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Undercoating Remove it or Not? #1345552
12/03/12 07:20 PM
12/03/12 07:20 PM
Joined: Nov 2012
Posts: 355
6
68gtx Offline OP
enthusiast
68gtx  Offline OP
enthusiast
6

Joined: Nov 2012
Posts: 355
So we have most of the GTX disassembled. The car was under coated. We are considering removing the under coating. We are trying to put it as it was in 1968 well as close as possible. So what are your opinions. Do we remove it or leave it and re coat it. I always struggle with this every time I do a car that was under coated. And if we do remove it what is the best process. Last one I did with a torch scrapper and then thinner. That sucked!!!! Thanks Larry J

Re: Undercoating Remove it or Not? [Re: 68gtx] #1345553
12/03/12 07:36 PM
12/03/12 07:36 PM
Joined: Jan 2003
Posts: 42,714
Spokane Washington
ScottSmith_Harms Offline
Mr Wizzard
ScottSmith_Harms  Offline
Mr Wizzard

Joined: Jan 2003
Posts: 42,714
Spokane Washington
Use a steam cleaner.....Most cars will take 3-5 hours. Trust me Ive used every method, its almost fun!

Re: Undercoating Remove it or Not? [Re: ScottSmith_Harms] #1345554
12/03/12 08:22 PM
12/03/12 08:22 PM

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Anonymous
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I was going to leave it on my front fenders but the more I took off the more surface rust I found underneath.

I used the propane torch/putty knife method.

Very therapeutic.

Re: Undercoating Remove it or Not? [Re: 68gtx] #1345555
12/03/12 08:26 PM
12/03/12 08:26 PM
Joined: Aug 2004
Posts: 2,132
New Mexico
J
JMCFAN Offline
top fuel
JMCFAN  Offline
top fuel
J

Joined: Aug 2004
Posts: 2,132
New Mexico
Quote:

So we have most of the GTX disassembled. The car was under coated. We are considering removing the under coating. We are trying to put it as it was in 1968 well as close as possible. So what are your opinions. Do we remove it or leave it and re coat it. I always struggle with this every time I do a car that was under coated. And if we do remove it what is the best process. Last one I did with a torch scrapper and then thinner. That sucked!!!! Thanks Larry J




Thats how I did it....and sucked is the correct word....


68 Charger 383/ AT Green/Green VT
70 Roadrunner 383/4sp Purple/Black VT
Re: Undercoating Remove it or Not? [Re: 68gtx] #1345556
12/03/12 08:39 PM
12/03/12 08:39 PM
Joined: Oct 2012
Posts: 1,106
Northeast
V
VincentVega Offline
super stock
VincentVega  Offline
super stock
V

Joined: Oct 2012
Posts: 1,106
Northeast
refresh it. worth the effort. take pictures before hand so you can put it back exactly like it was, if that's important to you


Looking for 1975 through 1978 B body 4 door sedan sheet metal or parts cars - monaco, fury, coronet. Please let me know
Re: Undercoating Remove it or Not? [Re: VincentVega] #1345557
12/03/12 09:02 PM
12/03/12 09:02 PM
Joined: Apr 2007
Posts: 2,940
Calgary, Alberta Canada
a12rag Offline
master
a12rag  Offline
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Joined: Apr 2007
Posts: 2,940
Calgary, Alberta Canada
On my 70 Sport Satellite, we left the original undercoating on it . . . the replacement trunk floor, extensions, quarter panels, and wheel tubs all got undercoated and the original undercoat was cleaned up and everything made to look same as when car was taken apart . . . sure I would have loved to clean it all off . . . but heck, it would have been wayyy more time and effort . . . .

Cheers

Mark

Re: Undercoating Remove it or Not? [Re: JMCFAN] #1345558
12/03/12 11:44 PM
12/03/12 11:44 PM
Joined: Jan 2003
Posts: 42,714
Spokane Washington
ScottSmith_Harms Offline
Mr Wizzard
ScottSmith_Harms  Offline
Mr Wizzard

Joined: Jan 2003
Posts: 42,714
Spokane Washington
Before

Re: Undercoating Remove it or Not? [Re: ScottSmith_Harms] #1345559
12/03/12 11:45 PM
12/03/12 11:45 PM
Joined: Jan 2003
Posts: 42,714
Spokane Washington
ScottSmith_Harms Offline
Mr Wizzard
ScottSmith_Harms  Offline
Mr Wizzard

Joined: Jan 2003
Posts: 42,714
Spokane Washington
Same car after 3 hours of steam, no chemicals, just hot water. All that's left is either body dip sealer/primer and factory paint over spray. What's nice, especially if doing a higher end restoration, is that it doesn't remove or ruin all the subtle factory details like a torch and a scraper can do. It's also handy for removing most cheap paint jobs while leaving factory paint.

Re: Undercoating Remove it or Not? [Re: ScottSmith_Harms] #1345560
12/04/12 02:18 AM
12/04/12 02:18 AM
Joined: Jan 2003
Posts: 42,714
Spokane Washington
ScottSmith_Harms Offline
Mr Wizzard
ScottSmith_Harms  Offline
Mr Wizzard

Joined: Jan 2003
Posts: 42,714
Spokane Washington
The tool. You can rent them or buy one. I got mine used for $1,200.00, best tool I ever bought!

7488368-Hotsy.jpg (275 downloads)
Re: Undercoating Remove it or Not? [Re: ScottSmith_Harms] #1345561
12/04/12 12:09 PM
12/04/12 12:09 PM
Joined: Apr 2005
Posts: 15,134
Kelowna, B.C. Canada
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DPelletier Offline
I Live Here
DPelletier  Offline
I Live Here
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Joined: Apr 2005
Posts: 15,134
Kelowna, B.C. Canada
Scott,

What does that use for a heat source; propane?

Dave


1970 Super Bee 440 Six Pack 1974 'Cuda 2008 Ram 3500 Diesel 2006 Ram 3500 Diesel 2004.5 Ram 2500 Diesel 2003 Ram 3500 Diesel 2006 Durango Limited [url] http://1970superbee.piczo.com [/url]
Re: Undercoating Remove it or Not? [Re: DPelletier] #1345562
12/04/12 01:09 PM
12/04/12 01:09 PM
Joined: Jan 2003
Posts: 42,714
Spokane Washington
ScottSmith_Harms Offline
Mr Wizzard
ScottSmith_Harms  Offline
Mr Wizzard

Joined: Jan 2003
Posts: 42,714
Spokane Washington
I use diesel but kerosene etc. works too. Btw, the nozzle tip you use makes a big difference, I use a spinning pin tip for maximum removal.

Re: Undercoating Remove it or Not? [Re: 68gtx] #1345563
12/04/12 01:10 PM
12/04/12 01:10 PM
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1 Offline
Too Many Posts
Challenger 1  Offline
Too Many Posts

Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
If you have the car on a rotissiere then heck yes I would remove it. Rent steam cleaner like Scott showed above or one like I have.
It does no damage unlike a scraper.
One afternoon and it's done and done well. Way better than any other method.


You can't get them this clean with anything else out there and still be able to see how the car was finished.

Now it'll take a very light media blasting to be completely bare ready for refinish with very little stress to the metal, unlike if you blasted off some of the undercoating with a media blaster.


the "machine" mine is fuel oil fired with a horazontal burner. 2000 psi and 4 gallons per minute at 212+ degrees. Mine sit's outside on my back porch hooked up year round, run anti freeze through it during the winter and use it then too, Have a hose reel mounted in my heated garage. It's the most useful tool I have.

GPM is what to look for not psi.


Like Scott said, it can be used to remove some paint jobs, in this case so I could see the factory spot welds better for drilling out.

Re: Undercoating Remove it or Not? [Re: Challenger 1] #1345564
12/04/12 01:32 PM
12/04/12 01:32 PM
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1 Offline
Too Many Posts
Challenger 1  Offline
Too Many Posts

Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
My gold 71 when it was red after pressure washing. You could have eaten off the bottem.

It does engine blocks real well too. Just got to get wet and sometimes burnt. lol

Re: Undercoating Remove it or Not? [Re: Challenger 1] #1345565
12/04/12 10:06 PM
12/04/12 10:06 PM
Joined: Mar 2011
Posts: 592
california
M
Mr D21 Offline
mopar
Mr D21  Offline
mopar
M

Joined: Mar 2011
Posts: 592
california
Any thoughts on a car not going to be rotisoried ?
Here's my underside - the car is being fully restored, so since Im not removing the old material, is there a good way to freshen it up?

Im thinking just spray new undercoating on top of the old - any thoughts?

7489483-underside.jpg (191 downloads)
Re: Undercoating Remove it or Not? [Re: Mr D21] #1345566
12/04/12 11:22 PM
12/04/12 11:22 PM
Joined: Jan 2003
Posts: 42,714
Spokane Washington
ScottSmith_Harms Offline
Mr Wizzard
ScottSmith_Harms  Offline
Mr Wizzard

Joined: Jan 2003
Posts: 42,714
Spokane Washington
Quote:

Any thoughts on a car not going to be rotisoried ?
Here's my underside - the car is being fully restored, so since Im not removing the old material, is there a good way to freshen it up?

Im thinking just spray new undercoating on top of the old - any thoughts?




Ok, not to sound too rough on you......But, I don't really see how you can call a car "fully restored" if you skip or just doll up the underside with a recoat cover job. If you do decide to leave the original undercoating I'd give it a REALLY complete cleaning with detergent and leave it alone, recoating never looks "correct" and most will figure you added it to hide something.

Personally? I'd make the investment and build or buy a rotisserie, I really didn't want to buy one myself but am glad I did, it REALLY simplifies things.


Re: Undercoating Remove it or Not? [Re: Challenger 1] #1345567
12/04/12 11:43 PM
12/04/12 11:43 PM
Joined: Jun 2003
Posts: 21,961
Enjoy life today, It has an ex...
gtx6970 Offline
Too Many Posts
gtx6970  Offline
Too Many Posts

Joined: Jun 2003
Posts: 21,961
Enjoy life today, It has an ex...
Quote:

the "machine" mine is fuel oil fired with a horazontal burner. 2000 psi and 4 gallons per minute at 212+ degrees. Mine sit's outside on my back porch hooked up year round, run anti freeze through it during the winter and use it then too, Have a hose reel mounted in my heated garage. It's the most useful tool I have.






Bring that thing over my place for a couple days


Enjoy life today, It has an expiration date
Re: Undercoating Remove it or Not? [Re: gtx6970] #1345568
12/05/12 12:02 AM
12/05/12 12:02 AM
Joined: Feb 2012
Posts: 110
S.E. WI
A
allmopar Offline
member
allmopar  Offline
member
A

Joined: Feb 2012
Posts: 110
S.E. WI
How hot is the water comming out of the tip, about 200 ? I can see how the heat softens up the tar/undercoat and the pressure blasts it off.
I am going to rent one to do my car.
I cleaned my engine bay with a just a pressure washer (no steam) and it was a black painted spray bomb job that some Chevy guy did before I owned the car. The pressure washer with a narrow tip removed 90% of the black spray bomb paint off without taking off the factory paint that was underneath.

Re: Undercoating Remove it or Not? [Re: gtx6970] #1345569
12/06/12 08:42 AM
12/06/12 08:42 AM
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1 Offline
Too Many Posts
Challenger 1  Offline
Too Many Posts

Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Quote:

Quote:

the "machine" mine is fuel oil fired with a horazontal burner. 2000 psi and 4 gallons per minute at 212+ degrees. Mine sit's outside on my back porch hooked up year round, run anti freeze through it during the winter and use it then too, Have a hose reel mounted in my heated garage. It's the most useful tool I have.







Bring that thing over my place for a couple days





I will, tell me when is good for you and I am pretty flexiable. Just need a 30 amp 220 plug and I even have some adaptors where I can use other 220 plugs.

Re: Undercoating Remove it or Not? [Re: Mr D21] #1345570
12/06/12 11:21 AM
12/06/12 11:21 AM
Joined: May 2008
Posts: 958
eastern, pa.
C
cudabitten Offline
super stock
cudabitten  Offline
super stock
C

Joined: May 2008
Posts: 958
eastern, pa.
If you are going to go over the old. I have used two kinds from a spray can, Duplicolor professional and Rustoleum. The Duplicolor worked very good. It does have some texture to it.










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