Painting MR MDF?

[steven_p_sparrow]

Hi All,

I'm making my first venture in larger outside signs in Moisture Resistant MDF (I have excellent dust extraction BTW!)

I'm hoping that someone will be able to give me advice on painting/priming/sealing the finished signs.

Also, does anyone have an idea what material would be better than MR MDF, i.e. similar properties apart from the ones that kill you!?

TIA

Steve

www.steamplates.co.uk (http://www.steamplates.co.uk)

[scootie]

Steven.
The material is "water resistant" so that means it is not water proof. By the time you get this type material sealed to prevent ANY moisture from getting into it you usually have more labor than the money you saved in the cost of the material. Once it is put outside in the weather even the slightest ding or scratch will soon become a major blemish. If you must use MDF, round over all the edges, seal twice with an epoxy or 2-part urethane, prime, and paint heavily, then pray. In a year or two when the customer calls and says "my sign is falling apart" you can replace it for free or get a reputation of building signs that won't hold up.
HDU is the choice for exterior dimensional work, if it gets a ding it will not take on moisture or cause further deterioration. Sure it's 4 to 5 times the cost, but it's the customer paying for it, not you. In 10 or 15 years the customer will call and say "my sign needs just needs a repaint", and you'll have a happy client.