Painting wooden doors - colour leaching through

[clueless78]

When I moved into my house the doors were varnished wood. I’d never painted a door before so didn’t know about the possibility of the wood leaching through so I just sanded them and painted with Dulux satin wood which said it didn’t need an undercoat.

I ended up doing 4 coats as there were a few dark bits showing through and was happy with the finish after 4 coats. It seems that with the passage of time some of the natural wood colour is leaching through, it’s not massively obvious but enough to annoy me!

I’ve bought some zinsser bin (which I now know I should have bought in the first place!). Can I just paint a 5th coat of the zinnser, and then a 6th coat of the Dulux satinwood or will I need to sand down the doors again before I do anything?

Would appreciate some input from those less clueless than me!

 

[misterhelpful]

BIN is the best product for blocking such stains but it can be a nightmare to apply to large areas because it has such a short 'open' time. Coverstain might have been a better option for ease of use, and is usually reliable for this kind of job, although it's not always 100% successful on sealing timber resin stains.

You can apply the BIN directly to the existing paint because it adheres to virtually any surface, as does the Coverstain, but it's always wise to give a very light sanding between any coat of paint. Even though BIN dries super quickly, always allow a minimum of a few hours, preferably overnight, before applying you topcoats. This allows it to cure and adhere, rather than just being 'dry'.

As you've found out, a primer is always needed on any bare wood and is highly recommended on sanded varnish/woodstains. Even though the satinwood requires no undercoat, the primer satisfies the porosity of the wood and also provides the ideal surface for your topcoats. Stain-blocking primers, like those mentioned, are good for sealing the resinous areas of timber, but if you use a basic wood primer, knotting solution should be used on those areas first.

 

[clueless78]

Thanks for the advice, I’m relieved to hear I don’t have to sand it back to bare wood to apply the zinnser!