how tough is matt varnish?

Hi.

I could suggest some nail clippers but that wouldn't be a serious answer.

The toughest paint finish would be a polyurethane(PU) paint. This is available as clear satin, clear gloss and also as a colour. If your door is painted a colour you can always paint over it with a clear PU lacquer. Although I can imagine even this finish will scratch eventually.

I don't know what type of door you have but another option would be to fix a protective plate to the door , stainless steel. Or if you want to keep the look of the dor and the colour then fix a piece of clear polycarbinate to the affected area, that way you will still see the colour but it can't get scratched. For me the last option is best.

By the way. A spray finish will apply a very thin coat and I think you need something more sunstantial.

Hope this helps.

You have several options. Since this is a painted door and not a natural finish (stained and clear coated) you are at an advantage. My first choice and I think the most durable is to re-enamel the door in the same color but in a different product. Industrial enamels are tougher than your run of the mill acrylic latex semi-gloss enamels from your local Walmart. Benjamin Moore has a product called Iron Clad. This is a satin finish alkyd modified oil enamel. Designed for metal applications in harsh conditions like those found in factories and manufacturing facilities. I would add a little paint thinner and also some penetrol. Two thin coats allowed to dry overnight in between each followed by a third full coat also dried overnight before any handling or use. Oh yeah I almost forgot before 1st coat hand sand thoroughly with 150 grit and dust/tack before applying, After 2nd coat has completely dried light powder sand door with 220 grit. Your doggy should wear out his nails before this job fails.

if she is a small dog, fit a flap door for her. I don't think the varnish will help much

buy /get a piece of plastic ..stick it on door where dog scratches ..

It is tough, but the alternative is to clip your dogs nails so they are not sharp. We always did this with our Labs.

UK