I am replacing my exterior trim with a composite primed material. This is a MDF type exterior grade material which I am spray painting. In my quest for a smooth finish, I am wondering what is the best way to fill the nail holes and seams. The manufacturer recommends a latex caulk, but I am unable to get a smooth surface. I would like some type of filler that I can apply proud of the surface then sand smooth, yet it would have to be pliable enough move with climate changes. What should I use?
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If it's an MDF-type product, I'd use an epoxy wood-filler.
bondo
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MinWax makes a two part filler thats excellent.
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andy
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Not to call into question the wisdom of those who are suggesting Bondo, but several years ago we did a large job that was mostly GP PrimeTrim exterior MDF. The painter used Bondo as filler and it flaked off the surface after about six months, leading to a re-paint. I think the mistake he made was not sanding it all off except for what was in the nail hole. In other words, there was a small patch of very thin Bondo that didn't bond well to the surface of the MDF.
Exterior grade MDF?
I would like more info on that product.
I use MDO (medium density overlay), which is a plywood product. Slick as a baby's butt when painted.
Bondo will fill the holes but not stick well to the surface of MDO unless it is roughed up with a good sanding.
Dave
There may be more than one, but the one I am familiar with is Georgia-Pacific PrimeTrim. We have been using it for about four or five years, and I think it's a good product. I know a few other people on Breaktime use it as well. It comes as 1x and 5/4 stock, not as a sheet good. Not a complete replacement for wood, but good for certain things.
thanks, Nick. I'll check it out at my lumder supplier.
Dave
There is also a product called MDX or med-x board. An exterior mdf product. I like it very much, runs around $40-50.00 a sheet. I use it a lot on exterior columns.
MEDEX by name.
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