Weldable or weld through primers

Jackalope

Active Member
Hi all,
Its been a long time since I've been on the forums, nice to be back!
So my question has to do with metal storage.
We purchase our steel in large quantities for the whole academic year and we are located in a town near the the Pacific ocean....i.e rust accumulates in short order. After a few months every project involves a lot of grinding, sanding, or sandblasting in order to weld which besides being a kill joy to metalworking, adds time to our construction projects. No room to store steel inside. Has anyone successfully precoated steel with weldable primer for storage reasons? If so:

1. Can you MIG weld through the primer or do you end up grinding the weld site?
2. How long does the primer hold up to the elements?
3. If cleaning the primer off before welding is required, do you find the removal of primer to be easier/faster than removing rust?
4. Do you have a product recommendation and source?

Thanks!
 
can you build a "case" for it that you can put an exhaust fan in and paint white? You're likely experiencing the steel heating up through the day and cooling overnight causing the condensation turning into rust, along with the humid air. If you can keep air moving over it and lessen the amount of temperature shift you might at least be able to mitigate the rust build up. That plus @Footer 's hudson of oil once in a while might get you by.
 
Welding through paint can create porosities in the weld weakening the overall strength of the weld. Pacific coast storage is tricky. We have this issue in construction of new power plants. Generally, everything we procure that is awaiting erecting is coated (some Oiled like @Footer suggested and some primed). Both require cleaning before welding. The oiled ones require lots of cleaning before painting. The Oil can create other hazards such as oily rags. Proper flammable materials becomes necessary if you go that route.

If it were me, I'd rather spot grind primer off of the weld area just before welding. Cleaning is part of weld prep anyway.
 
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For a while we bought steel that came primed with a weldable primer. It was great; we didn't need to do any cleaning. Turns out they were selling off a large over-supply and now we can't get it any more.

Here's a product called weld-through primer. Not sure if it's the same my supplier was using.
 
Hi All
Thanks so much for the replies. I think I am going to go to a weldable primer and then grind the weld sites and avoid having to clean the entire surface. I thought about the oiling idea a bit but in the end decided that all that excess oil may find its way to the drains in our scene yard as everything slopes towards them. Those of you who are coating steel, are you spraying it? That seems to be the fasted way to do it maybe
 
For a while we bought steel that came primed with a weldable primer. It was great; we didn't need to do any cleaning. Turns out they were selling off a large over-supply and now we can't get it any more.

Here's a product called weld-through primer. Not sure if it's the same my supplier was using.
I am going to order that and give it a try. I won't be able to test it out until we can work in the building again.
 

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