need MDF paint prep advise

[Lynn Kasdorf]

I'm making a motor cover for my old Powermatic TS so that it can have cabinet DC.

I'm making it out of 3/4" MDF (because I have a bunch of scraps laying about). I am doing a very precise job and intend to hide the seams and paint to match the saw cabinet. I want a nice smooth finish that looks like metal.

I figured I would fill any voids with Durhams wood putty, light sand and few coats of sanding sealer (which is laquer I think). Then, spray the vista green enamel on top.

Does this sound like a good approach- specifically, will enamel behave when sprayed onto sanding sealer? Maybe I should prime it with kilz or something.

Opinions?

[Jim Izat]

Whenever I try some new combination of substrates and finishes I usually (though not always) try out a sample to see how it'll work. What I do know for sure is that there are quite a few built in shelves and other things in my house that were made of mdf and they were painted with gloss enamel and sealed with painter's caulk, so I know that works okay.

Jim Izat

[Phil Phelps]

MDF is very porous. Sanding sealer will be slow to build but will dry fast. You can use urethane or an alkyd primer. I've said this many times. but I ues joint cement to fill the pours. I broad knife it on and scrape it clean. Sand with 220 and then prime. Then apply your enamel (don't dare use latex enamel) finish coats. Two minimum. It's all slow, but you do want a good job, no?

[Lynn Kasdorf]

Originally posted by Phil Phelps
but I ues joint cement to fill the pours

What is "joint cement"? Do you mean drywall joint compound?

How about polyurethane varnish as a sealer? I have a bunch of that- and maybe if I add Japan dryer it will actually dry in this cold, damp weather.

Then, there is always Deft wood finish (laquer) which dries in a few minutes (but stinks!).

I think the answer is to try test scraps.