Rusted metal roof - Paint Talk - Professional Painting Contractors Forum
CLICK HERE AND JOIN OUR COMMUNITY TODAY, IT'S FREE!
Go Back   Paint Talk - Professional Painting Contractors Forum > Professional Painters > Specialty Coatings


Like Tree1Likes
Reply
 
Thread Tools Display Modes
Old 06-11-2014, 12:53 AM   #1
Junior Member
 
Join Date: Mar 2012
Location: Lancaster, PA
Posts: 28
Rewards Points: 26
Thanks: 9
Thanked 4 Times in 2 Posts
View jacobs's Photo Album My Photos
Default Rusted metal roof

I have three jobs coming up that are metal roofs, with rust, and all three customers made similar comments: "that roof was painted 6 years ago, but it looked like that a year after the guy painted it". My sales pitch was that I would wire brush the rust, coat it with SW KembondHS, and then use SW DTM. Claiming that it should last much longer than their previous paint job. The other option I offered was to use an elastomeric coating. So then I go back to my local network of painters and SW rep and I get ten different descriptions of what I could do, what I should use and how long I could expect it to last before re rusting/peeling off. I prefer to use paint instead of elastomeric but I also prefer to not come back next year. Any comments/advice much appreciated.
Attached Thumbnails
Rusted metal roof-rusted-metal-roof-job-before-pic.jpg  

jacobs is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-11-2014, 05:32 AM   #2
Senior Member
 
cdpainting's Avatar
 
Join Date: Oct 2012
Posts: 8,620
Rewards Points: 922
Thanks: 4,519
Thanked 4,500 Times in 2,836 Posts
View cdpainting's Photo Album My Photos
Default

I have not done any metal roofs. Would a rust converter work? I would think a rust converter or sand/soda blaster.
Eagle Cap Painter likes this.
cdpainting is online now   Reply With Quote
Old 06-11-2014, 07:08 AM   #3
Senior Member
 
Delta Painting's Avatar
 
Join Date: Apr 2010
Location: Michigan
Posts: 1,285
Rewards Points: 1,106
Thanks: 4,182
Thanked 687 Times in 476 Posts
View Delta Painting's Photo Album My Photos
Default

Sand\ wire brush, then use penatrol too seal rust top with the coating of your choice...
__________________
http://www.deltapaintingmi.com/
Delta Painting is offline   Reply With Quote
 
Old 06-11-2014, 07:22 AM   #4
Senior Member
 
straight_lines's Avatar
 
Join Date: Oct 2007
Location: Wilmington, N.C.
Posts: 7,822
Rewards Points: 1,574
Thanks: 5,686
Thanked 5,171 Times in 2,980 Posts
View straight_lines's Photo Album My Photos
Send a message via Yahoo to straight_lines
Default

Quote:
Originally Posted by cdpainting View Post
I have not done any metal roofs. Would a rust converter work? I would think a rust converter or sand/soda blaster.
I agree that looks like one that needs blasting to get any longevity out of a new coating. House also looks pre 73 and there is a good chance there is lead there.
__________________
JHC Armorcoat


Primer makes everything better...

Last edited by straight_lines; 06-11-2014 at 07:27 AM..
straight_lines is offline   Reply With Quote
The Following User Says Thank You to straight_lines For This Useful Post:
cdpainting (06-11-2014)
Old 06-11-2014, 07:57 AM   #5
Senior Member
 
Join Date: Dec 2011
Location: mo.
Posts: 4,068
Rewards Points: 2,640
Thanks: 1,324
Thanked 2,055 Times in 1,349 Posts
View mudbone's Photo Album My Photos
Default

Similar situation awhile back and had sw rep take a look at it and what he recommended. Turned out the price for their products were higher then a new metal roof!
mudbone is offline   Reply With Quote
Old 06-11-2014, 09:28 AM   #6
Senior Member
 
journeymanPainter's Avatar
 
Join Date: Feb 2014
Location: Vancouver(surrounding area) BC
Posts: 2,860
Rewards Points: 674
Thanks: 3,270
Thanked 1,640 Times in 1,052 Posts
View journeymanPainter's Photo Album My Photos
Default

To do the job properly, yes the materials will probably cost more than getting a new roof (especially if you use BM, or SW). This is always something I've wanted to get into because there are probably 60-80 farms between me and the city.

Wire brush (go with a wire wheel on a grinder), rust inhibitive primer (or red oxide primer), then I personally would use a high build DTM primer, then your top coats.

I don't think an elastomeric coating will do anything for you or the owner.

Sent from my SGH-T989D using Tapatalk
journeymanPainter is offline   Reply With Quote
The Following 2 Users Say Thank You to journeymanPainter For This Useful Post:
jacobs (06-11-2014), Jmayspaint (06-11-2014)
Old 06-11-2014, 10:02 AM   #7
Junior Member
 
Join Date: Mar 2012
Location: Lancaster, PA
Posts: 28
Rewards Points: 26
Thanks: 9
Thanked 4 Times in 2 Posts
View jacobs's Photo Album My Photos
Default

Thanks, I got two of the three jobs and have one more estimate to prepare today. On this last job its a metal shingled roof (not the picture above)that roofing companies already priced there solution out of his range which was about the same as my on site quote of $3500 which I thought was competitive. I told him if he wanted to drop the price a thousand I could just wire brush it and paint with DTM but it probably wouldn't last two years and that I try to do things to make my jobs last a good ten years (not warrantied for that long of course) but that I try to produce high quality work. Ive been pretty steady 4 years now so I don't really need to low ball or take slop jobs. Im starting to get more calls for metal roofs and am trying to learn some of the options, like when do I coat a roof with roofing products instead of DTM, what is the situation that makes the difference, for pitched metal roofs with rust, My big question is what do I use to make it last ten years plus? Is the three product method that you mentioned going to make it last that long if prepped and applied properly?
jacobs is offline   Reply With Quote
Old 06-11-2014, 10:09 AM   #8
Lambrecht Painting
 
Lambrecht's Avatar
 
Join Date: Feb 2010
Location: Indiana
Posts: 1,607
Rewards Points: 1,094
Thanks: 1,797
Thanked 1,307 Times in 656 Posts
View Lambrecht's Photo Album My Photos
Default

Corotech 100% Solids Pre-Prime V155. This is a 2-part epoxy clear primer that encapsulates the rust and will not allow it to grow anymore. Coverage is approximately 1200 sq Ft per gallon. This is the only product I will use on heavily rusted exterior surfaces. I first used it on a heavily rusted scaling airplane hanger where the only prep work was pressure washing then topcoated with PPG industrial DTM. 3 years have past and no sign of any rust and the topcoat still looks freshly painted. I have also used it on many smaller buildings and have not had a single failure. Benjamin Moore carries it or can get it for you.
__________________
The easiest job you will ever have is waking up and going to work for someone else.
Lambrecht is offline   Reply With Quote
The Following 2 Users Say Thank You to Lambrecht For This Useful Post:
Delta Painting (06-11-2014), jacobs (06-12-2014)
Old 06-11-2014, 10:25 AM   #9
Senior Member
 
Jmayspaint's Avatar
 
Join Date: Mar 2013
Location: East TN
Posts: 3,812
Rewards Points: 4
Thanks: 1,778
Thanked 3,589 Times in 1,810 Posts
View Jmayspaint's Photo Album My Photos
Default

I have had the best luck on rusty roves using red oxide primer, and top coating with DTM. Rustolem Rusty Metal primer works really well, or Khem Kromic if you want something more heavy duty.

Something to look out for on those old metal shingle roves is that some of them are made from passivated galvanized metal. A copper sulfate test will show if the metal is passivated or not. If it is, extreme measures have to be taken to get any coating to stick.

This is a passivated shingle roof I ran into that was peeling horribly. The blue crystals are copper sulfate. On a regular galvanized roof, copper sulfate dissolved in water will cause a reaction than leaves a black residue on the surface. No black residue means the galvanized has been passivated.
Attached Thumbnails
Rusted metal roof-image-4155226376.jpg  

Jmayspaint is online now   Reply With Quote
The Following 2 Users Say Thank You to Jmayspaint For This Useful Post:
Delta Painting (06-11-2014), jacobs (06-12-2014)
Old 06-12-2014, 11:51 PM   #10
Junior Member
 
Join Date: Mar 2012
Location: Lancaster, PA
Posts: 28
Rewards Points: 26
Thanks: 9
Thanked 4 Times in 2 Posts
View jacobs's Photo Album My Photos
Default

How have you applied the corotech ? have you ever sprayed it?
jacobs is offline   Reply With Quote
Old 07-16-2014, 03:28 PM   #11
Member
 
Join Date: Aug 2013
Posts: 33
Rewards Points: 48
Thanks: 7
Thanked 9 Times in 7 Posts
View kentdalimp's Photo Album My Photos
Default

You can either fix the problems (blasting the rust off) or try and cover it up. The Problem with fixing it is the price will be high.

Other have suggested encapsulation. We've had good luck with Amerlock sealer as a primer. Just make sure and coat everything. Then you can topcoat with almost anything. (Latex, etc.) Should hold up for 5+ years if you cover all the rust well.

Look into Noxyde by Rustoleum (mathys) haven't used it but have really been looking for an excuse to.

Good luck!
kentdalimp is offline   Reply With Quote
Old 07-16-2014, 06:22 PM   #12
Junior Member
 
Join Date: Jun 2014
Posts: 16
Rewards Points: 30
Thanks: 57
Thanked 8 Times in 5 Posts
View Paint it Now's Photo Album My Photos
Default

Hand scrape, wire brush loose coating. Rinse. Two full coats non fibered asphalt aluminum roof coating. Highly reflective, attractive and will encapsulate the rust. Will not peel if the loose coating is removed and will Last.
Paint it Now is offline   Reply With Quote
Old 07-17-2014, 01:05 AM   #13
Senior Member
 
journeymanPainter's Avatar
 
Join Date: Feb 2014
Location: Vancouver(surrounding area) BC
Posts: 2,860
Rewards Points: 674
Thanks: 3,270
Thanked 1,640 Times in 1,052 Posts
View journeymanPainter's Photo Album My Photos
Default

Quote:
Originally Posted by jacobs View Post
Thanks, I got two of the three jobs and have one more estimate to prepare today. On this last job its a metal shingled roof (not the picture above)that roofing companies already priced there solution out of his range which was about the same as my on site quote of $3500 which I thought was competitive. I told him if he wanted to drop the price a thousand I could just wire brush it and paint with DTM but it probably wouldn't last two years and that I try to do things to make my jobs last a good ten years (not warrantied for that long of course) but that I try to produce high quality work. Ive been pretty steady 4 years now so I don't really need to low ball or take slop jobs. Im starting to get more calls for metal roofs and am trying to learn some of the options, like when do I coat a roof with roofing products instead of DTM, what is the situation that makes the difference, for pitched metal roofs with rust, My big question is what do I use to make it last ten years plus? Is the three product method that you mentioned going to make it last that long if prepped and applied properly?
Epoxy

Sent from my SGH-T989D using PaintTalk.com mobile app
journeymanPainter is offline   Reply With Quote
Old 07-17-2014, 09:21 AM   #14
Senior Member
 
painter213's Avatar
 
Join Date: Nov 2008
Location: Birmingham, Al.
Posts: 217
Rewards Points: 150
Thanks: 21
Thanked 97 Times in 51 Posts
View painter213's Photo Album My Photos
Default

Journeymanpainter, epoxy on a metal roof would crack and make it leak worse than it was in the beginning. Epoxy coatings are too rigid and lack the elongation needed for a metal roof. Metal roofs have a lot of movement and would cause the epoxy to crack and sheer. Someone above mentioned aluminum asphalt roof coating. For a inexpensive repair that just cannot be beat. I've seen them last for many years. That's what I would suggest.
__________________
NACE Certified Coatings Inspector Level III #7953,
SSPC Protective Coatings Specialist #2014-529-139
E-Mail: babbott@abbottcoatinginspections.com
Phone: (205-717-0292)
painter213 is offline   Reply With Quote
Old 07-17-2014, 08:37 PM   #15
Junior Member
 
Join Date: Jun 2014
Posts: 16
Rewards Points: 30
Thanks: 57
Thanked 8 Times in 5 Posts
View Paint it Now's Photo Album My Photos
Default

Check it out http://www.karnakcorp.com/images/PDF/28.pdf
Paint it Now is offline   Reply With Quote
Old 07-17-2014, 09:52 PM   #16
Senior Member
 
journeymanPainter's Avatar
 
Join Date: Feb 2014
Location: Vancouver(surrounding area) BC
Posts: 2,860
Rewards Points: 674
Thanks: 3,270
Thanked 1,640 Times in 1,052 Posts
View journeymanPainter's Photo Album My Photos
Default

Quote:
Originally Posted by painter213 View Post
Journeymanpainter, epoxy on a metal roof would crack and make it leak worse than it was in the beginning. Epoxy coatings are too rigid and lack the elongation needed for a metal roof. Metal roofs have a lot of movement and would cause the epoxy to crack and sheer. Someone above mentioned aluminum asphalt roof coating. For a inexpensive repair that just cannot be beat. I've seen them last for many years. That's what I would suggest.
Sorry but you are 100% wrong (please note, all read was about how epoxy on a metal roof will crack).

I know this because I sprayed epoxy on a METAL roof of the Best Western in Abbotsford BC, and Langley BC. The roofs went from green to black as well

Sent from my SGH-T989D using PaintTalk.com mobile app
journeymanPainter is offline   Reply With Quote
Old 07-17-2014, 10:54 PM   #17
NACE COATINGS INSPECTOR
 
mustangmike3789's Avatar
 
Join Date: Jun 2011
Location: Florida
Posts: 284
Rewards Points: 224
Thanks: 146
Thanked 178 Times in 116 Posts
View mustangmike3789's Photo Album My Photos
Default

i think that some epoxy coatings can withstand the movement of a metal roof depending on the type of epoxy but they will need to be top coated to keep it from chalking. I wouldn't put epoxy direct to the galvanized surface because the reaction from the alkaline levels in the zinc and the esters in the epoxy can cause saponification especially in humid environments.

Last edited by mustangmike3789; 07-18-2014 at 01:10 AM..
mustangmike3789 is online now   Reply With Quote
The Following User Says Thank You to mustangmike3789 For This Useful Post:
Jmayspaint (07-17-2014)
Old 07-18-2014, 09:22 AM   #18
Senior Member
 
painter213's Avatar
 
Join Date: Nov 2008
Location: Birmingham, Al.
Posts: 217
Rewards Points: 150
Thanks: 21
Thanked 97 Times in 51 Posts
View painter213's Photo Album My Photos
Default

Quote:
Originally Posted by journeymanPainter View Post
Sorry but you are 100% wrong (please note, all read was about how epoxy on a metal roof will crack).

I know this because I sprayed epoxy on a METAL roof of the Best Western in Abbotsford BC, and Langley BC. The roofs went from green to black as well

Sent from my SGH-T989D using PaintTalk.com mobile app
Spraying a true epoxy on a roof and it actually working is two different subjects. I know of a lot of people that have used different coatings on different substrates all the time. Do they actually work? I'll just say that I get paid a lot for performing consulting and failure analysis work. When we say epoxy, are we actually talking about a true epoxy "Polyamide Epoxy, Polyamine Bisphenol Epoxy or Novalac Epoxy" or are we talking about what I would call a Epoxy Hybrid such as a Epoxy Siloxane? A epoxy siloxane is labeled as an epoxy but it actually has an amount of polyurethanes in the chemistry.

A TRUE Epoxy does not have good elongation nor is it UV stable. Just because it may be labeled as being a epoxy material, does not make it a epoxy material. Some people think that just because the material is a two component material, that it makes it a epoxy. WRONG!!

Yes, there is roof coatings out there that claim to be epoxy's, but when you get down to the actual chemistry of the formulation, they are in fact a polyurethane elastomeric coating that has been labeled as an epoxy. The chemistry will have very little epoxy chemistry in fact. I do not know of any true epoxies that is UV stable.

So, if you take a true epoxy, let's say a polyamide type epoxy and apply it to a metal roof. With the expansion and contraction of such said roof, in time the epoxy will begin to crack and fail in all of the joints and attachments "screws" due to the movement of the roof.

Benny "Benjy" Abbott
Abbott Consulting & Coating Inspections
__________________
NACE Certified Coatings Inspector Level III #7953,
SSPC Protective Coatings Specialist #2014-529-139
E-Mail: babbott@abbottcoatinginspections.com
Phone: (205-717-0292)
painter213 is offline   Reply With Quote
Old 07-18-2014, 09:27 AM   #19
Senior Member
 
painter213's Avatar
 
Join Date: Nov 2008
Location: Birmingham, Al.
Posts: 217
Rewards Points: 150
Thanks: 21
Thanked 97 Times in 51 Posts
View painter213's Photo Album My Photos
Default

Quote:
Originally Posted by mustangmike3789 View Post
i think that some epoxy coatings can withstand the movement of a metal roof depending on the type of epoxy but they will need to be top coated to keep it from chalking. I wouldn't put epoxy direct to the galvanized surface because the reaction from the alkaline levels in the zinc and the esters in the epoxy can cause saponification especially in humid environments.
We specify epoxy over zinc all the time Mike. I've never heard of saponification between an epoxy and zinc. Now if you apply an Alkyd coating over a zinc or concrete substrate then yes, you will have saponification to occur, but I have never seen or heard of it happening between a zinc and epoxy coating before. Do you have any instance's of this happening?

Benny "Benjy" Abbott
Abbott Consulting & Coating Inspections
__________________
NACE Certified Coatings Inspector Level III #7953,
SSPC Protective Coatings Specialist #2014-529-139
E-Mail: babbott@abbottcoatinginspections.com
Phone: (205-717-0292)
painter213 is offline   Reply With Quote
The Following User Says Thank You to painter213 For This Useful Post:
journeymanPainter (07-18-2014)
Old 07-18-2014, 11:04 AM   #20
NACE COATINGS INSPECTOR
 
mustangmike3789's Avatar
 
Join Date: Jun 2011
Location: Florida
Posts: 284
Rewards Points: 224
Thanks: 146
Thanked 178 Times in 116 Posts
View mustangmike3789's Photo Album My Photos
Default

Quote:
Originally Posted by painter213 View Post
We specify epoxy over zinc all the time Mike. I've never heard of saponification between an epoxy and zinc. Now if you apply an Alkyd coating over a zinc or concrete substrate then yes, you will have saponification to occur, but I have never seen or heard of it happening between a zinc and epoxy coating before. Do you have any instance's of this happening?

Benny "Benjy" Abbott
Abbott Consulting & Coating Inspections
yes you are correct. we have done epoxy over galvanized metal also depending on the "type" of epoxy used, but as you said, some epoxy is more of a modified urethane and not a "true" epoxy.

some epoxy esters used are basically an oil based paint with epoxy resins used which when applied over galvanized metal (zinc) will saponify. I have applied cycloaliphatic amine epoxy over galvanized steel several times without any problems but I don't think that it would hold up on a metal roof because of the reasons that you mentioned earlier.
mustangmike3789 is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Metal Roof Roof Cleaning General Painting Discussion 16 01-10-2014 09:25 PM
Pine sap on metal roof. Jmayspaint General Painting Discussion 12 04-18-2013 06:49 PM
Metal Roof michfan General Painting Discussion 24 11-27-2012 06:58 PM
rusted metal structure dpainterman Surface Preparation and Application 10 10-15-2011 12:59 PM
need some advice on severely rusted metal paintr56 General Painting Discussion 18 03-17-2011 01:30 AM


All times are GMT -4. The time now is 03:20 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Our Pro Sites Network
ContractorTalk.com | DrywallTalk.com | ElectricianTalk.com | HVACSite.com | PlumbingZone.com | RoofingTalk.com