Any paint will adhere to lead based paint and seal it. Latex is the easiest. The lead will not bleed through and is not harmful as long as it is not flaking off. It is only harmful if a child chews on it and swallows it.
If the lead-based paint is sound and is not peeling or cracking, you can paint directly over it without the use of a primer because lead-based paint in itself is a form of primer.
That said, if children or pregnant women are using the painted area, it is safer to totally strip off all the old, lead paint down to the bare wood making sure that you use lead-safe work practices. (See the Sources and related links section, below, for more information)
An environmentally safe and clean method is to use Speedheater Infrared Paint Remover which doesn't vaporize the lead in the paint and create clumps of heated, soft paint for easy containment and disposal. Then you can either stain, varnish or prime and repaint.
NO! Latex paint will seal in the oil-based varnish and will lead to cracking and peeling, as well as not adhering properly, since any oil-based product never fully dries. It's ok if done the other way around though.
Indeed you can. As an example Most vehicles have base coat and lacquer finish these days. Adding varnish over a painted surface will preserve the paint.
Oil based paint can be used over wood varnish. I wouldn't recommend using a latex.
If it's enamel based, not latex based.
Yes, you can.
yes
Yes, you can. Use workable fixative or retouch varnish.
If the varnish hasn't already dried, I'm afraid the only way to conceal it will be to paint over it. If it hasn't, wipe it up quickly.
Start with a primer, Perma Seal is great. then I would use oil based paint.
Paint can be applied over varnish, but it needs to be a compatible type of paint for the type of varnish, and the surface needs to be prepared by removing loose material, dirt and sanding. If it is not a compatible paint the surface needs to be etch primed. Contact a local paint supplier for advice.
For oil paintings: best let it dry for a longer time (6 months or so), then put dammar varnish over it. The long drying time makes sure you can take off the varnish later, without harming the paint itself.
That is not generally recommended.
It will protect the paint as long as you use a water based varnish, never use oil based varnish over water based paint. Tip: "water based enamel= water based finish". "oil based enamel= oil based finish".
Yes, you can. Use workable fixative or retouch varnish.
If the varnish hasn't already dried, I'm afraid the only way to conceal it will be to paint over it. If it hasn't, wipe it up quickly.
Start with a primer, Perma Seal is great. then I would use oil based paint.
Paint can be applied over varnish, but it needs to be a compatible type of paint for the type of varnish, and the surface needs to be prepared by removing loose material, dirt and sanding. If it is not a compatible paint the surface needs to be etch primed. Contact a local paint supplier for advice.
Yes, but I usually sand it lightly first.
For oil paintings: best let it dry for a longer time (6 months or so), then put dammar varnish over it. The long drying time makes sure you can take off the varnish later, without harming the paint itself.
Usually yes. You'd be advised to use a water based varnish, and rough up the paint a little before coating.
Varnish preserves wood better than paint.
The crackelure (craquelure) on an oil painting are the small cracks that appear as a result of the paint and/or varnish shrinking.
You can but you will want to give the vaneer a light sanding first.