Ghetto POR-15 Wheel Well Hole Repair - PeachParts Mercedes-Benz Forum

shertex · #1 07-30-2012, 08:32 AM

Well, here goes. Today's my day to apply some POR-15 to three different cars: minor rust area on wheel well exterior of 91 300D, jack point rust on 87 300D, and wheel well holes on 92 300D (three of them

).

I discovered the wheel well holes when I found I was getting water in the passenger compartment when it rained....but only when the car was moving! Turns out the tires were spinning water through these holes. Took a while to figure out. Otherwise competent indie thought it was probably a windshield leak....so I needless bought a new windshield. But happiness is a new windshield, right? As a temporary measure, I made patches out of duct tape and that kept the water out throughout the winter.

Anyway, the holes are about 2" in diameter. My plan is to get the loose rust off, prep with Marine Clean and Prep & Ready, then apply the POR-15. Then, as the POR-15 is drying, I will make new patches (either of duct tape or the mesh that POR-15 sells), affix them to the drying paint, and then paint over the patch with POR-15.

Hardly a professional job, but should do the trick.

Anyone see any "holes" in my plan? I don't expect the approval of the purists!

David Wilson · #2 07-30-2012, 08:45 AM

I assume you will topcoat the POR-15 with your OEM color.
POR-15 can't handle UV. It will deteriorate and turn yellow in direct sunlight.
Just sharing my experience.

shertex · #3 07-30-2012, 08:48 AM

Quote:

Originally Posted by David Wilson

I assume you will topcoat the POR-15 with your OEM color.
POR-15 can't handle UV. It will deteriorate and turn yellow in direct sunlight.
Just sharing my experience.

No sunlight....holes are inside the wheel well. But I could certainly paint it for good measure.

Chad300tdt · #4 07-30-2012, 08:59 AM

Here's a couple of the threads showing some of the repairs I did using sheet metal, JB Weld, pop rivets, and POR-15 products.

http://www.peachparts.com/shopforum/body-repair-restoration/231360-hood-hinge-drain-rust-repair.html

http://www.peachparts.com/shopforum/body-repair-restoration/287388-another-rusty-surprise.html

http://benzobsession.com/phpbb/viewtopic.php?f=13&t=2286

Diesel911 · #5 07-30-2012, 09:28 AM

After the POR you could use the Fiber Glass Cloth thorughly saturated with JB Weld Epoxy.
PepBoys sells the larger Tubes of JB Weld and you can also get them on eBay for about the same or less cost.
The JB Weld with Fiber Glass Cloth once cured will make a solid repair.

cullennewsom · #6 07-30-2012, 09:40 AM

www.por15info.com/msds/POR-15MSDS.pdf

Citric acid is good for rust removal. I like it because I have a curious toddler.

So is phosphoric acid. Ospho is a rust treatment product that uses phosphoric acid.

Junkman · #7 07-30-2012, 09:49 AM

I found rust holes in the trunk wells on my new SD. I'll have a friend of mine patch them with metal. I'm planning on keeping the car so want it done. I mainly use POR to stop something that would be included in a more comprehensive project or if I never intend to really fix it.

I hate going behind someone that rigged a minor problem that later turned into a major project. If only a little thing like cruise is messed up, the car is fun to drive. If cruise, shocks, windows, climate vacuum, wood delaminating, seat springs on & on.......& now you have a beater which may become a cheap to purchase project car that may never be fixed properly.

pwogaman · #8 07-30-2012, 09:58 AM

Quote:

Originally Posted by Junkman

I found rust holes in the trunk wells on my new SD. I'll have a friend of mine patch them with metal. I'm planning on keeping the car so want it done. I mainly use POR to stop something that would be included in a more comprehensive project or if I never intend to really fix it.

I hate going behind someone that rigged a minor problem that later turned into a major project. If only a little thing like cruise is messed up, the car is fun to drive. If cruise, shocks, windows, climate vacuum, wood delaminating, seat springs on & on.......& now you have a beater which may become a cheap to purchase project car that may never be fixed properly.

Here is my 85SD trunk rust repair. It is still holding . . .

http://www.peachparts.com/shopforum/body-repair-restoration/124667-rust-never-sleeps.html

JamesDean · #9 07-30-2012, 12:19 PM

I'll throw my hat into the ring here:
http://www.peachparts.com/shopforum/body-repair-restoration/288453-300sd-rust-restoration-project.html

http://www.peachparts.com/shopforum/body-repair-restoration/304380-300sd-rust-restoration-project-2-a.html

PackerEdgerton · #10 07-30-2012, 02:17 PM

I ran into a few holes in the same areas on the 240D. I used Kent Bergsma's "Miracle Paint", which is a tough urethane paint that drives to a hard hermetically-sealed barrier.

Here's what I did:

1) Removed all unsound rust with a spinning wire wheel brush on the drill. I used a very rough wire wheel that took off paint, undercoat, sound insulation, and all loose rust.

2) Cleaned all areas with combination of lacquer thinner and brake cleaner.

3) Blew compressed air and repeated step 2 until it was very clean and dry and free of contaminants.

4) Coated all sound rusted areas plus a "good unrusted metal" margin of 1-2".

5) Went to TAP plastics, got some really good fiberglass with mesh on one side and non-directional mat on the other. Very thick.

6) Soaked the fiberglass in the miracle paint

7) Wait until the paint on the mat is really tacky - slightly dry.

8) Apply fiberglass/miracle paint patch to the hole. Check every few minutes to ensure it stays in place and fits the contour.

9) Apply several more layers of fiberglass (I did 3 of the extra-thick fiberglass) over a few hours.

10) Wait for it to all dry, then over-coat it with chip guard, also from Kent.

I think that the repairs I did look great and should hold up very well. It has sealed out the moisture and air from the area of corrosion, and there is a strong fiberglass patch over the top.

Good luck!

PE