Painting over black tar varnish

[Ferretmn17]

I am in the process of re-decorating the for-peak of my cabin. All of my frames are exposed and have previously been painted with black tar varnish. This is not the problem when, who ever it was did the black tar several runs and dribbles ended up on the inside of the planking. Now I am trying to paint over this (in white) it bleeds through the primer, undercoat and topcoat. Any suggestions on primers short of striping the areas back to bear wood?

 

[MasterofHera]

Black tar can be a problem. My FB was covered in it as antifouling ....you cant sand it off as it just melts clogs up the sand paper. You cant burn it off with a heat gun as it melts and wants to catch fire. So Anti foulded over the top ..it bled thru BUT if you leave it alone (for a couple of days) it will sort itself out ...then give it another top coat

 

[FAITIRA]

Might be worth trying 'Jotuns Viniguard' (sp?), it,s an aluminium based primer, I used it to form a barrier coat for coal tar epoxy, a bit to my surprise, it worked very well. Bill.

 

[Seanick]

3 to four coats of Aluminium wood primer usually works.

 

[Ferretmn17]

Thanks for the advice, tried the Aluminium primer at the weekend and it looks like its working.