Painting Freshly Cut MDF
#1
01-04-17, 07:50 AM
Painting Freshly Cut MDF
I'm making a subwoofer enclosure out of MDF with recessed baffle, and will be cutting a 1/2" roundover in the front baffle. I did this on a previous build and the area I cut was dull whereas the surrounding undisturbed surface was nice and shiny after the first coat. What's the best way to ensure the paint on the routed area looks the same as the un-routed areas? I am using a spray can of paint and primer in-one. I realize it's because the wood is soaking up the paint, so I'm trying to determine how best to prevent this.
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#2
01-04-17, 08:30 AM
Member
Try a glue size. Mix pva wood glue and water 50-50 and paint it on the cut area. Let it dry and then sand lightly with 220 grit sandpaper.
Another approach often used on MDF is to butter the cut edge with a thin coat of sheetrock joint compound, let it set, and then sand. This approach is better if you have any tearout in the cut areas, which is pretty common on MDF.
Another approach often used on MDF is to butter the cut edge with a thin coat of sheetrock joint compound, let it set, and then sand. This approach is better if you have any tearout in the cut areas, which is pretty common on MDF.
#3
01-04-17, 08:32 AM
Group Moderator
Paint and primer in one is not primer. I would use an actual primer first.
#4
01-04-17, 08:40 AM
Another approach often used on MDF is to butter the cut edge with a thin coat of sheetrock joint compound, let it set, and then sand.
#6
01-10-17, 07:47 AM
I ended up using DAP vinyl spackling on all the edges and routed cuts and sanded everything smooth. Now I need tips on the painting process, primarily how many coats and when to wet sand. For example, do I wet sand after each coat, or after every couple coats? Do I sand after priming, painting, AND clear coat? Is 400 grit a good grit to use or should I go with 600? Use a soapy solution?
#7
01-10-17, 07:50 AM
Group Moderator
I can't imagine wet sanding MDF. I wouldn't use a clear coat on it either.
#10
01-10-17, 09:01 AM
Painting metal usually requires thinner coats of paint and finer sanding than painting wood/mdf. With wood/mdf you want a heavier coating of paint to make the finish appear smoother, with metal you already have a slick surface. No need to wet sand when the heavier coating will fill in the minute sanding scratches.
#12
01-10-17, 11:20 AM
Just to be clear I wasn't suggesting to not use a primer. A raw substrate always needs a primer [including patches on previously painted surfaces] Repaints don't always need a primer. The big difference between painting metal versus wood or drywall is the mil thickness of the coating applied.
