Rust Repair Questions |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Rust Repair Questions |
bkrantz |
Sep 15 2019, 08:26 PM
Post
#1
|
914 Guru Group: Members Posts: 7,766 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains |
I have had my "new" 73 2.0 home for a week, and started into a detailed assessment. I have stripped out the interior to get a look at the floors. I found some rust holes around the seat brackets, the cross member on the passenger side, and both front corners. Looks like I will be doing some work!
First question: is it worth trying to cut in specific patches? The rust touches the inner longs in only one spot. Or do what I see most people do, drill out all the perimeter spot welds and use full floor panels? Second question: the front corners have serious but small holes. Should I aim for minimal patches in those spots? So far, the only other rust needing panel replacement is the right engine shelf, some holes in the upper firewall on the passenger side, and two tiny holes in the inner fender where the battery tray attached. The top of the hell hole has was looks like surface rust, but I will look at that once I have the engine out. Attached thumbnail(s) |
Nacho |
Sep 15 2019, 09:10 PM
Post
#2
|
Member Group: Members Posts: 219 Joined: 31-December 16 From: So. California Member No.: 20,716 Region Association: None |
Doesn't look that bad. Trim back to where you get clean metal and fab a small patch. You'll be fine.
|
rjames |
Sep 15 2019, 09:37 PM
Post
#3
|
I'm made of metal Group: Members Posts: 3,933 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
Get all of the tar up on the entire floor pan so you know exactly what you’re dealing with.
|
draganc |
Sep 15 2019, 09:42 PM
Post
#4
|
Senior Member Group: Members Posts: 725 Joined: 2-November 09 From: central new jersey Member No.: 11,000 Region Association: North East States |
Get all of the tar up on the entire floor pan so you know exactly what you’re dealing with. +1 Also, order a cheap oscillating multi tool (i.e. Harbor Freight) and use the metal scraper to remove the tar of the floor panels. took me maybe 20min for both sides. don't waste your time with a heat gun! |
pploco |
Sep 17 2019, 10:47 AM
Post
#5
|
Chief Toilet Flusher Group: Members Posts: 105 Joined: 15-June 18 From: boise, idaho Member No.: 22,225 Region Association: Rocky Mountains |
I used this scaler tool to remove all the crud from my floorboards. Works like a charm, just loud.
(IMG:https://live.staticflickr.com/65535/48735127397_091efc808a_c.jpg) |
dr914@autoatlanta.com |
Sep 17 2019, 11:09 AM
Post
#6
|
914 Guru Group: Members Posts: 7,864 Joined: 3-January 07 From: atlanta georgia Member No.: 7,418 Region Association: None |
if just concentrated in a few areas, wire brush or sandblast and see how far the rust goes and then you can patch by seam and spot welding depending on the area of the patch, we make rust panels to cover more than just an area in question, but often wind up cutting them down and only using a piece of the panel to do the minimum rust repari possible while preserving the original look and integrity of the body
I would never remove all of the floor pan tar except if it was already coming apart. We have factory look die cut floor pan tar panels to duplicate the original I have had my "new" 73 2.0 home for a week, and started into a detailed assessment. I have stripped out the interior to get a look at the floors. I found some rust holes around the seat brackets, the cross member on the passenger side, and both front corners. Looks like I will be doing some work! First question: is it worth trying to cut in specific patches? The rust touches the inner longs in only one spot. Or do what I see most people do, drill out all the perimeter spot welds and use full floor panels? Second question: the front corners have serious but small holes. Should I aim for minimal patches in those spots? So far, the only other rust needing panel replacement is the right engine shelf, some holes in the upper firewall on the passenger side, and two tiny holes in the inner fender where the battery tray attached. The top of the hell hole has was looks like surface rust, but I will look at that once I have the engine out. |
dr914@autoatlanta.com |
Sep 17 2019, 11:10 AM
Post
#7
|
914 Guru Group: Members Posts: 7,864 Joined: 3-January 07 From: atlanta georgia Member No.: 7,418 Region Association: None |
surprising that the front is rusted and the rear looks very good!
I used this scaler tool to remove all the crud from my floorboards. Works like a charm, just loud. (IMG:https://live.staticflickr.com/65535/48735127397_091efc808a_c.jpg) |
bkrantz |
Sep 17 2019, 09:27 PM
Post
#8
|
914 Guru Group: Members Posts: 7,766 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains |
Thanks, everyone. Anybody know a source for just the front corners of the floor?
|
Superhawk996 |
Sep 18 2019, 01:53 AM
Post
#9
|
914 Guru Group: Members Posts: 5,826 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
Thanks, everyone. Anybody know a source for just the front corners of the floor? All the usual suspects (Restoration Design, Auto Atlanta, Pelican) sell floor pans. You won't find just the front corner - as in a small 1' x 1' patch. RD and AA tend to be the original sources for metal. Just buy what you need and cut to size. Floor pans are sold in 1/2's. Either left / right or front / rear. I think someone might be offering in 1/4's but I'm not sure who at the moment. |
bbrock |
Sep 18 2019, 01:18 PM
Post
#10
|
914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
The easy way is to do as Phil ( @Superhawk996 ) suggests. The cheap way - and I mean really cheap - is to buy some 18 gauge sheet metal and bring out your inner tinsmith to fabricate your own patches. It is easier than you think. If I can do it, so can your dog. (IMG:style_emoticons/default/beerchug.gif)
Also, I sort of disagree with George about taking out the tar. That tar can hide a lot of ugly underneath it and unless you have the experience assessing good and bad floor pans with tar in place, I think it is wise to remove it and know the condition of your floor. My floor was a sandwich of rust held between a layer of tar on top and undercoating underneath that hid the horror in between. |
dr914@autoatlanta.com |
Sep 18 2019, 01:41 PM
Post
#11
|
914 Guru Group: Members Posts: 7,864 Joined: 3-January 07 From: atlanta georgia Member No.: 7,418 Region Association: None |
if the tar is well sealed and not loose it always looks good underneath, if it is not tightly glued sealed, then yes we see rust
The easy way is to do as Phil ( @Superhawk996 ) suggests. The cheap way - and I mean really cheap - is to buy some 18 gauge sheet metal and bring out your inner tinsmith to fabricate your own patches. It is easier than you think. If I can do it, so can your dog. (IMG:style_emoticons/default/beerchug.gif) Also, I sort of disagree with George about taking out the tar. That tar can hide a lot of ugly underneath it and unless you have the experience assessing good and bad floor pans with tar in place, I think it is wise to remove it and know the condition of your floor. My floor was a sandwich of rust held between a layer of tar on top and undercoating underneath that hid the horror in between. |
bkrantz |
Sep 18 2019, 09:14 PM
Post
#12
|
914 Guru Group: Members Posts: 7,766 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains |
So far I have exposed the metal, some very clean, some rusty to variable degrees, in all the "troughs" plus in any high areas that showed rust at all. I might go ahead and remove all the original asphalt, treat and paint anything I do not replace, and get new sound deadening stuff.
|
rjames |
Sep 18 2019, 10:49 PM
Post
#13
|
I'm made of metal Group: Members Posts: 3,933 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest |
So far I have exposed the metal, some very clean, some rusty to variable degrees, in all the "troughs" plus in any high areas that showed rust at all. I might go ahead and remove all the original asphalt, treat and paint anything I do not replace, and get new sound deadening stuff. That’s the right way to do it. |
Rand |
Sep 18 2019, 11:06 PM
Post
#14
|
Cross Member Group: Members Posts: 7,409 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
|
John |
Sep 19 2019, 01:58 PM
Post
#15
|
member? what's a member? Group: Members Posts: 3,393 Joined: 30-January 04 From: Evansville, IN (SIRPCA) Member No.: 1,615 Region Association: None |
QUOTE I would never remove all of the floor pan tar except if it was already coming apart. We have factory look die cut floor pan tar panels to duplicate the original If I were to order the tar (sound deadening), how would I get this stuff hot enough to stick and contour to the sheet metal? I removed all the tar from mine in order to assess the rust (which there was very little). Now, I'm wishing I would have left it alone, but it was dried out and crumbling. Now I wish it were a bit more quiet. Funny how loud relatively large flat sheet metal panels are. |
Superhawk996 |
Sep 19 2019, 02:22 PM
Post
#16
|
914 Guru Group: Members Posts: 5,826 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
QUOTE I would never remove all of the floor pan tar except if it was already coming apart. We have factory look die cut floor pan tar panels to duplicate the original If I were to order the tar (sound deadening), how would I get this stuff hot enough to stick and contour to the sheet metal? I removed all the tar from mine in order to assess the rust (which there was very little). Now, I'm wishing I would have left it alone, but it was dried out and crumbling. Now I wish it were a bit more quiet. Funny how loud relatively large flat sheet metal panels are. Dynamat works well if you don’t want the factory look. Heat gun will work for A.A. style tar mats. You are correct that untreated panels are very loud. |
bbrock |
Sep 19 2019, 05:24 PM
Post
#17
|
914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
There are a few less expensive brands than Dynamat that are pretty much the same thing and work just as well. I used 80 mil Noico on mine. I'm a tad bit anal about original appearance so I cut it to match the original tar pattern and then primered and painted it.
(IMG:http://www.914world.com/bbs2/uploads/post-20845-1540326236_thumb.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-20845-1540326945_thumb.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-20845-1542384779_thumb.jpg) |
doug_b_928 |
Sep 19 2019, 05:52 PM
Post
#18
|
Senior Member Group: Members Posts: 692 Joined: 17-January 13 From: Winnipeg Member No.: 15,382 Region Association: Canada |
I’m reluctant to put one of these sound deadeners back in due to concerns with having to remove it someday... are any of these relatively easy to remove?
|
Superhawk996 |
Sep 19 2019, 06:07 PM
Post
#19
|
914 Guru Group: Members Posts: 5,826 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
@doug_b_928
Repair the rust right - do it once. It will last the rest of your lifetime. With regard to take off in the future, any of the NVH (Noise Vibration Harshness) treatments will come off if needed but should never be necessary. Otherwise its the same scrape / multi-tool process at worst. To get the proper NVH reduction, the mat basically needs to be bonded to the steel as a constrained layer. Either as softer mastic or hard tar. That shear layer is what provides the noise reduction in conjunction with a mass damping effect. You could just lay in "shoddy" pad which is that underlayment you find in OEM cars under carpet. It will provide some noise decrease but is no where near as effective as a constrained layer of damping material. |
doug_b_928 |
Sep 19 2019, 06:21 PM
Post
#20
|
Senior Member Group: Members Posts: 692 Joined: 17-January 13 From: Winnipeg Member No.: 15,382 Region Association: Canada |
Interesting... I haven’t heard of shoddy pad. Thanks for the info.
|
Lo-Fi Version | Time is now: 18th May 2024 - 05:59 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |