Can I use metal paint on wood?

February 24, 2009 5:13 AM

What exactly does it mean for paint to be formulated "for metal substrates only"? Can I use it on wood?

My husband and I are working (very sloooowly) on renovating a 120-year-old-house. All the original woodwork was stripped out of the house before we moved in, and since we can't afford to redo it in natural oak, we're putting in poplar and painting it. Years ago I chose an oil paint but apparently didn't read the fine print, which I just noticed says the paint is "for metal substrates only." I've already used in on a few surfaces: doors, spindles, crown molding. However, we still have the bulk of painting ahead of us--all the base moldings, window and door frames, etc. Is it a bad idea to continue using this paint?

I'm particularly interested in durability, since this is an immense painting project (three-story house). The already-painted surfaces (painted in the range of two to five years ago) have chipped in places, but I'd attributed that to poor surface prep. The doors and spindles had been previously painted/varnished, and I lightly sanded before painting but probably could have scuffed them up a bit more. But now I'm wondering if the formulation of metal paint keeps it from adhering well to wood?

The paint is Glidden Ultra-Hide oil/alkyd interior/exterior semi-gloss. Any info on how paints & substrates work together will be much appreciated.

posted by torticat to home & garden (7 answers total)

IANA painter.

The surface does make a difference in how well a paint adheres. However, I've found that a paint that claims to stick to relatively non-porous materials (e.g. metal or plastic) tend to stick just fine to highly porous materials (e.g. wood).

The difference in formulation of a metal paint, however, may cause damage to wood surfaces. This may not be apparent on door, but it might be apparent on fine scrollwork.
posted by Netzapper at 5:24 AM on February 24, 2009

Gliddens data sheet seems to say it's OK for wood.
posted by Science! at 5:27 AM on February 24, 2009

not so much a painter as a paint formulator. The correct substrate is definitely something that matters in the type of paint used - either because the paint should have a sealing effect, or protect the surface in some way, it could also chemically bond with the substrate (rather than just drying over the substrate). Also the paint thinner used may, or may not, damage the substrate (water, solvent, etc.). It is important to match the correct paint to the correct substrate - and, especially important, that the substrate be well-prepared (cleaned, de-greased, etc.etc.).

It looks like, in this case, with the Glidden paint you've chosen (as Science! notes) that it's OK for wood - but please note the different types of primer needed based on the type of substrate (you could argue from a paint formulators perspective that your substrate is actually the primer layer, not the wood/metal/drywall.... but that's a loooong argument).
posted by alchemist at 6:13 AM on February 24, 2009 [1 favorite]

Gliddens data sheet seems to say it's OK for wood.

Hmm. The product listed there is 3517, and the stuff I'm using is 3527. This did help me identify the source of the original confusion, though--my old paint can is 3517, the stuff that's okay for wood, and it looks like Home Depot swapped in 3527. The main difference seems to be that 3527 is rust-preventative (and says "for metal substrates only"). So will the rust-preventative stuff eat up our wood, as Netzapper suggests?
posted by torticat at 6:20 AM on February 24, 2009

It shouldn't "eat up the wood" but it'll definitely make it water proof.
posted by Max Power at 6:32 AM on February 24, 2009

Is there a toll-free number on the can you can call and ask?
posted by rhapsodie at 7:29 AM on February 24, 2009

Definitely call / email the manufacturer for tech support. Odds are that it's probably okay, but is it really worth the risk when you compare the cost of a replacement gallon of paint to the work involved in stripping and repainting?
posted by jon1270 at 7:37 AM on February 24, 2009