Peeling Decoupage Finishes

Dealing with Peeling and Yellowing

Hi there. I have just found your site which has been very enlightening! I have been trying to crack this decoupage thing for over a year now and don't think I'm getting the combo right!

I have been decorating kids' old furniture- chairs/tables etc. I sand it then add an undercoat, usually water based, then I paint with eggshell because apparently it's more durable.

Ok the problem is with the varnish.

I have been using an oil base because again it's supposed to be hard wearing, but after a few layers it starts to yellow!

And if I scrape my fingernail over some areas it scratches off! Arhhhhhh! I'm getting really frustrated - what's the secret - pleeeeeese help me!!

Kate

I think you have two separate issues going on here.

Issue 1

You know the saying "oil and water don't mix"? That applies to when they are in their liquid states.

You can combine many oil and water-based paints and sealants if you allow each coat to cure before applying the next.

I don't mean dry-to-the-touch; I mean completely cured.

Drying and curing times are difficult to quantify since they depend on several factors: humidity; temperature; air circulation; and thickness of application. Assuming you are not trying to blend colors with additional coats, you can apply new coats of similarly-based media when the prior coat is dry to the touch.

However, do not apply an oil-based medium over a water-based one (or vice versa) until the undercoat has completely cured. If the undercoat has not completely cured when you apply the topcoat, you are sealing off the air required for the undercoat to complete its curing process.

Water-based media cure by evaporation. Water leaves the surface of the media and joins the surrounding air as long as there are spaces where the water molecules can go (less than 100% humidity).

Oil-based media cure by oxidation. Oxygen in the air is attracted to the oil molecules and chemically combines with them. The oxidized particles rise to the surface and dissipate into the air.

At room temperature and average humidity, the eggshell acrylic paint should dry within four hours and cure in two to three days.

Oil-based varnish will dry to the touch in about a day, but take two to four weeks to cure.

Issue 2

Oil-based varnish yellows over time. There is no stopping this.

If you want an antique look, oil-based varnish is fine. If you want the colors to stay as bright as the day you applied them, use an acrylic polymer varnish.

Hope this helps. I know how frustrating it is to put in so much effort on multiple layers (base coat, paint, decorations and finally varnish) only to have the piece disappoint you in the end.

You'll find additional tips on specific Child-Safe Finishes here.