Hood hinge drain rust repair - Page 3 - PeachParts Mercedes-Benz Forum

Chad300tdt · #31 11-18-2008, 08:17 AM

The deciding factor for me was down-time. The dash and everything below would have to come out for welding, plus maybe the front seat.

Using epoxy is far less invasive and many new cars are being assembled with it. I trust this type of repair FAR more than a fiberglass repair. For extra strength I would use a layer of POR-15 fiber sheet soaked with POR-15 rust preventative paint over the epoxied sheet metal.

bgkast · #32 11-19-2008, 12:19 PM

I have to say I'm leaning towards your type of repair, espically since I just pulled the dash two weeks ago...

Chad300tdt · #33 11-20-2008, 10:06 AM

Well things are still progressing. I finished the patches and need to topcoat and reassemble. I switched to black POR paint since I had a partial can and didn't want to open a new silver for the little work I have left. When the wife gets home tonight, I'll topcoat everything and dynamat the interior. Then tomorrow evening I can start reassembly of the fender and battery tray. Hopefully I'll be driving it again on Saturday.

More pics upon completion.

Dee8go · #34 11-20-2008, 11:36 AM

That looks like an abstract painting. You're quite the artist, Chad.

Can I drop Max off at your house? Donny and Johnhef got rid of a lot of the rust on max, but I'm afraid there's still more lurking in spots like this.

Chad300tdt · #35 11-20-2008, 11:40 AM

Quote:

Originally Posted by Dee8go

That looks like an abstract painting. You're quite the artist, Chad.

Can I drop Max off at your house? Donny and Johnhef got rid of a lot of the rust on max, but I'm afraid there's still more lurking in spots like this.

Sure, bring him over. Spring will be better as the warmth will allow quicker curing times.

Chad300tdt · #36 11-21-2008, 12:32 AM

I just finished!!

Dynamat inside:

Inside done:

Topcoated repair:

Upper drain topcoated:

Lower drain topcoated:

Closeup of drain after undercoating:

Repair undercoated:

All done and painted:

I took it out for a ride and all is well ... except for the weird noise my heater blower is making now.

Mike D · #37 11-21-2008, 07:28 AM

Great job!

I think you were right on the edge of requiring metal replacement though.

For future reference to other people reading this thread, Chad knows what he is doing and keeps a close eye on his car. Don't think you can just slap some patch on your W114 or W123, epoxy and seal it and the problem is solved. The floorpans on these models are a structural unit in the unibody construction. Body fillers, sealants and epoxies are NOT meant to be subjected to lateral stress and will crack. Chad uses the epoxy as a bond and as a sealer, NOT to replace the original metal.

If you have a hole in the floorboards you can watch the road go by in then you need to weld metal. If you have rot in the curve where the floorpans meet the door sills or the firewall, replace the metal.

The key is to remove ALL the rust and then do the repair. I guarantee you if you don't get all the cancer, it will just spread around and under the patch.

Dee8go · #38 11-21-2008, 08:15 AM

Maybe I missed it, but what do you use to be sure you've gotten ALL the rust out? Do you wore brush it down to bare metal?

Dee8go · #39 11-21-2008, 08:16 AM

Oh, BTW, great job, Chad! You seem to have an abundance of patience as well as skill when it comes to stuff like this.

Chad300tdt · #40 11-21-2008, 08:28 AM

Thanks Mike

I agree with what you're saying too. I've been lucky in that the holes in my wagon have been fairly minor and in the "right spots" for this type of repair. If the holes were any lower into the rocker area, where they would be a structural risk, I would have gone through with welding in a patch from a donor or attempted to shape metal for welding in.

Thanks Dee8go,

I use the POR-15 system. In order to resolve rust issues, you wire wheel it clean and scrape away the undercoating until you get a ring of clean metal. (With the POR-15 products, a rough surface actually works better for the longevity of the repair, it gives the paint a tooth to grab onto.)

Then you apply "Marine Clean" (a degreaser/cleaner), scrub if necessary, rinse and let dry.

Then you apply "Metal Ready" and keep it wet for about an hour. I use a spray bottle of it to keep applying it with ease. The "Metal Ready" neutralizes the rust and etches the metal drying to a Zinc Phosphorus coating which is the primer for the rust preventative paint.

Then you coat everything with 2-3 coats of POR-15 rust preventative paint to completely encapsulate the area. Finally, a coat of Chassis Black Topcoat to seal it from UV harm (unless it's in an area that won't see the sun. POR-15 is UV sensitive only in its color retention. UV won't degrade its protection.)

Finally, you don't want to sand through the POR-15 layers as any breech of the coating voids the protection it gives.

dieseldan44 · #41 11-21-2008, 09:31 AM

Nice job Chad, that looks really good. The POR-15 is great.

The cure for heater blower is to find a good one in a yard the swap it in. Buying a new motor for it costs $100 and the swap in is a pain! Finding another entire assembly is the fastest, least expensive, and most reliable fix.

dd

Chad300tdt · #42 11-21-2008, 09:47 AM

Quote:

Originally Posted by dieseldan44

Nice job Chad, that looks really good. The POR-15 is great.

The cure for heater blower is to find a good one in a yard the swap it in. Buying a new motor for it costs $100 and the swap in is a pain! Finding another entire assembly is the fastest, least expensive, and most reliable fix.

dd

Thanks Dan.

I appreciate the advice. How much would you pay for an assembly? I found a lead on one that's available, but don't know what to offer or what's fair.

EDIT: I already have one on the way for $75 shipped.

Thanks again for the tip.

EDIT#2: All fixed.

What an easy repair.