# Corroseal under Corothane 1 HS?



## futtyos (Aug 11, 2013)

I am currently prepping a metal balcony divider on a hi rise in Chicago at a unit I painted earlier this year. The divider separates the baclony for the bedrooms of 2 adjoining condos, so I am actually only doing 1/2 of the divider. The building specs Corothane Mio-Aluminum primer:

https://www.paintdocs.com/docs/webPDF.jsp?SITEID=STORECAT&doctype=PDS&lang=E&prodno=B65S14

with a top coat of Corothane 1 HS:

https://www.paintdocs.com/docs/webPDF.jsp?SITEID=STORECAT&doctype=PDS&lang=E&prodno=B65W50

I have struggled to get as much rust off as I can. I am thinking of using Corroseal rust converter before the Sherwin Williams primer and paint mentioned above:

http://www.corroseal.com/

I will probably call Corroseal later today and ask, but I thought I would float this question here first. Below are before and after pics of the metal divider. What rust that can be seen on the after is pretty well scraped, not too much loose rust even if it looks like there is. Any thoughts on using Corroseal (or a better rust converter in your opinion?) before the SW products?

















futtyos


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## sayn3ver (Jan 9, 2010)

Wouldn't a wire wheel or flap disc make that rust free pretty easily or does the neighbor/situation limit the creation of an airborne mess? 

Looks like corregated metal roofing or decking.


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## CApainter (Jun 29, 2007)

I haven't used much of the Corroseal. But a coat of Devoe Bar Rust, followed by their suggested polyurethane top coats, would guarantee a long life cycle. (Note , both products are two component)


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## futtyos (Aug 11, 2013)

*Wire wheel or flap disc*



sayn3ver said:


> Wouldn't a wire wheel or flap disc make that rust free pretty easily or does the neighbor/situation limit the creation of an airborne mess?
> 
> Looks like corregated metal roofing or decking.


I will have to try both of those. The divider is made up of separate vertical slats roughly drawn below. There is a front-top-back gap between each slate of about 1/4" to 1/2" and the slat on the left angles past and behind the slat next to it on the right aboput 1/4":









I had to find scrapers and sanding tools (Black % Decker sander/polisher and Dremel Multi-Tool) that could reach behind the 1/4" edge to get the inside edge of the angled vertical slats, but perhaps one or both of the tools you mention would be in order to get as much more of the rust off as I can. There is not much loose rust left. I imagine that a wipe down of some fast drying solvent will get most of the rust powder off as well. The solvent for the SW Corothane 1 HS costs $50.00 per gallon!!! I wonder if I can use something else, even if the SW Commercial salesman said no.

The neighbor appears to be out of town. I am vacuuming up periodically as well - even used a leaf blower to blow out the scrapings at the bottom of the slats where vacuuming does not work too well.

I will have to check out CApainter's suggestion of Devoe Bar Rust as well. Thanks, guys.

futtyos


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## CApainter (Jun 29, 2007)

It's an interesting project in terms of what coating system to use. And there is a lot to consider. For example;

Environmental Conditions
1. Is there a lot of salt, moisture, and abrasion (due to high winds)
2. Are there UV concerns (Typically south side of structure)

Aesthetics
1. Are there sheen and color requirements (polyurethanes typically have higher sheens and darker colors will fade faster). 

Occupant/Environmental Safety concerns:
1. Will solvent borne products present a problem
2. Can you manage waste from two component products
3. PPE limitations

Material
1. Need quick turnover
2. Easy clean up
3. spray or brushable
4. Performance requirements
5. surface condition and prep requirements
6. recoatable

Substrate
1. Flexible non flexible
2. Hot cold

Etc.


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## sayn3ver (Jan 9, 2010)

If you do a search for Oxalic acid it's used for both rust conversion and wood brightening for deck work. It's the active ingredient in some ready to use rust products. However if you do any deck work you may already have what you need if you want to go down that route. 

I prefer to physically remove as much rust if not all if possible, clean and immediately prime with even a rattle can of metal rust primer which can be sanded or attended to later.

It might be worth using a rust convertedr in the nooks and creases but I'm sure all need rinsing and some need neutralizing. 
That may play a role if this divider is a single layer of that overlap metal vs one layer per side of the divider as you don't want it or paint on the neighbors side unless you are being paid to do both and the neighbor has signed your contract as well.


It's also worth jumping to a car restoration sit or talking to a friend who does body work or does industrial painting like bridge work. They deal with rusted ferrous metal and oxidized non ferrous metal much more often than a typical residential painter. 

Again all advice given depends on the customer and price of the job. Some might just want to pay for a scrape and coating of dtm with the anticipation of future touch up or maintenance coats. 

Rust never sleeps.


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## CApainter (Jun 29, 2007)

sayn3ver said:


> If you do a search for Oxalic acid it's used for both rust conversion and wood brightening for deck work. It's the active ingredient in some ready to use rust products. However if you do any deck work you may already have what you need if you want to go down that route.
> 
> I prefer to physically remove as much rust if not all if possible, clean and immediately prime with even a rattle can of metal rust primer which can be sanded or attended to later.
> 
> ...


Surface tolerant coatings like Devoe Bar Rust, PPG Pitt Guard, and Amerlock 2, do work at controlling rust. They are typically high solid epoxies that allow for the high build barrier necessary to prevent moisture permeation. You could go even one step further by adding a pre-coating treatment like Devoe 167. 

My biggest concern with this particular item, would be the flexibility required from the coating. Two component epoxies, and polyurethanes, tend to be a lot less flexible than a single component Acrylic DTM. How much does that privacy screen flex?


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## Brushman4 (Oct 18, 2014)

futtyos said:


> I am currently prepping a metal balcony divider on a hi rise in Chicago at a unit I painted earlier this year. The divider separates the baclony for the bedrooms of 2 adjoining condos, so I am actually only doing 1/2 of the divider. The building specs Corothane Mio-Aluminum primer:
> 
> https://www.paintdocs.com/docs/webPDF.jsp?SITEID=STORECAT&doctype=PDS&lang=E&prodno=B65S14
> 
> ...


I must say I'm a bit confused if this is a privacy/security screen why doesn't it extend all the way out to the railing?


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## kentdalimp (Aug 15, 2013)

If it were me, I would do this: (However I would confirm with your SW Rep they will warrant it first.)

Primer: SW Maropoxy 5000 Sealer. 

It's Basically SW's Amerlock Sealer but takes longer to dry. It will go over marginally prepared steel, and you can top coat it with almost anything. (It's not cheap though. 2 part epoxy)

From there you can topcoat with the Corothane, no problem. SW makes both so you should have no problem getting a warranty. And it will last a long time. Charge enough for it, because it's not cheap or easy. But the Macropoxy should act as a barrier and bonding coat. Best thing you can do without blasting it to bare metal!


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## futtyos (Aug 11, 2013)

*No choice in primer or paint*



CApainter said:


> It's an interesting project in terms of what coating system to use. And there is a lot to consider. For example;
> 
> Environmental Conditions
> 1. Is there a lot of salt, moisture, and abrasion (due to high winds)
> ...


CAp, the condo association has pretty much limited the primer to Corothane Mio-Aluminum and the top coat to Corothan I HS. All I want to know is if it would help matters better if I used Corroseal (or some other rust converter) to convert as much of the rust as possible before priming and painting with the SW commercial products I just mentioned. The paint and primer actually have to be purchased from the condo association.

futtyos


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## kentdalimp (Aug 15, 2013)

futtyos said:


> CAp, the condo association has pretty much limited the primer to Corothane Mio-Aluminum and the top coat to Corothan I HS. All I want to know is if it would help matters better if I used Corroseal (or some other rust converter) to convert as much of the rust as possible before priming and painting with the SW commercial products I just mentioned. The paint and primer actually have to be purchased from the condo association.
> 
> futtyos


If that's the case I would just go with whats spec'd. If you add something and it fails, you are now liable. If you follow the system they provide and it fails, you are covered. 

Reading through the Product data for the Corothane Primer, It's good stuff, should work for what you are doing. But like I said, I would avoid changing whats perscribed unless I am sure what's in the spec is wrong. (At which pint I make them aware and let them change it.) 

From the PDS: Universal primer for poorly prepared surfaces, old paint, tightly adherent rust, weathered galvanized steel, and concrete.


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## CApainter (Jun 29, 2007)

futtyos said:


> CAp, the condo association has pretty much limited the primer to Corothane Mio-Aluminum and the top coat to Corothan I HS. All I want to know is if it would help matters better if I used Corroseal (or some other rust converter) to convert as much of the rust as possible before priming and painting with the SW commercial products I just mentioned. The paint and primer actually have to be purchased from the condo association.
> 
> futtyos


I'm certainly in agreement with you. I would also follow the specifications. And I would also apply an easily applicable rust converter. Those records will help you in the future.


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## futtyos (Aug 11, 2013)

*Corroseal info*



CApainter said:


> I'm certainly in agreement with you. I would also follow the specifications. And I would also apply an easily applicable rust converter. Those records will help you in the future.


CAp, I am inclined to follow what you and Kentdalimp say about following directions as far as liability goes. I got off the phone about 30 minutes ago with Joe from tech help at Corroseal. He said that Corroseal rust converter over clean galvanized metal (I do believe the balcony divider is galvanized, but not the railings) would not dry properly to be able to prime or top coat. He did say that if I brushed the Corroseal directly over the rusty areas and take care not to get it on any clean areas, that it would be okay as Corroseal is supposed to work over rust. I am thinking that if I am careful not to apply Corroseal over any non-rusty areas I should be okay.

On a side note, yesterday I took a break from scraping and sanding the balcony divider to vist the GC I do work for at the hi rises in question. This is the same contractor that I have been trying to convince me to use Gardz over everything! I spoke with him about how much work I am doing to clean the divider. He said "why don't you use Gardz?" From what I have seen on videos, Corroseal looks like and goes on like Gardz!

Ha ha

What I am not looking forward to is using the Corthane primer and top coat. It seems that the only solvent that is acceptable for use with these products is "Something 15" that SW sells for $50.00 a gallon. No quarts. Does anyone here know of a substitute solvent that i can afford to use? I can charge for the solvent if it comes down to that, but I have a feeling that the condo owner might start to wonder about the cost of all these products. The top coat is supposed to be Corothane I HS. The condo owner has left me most of a gallon of this that he wants me to use. From what I understand, once you open a can of either Corothane primer or topcoat, you have only 7 days to use it before it goes bad. The can he left for me has dried black paint drooling down the sides. My best guess is that this paint is now toast.

Presuming that the owner springs for new paint, I wonder if, here in the Chicago climate for early November, I should attach a glove-warming pad to my cut or mini roller bucket. I once did a board-up of a detached garage on the south side of Chicago that had become mostly studs. The weather was well below freezing and close to zero F. I bought some glove and boot heating pads and a few knit hats and used both to keep heating pads under the batteries of the screw guns we were using. Worked very well.

futtyos


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## CApainter (Jun 29, 2007)

Did you price the R7K 100 reducer? Corothane 1 recommends it for brush and rolling moisture cured urethanes. See Corothane 1 MIO Aluminum TDS

The following is a TDS for SW solvents
http://protective.sherwin-williams.com/detail.jsp?A=sku-31130:product-10271


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## futtyos (Aug 11, 2013)

*Reducers*



CApainter said:


> Did you price the R7K 100 reducer? Corothane 1 recommends it for brush and rolling moisture cured urethanes. See Corothane 1 MIO Aluminum TDS
> 
> The following is a TDS for SW solvents
> http://protective.sherwin-williams.com/detail.jsp?A=sku-31130:product-10271


The R7K 100 is indicated for brushing and rolling of the Mio-Aluminum @ about 40.00 per gallon only. The R7K 15 is indicated for brushing and rolling of the Corothane I HS @ about 50.00 per gallon only. I doubt I would be going through more than a pint of each. Perhaps the condo association will sell me a small amount.

futtyos


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