Corrosion Question

[Ryce Stallings]

I’m about to do a second front suspension pan replacement. My question is about how to stop the galvanic corrosion that I suspect happens at the suspension attachment points specifically the driver side. In this area there are several different alloys and proximity to the body ground and battery. I would like to treat this area with something to protect it. Zinc rich paint or rust converter come to mind.

Anyone know what’s best?

[Ryce Stallings]

I left out the idea of using weld through primer.

[HarryD]

What kind of battery are you using? If it is not an Optima or equivalent, the acid fumes are eating your pan.

You need to pull the conventional batteries every 6-12 months to neutralize the acid residue. This is why I went up an Optima years ago.

[Ryce Stallings]

Originally Posted by HarryD

What kind of battery are you using? If it is not an Optima or equivalent, the acid fumes are eating your pan.

You need to pull the conventional batteries every 6-12 months to neutralize the acid residue. This is why I went up an Optima years ago.

I use Optima

Anyone know which is the best copper weld thru primer?

[chrismorse]

Originally Posted by Ryce Stallings

I use Optima

Anyone know which is the best copper weld thru primer?

I just picked up 3M weld through primer 05917 from Napa. I choked a bit at the price $44 for a 12 Oz spray can. I found it odd that the local welding supply house did not have any. It is a Zinc rich, (not copper) corrosion resistant coating and they specifically state that it is not a "primer". My mechanic guru swears by it and masks as well :-)

I would recommend a welding mask that is designed to protect you from Zinc and Chromium vapors, along with a fan to drive away the fumes.

In college, i had a metal shop instructor that had done a lot of welding on galvanized and had zinc poisoning so bad that even a whiff of zinc fumes would cause his sight to narrow down to tunnel vision and make him nauseous.

Take care,
chris

+1 on the Optima

[Ryce Stallings]

I read that the zinc/ copper primers give better conduction and are easier to weld through, but I don’t actually know.

[Ryce Stallings]

U-Pol or SEM?

[Bill Douglas]

Ryce you could get new part hot dip galvanised before you fit it up. Of course you'll need to grind of the galvanising where you weld it, and treat that area with something of your choice. But it will stop it rusting at the points you mentioned.

[HarryD]

Originally Posted by Ryce Stallings

I use Optima

Anyone know which is the best copper weld thru primer?

I just used the copper weld thru primer my automotive paint supplier gave me. I am not home do I can’t look it up.

[jjeffries]

Amazing to me that the car needs a second pan. I’d be asking some broader questions as to how the first one was installed, prepped and painted. Maybe the salt air in Miami is brutal?

John

[Ryce Stallings]

Yes I would like to avoid a third pan. I now see the galvalume pans come drilled for drainage. The questions about weld through primer are to try and stop the rust between the gas tank support and the pan. Having mounting bolts, threaded insets and current flow though that area to the ground were designed in to fail. Just my opinion. My car lived outside for thirty years.I’m sure it would do better if it was in a garage.

[kltarga72]

I use UPOL-2

How long did the second support pan last? I have seen many autos rust away because of the location near an ocean and salt air, but I thought with the modern primers and paints your second pan would not have rust issues.

[Ryce Stallings]

Originally Posted by kltarga72

I use UPOL-2

How long did the second support pan last? I have seen many autos rust away because of the location near an ocean and salt air, but I thought with the modern primers and paints your second pan would not have rust issues.

Did the U-POL cause any welding issues?

The second pan lasted 10-15 years I don’t remember but started rusting a few years after I installed it.

[kltarga72]

I have used U-POL for many years with no issues.

U-POL 2 Quote: Before welding, weld-thru primer is sprayed or brushed onto the bare metal around the welding area. ... Let the primer cure thoroughly before welding to ensure the zinc bonds properly to the metal. After welding, remove any remaining weld-through primer before painting to ensure paint will adhere to painted surfaces.

I would use a good epoxy primer before painting finish color. Be sure to follow directions which ever brand paint you choose. Automotive paints and the process to follow change as often as software changes are made

[GG Allin]

I thought I clicked on the "Front Toe Question" thread for a second.

[Ryce Stallings]

Originally Posted by kltarga72

I have used U-POL for many years with no issues.

U-POL 2 Quote: Before welding, weld-thru primer is sprayed or brushed onto the bare metal around the welding area. ... Let the primer cure thoroughly before welding to ensure the zinc bonds properly to the metal. After welding, remove any remaining weld-through primer before painting to ensure paint will adhere to painted surfaces.

I would use a good epoxy primer before painting finish color. Be sure to follow directions which ever brand paint you choose. Automotive paints and the process to follow change as often as software changes are made

Do you recommend cavity wax?

[kltarga72]

Originally Posted by Ryce Stallings

Do you recommend cavity wax?

I have never used it. You should ask local body shops, salt air and Florida humidity cavity wax may not be the correct product for you.

[Bill Douglas]

Originally Posted by Ryce Stallings

Do you recommend cavity wax?

Cavity wax won't do a ferkin thing. It's OK for the inside of doors. But the amount of grief (salt/water flushing it out) it will get under the car it will be gone in no time. The advice the guy gave you in post 8 is helpful should you decide to use it.