Anyone here ever painted a galvinized metal building?

[warhammer]

I have a 1950 vintage quonset type building on my property that has sat unused for quite a few years. Many of the panels have rusted.

The roof panels in particular look to be in an advanced rusty state on the outside but show no corrosion on the inside. The dirt on the floor looks undisturbed and dry after a rainstorm so the building seems to be reasonably water tight.

I was looking at some of the rust inhibitor paints on the internet and they are sold as converting the active rust to an inert form and adding a few mils of metal to the painted surface. Has anyone had any luck with this type of product?

From searching around it looks like it would cost almost the same price to replace the panels the as it would to put a new metal building or pole barn on the existing slab.

Warhammer

 

[mikim]

the rust converters work if you want to go that route. From what you've said I gather your options are: 1. least $$ is to repair with a rust converter then paint .... 2. replace panels at more $$ ... 3. build new at a bit more $$
so - how much ya wanna spend on it? Personally if it isn't leaking - I'd go with the rust converter then paint with mobile home roofing over that.

 

[MrJimi]

I love the building
I wish it was mine
get some Rust0leum primer and paint and have at it and be careful
Jim

 

[IllMarty1]

Painting over galvanizing can be tricky.You need a coatings that will adhere to the galvanizing.

Here is what I recomend:

1) Wirebrush or sand all loose rusty areas.
2) Pressure wash the whole building to remove all dirt, mold, etc.
3) Prime those rusted areas with Direct to Metal acrylic primer.
4) Apply 2 coats by spray waterborne acrylic dry fall.

The wire brushing doesn't have to be down to the base metal, just go over it a bit to knock off the loose stuff. After looking at the picture, a light sand blasting off the whole building will work also. Again, not removing all rust, just knocking rthe loose stuff off. You don't need to blast the galvanizing.

Please check to make sure the coating you select in 4) can be applied direct to galvanizing. Sherwin Williams has a product called Spraylastic that will work well. It says it's semigloss, but is not real shiny.

Marty

NACE Certified Coatings Inspector #13714

 

[ToadHill]

I've painted galvanized roofs with the roof coating made for motorhomes. It comes in 5 gal pails and has tar that drys ot an aluminum tint.

 

[reasley]

Good evening, Warhammer --

I just painted one several months ago. It was built around 1978 and, because it is a horse stable, it had some rusty holes along the bottom from the stalls.

I researched it quite a bit on-line and off before beginning painting it and here's what I did:

1. Prior to committing to the below process, I "test-painted" a small section with the final Direct-to-Metal paint, to satisfy my curiousity. I found it very, very hard to scratch the paint to remove it. This gave me confidence that this process would work.

2. The old paint was oxidized and very thin and a 4000 psi pressure washer removed virtually all of it. [The paint that did not come off wasn't going to come off.]

3. Using Rustoleum Rusty Metal Primer, I spot primed all rusty areas next.

4. Using Valspar Direct-to-Metal paint, I then painted the entire building with an airless sprayer.

Enclosed is a picture of the finished building.

I stumbled across the Valspar Direct-to-Metal paint at my local TSC. It comes in one gallons in store and 5 gallons by special order. When I read the label, I was excited to know that there was a paint for steel buildings that did not require a full primer coat (just the spot priming for rust).

Obviously, I have not seen the effects of a central Texas summer on it, but I feel very confident that I ended up with a very good result. I can tell you that it made an old building's outer surfaces look almost new again.

Richard

 

[reasley]

Painting over galvanizing can be tricky.You need a coatings that will adhere to the galvanizing.

Here is what I recomend:

1) Wirebrush or sand all loose rusty areas.
2) Pressure wash the whole building to remove all dirt, mold, etc.
3) Prime those rusted areas with Direct to Metal acrylic primer.
4) Apply 2 coats by spray waterborne acrylic dry fall.

The wire brushing doesn't have to be down to the base metal, just go over it a bit to knock off the loose stuff. After looking at the picture, a light sand blasting off the whole building will work also. Again, not removing all rust, just knocking rthe loose stuff off. You don't need to blast the galvanizing.

Please check to make sure the coating you select in 4) can be applied direct to galvanizing. Sherwin Williams has a product called Spraylastic that will work well. It says it's semigloss, but is not real shiny.

Marty

NACE Certified Coatings Inspector #13714

Good evening, Marty --

I just noticed your post on this thread and noticed that you are a coatings inspector. I would be grateful to hear from you about the process that I did in my previous post. One thing that you mention above that I'd like clarification on is the caution about painting galvanized -- isn't it true that, on very old galvanized buildings, the fact that it's galvanized is not a huge factor because a) it is not new and b) because of the deterioration of the galvanization?

Couple of other questions:

1. I've enclosed the jpg of the paint that I used -- are you familiar with it and, if so, how would you rate it?

2. Related to #1, this paint is around $105 per 5 gallon pail at TSC but I also checked Sherwin-Williams before purchase to see how much their Direct-to-Metal costs -- it is $250 per 5 gallon pail. Are there significant differences in materials between the two paints?

Thanks in advance . . .

Richard

 

[warhammer]

Thanks for the replies.
The building is a pretty cool style. The wind can be really blowing hard and it is silent inside the building. No creaks, groans or wind noise at all.
Its near impossible to find anyone that actually works on this style building though. Getting curved to fit panels also looks to be a daunting (expensive) task.

Rust Bullet – Rust Prevention Products & Corrosion Inhibitor Paint Product

Above is a link I found to a product that states that you knock the loose stuff off and spray two coats several hours apart and you are good to go.

Anyone heard of this product? Kind of pricey but looks like its made for this type of application.

As soon as I get the barn squared away I can buy a tractor as I have lined up insurance, OK from Wife, downpayment etc. ;o}

Warhammer

I love the building
I wish it was mine
get some Rust0leum primer and paint and have at it and be careful
Jim

 

[warhammer]

I think painting is the way I am going to go.
What is "mobile home roofing" ?
I have a decent airless sprayer can it be applied with that?

Warhammer

the rust converters work if you want to go that route. From what you've said I gather your options are: 1. least $$ is to repair with a rust converter then paint .... 2. replace panels at more $$ ... 3. build new at a bit more $$
so - how much ya wanna spend on it? Personally if it isn't leaking - I'd go with the rust converter then paint with mobile home roofing over that.

 

[mikim]

mobile home roofing is a tar like substance that is a gold color when it is first applied (I used a 6" short nap push broom -- almost a scrub brush on a long handle) but then it dries to a silver color. It's thick to apply and it's not real cheap - but it lasts for years. It's made to go on galv roofs. I used the stuff twice - both times I washed the roof down with bleach, let it dry overnight, then applied the roofing the next day. I never had to reapply - and the one I did was on an old 12 X 60 mobile from 1970 .....I recoated it in 1992 and we're still using it as a weekend place. Roof hasn't leaked yet. I never had much rust to deal with though. I'm thinking wire wheel on the loose rust, spray or paint on the rust converter of choice, then mobile home roofing or that new paint the others are talking about and you should be good to go. -- Lot of work ahead of you regardless. - have fun. ----and hurry - it's gonna get hot real soon.