Surface Rust

[GarageDog]

OK, it really looks worse than it is.
This is the trunk bed of a 50 year old MB 190 SL. Though no other signs of rust anywhere on the car, the trunk which had a rubber mat placed on top would trap moisture. Sadly, this is typical in this model.

Since I took the photo I did scrape away all of the loose debris, no holes. Aside from some pitting, I don't think it needs to be replaced - other than for cosmetic reasons.
Looking for suggestions on what to use to stop or neutralize the rust.
Thanks, Bill

 

[k-os]

I've ready of many people using POR15 to stop and prevent rust. Haven't used it myself however.

http://www.por15.com/

 

[aojo]

first of all clean up all the area with a wire brush.. as for a preventative I use a product I buy on line ... Gibbs.. this stuff is amazing. There are cars that have been stripped to bare metal and then coated with Gibbs and months later no surface rust.. it is also easy to clean off prior to primer/painting...

 

[rob in nh]

there is a product called rust mort, it a rust converter and made by sem products.

 

[4xdog]

I've used POR-15 and their associated products many times, and give them a definite thumbs up.

Their cleaner, Marine Clean does a good job of degreasing. Metal Prep (there may be a new name for it now) is their water-based phosphate rust converter, and I like this product a lot.

POR-15 itself is one of the more difficult paints you'll ever use. Sticky, viscous when brushing, thins a lot after brushing to level out marks (which can also mean runs if film thickness is too high). But, d**n, does that stuff protect. I did the windshield frame on my 1988 Cherokee many years ago and after a windshield replacement about ten years later not a hint of rust. I've done dozens of things with POR-15, and they're simply indestructible.

It is not UV stable, though -- it turns chalky and flat compared to its normal hard glossy self if exposed to ultraviolet and sunlight. It doesn't take too long for this to happen, either. Underhood, or in the trunk, it will be fine. And it can be topcoated to give it competely resistance to UV. I'd guess you're going to overcoat in the the 190SL's original color, yes? In that case no issues.

Wear gloves when you apply it, 'cause if it dries on your hands it'll take the skin wearing off before it's gone. I don't recommend spraying it -- too much a PITA. Cleans up OK with common solvents, like mineral spirits -- before it dries.

POR also makes highly rust-resisant color coats that don't need topcoating. They'd probably be fine for what you're doing. But I'd go all the way and use the big gun on it -- original POR-15.

Don

 

[Dan Babb]

Rustoleum has a rust converter in a spraycan or wipe on. Dries flat black and very durable. Eastwood has a bunch of rust converters on their site too.

Just clean off the loose stuff and coat...you're done.

 

[zoomzoomjeff]

What about Evapo Rust?

 

[Bull]

first of all clean up all the area with a wire brush.. as for a preventative I use a product I buy on line ... Gibbs.. this stuff is amazing. There are cars that have been stripped to bare metal and then coated with Gibbs and months later no surface rust.. it is also easy to clean off prior to primer/painting...

Where do you buy this stuff? I've always used Ospho, but am always open to trying new super-products.

 

[retrobuilder]

Many of the mentioned treatments are good.

You need to get to the metail grain to best eliminate repeat rust issues later or oxide through paint bleeding.

I use Cortec corrosion clean/prep products with great success and no corrosive skin burning problems and time consuming residue cleaning.

FYI- "google" Southern Precision Urethanes for excellent info on best methods- particularly for 2 part epoxy primers. good luck!

 

[GarageDog]

Thanks for all of the input, will consider each carefully.
If POR 15 is used, can you apply paint on top of it? Trunks and engine compartments on these cars were all painted a low gloss or satin black color.
Is POR 15 a two part application? (catalyst based) Want to avoid too thick of a build up.
Thanks

 

[GRX]

POR-15 is not catalyst based per say, but it is a three part application system. You might want to read the instructions on their page.

http://www.por15.com/quickindex.asp

Also do a search of these forums for advice from others who have used it.

 

[38Chevy454]

POR-15 is a good choice for your trunk. It should have the full prep, but if you just wire brush the loose rust and then apply it will be fine. Have done many floorboards with my angle grinder and a wire brush. The paint actually uses the rust to help form the mechanical bond. It does not work good on new clean steel, it needs something to grab onto.

It is a moisture cured paint, single stage. Brush it on, wear disposable gloves and clothes that you do not care about. Any paint that gets on you or clothes will be there. I use lacquer thinner to clean up when it is wet, but once dry, nothing will affect it. I believe they have a semi-gloss black or flat black version, but the original is gloss black when dry. It will turn flat black due to UV, but it does not make it less protective.

POR-15 does not convert the rust, it just encapsulates it so no more rust can form. It is just a super good barrier.

 

[4xdog]

POR-15... is a moisture cured paint, single stage...

Exactly right. It's a urethane at heart, so it reacts with things like water. I use it right from the can with no thinning.

Best to cover it quickly, even when using, seal well, and use promptly.

I buy only the tiny metal cans, often in the six-pack. Once a can is opened one should really plan to use it quickly and seal it *very* well between uses. I put a piece of polyethylene film between the lid and can to make sure the POR-15 doesn't seal the can shut. I try to remember to store the little can upside down so if a hardened film does form where it's in contact with moisture in the air trapped inside the can, that it forms on the bottom of the film. That works so-so.

 

[1967marti]

prep -n- etch (from homedepot/ lowes) then paint with any good paint.

 

[HotrodHR]

Try Picklex 20... no need to remove prior to painting as some others have suggested. Takes care of flash rust on bare body panels etc. http://www.picklex20.com/

Or just go with POR (paint over rust) as others have suggested... it's not going to daylight so you really don't have to worry about "UV" protection. Slap on their black product and be done with it... unless of course you're going for a concours restoration.

 

[James Aiello]

POR-15 is very dangerous also.. do not breath the vapors brushed or sprayed..
I got real sick after painting with a brush and for some stupid reason turned off my shop fan that I use when painting..

 

[Mrcamaro]

I hear naval jelly is awesome too, have a container I have yet to use, for that I would look into to blasting it with a spot blaster with using glass as the most aggressive method, not aluminum oxide, and if using glass start out slow with lower pressure. I have used molasses with good results, it would also work here but not as practical as having a barrel and dipping smaller parts in, you would have to mix it then pour it then let it sit a few days then vacuum it up with a shop vac..... all natural though and don't have to worry about any chemicals.

 

[JamieK]

USe a wire brush in a drill to clean the rust off until its bare metal again. Spray with some epoxy primer and then topcoat with color. It'll be fine.

POR-15 is supposed to be great, but you can't apply it to clean metal. Best used for heavy steel thats rusted, like frames and suspension parts.

 

[MoonRise]

Wire-brush off any loose rust and remove dirt/grime/oil/grease/body fluids (it is a trunk in a Mercedes, more likely in an older Cadillac or Lincoln like from the 70's or 80's )

Apply a rust-converting (chemically converts the rust into a different molecule, usually applies as a 'milky' whitish product and then turns the rust into a blackish phosphate layer) or encapsulating (POR-15 or similar) product.

http://www.eastwood.com/eastwood-rust-converter.html

http://www.walmart.com/ip/Rust-Oleum-Rust-Reformer-8-oz/16652306

And available at about a thousand other places, both 'local' and online.

Prime and top-coat as desired.

Or wire-brush (angle grinder and a cup wheel) to clean shiny steel, prime and paint as desired. Body-filler optional (under the trunk carpet/mat).

 

[Mrcamaro]

Here are my results with a 9/1 sulphated molasses mixture. Good as new, after a little clean up and maybe some buffing it will shine up real nice.

Edit: Not the exact side but was in the same condition, will be pulling everything out in the next few days though.

 

[4xdog]

POR-15 is supposed to be great, but you can't apply it to clean metal. Best used for heavy steel thats rusted, like frames and suspension parts.

Not true. POR-15 is indeed best on rusted metal, and good on sandblasted/seasoned metal. But I've used it on fresh clean metal many times and it works fine. I suspect they're most concerned about adhesion, where a little more tooth to the surface gives better POR-15 bite.

It'll work on most any steel. The POR-15 data sheet is HERE for more detail.

 

[JMURiz]

Good info above, I had the same scenario with my W114.
Be sure to get a new trunk seal when you have repaired/repainted the trunk.

 

[78Bird]

POR will stick to clean metal, it just cant be nice, SMOOTH, clean metal. It needs something to grab onto, so blast, abrade, etch, or something to give it tooth to grab onto. It doesnt have any self-etching properties to bite onto shiny smooth metal.

 

[GRX]

Indeed. POR-15 needs something to grab on to. Which is why one must follow the product directions and use the three part system. Notice step #2 in the directions below:

>> http://www.por15.com/quickindex.asp <<

1] -
MARINE-CLEAN cleans and degreases in one application without leaving residues, noxious fumes or flammable solvents. No other cleaner works as fast or as well. It makes petroleum-based cleaners almost obsolete because MARINE-CLEAN can be diluted with water up to 3, 4, 5 and even 10 times its volume while remaining more potent than other cleaners.

2] -
PREP & READY provides the best adhesion for POR-15® on any surface, including aluminum and shiny polished metal surfaces. Our simple process gently etches metal, creating an ideal anchor pattern for coatings such as POR-15®, while simultaneously leaving a zinc phosphate coating to insure chemical bonding of paint and steel.

3] -
POR-15® is a high-tech, high performance rust-preventive coating designed for application directly on rusted or seasoned metal surfaces. It dries to an incredible rock-hard, non-porous finish that won't chip, crack, or peel, and it prevents rust from recurring by protecting metal from further exposure to moisture.

 

[nonhog]

I figure spend your money were you feel good. For me POR 15 is too expensive compared to epoxy primer, which often is used anyway.
I'd wire wheel it and lay some vinegar wetted towels on it. Neutralize it.
Sand, paint.

If your o.k. with thick "nail polish" looking paint POR 15 is somewhat easier.

I soaked this balancer in vinegar and wiped it down, no sanding, wire wheel or even a scrub brush.
FWIW

 

[Lippyp]

I use some great products from a company over here called Bilt Hamber Labs, they make a rust remover called DEOX-C, it comes either as a powder you dissolve in water to soak stuff in (works even better if you can keep it warm) 24 hours and it comes out clean for all but the heaviest rust. They also do it as a gel which would be ideal for your trunk floor, you paint it on and then cover with cling film (saran wrap) and leave for 24 hours, then you simply wash it off with water. they also do a great rust converter called Hydrate 80 that I would then use to deal with any rust that might be lingering. After that you can simply paint with your normal paint systemm

TBH I don't like POR15, I used it on my trucks floor and found it to be a pig to apply, its very thick and it hasn't stood up that well as rust is coming through it. To be fair I didn't use the metal ready stuff, just marine clean and then a good wire brushing with a cup brush ina grinder and then the paint.

I did some very old steel shutters with the DEOX-C a few years back and they came out looking like they'd been sandblasted plus it gets into the bits you can't blast like cavities. I made a temporary bath by digging a suitable sized hole in the earth floor of my cellar, lined it with a sheet of heavy polythene and soaked them for about 36 hours, every so often I lifted them out and agve them a gentle wire brushing to loosen the black gunk that it lifts off. This is how they came out.

 

[DonnyT]

What about Evapo Rust?

AWESOME STUFF..... POR (Paint over rust) is garbage. Also here is another great option:
http://www.safestrustremover.com/

 

[SlappyWhite]

I have lots of experience with chassis saver which is similar to por15 as I am told. Just like others have noted, the fumes are intense, spraying makes it worse!

We did some testing on adhesion. I used it as a blackening and "insulating" layer under some carbon fibre (to be bonded to steel). To make sure we would not have a problem we painted a relatively clean and smooth area where we were going to do the CF on and let it cure (it like rough better, that is why we picked smooth). We then scuffed it up very well and bonded a chunk or steel to the chassis saver with the epoxy we were using for the CF. Well at first we could not remove the steel and thought we were going to be grinding them apart (why did we do this on the car...). After some VERY serious prying with lots of leverage and cursing the two parts came apart, the epoxy failed before the chassis saver!

I must say we did not learn, they tell you to put clingwrap under the lid once you open the can. We did not, at one point we had to cut the can open, the lid was glued on, no amount of prying was getting it off, the can top was just deforming.

I have painted over the stuff with both paint and bedliner. Make sure it is well cured, I have had some minor spidering when in too much of a hurry. It is pretty slow curing. Make sure it is well scuffed, it is very hard so it is a pain to scuff. I use scotch brite in a palm sander for any of the flat areas just to save myself grief.

Wear gloves and cover your arms. I does not come off with anything but time!

It is single part, it is a good idea to spray some butane or other heavier than air "gastane" into the can right before sealing it up. We have had a couple of cans turn to pucks after a couple of months on the shelf. The gas will sit on top and prevent curing in the can.

 

[GRX]

Typically some people have trouble discerning between rust encapsulators like POR-15 and rust converters like Evapo Rust. Both have their place and respective weaknesses. Not saying this applies to anyone here, one thing I have noticed with many who say POR paint is junk is that they tried to apply it by itself without properly preparing the surface - i.e using degreaser and prep & ready. Or they do not realize it is UV sensitive.

 

[DonnyT]

Evapo Rust is a rust REMOVER, NOT a rust converter.
http://www.theruststore.com/Evapo-Rust-Gallon-P1C1.aspx

 

[TheClaw]

Evapo Rust is a rust REMOVER, NOT a rust converter.
http://www.theruststore.com/Evapo-Rust-Gallon-P1C1.aspx

The Rust Store site is awesome. I need to remove some rust from my scissors lift and touch up the paint. Looks like I'm going to order so of their converter.

 

[TheClaw]

I tested some Rust Converter from the The Rust Store. It seems to work pretty good.

Here's a section of my lift that's been treated. You can see in the bottom right hand corner that it's turned a dark gray color.

Jeff

 

[Jerriffic]

Dehydrated EVAPO-RUST

http://store.rustremover.biz/5-GalDehyd-Evapo-Rust.html

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=tools&field-keywords=Dehydrated EVAPO-RUST

This concentrate must be mixed 1 - 5 with water or it will not work. Less won't work nor will more.

 

[n8n]

you can paint over POR-15, but for it to stick, you have to dust it with primer or paint while the POR-15 is not completely set up, otherwise nothing will ever stick to it.

 

[Highbeam]

I have not been impressed with por15. I bought the full multistep kit and followed instructions exactly. Rust came back. I found I was better off with the permatex rust converter that's like thick milk and then rustoleum top coat.