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Thu Apr 12, 2012 12:41 pm

Hello all,

I'm trying to figure out the best way to approach rust proofing my front wheel wells.

I've got a combination thick dried undercoating that is slowly cracking off, then surface rust in places where the under coating has cracked off, and patches of almost new surface from where the rust proofing has recently fallen off.

So far I've applied some oven cleaner and decreasing trying to remove the rust proofing. I've tried to use plastic scrapers and even a razor blade to chip the old rust proofing off. This method is slow going and I don't think will get the results I want. Also, I've removed some old cracked seam sealer that wasn't doing anything but causing the underlying metal to rust.

I was hoping to chip off all the rust proofing and try to save as much as the good OG paint as possible. I've read doing this is a good idea as the factory primer and paint is the best. Then I would Por 15 the rusted areas, then spray some POR 15 rubberized undercoating and finish with a topcoat the entire wheel well.

My next theory is purchase a sand blaster and just take everything down to metal and prime and paint.

I'm looking for suggestions of a good method you used to get off this undercoating. With enough time and patience, I could probably chip this stuff off, but half the summer would be gone. I'm also looking for recommendations of a good quality sandblaster for home use.

Thanks!

Thu Apr 12, 2012 12:44 pm

Do a search on POR-15.... I have had super good results with it!

Thu Apr 12, 2012 12:46 pm

dreadzeplin666 wrote: Do a search on POR-15.... I have had super good results with it!

I've used it on rust metal with good results. But does it work on metal that isn't rusted? If I sandblast it to metal POR 15 will act just like a regular paint.

Thu Apr 12, 2012 12:50 pm

Sure does! Just rough up the metal w a wire brush or sandpaper, apply the "metal ready", let that dry and then POR it.... Did the entire underside of my bus on roached parts as well as good stuff :D

Thu Apr 12, 2012 12:53 pm

dreadzeplin666 wrote: Sure does! Just rough up the metal w a wire brush or sandpaper, apply the "metal ready", let that dry and then POR it.... Did the entire underside of my bus on roached parts as well as good stuff :D

Good to know. Do you think I just just wire wheel the old paint and not concern myself with trying to save it?

Thu Apr 12, 2012 1:02 pm

Look at ccpalmers front end thread. I think wire brushes and putty knives and scrapers should do the job. Maybe a little sandpaper. An air compressor to blow all the dust off and some wax and grease remover to wipe it all down with. You don't need it to be pristine to apply undercoat. Sandblasting would be overkill and the media would get everywhere you didn't want it to be. Some of the products I use pretty much everywhere on the seams are brushable seam sealer and 3M heavy drip check. 3M Body Schultz is what I use as an undercoat. It just take time and effort.

Thu Apr 12, 2012 1:02 pm

The "undercoating" from the factory is the good stuff not the paint.... the paint just stayed nice seeing as that coating covered it. If the OG color is what your after then try the POR-15 Tie Coat..... which then allows the use of paint over the POR-15? Extra step but could be done!

Thu Apr 12, 2012 1:12 pm

Brionp wrote: Look at ccpalmers front end thread.

That's what I was reading when I came up with this question. I didn't want to high-jack his thread.

Thu Apr 12, 2012 2:26 pm

I didn't remove the factory undercoating. If you want to do that, I would first try kerosene (somehow let it soak for 30 minutes) and if that doesn't work Eastwood sells an undercoating remover product that might work - your local auto paint shop might too.

You could also try PPG DX330 degreaser - that stuff is amazing.

Plastic scrapers of course are great. Brass wire wheel maybe? I find carpenter's wood shims to be handy tools too.

And I'm a huge fan of POR15 so far. It does need a top coat for UV protection; you can topcoat with anything if you do it right. The local paint shop says people use it for undercarriage stuff without topcoating figuring that UV light doesn't really get under the car. Personally I would still topcoat.

But I agree that it's a shame to remove factory paint. Sandblasting might be the easiest though. If you do that convention says to use epoxy primer - POR is really for rusty areas. I like that I can use it outside when it is humid out. Epoxy not like humidity, POR like it.

Good luck! Have fun!

Thu Apr 12, 2012 3:04 pm

One way to go about it is to just hit anything with Waxoyl as that ancient old undercoating flakes off. Steam clean the general area first if you can, if not take some car ramps or blocks down to the car wash and run your van up on them and spray everything off the best you can, then once it dries hit it with the Waxoyl. Doing this year after year will slowly get the Waxoyl into every last crevice. Be sure to spray it into every possible opening in the rockers, doors and such.

Not as pretty has a POR 15 job, but the Waxoyl will get into places the POR 15 can't, but the salt still can.

Thu Apr 12, 2012 4:39 pm

Wildthings wrote: One way to go about it is to just hit anything with Waxoyl as that ancient old undercoating flakes off. Steam clean the general area first if you can, if not take some car ramps or blocks down to the car wash and run your van up on them and spray everything off the best you can, then once it dries hit it with the Waxoyl. Doing this year after year will slowly get the Waxoyl into every last crevice. Be sure to spray it into every possible opening in the rockers, doors and such.

Not as pretty has a POR 15 job, but the Waxoyl will get into places the POR 15 can't, but the salt still can.

paint can allow air under it and rust can still occur. The Waxoyl, Cosmoline etc form a wax/paraffin/oil barrier that is soft enough it flows and keeps air away.

Thu Apr 12, 2012 8:07 pm

Thanks Wildthings.This stuff is neat, I remember seing it on the undercarraige of cars but not realizing it was available retail. Just a note ships use wax to seal out moisture on fasteners and from talking to some boat guys from what I understand it works well. You could drill an access hole in those areas that are inaccessible and are prone to rusting from the inside out. Use the spray wound to spray the area and plug the hole with a rubber plug for later applications.

Fri Apr 13, 2012 5:15 am

Usually a good pressure washer will take most of the undercoating off.

Fri Apr 13, 2012 7:09 am

ccpalmer wrote: I didn't remove the factory undercoating.

Did you just paint over the OG undercoating? I would rather do that, but my guess is that the under coatin will continue chipping off even if I paint over it. Then, I would have to keep and eye on it and touch up as it chips away. But if I can just leave alone, I'd rather do that.

Wild things: How does Waxoyl remove the OG undercoating? I would guess it's nothing close to any kind of solvent.

I'm getting a goo picture of what needs to be done. Thanks for your continued help. Who knows, you might get some photos out of this.

Fri Apr 13, 2012 10:04 am

Manfreds78bay wrote: Wild things: How does Waxoyl remove the OG undercoating? I would guess it's nothing close to any kind of solvent.

I doesn't do any removing. The pressure washing will take off what isloose, but more will loosen and come off each year, so annual inspection and spot treatment are necessary.

Fri Apr 13, 2012 1:47 pm

VW treated different era Bays differently in regards to underside and wheel well metal protection and coatings. We discussed this quite a bit in detail in the past. It seems like the original actual metal prep before any spray coatings was a complete dip process and even that was evidently done differently between years. But with a metal chemical treatment process before any primers or paints. .Some kind of an electro-chemical dip process. Amount and location of paint application varied by years and the undercoating material did also. I've only done '70 and '71 wheel wells which were the same but it seems like BusDaddy was familiar with some of the later years.

Yours is a late year and different climates would have a big differing affect on them over the years but it sounds as if your wheel well undercoatings are about the same condition as mine were. Wheel wells fully undercoated but some dried and flaking off, some can be flaked off and other areas it is not possible to flake it off or fully scrape it off because it is still fully adhered to the metal. It's not dry, crisp and flakable but rather still somewhat like tar.
If yours is in about the same condition as mine was here is the way I'd go about it-

-A do it yourself coin-opp car wash and maybe degreaser. It's the high pressure that will do the good work. Or get your own pressure washer. $100 or under will do it. Don't waste oven cleaner until after you do the initial cleaning.

-With a sharp scraper get all the undercoating that will flake and scrape off. Even a steel scraper will work if you're careful to not dig into the paint. Any gummy, non-flaky you won't be able to scrape it down to the paint or metal so use some real potent solvent such as lacquer thinner. Get every bit of undercoating off. If you don't it will be a future trouble area.

-Scrape out and dig out all seam sealer.

-Sandblast any rust areas or places where the original paint is not wonderfully adhered to the metal. Get to clean metal if you can. You don't need massive costly equipment to sandblast. A cheap gun from Harbor Freight and a tank to store air from a smaller compressor will work. It's no problem to blast a bit then let is store up air again. Get a bag of Silica or sandbox sand from Home Depot.

-Concentrate on cracks, seams, and hard to get to areas. And the areas you don't see unless you are underneath or inside of the fender well. Using oven cleaner somewhere through your process really helps get it clean and a pressure washer again really helps. That (oven cleaner) should get rid of any petroleum related contamination. Follow up with a real hot water sudsy soap scrub and fresh water rinse. Then allow it to thouroughly dry. An air gun will help. It's any water remaining in cracks and seams that will cause your work to be useless. Plan on letting it air dry for a few days while you wish you had our single digit humidity. If you can still find any spots or specs of black (undercoating) or white (seam sealer) it's not cleaned well enough.

-So then I'd do POR 15 on any remaining rust spots but not on clean metal.

-Then I'd spray it with a good metal primer. For something like that I'd recommend an industrial primer and not an automotive primer. I've had excellent proven results with something like Rustoleum. But I always mix and thin it with a portion of some hot automotive reducer instead of just mineral spirits or common paint thinner. Best to use a small gun to be able to concentrate getting paint into critical areas. You should be able to get a real practical gun for $10 - $20 at FLAPS or HF. You can not get the critical areas coated with a gun that does a big spray.

-After prime the go over all seams and cracks with seam sealer. 3M Auto Body Sealant is the good stuff.

-Then prime again over the seam sealant and finish with your top paint. Again, I always highly prefer to use an industrial type paint.

-If you wish then apply any type of undercoating or protective coating. Remember, any coatings do very little if the substrate underneath is not good. Any place where the undercoating, paint, or seam sealer underneath comes loose is where you will have future problems.

I didn't take any pictures of the ferderwells after all the cleaning and before primer. Or a pic of the new seam sealant before final prime.

Mon Apr 16, 2012 1:32 pm

Desertbusman wrote: VW treated different era Bays differently in regards to underside and wheel well metal protection and coatings. We discussed this quite a bit in detail in the past. It seems like the original actual metal prep before any spray coatings was a complete dip process and even that was evidently done differently between years. But with a metal chemical treatment process before any primers or paints. .Some kind of an electro-chemical dip process. Amount and location of paint application varied by years and the undercoating material did also. I've only done '70 and '71 wheel wells which were the same but it seems like BusDaddy was familiar with some of the later years.

Yours is a late year and different climates would have a big differing affect on them over the years but it sounds as if your wheel well undercoatings are about the same condition as mine were. Wheel wells fully undercoated but some dried and flaking off, some can be flaked off and other areas it is not possible to flake it off or fully scrape it off because it is still fully adhered to the metal. It's not dry, crisp and flakable but rather still somewhat like tar.
If yours is in about the same condition as mine was here is the way I'd go about it-

-A do it yourself coin-opp car wash and maybe degreaser. It's the high pressure that will do the good work. Or get your own pressure washer. $100 or under will do it. Don't waste oven cleaner until after you do the initial cleaning.

-With a sharp scraper get all the undercoating that will flake and scrape off. Even a steel scraper will work if you're careful to not dig into the paint. Any gummy, non-flaky you won't be able to scrape it down to the paint or metal so use some real potent solvent such as lacquer thinner. Get every bit of undercoating off. If you don't it will be a future trouble area.

-Scrape out and dig out all seam sealer.

-Sandblast any rust areas or places where the original paint is not wonderfully adhered to the metal. Get to clean metal if you can. You don't need massive costly equipment to sandblast. A cheap gun from Harbor Freight and a tank to store air from a smaller compressor will work. It's no problem to blast a bit then let is store up air again. Get a bag of Silica or sandbox sand from Home Depot.

-Concentrate on cracks, seams, and hard to get to areas. And the areas you don't see unless you are underneath or inside of the fender well. Using oven cleaner somewhere through your process really helps get it clean and a pressure washer again really helps. That (oven cleaner) should get rid of any petroleum related contamination. Follow up with a real hot water sudsy soap scrub and fresh water rinse. Then allow it to thouroughly dry. An air gun will help. It's any water remaining in cracks and seams that will cause your work to be useless. Plan on letting it air dry for a few days while you wish you had our single digit humidity. If you can still find any spots or specs of black (undercoating) or white (seam sealer) it's not cleaned well enough.

-So then I'd do POR 15 on any remaining rust spots but not on clean metal.

-Then I'd spray it with a good metal primer. For something like that I'd recommend an industrial primer and not an automotive primer. I've had excellent proven results with something like Rustoleum. But I always mix and thin it with a portion of some hot automotive reducer instead of just mineral spirits or common paint thinner. Best to use a small gun to be able to concentrate getting paint into critical areas. You should be able to get a real practical gun for $10 - $20 at FLAPS or HF. You can not get the critical areas coated with a gun that does a big spray.

-After prime the go over all seams and cracks with seam sealer. 3M Auto Body Sealant is the good stuff.

-Then prime again over the seam sealant and finish with your top paint. Again, I always highly prefer to use an industrial type paint.

-If you wish then apply any type of undercoating or protective coating. Remember, any coatings do very little if the substrate underneath is not good. Any place where the undercoating, paint, or seam sealer underneath comes loose is where you will have future problems.

I didn't take any pictures of the ferderwells after all the cleaning and before primer. Or a pic of the new seam sealant before final prime.

Thanks for taking the time. Not sure if I can do all of this right now. But sound advice.

So this weekend I bought a metal puddy knife. I had been using a plastic one to avoid scratching the paint as much as possible. Wow what a difference. That stuff came off instantly. A lot more OG paint than I thought there would be.

I've decided I'll waiting on a good paint job until I decided to pull the front beam. Which is not happening right now. I'm going to por15 the rust spots and use waxoyl for now.

Is waxoyl clear or is it dark? I'd like make the wheel wells look a little better. If it's clear I may just por 15 the entire wheel well then do the waxoyl treatment.

Sorry still no pictures. My garage is dark and didn't feel like putting the wheel back on to role it out into the light. Will set up some lighting and post pics soon.

Tue Apr 17, 2012 4:28 am

Manfreds78bay wrote: Desertbusman wrote: VW treated different era Bays differently in regards to underside and wheel well metal protection and coatings. We discussed this quite a bit in detail in the past. It seems like the original actual metal prep before any spray coatings was a complete dip process and even that was evidently done differently between years. But with a metal chemical treatment process before any primers or paints. .Some kind of an electro-chemical dip process. Amount and location of paint application varied by years and the undercoating material did also. I've only done '70 and '71 wheel wells which were the same but it seems like BusDaddy was familiar with some of the later years.

Yours is a late year and different climates would have a big differing affect on them over the years but it sounds as if your wheel well undercoatings are about the same condition as mine were. Wheel wells fully undercoated but some dried and flaking off, some can be flaked off and other areas it is not possible to flake it off or fully scrape it off because it is still fully adhered to the metal. It's not dry, crisp and flakable but rather still somewhat like tar.
If yours is in about the same condition as mine was here is the way I'd go about it-

-A do it yourself coin-opp car wash and maybe degreaser. It's the high pressure that will do the good work. Or get your own pressure washer. $100 or under will do it. Don't waste oven cleaner until after you do the initial cleaning.

-With a sharp scraper get all the undercoating that will flake and scrape off. Even a steel scraper will work if you're careful to not dig into the paint. Any gummy, non-flaky you won't be able to scrape it down to the paint or metal so use some real potent solvent such as lacquer thinner. Get every bit of undercoating off. If you don't it will be a future trouble area.

-Scrape out and dig out all seam sealer.

-Sandblast any rust areas or places where the original paint is not wonderfully adhered to the metal. Get to clean metal if you can. You don't need massive costly equipment to sandblast. A cheap gun from Harbor Freight and a tank to store air from a smaller compressor will work. It's no problem to blast a bit then let is store up air again. Get a bag of Silica or sandbox sand from Home Depot.

-Concentrate on cracks, seams, and hard to get to areas. And the areas you don't see unless you are underneath or inside of the fender well. Using oven cleaner somewhere through your process really helps get it clean and a pressure washer again really helps. That (oven cleaner) should get rid of any petroleum related contamination. Follow up with a real hot water sudsy soap scrub and fresh water rinse. Then allow it to thouroughly dry. An air gun will help. It's any water remaining in cracks and seams that will cause your work to be useless. Plan on letting it air dry for a few days while you wish you had our single digit humidity. If you can still find any spots or specs of black (undercoating) or white (seam sealer) it's not cleaned well enough.

-So then I'd do POR 15 on any remaining rust spots but not on clean metal.

-Then I'd spray it with a good metal primer. For something like that I'd recommend an industrial primer and not an automotive primer. I've had excellent proven results with something like Rustoleum. But I always mix and thin it with a portion of some hot automotive reducer instead of just mineral spirits or common paint thinner. Best to use a small gun to be able to concentrate getting paint into critical areas. You should be able to get a real practical gun for $10 - $20 at FLAPS or HF. You can not get the critical areas coated with a gun that does a big spray.

-After prime the go over all seams and cracks with seam sealer. 3M Auto Body Sealant is the good stuff.

-Then prime again over the seam sealant and finish with your top paint. Again, I always highly prefer to use an industrial type paint.

-If you wish then apply any type of undercoating or protective coating. Remember, any coatings do very little if the substrate underneath is not good. Any place where the undercoating, paint, or seam sealer underneath comes loose is where you will have future problems.

I didn't take any pictures of the ferderwells after all the cleaning and before primer. Or a pic of the new seam sealant before final prime.

Thanks for taking the time. Not sure if I can do all of this right now. But sound advice.

So this weekend I bought a metal puddy knife. I had been using a plastic one to avoid scratching the paint as much as possible. Wow what a difference. That stuff came off instantly. A lot more OG paint than I thought there would be.

I've decided I'll waiting on a good paint job until I decided to pull the front beam. Which is not happening right now. I'm going to por15 the rust spots and use waxoyl for now.

Is waxoyl clear or is it dark? I'd like make the wheel wells look a little better. If it's clear I may just por 15 the entire wheel well then do the waxoyl treatment.

Sorry still no pictures. My garage is dark and didn't feel like putting the wheel back on to role it out into the light. Will set up some lighting and post pics soon.

I waxoyled and it was black.

Tue Apr 17, 2012 10:58 am

curtis4085 wrote:

I waxoyled and it was black.

I'll just do that then. Ordering now.

Tue Apr 17, 2012 3:09 pm

Manfreds78bay wrote: I'm trying to figure out the easiest and quickest way to approach rust proofing my front wheel wells.
Edited it for you. You saved a massive amount of work but just keep close tabs on it.