Caustic soda bleed through on paint finish

[bexupnorth]

Hi All,

We've had some doors stripped using caustic soda. They were clean and stain free when they arrived back from the people who did it so I sanded and painted with two coats of oil based primer. I noticed some bleed through occuring, but not from anywhere you might expect, it's as if the wood itself had soaked the soda up and is now releasing it. I've tried meths and tack rags and all manner of other items, but I still get the bleed through. Can anyone recommend a way of sealing/stopping the problem.

Thanks,

Ade.

 

[Jacob]

..... it's as if the wood itself had soaked the soda up and is now releasing it. ......

That's what it does and is one of the several good reasons why caustic soda should be avoided.
Nowt much you can do except strip paint off the affected areas (don't use caustic soda!) and give a good long soaking (several days in a bath made up of polythene sheet in a 3x2 frame) and hose down with clean water. Then wash with vinegar solution and let it dry for quite a long time. Then paint with aluminium primer, which covers most things.

 

[bexupnorth]

Thanks for the advice Jacob. Completely NOT the answer I was hoping for though, bugger....