Weldless Rust Repair: A Miracle

[TempleUWS6]

So I've been wanting to deal with my severe rust issues (holes in floor) in my '90 245 DD for well over a year, but I could never afford the down time to fix it the "right" way (weld in patch panels). I even saved the good panels from an '84 245 GL that I chopped up.

After researching alternatives, I stumbled upon a method using fiberglass and a resin-like paint called Miracle Paint. "A moisture cured non porous paint that bonds to rusted and corroded metals like no other coating. It dries rock hard and will not chip, crack or peel. Impervious to gasoline, lacquer thinner, salt and most acids. Can be painted directly over rusted surfaces. Is strengthened by moisture. Will seal concrete, grout, wood, metal and porous tile like nothing else. Can be sprayed, rolled or brushed."


I bought a starter kit offered by Kent Bergsma of Mercedes Source in Bellingham, WA seen HERE.


Its very straight forward and the results are great. I'll let the pictures do the talking...

Step 1) Clean up all the rust scale and under coating at least 1" from affected area. (Some of the black over the rust is a urethane primer used for auto glass. I work at a glass shop and put it on months ago. I was sure to sand and clean the areas well.)







Despite Volvo's attempt to combat rust with galvanizing and undercoating, my car rusted from the inside out from water leaks into the cabin and festering under the foam/rubber sound deadening and carpet.

I used the air scraper from Hobo Freight to bust up the scale and clear the undercoating.





Step 2) Apply the Miracle paint to all exposed areas, overlapping about an inch.

Step 3)Let it get tacky, takes 1-3 hours. Cut fiberglass pieces to size. Coat pieces thoroughly with Miracle Paint, use the thicker chopped fiberglass mat to cover holes and the thinner woven glass goes on top. Lay the pieces over holes and paint in edges. I used only the fiberglass that came in the Mercedes Source kit, which was just barely enough to cover my holes. I could use a second application as you can see pinholes where just the chopped mat was used.

Here is the final results:

Still drying here:




Fully cured (takes about 24hrs):




There you have it. The fiberglass that fills the holes is very very strong; when you knock on it, it sounds just as dense as the metal does. All together this cost me about $100 (if that) in all the supplies including the Miracle Paint kit from Mercedes Source, and about a days worth of work. I did this at my parents house and had to leave after only letting the last coat with fiberglass dry for maybe 4-5hrs, and it was almost completely set by then!

I highly recommend this method and might consider it better than the traditional cut and welding as its quicker, cheaper, and will never rust again.

This was done on the floor pans so I wasn't worried about looks, but for areas that will be seen you can sand and paint the area. The kit also comes with a nice can of stone chip/rock guard to give you a factory appearance. I plan on applying more fiberglass to the underside and smoothing it all out.

[Dan]

Looks interesting, bookmarked

[Sine Qua Non]

Might work fine in hidden areas but on outer panels of the car.....probably not.

[Ursan]

So, POR-15 and Power mesh?

[Stiggy Pop]

I did the same thing with Rust Bullet and regular fiberglass cloth. Worked great.

[Mueller]

Depending on the car, this is considered a huge hack repair job for resale value, not saying you are doing this, but if this was a collectable that not a cool repair..okay for a beater...

[sim]

I can see how that product could solve some crappy problems easily,
but if anyone goes in there to weld in the future, they are going to be pissed.

Looks like a good product to keep a beater on the road.

[JW240]

Originally Posted by Mueller

Depending on the car, this is considered a huge hack repair job for resale value, not saying you are doing this, but if this was a collectable that not a cool repair..okay for a beater...

+1

I fully understand it is hard to find a good welder (usually car mechanics cant weld) and/or someone who does good work for fair price.. Been there and bought a machine myself and try to fix it myself, skills wise no problem but also not much time for down time!

Curious to see long therm results!

[petiww]

It probably works okay for deeper surface rust spots, like the floor.
But if the car is rotted structurally at the joints, this wont help.

[Jack]

Originally Posted by JW240

+1

I fully understand it is hard to find a good welder (usually car mechanics cant weld) and/or someone who does good work for fair price.. Been there and bought a machine myself and try to fix it myself, skills wise no problem but also not much time for down time!

Curious to see long therm results!

take welding 101 at your local college or local workshop, after 3-2 classes you will know to weld

[JW240]

Originally Posted by Jack

take welding 101 at your local college or local workshop, after 3-2 classes you will know to weld

true, I took 3 modules, MIG/MAG, TIG, improved from there and taught TIG (and some MIG/MAG and Oxy-braxzing) at the university I used to work
But still, it takes time, $$, etc etc so I fully understand it when ppl can't.

[Dan]

Eh, for a show car or a high dollar car, I will weld.
I have fixed a few holes this way, if its not structural and you stop the rust. I think these methods will work for years.
My 740 was too far gone to do this one, so I welded it, but on cars with small holes, I clean, POR 15, fiberglass, then spray rubberized undercoating on. It's not like you are stuffing a hole with newspaper and bondo... I would think as long as the hole is less than 20 square inches of so, it should outlast the car..

Welding can take some time, gotta fab a patch, clean the hole, shape it, weld, then treat it anyway to keep it from rusting

[Jack]

Originally Posted by Dan

My 740 was

thats enough

[quillc]

Originally Posted by Ursan

So, POR-15 and Power mesh?

Yup, looks exactly like it. Great for a cheap fix on a DD. Worthless for a restoration.

No matter what, it's better than a rusty hole.......