the metal sit out in my garage before flash rusting? I probably won’t get to epoxy it for about a week

 

['68 Coronet R/T]

It sometimes takes more than one application of Ospho to turn the metal black (rust converted).
Personally, I would leave it covered in Ospho until you get closer to painting. Then apply another wet coat and go through the neutralizing process.

If the pros disagree, I am sure they will chime in to correct me.

 

[JohnMartin]

Thanks man

 

[chevman]

If I'm going to leave bare metal, I just wipe it off with a rag, and no rinse. It lasts a long time that way, but my space is always heated.

 

[JohnMartin]

If I'm going to leave bare metal, I just wipe it off with a rag, and no rinse. It lasts a long time that way, but my space is always heated.

How long do you leave it on before wiping ? Just a min or two ?

 

[chevman]

I'm usually scrubbing the panel clean all over before wiping it off, but I guess 5 min should do it.

 

[JohnMartin]

I'm usually scrubbing the panel clean all over before wiping it off, but I guess 5 min should do it.

Thanks for the reply Chevman- how do you go about your adhesion test after you lay some primer down ?

 

[chevman]

I've been using it so long that I don't test it anymore, but in the past I have used a razor blade to cut 6 or 7 lines one way, then 6 or 7 lines crossing those (making squares), then try scraping it off with a razor blade. It needs to cure for 7 days first though.

 

[JohnMartin]

I've been using it so long that I don't test it anymore, but in the past I have used a razor blade to cut 6 or 7 lines one way, then 6 or 7 lines crossing those (making squares), then try scraping it off with a razor blade. It needs to cure for 7 days first though.

When I scrape with the razor , if I even get the slightest amount of primer to scrape off we could say the adhesion is not as good as it could be ?

 

[chevman]

I would think of it as temptation. The razor blade has edges to grab hold of, but it shouldn't be able to scrape all the epoxy off. I got this from Barry long ago, maybe he will elaborate on it.

 

[chevman]

It tends to just scrape the top off, even with the cross hatch, and that tells that you have good adhesion. Make sure you use a high quality razor blade.