DIY Home Improvement, Remodeling & Repair Forum > DIY Home Improvement > Painting Forum > Can Security Magnets Cause Blistering Paint?




Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old 06-27-2014, 03:09 PM  
MacInAction
Junior Member
 
Join Date: Aug 2012
Posts: 7
Liked 1 Times on 1 Posts

Default Can Security Magnets Cause Blistering Paint?

I've now seen two metal front doors that have large, growing blisters of paint, both of which had security magnets drilled into them for the home security system. Can the magnets cause a chemical reaction that causes the paint to blister?

I tried to help my neighbor a few years ago to repair the blisters. The blistered areas were sanded to the metal, and painted with one of the major brands that was listed as rusty metal primer. To my surprise, the rust began to reappear as the paint was drying! The job failed, and my neighbor mentioned that the security system was installed a few months before the blisters appeared. Could there be a connection?

I was recently asked to repaint a door for someone in another home that had the same occurrence of random blisters. This door also had an alarm system with a magnet drilled into the door.



__________________

Last edited by MacInAction; 06-27-2014 at 03:11 PM. Reason: Typo in Title
MacInAction is offline  
 
Reply With Quote Quick reply to this message
Old 06-27-2014, 04:31 PM  
CallMeVilla
Contractor
 
CallMeVilla's Avatar
 
Join Date: Feb 2010
Location: San Diego
Posts: 1,220
Liked 353 Times on 278 Posts
Likes Given: 141

Default

If there is a cause, it must be condensation, not the magnets ... This is not a "weird science" moment.



__________________
CallMeVilla is offline  
 
Reply With Quote Quick reply to this message
Old 06-28-2014, 08:29 AM  
DFBonnett
Member
 
Join Date: Apr 2012
Posts: 68
Liked 16 Times on 16 Posts
Likes Given: 11

Default

OP,
As CMV noted, there is a cause or causes but the magnets are not one of them. Incorrect product selection and/or application or poor surface preparation are more likely the cause.

__________________
DFBonnett is offline  
nealtw Likes This 
Reply With Quote Quick reply to this message
Old 06-29-2014, 09:19 AM  
kok328
Supporting Member
HRT_SUPPORTER.png
 
Join Date: Nov 2007
Location: Grand Blanc, MI
Posts: 2,171
Liked 102 Times on 89 Posts
Likes Given: 61

Default

when you drill through the rust protective layers to install a screw, you've now exposed bare metal to the elements. Over time, it will begin to rust. From there it's all downhill.
The magnet itself is not the cause, just the installation of it.
Likewise for a door knocker.

__________________
kok328 is offline  
 
Reply With Quote Quick reply to this message
Old 06-29-2014, 11:03 AM  
MacInAction
Junior Member
 
Join Date: Aug 2012
Posts: 7
Liked 1 Times on 1 Posts

Default

What would cause the rust to appear moments after paint application? These new rust spots appeared almost immediately, and they grew as we watched. The metal was sanded until it was bare. I assume the 'rusty metal primer' I purchased from the big box store must be the culprit?

I've never seen rust grow before my eyes, and it always baffled me as to how that can happen.

__________________
MacInAction is offline  
 
Reply With Quote Quick reply to this message
Old 06-29-2014, 12:08 PM  
oldognewtrick
Moderator
HRT_MODERATOR.png
 
oldognewtrick's Avatar
 
Join Date: Jul 2009
Location: Nashville, TN
Posts: 4,761
Liked 378 Times on 314 Posts
Likes Given: 123

Default

It doesn't sound like rust, but more of a reaction to contaminates on the metal. Oil, dirt will cause blisters. What measures did you take to prep the surface? Are you using compatible primer and topcoat?

__________________
oldognewtrick is offline  
 
Reply With Quote Quick reply to this message
Old 06-29-2014, 05:12 PM  
CallMeVilla
Contractor
 
CallMeVilla's Avatar
 
Join Date: Feb 2010
Location: San Diego
Posts: 1,220
Liked 353 Times on 278 Posts
Likes Given: 141

Default

The door is probably painted with latex paint. The spray primer is solvent based. The "blisters" you see are the reaction of the latex paint to the solvent. Yes, you got to bare metal but the perimeter still has latex paint and I would bet the reaction is there, not on the bare metal.



__________________
CallMeVilla is offline  
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 On
Refbacks are On


Similar Threads
Thread Thread Starter DIY Home Repair Forum Replies Last Post
peeling paint ukpete Painting Forum 0 09-11-2013 05:31 AM
peeling paint bob bragg Painting Forum 1 08-31-2009 12:43 PM
Peeling Paint Akshay Walls and Ceilings 2 03-18-2009 12:36 PM
Barhroom Ceiling Peeling sjm1027 Walls and Ceilings 3 02-25-2008 06:55 PM
peeling bathtub drunkugly General Home Improvement Discussion 1 07-12-2006 08:43 PM