Possible Mazda panel joint compound corrosion issue.
10-27-2013, 05:31 PM
#1
Possible Mazda panel joint compound corrosion issue.
I sent a PM to AaronCake over at rx7club.com and to save me the hassle, I'll just quote it.
Again, the paint bubbling is all located at the joint compounds used for the panel seams int he jambs. So far I have discovered it to only be on the aluminum hood and the passenger and driver side door panel joints in the jambs. Primarily the drain holes at the bottom of the panel where the weather strip is located. No holes or perforations yet. Just surface corrosion under the joint compound and paint.
My RX-8 is religiously taken care of. Those who have seen it in person can attest to that as it is simply pristine minus the mentioned issue. Hence the reason I am directly pointing fingers at Mazda for this issue.
I have attached pictures, and they are pretty much self-explanatory. Does not include pic of the panel prior to sanding and after wire wheel. Fortunately the section underneath the weather strip cannot be seen as the strip covers it (without making direct contact to the refinished section). I do have confidence that the refinished section will hold its own against corrosion with POR-15. I am no expert at fighting body corrosion, hence the reason I have asked Aaron Cake for advice. For those knowledgeable, feel free to contribute as well.
I suggest everyone to check said locations for paint bubbling as well. Even if you have rust/corrosion warranty, it will only be covered when there is perforation (hole/s), which is too late already.
I have been trying to tackle some rust issues on my RX-8. Having learned the properties of POR-15 and watching your Cosmo restoration videos. I decided to use it for my application. I purchased a small POR-15 Starter Kit with Marine Clean, Prep & Ready, and a small can of POR-15.
I do have a few concerns. My RX-8 is an 04 and has never been driven in snow. It was garage up until 2009. Seemingly a pristine RX-8 as it is a good day only car, has 58k miles, and wash/detailed religiously. That includes proper washing/drying (of all jambs also) and paint sealing/waxing. Recently I have noticed a bit of an issue with small paint bubbling around panel joints. All located beneath the exterior surface- the jambs.
Mazda seems to use some sort of joint compound at the edge of the panel seams. This is were the paint bubbling is forming. The area I first discovered it is the aluminum hood with no references as to where it started (no drain holes at seams). Recently I discovered it on the front driver side and passenger doors. Of course, as with most painted areas with corrosion, much more was revealed after I poked and chipped away the paint. Right below the weather stripping at the three drain holes (front middle rear of door) is primarily where the corrosion is. The bubbling has spread to the vertical seams as well, which may or may not be due to the section mentioned before.
I left the hood be at the moment. I began tackling the passenger side door this weekend. First using the cylindrical sander attachment with my Dremel. I hit all the bubbling spots and began digging away under the joint compound, revealing more corrosion. Finished it off with the small fine wire wheel. Cleaned with Marine Clean, rinsed, Prep & Readied, rinsed, dried, and applied two layers of POR-15. I was only able to tackle the corner section before I ran out of light. Ambient temp was ~ 52*F.
I do have a few concerns. My RX-8 is an 04 and has never been driven in snow. It was garage up until 2009. Seemingly a pristine RX-8 as it is a good day only car, has 58k miles, and wash/detailed religiously. That includes proper washing/drying (of all jambs also) and paint sealing/waxing. Recently I have noticed a bit of an issue with small paint bubbling around panel joints. All located beneath the exterior surface- the jambs.
Mazda seems to use some sort of joint compound at the edge of the panel seams. This is were the paint bubbling is forming. The area I first discovered it is the aluminum hood with no references as to where it started (no drain holes at seams). Recently I discovered it on the front driver side and passenger doors. Of course, as with most painted areas with corrosion, much more was revealed after I poked and chipped away the paint. Right below the weather stripping at the three drain holes (front middle rear of door) is primarily where the corrosion is. The bubbling has spread to the vertical seams as well, which may or may not be due to the section mentioned before.
I left the hood be at the moment. I began tackling the passenger side door this weekend. First using the cylindrical sander attachment with my Dremel. I hit all the bubbling spots and began digging away under the joint compound, revealing more corrosion. Finished it off with the small fine wire wheel. Cleaned with Marine Clean, rinsed, Prep & Readied, rinsed, dried, and applied two layers of POR-15. I was only able to tackle the corner section before I ran out of light. Ambient temp was ~ 52*F.
Again, the paint bubbling is all located at the joint compounds used for the panel seams int he jambs. So far I have discovered it to only be on the aluminum hood and the passenger and driver side door panel joints in the jambs. Primarily the drain holes at the bottom of the panel where the weather strip is located. No holes or perforations yet. Just surface corrosion under the joint compound and paint.
My RX-8 is religiously taken care of. Those who have seen it in person can attest to that as it is simply pristine minus the mentioned issue. Hence the reason I am directly pointing fingers at Mazda for this issue.
I have attached pictures, and they are pretty much self-explanatory. Does not include pic of the panel prior to sanding and after wire wheel. Fortunately the section underneath the weather strip cannot be seen as the strip covers it (without making direct contact to the refinished section). I do have confidence that the refinished section will hold its own against corrosion with POR-15. I am no expert at fighting body corrosion, hence the reason I have asked Aaron Cake for advice. For those knowledgeable, feel free to contribute as well.
I suggest everyone to check said locations for paint bubbling as well. Even if you have rust/corrosion warranty, it will only be covered when there is perforation (hole/s), which is too late already.
Last edited by SayNoToPistons; 10-27-2013 at 06:32 PM.
10-27-2013, 06:59 PM
#3
I am assuming it's "Rear Fender Arch RUST" TSB ref "E034/07B" posted in:
https://www.rx8club.com/series-i-tro...letins-183774/
That is the only TSB I am aware of for corrosion.
https://www.rx8club.com/series-i-tro...letins-183774/
That is the only TSB I am aware of for corrosion.
10-27-2013, 09:21 PM
#6
Ive honestly never looked under the doors, I wipe them off whenever I wash but I never inspected them closely, I do notice dirt and grim accumulate very easly in those ares even with seldom driving in good conditions. I'll have to inspect mine.
I do notice the rock guards around the rear doors also seem to attract a lot of dirt and even gets under them
great concepts, terrible execution
I do notice the rock guards around the rear doors also seem to attract a lot of dirt and even gets under them
great concepts, terrible execution
10-27-2013, 09:26 PM
#7
As ya'll can tell from the cleanliness in pic. My jambs are always dried after washing. I even go as far as using Klasse AIO and QD on them. Drain holes are free of dirt obstruction as well. What's confusing is the some of the bubbling start at the joint compound/adhesive. Seemingly where water cannot get in, or ISN'T SUPPOSED TO.
I recall Ford having a problem with their primer and panel joint adhesive which led to corrosion. I wonder if Mazda had the same problem. 1st gen Mazda 3's and 6's had issues with corrosion.
I recall Ford having a problem with their primer and panel joint adhesive which led to corrosion. I wonder if Mazda had the same problem. 1st gen Mazda 3's and 6's had issues with corrosion.
Last edited by SayNoToPistons; 10-27-2013 at 09:47 PM.
11-04-2013, 11:27 AM
#10
No updates as to what initiated moisture penetrating the paint and joint compound yet. No updates to any fixes I've performed either. Haven't had the time to even look at my 8 since I posted this thread...
Any luck with your panels?
Any luck with your panels?
11-04-2013, 02:30 PM
#11
Rotary Evolution
water is going to get inside the door no matter what, the window seals can only try to prevent the majority from running straight down. if the water is from salty roads like back east then your best alternative is to actually seal the seam from inside the panel and not the area you see rusting primarily.
cars rust, there's no getting around it.
cars rust, there's no getting around it.
11-04-2013, 10:24 PM
#12
The rust isn't forming from inside the panel. It is where the joint compound is. In the 10 year life span of this car, it has never been driven on salty roads. Kept in hibernation every winter.
Cars rust, true. Steel corrodes, and so does aluminum. But question why would a vehicle given the situation be corroding so quick and in these specific areas where there compound is applied? And how does one best treat the corrosion for the interim without having it be sent to a body shop for some extensive repairs?
Cars rust, true. Steel corrodes, and so does aluminum. But question why would a vehicle given the situation be corroding so quick and in these specific areas where there compound is applied? And how does one best treat the corrosion for the interim without having it be sent to a body shop for some extensive repairs?
11-06-2013, 10:35 AM
#14
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The rust isn't forming from inside the panel. It is where the joint compound is. In the 10 year life span of this car, it has never been driven on salty roads. Kept in hibernation every winter.
Cars rust, true. Steel corrodes, and so does aluminum. But question why would a vehicle given the situation be corroding so quick and in these specific areas where there compound is applied? And how does one best treat the corrosion for the interim without having it be sent to a body shop for some extensive repairs?
Cars rust, true. Steel corrodes, and so does aluminum. But question why would a vehicle given the situation be corroding so quick and in these specific areas where there compound is applied? And how does one best treat the corrosion for the interim without having it be sent to a body shop for some extensive repairs?
That defiantly looks like corrosion under the seam sealer, and not from clogged drip holes. I wonder if it was bad weld threw primer that they use after the skin is wrapped over the door, and spot welded on.
11-07-2013, 04:10 PM
#16
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I going to suggest that the panels where in the process of being built when a storm hit in the middle of their production. Raw damp metal, then sealer on that before going to paint. Typhoon Maemi ?
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