Painting Metal Ductwork

Traditions2

I have a client that wants their ceilings painted black. In addition to this they want their heat/ac ducts painted black. They are the big tubular kind. He said they have a film on them now. What would be the best method for painting these? Clean with TSP? Paint with a dtm? What about heat issues? Advice?

ShaneWarne

I might be able to help. Can you tell us what type of metal/material the duct is made out of???

NAV

the duct work has to be galvanized. you can either wipe it down with denatured alcohol or white vinegar. Use the DTM Primer Finish...it will save you time.

Make sure you dont use an oil based paint.

Traditions2

Glad I checked. Is the dtm primer finish a flat finish or semi? They said there is a film on it. Wipe it and spray away? Great. Thanks

thom

depends on the film. If it's an oily film:

first wipe down with mineral spirits or a degreaser.
then wipe down with white vinegar
then prime then paint.

The white vinegar will etch the zinc so the primer can bond but it won't clean off the oil. the degreaser will remove the oil but won't etch the zinc.

ShaneWarne

I would take extra precautions. A lot of waterbourne acrylic DTM primers only have around a 140 farenheit heat resistance. It would be worth contacting the manufacturer of the heat duct and inquire about what sort of temperatures one would expect the duct to get. Then go at least double that for resistance sake. It might be worth investigating. A standard dtm epoxy mastic has heat resistance of 300 farenheit. If using this don't wipe down with vinegar at the beginning as epoxies don't like vinegar. An inorganic zinc silicate primer will offer around 750 farenheit resistance. So check out zinc rich epoxy primers or zinc silicate primers and check their heat resistance. Also, is this system purely functional or does it serve an aesthetic purpose as well??

We Fix Houses

The heat running through the ductwork if it is fossil fuel, gas, propane oil is 110 - 120 deg F. A heat pump is about 95 deg F. You should be ok with acrylic latex (or DTM). Its used all the time on comm ceilings.

Is this a comm job. Most are done in flat that I see. DTM only comes in gloss, not sure ?? Go to the mall and look around.

Every mall has a const coordinator that works with the local / regional crews to get the stores opened on time, fire marshall approval, acceptable materials etc. Maybe worth a try to contact this person or a similar person who handles these issues regardless of the type of store.

gideond

The DTM I sell, Davis Classic DTM, comes in gloss and satin. I'm pretty sure Pratt & Lambert and SW have at least a Semi-gloss.

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Traditions2

I would like for it to be flat. We are doing the ceiling flat. It would make it much easier to do all at once. Probably won't work out that way. It is commercial

NAV

I don't think you can get a DTM in flat. it would look better in a semi-gloss.

John the estmtr

Can't post a link cause I'm under 15 posts, but dryfall from most paint stores will have the DTM properties you're looking for. As well as a direct to everything under a ceiling you could imagine. This is what they use inside all the commercial stores you see where ceilings and ducts are the same color...
I'd clean them if they're visibly oily, like the film you mentioned. Also need to remove the dust obviously.

Dryfall is your friend for ceilings. As long as you've got about 9ft under the ceiling, you just sweep the dust after painting (no masking required, but I personally wouldn't let it drop onto carpets, harder to clean). Dryfall will stick to just about everything you find on a commercial ceiling, we've sprayed it in hundreds of places with zero issue.

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Experience: Formerly an outside sales rep for a paint manufacturer. Was offered a better job as an estimator for a paint contractor company and never looked back. So when I give my .02 cents, well it still doesn't matter...

Traditions2

I've never used a dryfall before. What kind of finish? Flat? Semi? Sounds like the ticket.

NAV

You will have to use latex dryfall or epoxy ester dryfall.

it comes in all sheens up to semi-gloss

THINKPAINTING

Devoe and PPG both make a DTM Flat Finish, we would use dryfall if possible.

WisePainter

Bottom line, that is the only time for using a "dryfall".
I have used it when spraying the deck in new Home Depot stores.
It turns to a powder that easily (pretty much) sweeps away.
Dryfall saved us from laying out the 200' x 1,000,000,0000000670548 ft. plastic.

You can also use the dryfall to make neat little snowmen on the rails of your scissor lift!

Good times!

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My advice: Hire a real painter to do it.

John the estmtr

Dryfall is bomb. It's available in colors now-a-days and comes in any sheen you like ('cept high gloss). When I was a paint rep for ICI, a customer of mine used the oil base for new construction (a new Wal-Mart). He claimed it had less odor than the Sherwin Williams latex dryfall and actually enjoyed spraying it because it covered a lot better than he was used to seeing.

__________________
Experience: Formerly an outside sales rep for a paint manufacturer. Was offered a better job as an estimator for a paint contractor company and never looked back. So when I give my .02 cents, well it still doesn't matter...