Author Topic: Undercoating on New Restoration....Would you?  (Read 567 times)

Offline mark22

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  • Name: M. Nikbakht
Undercoating on New Restoration....Would you?
« on: June 13, 2017, 10:33:17 PM »
Hello to all on the forum, this is the second time I'm posting this due an error....

My original question was what your thoughts were about putting undercoating on a frame-off rotisserie restored car. I am restoring my 54 Series 62 convertible and replacing all floor metal and trunk. The car has been  taken down to bare metal. I am familiar with POR-15 and other rust inhibitors, but wanted your opinions on using spray bedliner like Line-X or something similar. It will offer great protection, and some sound deadening as well as weight. I'd like to know if this would detract from the look, appeal, and value of the the car.  Again, this is going to be a show quality full frame off restoration. Would you turn away if you saw this on the underside and do you have any other recommendations on how to tastefully protect the metal?

Thanks!

Offline Chuck Swanson

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Re: Undercoating on New Restoration....Would you?
« Reply #1 on: June 13, 2017, 10:59:20 PM »
I personally would not, unless from factory in certain areas.  I would not do entire undercarriage myself.  Maybe someone who has an authenticity manual can confirm for your year (or get one).  On all my '66s I see some undercoating in the rear wheel well only, and a little of overspray by the side of gas tank.   I was debating to even do there on my '66 frame up resto, as you can eat off the bottom of my car, but I am going to add to that area only. With the skirt on you can hardly see anyway, but want to keep mine original and will reduce noise in that area.  There was a minor amount in the front wheel wells, but I don't think I will spray any there...I can always add later :)  I'll  also be using Dynamat under carpet.

As a side note, I regret spraying on my '67 Nova rotisserie resto (gas tank and surrounding area), but my grandfather bought new, and I knew it was on there.  Some people think you are hiding something when you use, so I try not to use anymore.   Chuck
« Last Edit: June 13, 2017, 11:20:50 PM by Chuck Swanson »
66 DeVille Convertible -Blue/White int (Profile pic of car in '81)
66 DeVille Convertible - Red/Red
66 Sedan DeVille hardtop
65 Eldorado (vert w/bucket seats)
65 Eldorado Bk/Bk
67 Chevy II Nova (AACA GN 2016)
69 Dodge Coronet R/T
Others:
2010 Prius IV
2007 Ford 500 (2)
97 Dodge Ram 1500
98 Fleetwood American Tradition 40' DP RV
AACA Lifetime
Like the 65-66 Club here: www.facebook.com/6566Cadillac

Offline mark22

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  • Name: M. Nikbakht
Re: Undercoating on New Restoration....Would you?
« Reply #2 on: June 13, 2017, 11:30:31 PM »
Chuck, I totally agree about people thinking that undercoating means "there's something to hide," but if i have pictures of the restoration, would that validate using it? It's my one change to never have to worry about it again. Do you think POR 15 or other chassis rust protectants will suffice?  Granted, the car won't see rain, so there shouldn't be a problem, but there is ton's of humidity in Texas....

Offline Carl Fielding

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Re: Undercoating on New Restoration....Would you?
« Reply #3 on: June 14, 2017, 03:36:29 AM »
Lots of guys go to great lengths to clean undercoat off their cars. I don't see how you will need to consider this in your location , and the use you propose with your car.  - Carl

Offline mark22

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  • Name: M. Nikbakht
Re: Undercoating on New Restoration....Would you?
« Reply #4 on: June 14, 2017, 08:21:50 AM »
Carl, I agree about wanting to remove it.  The reason is usually because it is unattractive and obscures potential flaws in the metal. The newest coatings are much thinner, resilient, and are color matched. I'm just thinking of this is the one chance to protect brand new metal, why not?

Offline cadillac ken

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Re: Undercoating on New Restoration....Would you?
« Reply #5 on: June 14, 2017, 08:39:39 AM »
In a word: value

Also you say you are going to have a class A restoration done on the car.  I can only assume you will drive it very sparingly and mostly will show it.  I can't see the wisdom in doing undercoating.  I know it will probably give you peace of mind, but in reality, there is no advantage and the application will hurt the value of the car in that most buyers, IMO, would be greatly "turned off" by it.

As a professional shop owner, I can tell you that with the correct prep and primer, you will have many, many years of protection without it.


Offline 5390john

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Re: Undercoating on New Restoration....Would you?
« Reply #6 on: June 14, 2017, 11:32:43 AM »
I would strongly recommend NOT undercoating. My '55 6237 DX was completely stripped and repainted starting with DP 90 epoxy primer. It is FAR better than POR 15 or similar coatings. Also commonly available and made to work with car paint. See photo, this is how my car looks underneath. It was undercoated when I started the project, it looks way better now!
John Adams

Offline INTMD8

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Re: Undercoating on New Restoration....Would you?
« Reply #7 on: June 14, 2017, 11:52:43 AM »
Agree with many above, would not undercoat it.
Jim Moran.   1959 Series 62 Convertible

Offline 59-in-pieces

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Re: Undercoating on New Restoration....Would you?
« Reply #8 on: June 14, 2017, 01:17:57 PM »
Mark,
NO. >:( :(
Have fun,
Steve B.
S. Butcher

Offline Jeepers Creepers

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Re: Undercoating on New Restoration....Would you?
« Reply #9 on: June 14, 2017, 03:56:32 PM »
I wouldn't do the underside at all and this is the reason why.




The last thing I would want is something like this coated over.

I did however, use Por-15 on the internal floors of a HQ Holden here in Oz. If you are intending to use dynamat on the floors, Por-15 will give a very nice finish to use as a base for the mat to stick to.

That's my 2 cents worth, I'll go back to my corner now.  ;)

Kevin and Astrid Campbell
Tin Can Bay,
Australia
1st time Cadillac owners.
64 Fleetwood.

Offline kkarrer

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  • Name: Ken Karrer
Re: Undercoating on New Restoration....Would you?
« Reply #10 on: June 14, 2017, 11:43:34 PM »
Here's my 2 cents worth on this subject...I've restored many 55 and 56 Cadillacs.  From the factory they had red oxide primer on the underside of the body (not the frame).  That red oxide should just barely be seen as you look under hood and down the firewall and body color should Overspray a bit on the rocker areas as well.  On some of my restorations I've just had a paint jobber mix up some single stage paint that matches the color of the red oxide primer, but I've used the primer as well.  Many, probably most new cars were undercoated at the dealerships.  That stuff was thick and heavy, but after 40-50 years it tends to begin to flake, curl, and chip off and can hide some rusted areas on the floor pan so,on a frame off resto I always remove it.  Once the body is lowered onto the frame you can still apply the red oxide paint or primer, but it's more difficult and you'll really want the exhaust and gas tank out of the way and the fuel and brake lines can be a pain to work around as well.  It usually takes a full day for me to do it that way as you have to come back and reverse mask for touch ups. Early and mid 50's cars are easier to do "after the fact" than the later 50's cars due to the differences in the area behind the differential.
Ken Karrer
CenTex CLC Reg. Dir.

Offline Scot Minesinger

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Re: Undercoating on New Restoration....Would you?
« Reply #11 on: June 15, 2017, 07:02:18 AM »
DO NOT UNDERCOAT A FRAME OFF RESTORED CAR
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Offline mark22

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  • Name: M. Nikbakht
Re: Undercoating on New Restoration....Would you?
« Reply #12 on: June 15, 2017, 02:18:10 PM »
Thank you to everyone for the recommendations.  I understand loud and clear that it is not advisable to coat it. I won't. Is there any specific recommendations from anyone of the forum of a proper primer/coating to use before paint?  I do want something durable and strong. As you can see, I just want the best for this car. And I DO plan on driving it. Lastly, was the underside red oxide from the factory?  I did purchase the authenticity manual, but I have not confirmed this yet.

Offline Chuck Swanson

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Re: Undercoating on New Restoration....Would you?
« Reply #13 on: June 15, 2017, 02:45:30 PM »
I used a quality epoxy primer under the car.

Chuck
66 DeVille Convertible -Blue/White int (Profile pic of car in '81)
66 DeVille Convertible - Red/Red
66 Sedan DeVille hardtop
65 Eldorado (vert w/bucket seats)
65 Eldorado Bk/Bk
67 Chevy II Nova (AACA GN 2016)
69 Dodge Coronet R/T
Others:
2010 Prius IV
2007 Ford 500 (2)
97 Dodge Ram 1500
98 Fleetwood American Tradition 40' DP RV
AACA Lifetime
Like the 65-66 Club here: www.facebook.com/6566Cadillac

Offline INTMD8

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Re: Undercoating on New Restoration....Would you?
« Reply #14 on: June 15, 2017, 08:45:33 PM »
Thank you to everyone for the recommendations.  I understand loud and clear that it is not advisable to coat it. I won't. Is there any specific recommendations from anyone of the forum of a proper primer/coating to use before paint?  I do want something durable and strong. As you can see, I just want the best for this car. And I DO plan on driving it. Lastly, was the underside red oxide from the factory?  I did purchase the authenticity manual, but I have not confirmed this yet.

As mentioned, red oxide is going to be the correct color (with body colored overspray).

Even though not correct however, I really like the look of the floors being painted in the same manner/color as the rest of the body.

So, just regular primer/paint and clear if using it.   

Not really much to worry about here in terms of longevity in my opinion. The floors will be less likely chipped than the outside of the car and a few coats of primer or primer and paint will have more material on the metal than the factory did.

Jim Moran.   1959 Series 62 Convertible

Offline walt chomosh #23510

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Re: Undercoating on New Restoration....Would you?
« Reply #15 on: June 17, 2017, 09:54:30 AM »
HELL no!.....walt...tulsa,ok

Offline Eric DeVirgilis CLC# 8621

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Re: Undercoating on New Restoration....Would you?
« Reply #16 on: June 17, 2017, 10:29:10 AM »
Even the example of '64 above with the stenciling on the frame is still showing undercoating on the floorpan which had probably been on since the car was new.

An awful lot of cars of this era were undercoated. It's my opinion that the majority were, and for what it's worth, of the 10 Cadillacs I've owned from 1959 - 1964 only one had not been undercoated - a triple black 1960 S 62 Convertible sold new in CA.

I'm not certain how undercoating is treated for purposes of judging. For restoration purposes, I would undercoat the floor only and paint the frame black. If cost was no object, I would probably have the floors done in red oxide primer.

Personally, I'd rather see undercoating than the floorpans being finished in body color. Undercoating had also been promoted for sound deadening as well as rust prevention. It does make a difference.
« Last Edit: June 17, 2017, 10:34:04 AM by Eric DeVirgilis CLC# 8621 »
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline 59-in-pieces

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Re: Undercoating on New Restoration....Would you?
« Reply #17 on: June 17, 2017, 11:51:57 AM »
Wouldn't you expect to see more undercoating on the car from the east coast, or in the northern states - what with salting and snow and ice - and not so much on the west coast or southern state.

Was undercoating put on as an option to be ordered and applied at the factory or was it dealer applied - I DON'T KNOW.

A frame off - or full restoration deserves to hold true to how the car was born - naked on the bottom.

IMHO
Have fun,
Steve B.
S. Butcher

Offline Dan LeBlanc

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Re: Undercoating on New Restoration....Would you?
« Reply #18 on: June 17, 2017, 04:40:45 PM »
Undercoating was definitely a dealer applied accessory. Under the new judging rules, it is now a deduction   
Dan LeBlanc - CLC # 27657
1970 DeVille Convertible
1953 Series 62 Sedan (Parts Car)
1953 Fleetwood (Project Car)
2004 Deville

Offline Brad Ipsen CLC #737

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Re: Undercoating on New Restoration....Would you?
« Reply #19 on: June 18, 2017, 03:53:49 PM »
At least in 49 that was not true.  It was applied at the factory at least on some parts.  I just removed the data plate with original rivets from a 49 CDV and there is undercoating under it.  The car had been soda blasted to remove undercoating but the data plate had not been removed.  Picture attached.  These are the kind of details that no one can make a judging manual that is 100% accurate.  It is not possible.  The factory was not that consistent in everything they did. 
Brad Ipsen
1940 Cadillac 60S
1938 Cadillac 9039
1940 Cadillac 6267
1940 LaSalle 5227
1949 Cadillac 6237X