undercarriage restoration experience/suggestions

[jabowman]

I searched around a LOT and didn't really find much on this specific topic besides some discussion about specific undercoating products. I know there is a hot debate about using a rubberized undercoating vs a wax based (waxoyl) or similar.

I have EVERYTHING removed from the bottom of my van (90 GL). I have started scrubbing the crap out of everything with degreaser, which will take days.

So here are my questions, hopefully some folks who have gone to extremes on the bottom of there van can share there experience:

1. There is a thick waxy coating in the wheel wells that is color matched, and looks stock. What is this? Should it be removed? Will any undercoating products stick to it?

2. Some areas of the underbody have slight rust, but mostly it's just little spots here and there. What is the best way to deal with these?

3. Any tips on surface preparation, degreasing, etc? I would just sand blast the vehicle, but I think it's valuable to leave the original paint on there in areas where it is still good.

4. My biggest concern is ADHESION. There are least 4 different surfaces on the bottom of my van, and the vary widely in terms of cleanliness/condition. I would love to use a bedliner type product, but I am super nervous that I will have a hard time getting much to stick well. Any experiences with bed-lining the entire underside of a van?

5. I was thinking POR 15 over the entire chassis/frame rails and any other areas with rust. I am skeptical of the POR-15 though, because it would have to overlap onto painted areas, and I am not sure if the product is made for that?

Here are some photos

[0cean]

I was also wondering about this. Glade you posted.

[climberjohn]

Dylan (Insyncro) has some expertise in this area, hopefully he will chime in.
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'86 Westy, 2.5 Subaru power
Know your limits. Exceed them often.

[jabowman]

nobody? come on!

After more pondering and product review, I am leaning towards using a combination of POR 15 products. First I would paint all rusted areas with regular POR-15, then coat over the entire chassis/frame rails with Chassis Coat Black, and then put a final coat of Pow-r Liner urethane bedliner over the entire bottom. It will expensive, I am still worried about the adhesion of the bedliner to the pre-existing material in the wheel well.

Anyone sprayed bedliner into their wheel wells? What prep did you do, how did it go?

[ZsZ]

Here is a good german article about testing long time rust protection:
http://www.vw-bulli.de/de/technik-design/timemax-rostschutz-das-volle-programm.html

I am trying fluidfilm products, but no long term experience.

(Tryed to link google translated ling but it didn't work)
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Zoltan
1.9 MTdi 2wd Multivan (ex Caravelle)
Van since 2006, engine since 2008

[bluebus86]

POR15 is a very hard, non flexable material, it is a poor choice for this. the chassis will flex, and that will crack the hard POR 15, and thus allow water to enter.

The chassis black is a Eastwood Product and that is the bottom of the scale of quality paint. I have had numerous problems with eastwoodd's paints and coating, i avoid eastwood at all costs. eastwood coatings are poorly formulated and they have horrible customer support, in fact with one product they admitted it was causing failures (promoting rust) yet they kept selling that product anyway. I spoke with their techinical department and found that they had no idea of what they are doing. I hae much experience in coatings and chemistry thru my job, I would never use Eastwood junk again.

A aulity epoxy paint such as DP primer or simulr would be a good choice for basic paining, not too thick (thick paint will crack eventually) look for4 products made by SEM, Dupont, PPG and such, these are name brandsused by profesional restoreres who dont cut corners, and by OEM car manufacturers.

for the rust, the best bet is to remove it,t o bare metal, then use a quality name brand epoxy paint. there are some rust converters you can use as a short cut, SEM makes Rust Mort and Rust Seal both are good products, (avoid at all cost Eastwood rust converter, it actually promotes rust, I have done extensive scientific testing of it after i had failures and found it to promote rust under the paint).

note thatmany rust converter do conatain acids, and acid residur\es will effect many top coat's curing, some paints will not cure when topped over an acidic coating.

You can look up on the internet the spcification for many name brand paints, there you will find what they recommend for under coats, be sure you understand all the coatings and how they interact, some combinations are bad. many name brands also offer professional telephone advice, so you can call DuPont, PPG SEM etc and ask them what they recommend.

do deal with the flexxing under a cahsiis you need some flexable coatings, the VW applied wax caoing is good stuff, these types of coatings can take a good deal of flex and remain water tight, they flow well into the nooks and crannies well, some even self heal if scrathed. in genreal you cannot paint over wax sealers.

i am not a fan of using bead liner, it too is a thick coatin but it is not that flexable, and has the property of hiding any rust that forms under it, you may not notice bad rust under it until the metal is gone.

Wurth makes a very nice sprayable under coat that would be a good choice in the wheel wells. but I would hesitate to use it under th whole chassis as there are too many nooks and cranies that can be missed, it will not self heal.

franky with a little bit of surface rust , there are some wax type coatig with rust inhibitors that can be sprayed on over. this will greatly reduce the rust from growing, and allow reapplication and inspection. this can keep rust in check for decades more.

The bentely manual has recommendations for undercoating in the body work section. products are listed, although many of these products may be superseded since teh manual is 20+ old now.

again a call to a major paint maker like PPG, DuPont etc... will gain you lots of useful info on what products are simular to the old ones, or even better. read the Bentlay recommendatons then call a major supplier or two and and find what they recommend.

remember bed liner may look great for a while, but it can hide lots of rust that will creap under it. I hear all the time how great POR 15 looks, but the bottom line is it is too hard to be flexable, and will do a good job at hiding creeping rust, this is not ideal.

sty away from Eastwood paints at all cost, total junk, they were crimminal in teh way they kept selling their garbage after they knew they had failed in formulation, they are rookies at chemistry, they buy bulk cheap paint and relable it as their own.

DuPont, PPG ,SEM spend millions upon millions each year in Reasearch and developement and employ an army of PHd chemists to create exclellent coatings, I trust them, they offer an entire range of compatible coatings for a wide rage of conditons. POR15 is a one product company and hence does not have the research and developement resources needed for the multible type of coatings you need. yes they may be good at making a coating that is good for painting an oil rig, (per their ads) but they offer no automotive coatings that can be top coated properly, or remain flexable. they likley spend more on advertising to the home mechanic than they do on developing a range of good coatings, do not fall for their advertising hype, there are some places where it can be used ok on a car, but not the entire underside, there are much better products for that

your be better off with brush on Rustoleum primer than using POR 15 or eastwood chassis black (rustoleum does take a long time to cure however) look up DP primer for the paint, it is good, then consider a name brand wax based under coat that will remain flexable, and self heal. do not use eastwood wax coating, more junk chemisty from them, the importers of cheap junk.

name brands and coating compatibility are key to success, readup on the bentely chassis caoting instruction in your manual.

PS if you want to top coat the undercoating in the wheel wells, the Wurth product is paintable, so that would be a good choice in the wheel wells, then paint the color, then finally top off with a waxed bases rust proofing. for the underside an epoxy based name brand paint (with or without a COMPATIBLE rust converter under it) followed by a wax type coating would be good

[Phishman068]

Great post!!!

i'm blasting all my undersides with fluid film annually now.
However, on my new syncro that I plan to make a winter car I plan to hold off on the fluid film until the bottom is properly dealt with using products like those mentioned above (was planning on the wurth wax mainly)

Wurth Rust Guard is a remarkable product. Very similar to POR15 and i have real world experience with this working well on some vanagon frame parts for a few years of abuse in salt environments.
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http://www.thesamba.com/vw/forum/viewtopic.php?t=559766&highlight=winter+rust
http://www.thesamba.com/vw/forum/viewtopic.php?t=482402&highlight=sunroof+syncro
http://www.thesamba.com/vw/forum/viewtopic.php?t=569774
http://www.thesamba.com/vw/forum/viewtopic.php?p=6864936#6864936

"Along with the ability to go fast, one looses the desire to hurry."

[randywebb]

why is the color match inside the wheel wells an issue?

you can paint over some products - Porsche did it on turbos for example
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1986 2.1L Westy 2wd Auto Trans.

[randywebb]

why is the color match inside the wheel wells an issue?

you can paint over some products - Porsche did it on turbos for example
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1986 2.1L Westy 2wd Auto Trans.

[syncrodoka]

Do a search for the corter van.

Please get some safer supports under the van.

[ajdenette]

I believe Dylan was talking in the Corter project and has mentioned it other times that he uses steam to clean everything off all undercoating and road grime the biggest thing to think about before steam cleaning is the cleanup of the removed stuff that will need to be done afterwords.
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1985 2wd Westy with 2000 Subaru 2.2 current driver
https://www.thesamba.com/vw/forum/viewtopic.php?t=685635
1986 Syncro Doka Project next in line
https://www.thesamba.com/vw/forum/viewtopic.php?t=732777
1990 Vanagon Syncro Base awaiting body work

[MsTaboo]

Nice project!
Highly recommend Ospho rust converter (follow directions!)
There is a ton of info in the Body/Paint section of this forum. Including a lengthy thread on rust control products.
Good luck and post lots of pics!
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[Syncrozilla]

From what I can see in those pictures that van looks very rust free underneath. In my opinion you would be wasting time and doing a disservice to the van to take off the factory paint and undercoating if there is actually not a problem. I would just pressure wash or steam clean it. while your under there make sure the body drains are not blocked. It there are small areas that have some light surface rust then deal with those areas individually. I'd then apply a fresh coat of wurth undercoat or maybe even a light wax film product.

If your planning to move to say upstate NY or New England, Old England, Germany etc in the near future you may want to consider additional measures but otherwise looks like she's holding up pretty well to me.

Or maybe you just want your rig to be all nice and shiny underneath. That's cool but I'd put the shiny over what you already got.

Get some better support for that thing what ever you do. That looks scary
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[outwesty]

[costal_cat]

I dont post a lot because there is usually great post like this that give me most of my info... I'm getting ready to do the undercarriage of my syncro this winter.. I have heard a lot of different thoughts but a local shop i know that does a lot of classic restorations recommend this product line

http://www.eastwood.com/extreme-chassis-blk-w-rust...nt_id=5512

Seems that there is a rust converter, pre paint cleaner and then paint. Has anyone heard of them or have any thoughts? I have to do something here on the carolina coast
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87 Syncro Westy
TDI Overland Parts engine conversion

[bluebus86]

[Petervw]

There are so many ways at looking at this, especially when I would think so many people would be happy to live with such a minimal amount of oxidation..After using some of the Eastwood products and Por 15 (20yrs ago)..to make a long story short..."never again"..Personally I like to have the possibility to see with my own eyes any potential rust that may develop on the vehicle, ...first using a power wash to clean,.. next cover everything with a rust convertor,...after that, then cover with a very light oil such as Gibbs or similar and finally spray over that with a heavy body inhibitor (slightly heavier then fluid film) like a Wurth or CRC product such as this @ http://www.crcindustries.com/auto/?s=06026 or http://www.youtube.com/watch?v=3H6zfUcijWQ ...for your interst a good place to start at @ http://www.youtube.com/watch?v=AvJmBflOEB4&list=PLF9ABA991D496B0EB

[costal_cat]

All right I get the gist now.. Thanks for that advice seems that the best way to go on this is with a respectable name brand and deal with the cost that goes along with it. I will check out some of the body and paint threads on rust control.
I just found a garage I can rent a bay with a lift from over the winter so i can do most of the work myself. I will post out some pictures once I get it rolling....
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87 Syncro Westy
TDI Overland Parts engine conversion

[jabowman]

Thanks for all of the help everyone. There has been a lot of good input here. Couple of things:

1. I definitely will not be covering the entire chassis with POR 15. I would only use it to treat a few small heavily rusted areas,such as the radius arm bushing surfaces visible in the photo I posted. These spots are by far the biggest/ worst on the whole underside.

2. The chassis coat black I am referring to is a POR product, and is made to coat a chassis with variable surfaces such as a mixture of POR-15, paint, and primer. I have heard great things about it, as long as the prep is done right (like everything). I will definitely stead clear of Eastwood, not the first time I've heard that tirade.

3. POR boasts about the flexibility and durability of their products on their website. Also, I have researched this topic on many different forums and it seems that POR products are some of the most highly regarded products available for this exact application. I havent heard reports of any issues with either POR-15 or Chassis Coat due to bending/flexing of the chassis. That is, after all, exactly what the product is made for. As long as the chassis is prepped meticulously, this seems to give some of the most consistent results. Has anyone personal had a bad experience with POR-15 or Chassis Coat on a vanagon frame AFTER thoroughly prepping the surface exactl as recommended?

4. Based on what I have been hearing, I am becoming more skeptical of any type of "hardening" product as the final top coat over the entire underbody. I don't see much of a difference between the rubberized undercoating products ( wurth) and bed liner type products, quite frankly. They both create a "shell" layer than can trap and hide moisture/corrosion. I think the best solution is a non-hardening, self healing type product such as Noxudol or waxoyl. Fluid film looks like an amazing product for corrosion protection by I doubt it does much for sound deadening or physical protection. My biggest concern with a wax based non hardening produc is, again, adhesion. But let's face it, with a sand blaster and a year of free time, I will never get the entire bottom of the van to where a bedliner or rubberized product will ever stick. At least with Noxudol type products I can crawl under there periodically and touch things up with minimal prep.

5. Someone suggested wurth products: Just to make sure I am not missing anything, do they offer a non hardening or wax based product or only the rubberized undercoating stuff? Any other non-hardening products that folks want to recommend? I think there is another forum on this...

Thanks ya'll

[chojinchef]

I am going to be trying this product on the undercarriage of the Thingamajigger:

http://pc.dupont.com/dpc/en/US/html/visitor/common...nishes.pdf

Only difference is that my Corlar is black.

The parts are already sprayed in black Imron awaiting undercarriage preparation and refinish.

Come late October I will start the blasting and cleanup to spray the Corlar. Still enjoying the summer to start a project that large.

Body man friend used this on the undercarriage of his 67 GTO and it has held up exceptionally well for a number of years. Topcoat friendly, I may spray Imron color on top of it. Have not decided yet, still have some time to decide.
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