Surface rust treatment after welding?

[baj25]

I’ve been doing some car bodywork recently and because I have to do it outside with the ‘interruptions’ that the British weather gives, some of the earliest welds I did have got a light surface rust on them now. These are all in cavities and will be hidden when the outer panel goes on. Any suggestions for how to treat this, do I need to? Seam sealer or POR15 was what I was considering using. The surrounding steel still has weld-thru spray on, and cavity will be sprayed with dinitrol when I’m finished. TIA, Brian

 

[Chickenjohn]

If the steel surrounding the weld seam has flash rusted, you can remove the rust with 10% phosphoric acid and wire brushing. Then dry off/wire brush the area and paint with zinc paint.

You only need seam sealer on an exposed area where water can get to- eg wheelarches and sills.

 

[PaulMcElhinney]

I use Jenolite which is phosphoric acid based. I have heard may people recommending Bilt Hamber products, hope I've spelt that right.

Good luck,

Paul.

 

[baj25]

Thanks for the replies. I used the POR15 metal ready stuff which is phosphoric acid based. Cleaned it up a treat. Ta again, Brian