Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Miscellaneous and Off Topic Forums > Paint, Bodywork & Detailing Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jun 2018
Posts: 5
Underpan Rust Repair

Discovered some surface corrosion on the rear right corner of my 1975 911s. The rest of the underpan is free from corrosion. I need help understanding if this is a major repair job or can be controlled from getting worse. The car is in California and does not see rain or snow.

Does anyone have similar experience with this type of rust? Your help is appreciated.


Old 06-24-2018, 02:26 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Jun 2018
Posts: 5
bump, would really appreciate any advice as I am about to do major work
Old 07-01-2018, 09:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
The Mighty Pieholio
 
Bob Kontak's Avatar
 
Join Date: Nov 2007
Location: North Canton, Ohio
Posts: 14,227
Garage
Quote:
Originally Posted by djr911 View Post
Discovered some surface corrosion on the rear right corner of my 1975 911s.
That is beyond surface corrosion.

I do not have specific belly pan experience. However, that rust is through the metal.

Best thing to do is get one of those knock off Fein tools at Harbor freight (electric) and shave the undercoating off and see what you are up against. Always worse than it appears.

Then post pics for a better assessment.

Given you are in California it may not have terminal cancer and something other than a big panel replacement may be appropriate.
__________________
1981 911SC Targa
Old 07-01-2018, 11:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Oct 2010
Posts: 748
Garage
As Bob says, those look like holes and you'll need to strip the underseal/schutz before you can understand the full extent of what's going on. If you're not a welding kinda-guy, I'd get it looked at by someone who knows what they're doing. If the rust is genuinely localized, you could section is pieces from a donor-parts floor or from a new replacement section (e.g. Restoration Design). But you won't know that until you give it an unsentimental inspection with a sharp metal instrument like an awl. Also, a statement if the obvious: Cali cars that live near the beach can rust like cars from less idyllic areas of the country. Best of luck to you, John.
Old 07-01-2018, 11:39 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Jun 2018
Posts: 5
Thank you Bob and John! I will start the underseal removal next weekend to see what I discover. Hoping it is localized and I can replace sections. I discovered bad rust in the front suspension pan as well, about an inch from the A-arm mounting hole. It seems the rust started from the battery area and migrated down. The other side seems okay.



I had believed this car to be rust free. Never good news to learn your car is eating away at itself. I'll take this as an opportunity to learn some new skills.

My plan forward is:

1. Strip underseal to see where the damage has spread
2. Strip out carpet to see where rust may have spread. I was planning on installing a new carpet kit in the near future, so this may be a good time.

Any tips on going forward? It seems like I would need these two panels from restoration design at minimum. Any idea what a shop would charge for replace both?

Old 07-02-2018, 09:29 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
ckissick's Avatar
 
Join Date: Jan 2003
Location: the beach
Posts: 3,866
I just finished stripping the whole pan on my '66 912 not 10 minutes ago. It looked like yours and these pics show what it looks like now. I'm doing a full resto, so it's all apart and on a rotisserie. That made it real easy. I used a propane torch to heat up the undercoat and it came right off with a wood chisel. This would be a real pain if it wasn't on a rotisserie.

I don't know that you need a new pan. I don't plan on it. I have mostly surface rust and a few small holes. You may have a fair amount of surface rust under the undercoat too. The small holes can be patched with small bits of steel or other means. I'm researching that right now, as I've never done this before. For now, I plan on grinding off most of the rust, hitting it with a rust converter, patching the holes, then prime and spray on Wurth Schutz.

Do you live in the Bay Area? I'm in Half Moon Bay if you want to check out my project.


__________________
Charlie
1966 912 Polo Red
1950 VW Bug
1983 VW Westfalia; 1989 VW Syncro Tristar Doka
550 Beck Spyder, 1989
Old 07-03-2018, 06:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Jun 2018
Posts: 5
Thanks Charlie. Very nice of you to offer to view your project, glad to see your '66 getting a full restoration. I am in Socal so a little too far!

I noticed there is a slight sag happening in the rear portion of my belly pan. The front belly pan seems to be tighter. Is this normal for our cars?

1. I stripped from the inside out, peeling the carpet(The carpet needs replacing anyways). I also wanted to see how much damage I was facing without removing all of the undercoating(In case I only replace parts of the belly pan). Under the 1/8" thick sound insulation, there was crumbling bits of metal. I will continue to the rear seats and the front belly pan to see if there is any rust there before I plan my attack. See pics below:




2. Front suspension pan is mostly effected from the outside, where all the load is from the A arm. The battery tray inside the car is still structurally sound, mainly surface rust, the real rust lives below. I am thinking a new panel from Restoration Design and cutting it to fit the rusted area.

Old 07-05-2018, 08:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Oct 2010
Posts: 748
Garage
I don't envy you....some filthy, noisy work ahead of you! Please use good safety gear.

I'd pull the gas tank to get a complete look at the front tank support/cross member from above....not difficult. I'd also check the torsion tube in back just to be sure it is OK...most likely is, but that's some pretty aggressive rust you've got going there.

The excellent Irish shop, classiccarreras.com does a great job of posting photos of their work on customers' cars and being there on the edge of the North Atlantic, they do much rust work. It can be useful to peruse such photos to give yourself an idea of what's likely in store for you and how to attack it. Best, John
Old 07-05-2018, 02:26 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Jun 2018
Posts: 5
A quick update and some questions. I have been cleaning the surrounding areas up to take a better look at the extent of the rust and to understand if other panels need replacing.

It looks like the rust has spread to the heel panel as well. Does anyone know what options I have ? Is it easier to fab a piece for the lower section of the heel panel or use the off the shelf panel from RD?




As for the tunnel? I could not punch holes so it seems like there is a good amount of metal behind the surface rust. Any one have thoughts on this ?

Old 07-31-2018, 12:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 07:46 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.