Hopefully the original poster has got this sorted out now. Unfortunately it is something that will affect any water based paint. Don't be pigged headed and keep adding coats of paint in the hope that it will go away. It won't ! Stains need to be sealed. Shellac is what is normally recommended (nb the premixed variety does have a short shelf life) and here I would recommend applying it with a rag or cloth as it wrecks brushes very quickly. It only takes a few minutes to dry and then can be painted over. No need to treat the entire piece only where it has stained. One of the problems with furniture painting is knowing what you are painting. Some woods, mahogany in particular, can be problematic or it may have been treated with a furniture stain.It is always worth trying a test area first.
In the absence of Shellac or even knotting solution you can try applying a couple of coats of wax to form a barrier but this is not always a guaranteed solution. Zinsser is a very popular alternative but is pricey.
In France shellac tends to be sold in flake or crystal form. It is called gomme (de) lacque or sometimes gomme shellac. You just need to add some alchool a brulé (methalated spirits) to make up as little or as much as you need. Most stockists have the Liberon version which comes in a multitude of colours. The clear or blonde version is best depending on what colour you are painting.
It is normally available from a droguerie or one of the brico stores. The latter normally haven't a clue what it is and will deny having it. Ignore this as it is normally in with coloured waxes, varnishes etc. You will also find it on amazon.fr. There are a variety of uk brands of knotting solution available there too.
Hope this helps...
It
is normally available from either a droguerie or brico store.(The
latter tends to hide it away and tell you they haven't got it.) It is
called gomme laque or gomme shellac which comes in crystal form which
you then dissolve in Alchool a brulé. I have seen packets of crystals
under the Liberon name tucked away with coloured waxes in various brico
stores.Depending on what colour you are planning to paint it may be
prudent to search out the clear or blonde version. As a bit of advice
apply with a rag as it wrecks brushes very quickly. I have a feeling
there are assorted brands avalable from amazon.fr - See more at:
https://www.angloinfo.com/poitou-charentes/discussions/topic/1309428#sthash.fO5X1UzG.dpuf
It
is normally available from either a droguerie or brico store.(The
latter tends to hide it away and tell you they haven't got it.) It is
called gomme laque or gomme shellac which comes in crystal form which
you then dissolve in Alchool a brulé. I have seen packets of crystals
under the Liberon name tucked away with coloured waxes in various brico
stores.Depending on what colour you are planning to paint it may be
prudent to search out the clear or blonde version. As a bit of advice
apply with a rag as it wrecks brushes very quickly. I have a feeling
there are assorted brands avalable from amazon.fr - See more at:
https://www.angloinfo.com/poitou-charentes/discussions/topic/1309428#sthash.fO5X1UzG.dpuf
It
is normally available from either a droguerie or brico store.(The
latter tends to hide it away and tell you they haven't got it.) It is
called gomme laque or gomme shellac which comes in crystal form which
you then dissolve in Alchool a brulé. I have seen packets of crystals
under the Liberon name tucked away with coloured waxes in various brico
stores.Depending on what colour you are planning to paint it may be
prudent to search out the clear or blonde version. As a bit of advice
apply with a rag as it wrecks brushes very quickly. I have a feeling
there are assorted brands avalable from amazon.fr - See more at:
https://www.angloinfo.com/poitou-charentes/discussions/topic/1309428#sthash.fO5X1UzG.dpuf
It
is normally available from either a droguerie or brico store.(The
latter tends to hide it away and tell you they haven't got it.) It is
called gomme laque or gomme shellac which comes in crystal form which
you then dissolve in Alchool a brulé. I have seen packets of crystals
under the Liberon name tucked away with coloured waxes in various brico
stores.Depending on what colour you are planning to paint it may be
prudent to search out the clear or blonde version. As a bit of advice
apply with a rag as it wrecks brushes very quickly. I have a feeling
there are assorted brands avalable from amazon.fr - See more at:
https://www.angloinfo.com/poitou-charentes/discussions/topic/1309428#sthash.fO5X1UzG.dpuf