Moparts
Removing undercoating?
Posted By: Anonymous
Removing undercoating? - 03/01/08 11:16 PM
Whats the easiest way?
I tried to steam pressure wash the undercarriage today but it did nothing.
I've heard people using a torch and scraper, or paint remover.
Is there any way to make the job simpler?
Posted By: bigdad
Re: Removing undercoating? - 03/01/08 11:25 PM
Well .. I've done a couple cars and,, There is no easy method
I suppose the 64 took me 150 total hours to make perfectly clean.
Anything you use , be careful to not
1) start a fire !
2) don't get anything in your eyes
3) Use mechanics gloves
4) wear a mask .. I think that junk is haz mat ?
I used the propane torch and putty knife allot.
Wire wheel in drill in some areas (wear goggles)
Acetone and a rag to soften areas where you can't get at easy ..
I scraped over 100 lbs off my car ..It was really caked on in places
awful, awful job ..Plopped it on jackstands and worked an area till clean and then moved on
if you jump around , you get bummed out
elbow grease ..I hope to never do it again
if you were doing a complete
put it on a rotessire and blast it but then you have the left over sand, media to deal with
My truck I cut the floors out and built new ones
Posted By: Mr T2U
Re: Removing undercoating? - 03/02/08 12:27 AM
i read on this site that engine degreaser will soften up rustproofing so you can pressure wash it off.
spray it on and keep it wet with the degreaser for about 30 min then most of it will wash off.
never tried it myself.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:27 AM
I saw a guy on Moparts had his car on a rotisserie and blasted it with steam and it came off.
I tried this today with a forklift and power washer but it did nothing.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:29 AM
Another
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:30 AM
I guess i should have tried degreaser or something of the sort.
I was trying to blast it off.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:30 AM
The places where its off was already gone.
I was blasting the other spots and it basically did nothing.
Posted By: Neil
Re: Removing undercoating? - 03/02/08 12:33 AM
I used a propane torch and a scraper to get the majority of it off. Carb cleaner and lots of elbow grease to get the leftover residue off. Thankfully my car wasn't fully undercoated.
Posted By: bigdad
Re: Removing undercoating? - 03/02/08 12:34 AM
Nice wheelie !
there is no easy way, its not going to "just wash off"
You would have to get it to melting point
Not sure what that is but ..I KNOW with a propane torch , it takes a minute or so before it softens
up , and it cools right back down
So, you can only do an area 6" x 6" maybe ?
and often it leaves a residue that you have to clean off with a rag soaked in ..
Its a PITA ..
how fancy is this beast going to be ?
Posted By: 73DUSTCLOUD
Re: Removing undercoating? - 03/02/08 12:36 AM
Propane torch and a scraper is how I've seen it done.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:38 AM
Quote:
how fancy is this beast going to be ?
Not fancy at all. Its a father son project with my dad and i and it's going to be a DRIVER! Definitely far from perfect. I just want to get all of it off so i can treat the floor pans with rust bullet or something.
I'm not looking for a 100 point car by any means.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:41 AM
Quote:
Nice wheelie !
Posted By: bigdad
Re: Removing undercoating? - 03/02/08 12:41 AM
I'd take a visual on the floors
if they look soild , just use a can of new undercoating ..freshen it up a little
Unless, you want to get real, real dirty
Cause its a thankless job
Posted By: Pacnorthcuda
Re: Removing undercoating? - 03/02/08 12:45 AM
Quote:
I scraped over 100 lbs off my car ..It was really caked on in places Quote:
omg!!! Did you weigh it? Or somehow try to accurately estimate? Thats amazing. I would think a 5 gallon bucket of undercoating would not even weigh 100 pounds.
And I've done some dirty jobs before but this is one I don't think I will ever do.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 12:45 AM
The floors are real solid but have a lot of surface rust that i don't want to get any worse.
Posted By: bigdad
Re: Removing undercoating? - 03/02/08 12:52 AM
Quote:
Quote:
I scraped over 100 lbs off my car ..It was really caked on in places Quote:
omg!!! Did you weigh it? Or somehow try to accurately estimate? Thats amazing. I would think a 5 gallon bucket of undercoating would not even weigh 100 pounds.
And I've done some dirty jobs before but this is one I don't think I will ever do.
Yes .. I did ..
Took me over a month at night to do it and get it all cleaned off
Posted By: bigdad
Re: Removing undercoating? - 03/02/08 12:57 AM
Quote:
The floors are real solid but have a lot of surface rust that i don't want to get any worse.
I doubt it will ....
That rust prevent stuff is pretty good ,Will need a clean surface to paint to though
Get some wire cup brushes and a drill , set her on jackstands and work on it till you hate the car ..
Take a break and attack it again
watch those dang wires, those fly off and will stick right in your eye DAMHIK
Also ..don't rub your face when its dirty
Posted By: 68Cbarge
Re: Removing undercoating? - 03/02/08 01:07 AM
Like everybody else,I used a propane torch,scraper,hammer & chisel,wire wheel brush,etc.Lots of elbow grease.
Very time consuming.But worth every minute of it.
Posted By: CYACOP
Re: Removing undercoating? - 03/02/08 01:09 AM
Quote:
I'd take a visual on the floors
if they look soild , just use a can of new undercoating ..freshen it up a little
Unless, you want to get real, real dirty
Cause its a thankless job
Unless, you want to get real, real dirty
Cause its a thankless job
I removed it on my 71 and will never do it again. If its that hard to get off, its protecting and will protect the metal better than anything you will replace it with. My next car has it really thick and I intend to leave it and just recoat the areas that were missed the first time. As Bigdad says.
Posted By: 68Cbarge
Re: Removing undercoating? - 03/02/08 01:13 AM
It is more important to remove the undercoating that is already lifting as moisture can creep under it.As I removed some of it there was surface rust underneath.The really hard to remove schtuff will have mint paint/metal underneath.As mentioned,leave the really good stuff on.I did.
P.S. I wear a face shield and my worst clothes.I also lie down on a foam mat to be somewhat comfortable.
Keep your beer away from the working area,too!! Nobody likes black chunks in their favorite brew!!
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 01:17 AM
Posted By: JSSuperbee
Re: Removing undercoating? - 03/02/08 01:30 AM
I have to disagree. It ain't worth every minute of it. It was the most miserable automotive undertaking I've ever experienced. I would rather be dead than have a job doing that every day. That tar doesn't just soften..IT IGNITES and flys everywhere when you scrape it off. That hot tar continues to be on fire even when it's stuck to your skin. I for one would never do it again for any reason. It's an experience I'll never forget.
Jim
Posted By: mxbeep
Re: Removing undercoating? - 03/02/08 01:45 AM
Wurth sells a tool that grinds off the undercoating , its like spinning teeth that chews off the undercoating.
Might not reach in all the cracks but saves a lot of time scrapping.
My body man told me he paid a little over $200.00 for his tool. He uses all the time in his shop to remove undercoating inside doors, floors, etc on his clients vehicles, saves him a lot of time scrapping
Posted By: 469runner
Re: Removing undercoating? - 03/02/08 01:47 AM
I've done two cars a 1970 Cuda and 1970 Roadrunner. It took a long time, but I only did it an hour a day or so; all I could stand. All I used was a scraper and a few worn old flat bladed screwdrivers. The undercoating was so dry it basically just scraped right off. Probably one of the best improvements I've done to these cars. Now I don't mind working under them at all, and it is very easy to maintain; just wipe it down every now and then. BC/CC paint holds up
just fine.
Posted By: JSSuperbee
Re: Removing undercoating? - 03/02/08 02:04 AM
Now ya tell me.....
Posted By: 68Cbarge
Re: Removing undercoating? - 03/02/08 02:10 AM
JSsuperbee,I hated doing the work,but the end result was well worth it.
I did leave what was still in good shape and freshened it up.The dry,chipped stuff I removed.
My car will be a driver so not many will crawl up under to see how well I do in judged/points shows.
At least I know in my mind there is no rot underneath..
Plus it's a C so I have more area to recover..LOL!
Posted By: DaytonaTurbo
Re: Removing undercoating? - 03/02/08 02:14 AM
IMO it sounds like you're better off just scraping off what's loose/flaking off, treating the rust with whatever rust product you were planning on doing, then re-doing the entire undercoating, applying fresh stuff over top of the original undercoating that was still in good shape.
Posted By: unclemike
Re: Removing undercoating? - 03/02/08 02:37 AM
I read some where that the undercoating on early cars might contain asbestos. I don't know for sure but be careful. Also Kerosene or Diesel fuel might soften it somewhat.
Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 02:41 AM
Quote:
IMO it sounds like you're better off just scraping off what's loose/flaking off, treating the rust with whatever rust product you were planning on doing, then re-doing the entire undercoating, applying fresh stuff over top of the original undercoating that was still in good shape.
I'm probably going to do this.
Posted By: Challenger 1
Re: Removing undercoating? - 03/02/08 03:37 AM
Quote:
Well .. I've done a couple cars and,, There is no easy method
I suppose the 64 took me 150 total hours to make perfectly clean.
Anything you use , be careful to not[/quote
150 hrs?
There's a faster way, no fire, no burns and you don't breath any dust. A very hot steam cleaner...
I can do the bottem in about 3 1/2 hours.No scrape marks or gouges anywhere. I used a steam pressure washer. I did it in one afternoon and was done with it.
It's still wet in these pictures, those are water droplets hanging off the car.
Big Mike, Here's a tip for ya. That aluminun tank in the picture below, has reg 87 oct gasoline in it. It's a pressurized tank with spray wand. (I used it for years at the track to clean parts) I spray the heavy off first with the presure washer and then spray it with gasoline. It softens the road tar and under coating and speeds things up. I'll spray it wait two minutes or so and then blast it off.
I've been cleaning heavy duty trucks for years with these type of pressure washers. Go rent one from a pressure washer place or a tool rental.
I used about two gallons of gas doing the job. You would think the run off would kill the grass but it does'nt. I think most of it evaporates before getting to the grass, it's very hot and steamy to the point where you can't really see to good, so most everything evaporates quickly.
If diesel fuel or kerosene were used it would be a nasty oilly mess when done and would get to the grass. My 
Posted By: MonGoo$e
Re: Removing undercoating? - 03/02/08 03:54 AM
I've been doing this for weekends now..man what a pain, only i didn't have factory undercoat, i had this thick, greasy, sticky tar like garbage someone sprayed in every seam ever made(74 Challenger) and i have wire wheels of different sorta, scrappers, flat head screwdrivers, wire brushes,
What i did was take the parts-cleaner fluid that i was going to dispose, put it in a spray bottle, and sprayed it all over the underside of car on stands.. Most of it soaked in after a few days, got soft and scrapped off, some areas were still tight, theres where the tools come in, I have the leafs/axle out right now.. and doing all that, i swear those truck extentions are a nightmare, the body grooves and pinche welds and tight spaces...ugh..after big work, hit it with brake cleaner ( a few cans) then let it dry..then degreaser... then water..soak it..and wash it off.
wipe what you can, dry it out and hit with whatever, por15, zero rust..etc
Posted By: Slim Smitty
Re: Removing undercoating? - 03/02/08 07:39 AM
Quote:
Like everybody else,I used a propane torch,scraper,hammer & chisel,wire wheel brush,etc.Lots of elbow grease.
Very time consuming.But worth every minute of it.
Posted By: Challenger 1
Re: Removing undercoating? - 03/02/08 03:13 PM
Posted By: 4BBodies
Re: Removing undercoating? - 03/02/08 03:54 PM
I only romoved it where I had to, but my car was pretty rust free. Paint stripper works good, and is a lot less work too. (Use it outside!) Hit it with an old wire brush as it is working, a few times. Then use a putty kife. After all the metal work is done, I paint it and re-udercoat it with 3M body shutz and a shutz gun. The stuff dries hard, like the original. It doesn't have exactly the same texture (big deal) but I know it will last, and I won't have to worry about it comng off.
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Posted By: Anonymous
Re: Removing undercoating? - 03/02/08 10:16 PM
I used the torch and scraper method a few hours at a time for what seemed like months. Paint thinner does remove the residue.
I just saw a product in the Eastwood catalog that claims to be a spray on then scrap it off. I don't know if it works but may be worth a try.
Posted By: Demonizer
Re: Removing undercoating? - 03/03/08 01:32 AM
Had "dealer installed" undercoating covering most of the under hood area on my 71 Demon.I used many rags applied with lots of mineral spirits-old tooth brushes for tight areas and
lots and lots of elbo grease . Good luck!
Posted By: QuickBpBp
Re: Removing undercoating? - 03/03/08 01:40 AM
Quote:
Paint stripper works good, and is a lot less work too. (Use it outside!) Hit it with an old wire brush as it is working, a few times. Then use a putty kife.
This is the way to do it then just wipe it down with laquer thinner....Removed quite a bit this way and it goes pretty quick...In your case make sure you wear protective clothing and eye wear cause that stuff does burn...
Posted By: 71rm23
Re: Removing undercoating? - 03/03/08 01:55 AM
I had luck with just a heat gun. The heat gun and or propane torch should work.
Posted By: vancamp
Re: Removing undercoating? - 03/03/08 02:54 AM
before torch and putty knife,wire wheel,sandpaper, thinner, etc.
Posted By: vancamp
Re: Removing undercoating? - 03/03/08 02:55 AM
after
Posted By: RalleyA12
Re: Removing undercoating? - 03/03/08 06:12 PM
Where you can, apply heat from inside the car. You don't need to heat the undercoating all the way through, you just need to break the bond it has to the sheet metal. Two people works great for this job. One to scrape, while the other heats. Use mineral spirits, or engine degreaser for the residue.
Posted By: whitemtnelf
Re: Removing undercoating? - 03/03/08 09:02 PM
I was able to get it off with sandblaster using black beauty fine grit for media and 75psi. I did a quick pass with a scraper then hit it with the blaster. Very nasty job, used a full face mask respirator and a bunny suit just in case the undercoating was made up of nasty stuff.
The cheapest and easiest solution that I've found are the 'roto strippers' that you can buy at hardware stores and on eBay.
Posted By: Anonymous
Re: Removing undercoating? - 03/10/08 01:00 AM
The way to do this is to use Gunk Engine De-greaser. Spray it into a contrainer and use a brush to work it into the undercoating.
Keep the area wet and use a poly tarp under the car. The undercoating will practically scrape off like butter.
I did my '66 Dodge Monaco this way, and I had previously tried all of the above mentioned methods, but none worked as good as this.
Brad
1966 Dodge MOnaco (Canadian Built)
Posted By: Challenger 1
Re: Removing undercoating? - 03/30/09 12:32 AM
Posted By: SSAAHemiFan
Re: Removing undercoating? - 03/30/09 01:46 AM
Challenger1 , Is a hotsey the same thing as the steam pressure washer?
I just rented one for work. It sprayed hot water and the output was around 2500 psi.
Are you using something different?
Thanks
Posted By: Challenger 1
Re: Removing undercoating? - 03/30/09 11:26 AM
Quote:
Challenger1 , Is a hotsey the same thing as the steam pressure washer?
I beleive so... We used to have Hotsey hot box that we used for a few years.It was just a box that heated the water after the cold water pressure washer. But I think your talking the heated pressure washer with the vertical burner. Yes it should do the same thing. Please read these threads for a few tips.
Check out this thread: web page
