Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
  We salute a legendary member of the community.
Thank you for selflessly sharing your wisdom with us...
Go Back   Pelican Parts Technical BBS > 5 - Miscellaneous > Paint & Bodywork Discussion Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Need help welding in sunroof panel

In the middle of building my new race car build and I'm welding in the sunroof panel.

Resurrecting a Legend

I cut the entire old sunroof out and replacing it with a section for another 911. Everything was fine till I started getting to the end. Then sections started caving in. I worked out most of that and thought it still had hope. I then took a break and from the next room I heard a loud pop and I knew the roof caved in again. This happened about 15 minutes after I was last working on it. I checked and sure enough about a 1/3 of the roof panel caved in again and it was a section that was previously ok.

So what am I doing wrong. Is there any way to salvage this or do I need to start over?
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-20-2012, 10:00 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Jan 2012
Location: Alberta, Canada
Posts: 1,111
Just finished doing mine, did a lot of research on it before I took it on and decided that the best answer was to flange the joint and then weld it from there (as opposed to butt welding it). My research suggested that with the low crown panel, the flange gave it a bit of continuity.

As it was, I did a lot of hammer/dolly work to keep the waves out and had at least one event where I began to oilcan a little....sort of the pop/caving you describe I think. I needed to shrink some of the metal to restore the curve and get rid of the caving.

Very tiring and very scary, but I got it down pretty well and then leaded the joint.

Here are a couple of pictures in process...









Dennis
Old 05-20-2012, 10:59 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Thanks for your input Dennis. When you say flange the joint - do mean to flange the panel and lap weld it? I was hoping to to butt weld since the car wont have a headliner. I was thinking the problem was caused by localized heat expanding the panel near the weld. But when I tried to shrink the metal again it really didn't do anything. I was thinking a solution might be to anneal the panel before trying to weld it in, or shrink each tack weld as you go. I'm wondering if it will do anything if a cut a relief in the panel and re-weld it?
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-21-2012, 01:18 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Jan 2012
Location: Alberta, Canada
Posts: 1,111
Quote:
Originally Posted by j911brick View Post
Thanks for your input Dennis. When you say flange the joint - do mean to flange the panel and lap weld it? I was hoping to to butt weld since the car wont have a headliner. I was thinking the problem was caused by localized heat expanding the panel near the weld. But when I tried to shrink the metal again it really didn't do anything. I was thinking a solution might be to anneal the panel before trying to weld it in, or shrink each tack weld as you go. I'm wondering if it will do anything if a cut a relief in the panel and re-weld it?
I wasn't brave enough to butt weld it, mainly as I was uncertain as to whether I could deal with the warping of the metal in that scenario, so yes, I modified a cheap flanger to give the correct offset flange and then did it that way. Mine will be hidden with a head liner, but it still looks pretty good...flange is pretty innocous.

From what I have read and seen on various YouTube video's and a DVD I got from a fabulous sheet metal worker in the UK (its called Bodywork Restoration Tutorial), MIG welding generally shrinks the metal, so you typically need to do some on-dolly work after each weld to expand it to where it needs to be.

I must admit, it was a tough job, I think I would replace the entire roof panel as many suggest here if I had to do it again (I also took off my drip rails...what a pita).

I really can't advise you all that much more, other than look at the way the metal flows and figure out where the upset really is...and whether the metal is shrunken or expanded and go from there. It is truly fussy work. I also admit to using lead to deal with a couple of minor spots, and I am sure on final finishing I will have a few moments of cursing at one low or another.

D.
Old 05-21-2012, 02:51 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by Iciclehead View Post
I wasn't brave enough to butt weld it, mainly as I was uncertain as to whether I could deal with the warping of the metal in that scenario, so yes, I modified a cheap flanger to give the correct offset flange and then did it that way. Mine will be hidden with a head liner, but it still looks pretty good...flange is pretty innocous.

From what I have read and seen on various YouTube video's and a DVD I got from a fabulous sheet metal worker in the UK (its called Bodywork Restoration Tutorial), MIG welding generally shrinks the metal, so you typically need to do some on-dolly work after each weld to expand it to where it needs to be.

I must admit, it was a tough job, I think I would replace the entire roof panel as many suggest here if I had to do it again (I also took off my drip rails...what a pita).

I really can't advise you all that much more, other than look at the way the metal flows and figure out where the upset really is...and whether the metal is shrunken or expanded and go from there. It is truly fussy work. I also admit to using lead to deal with a couple of minor spots, and I am sure on final finishing I will have a few moments of cursing at one low or another.

D.

Thanks again. I might consider replacing the entire roof if one was available locally. I have a friend with more skills than me and I'm going to try to solicit his help. Problem is he tends to be lazy and only works when he feels like it. Last time was 2008.
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-22-2012, 10:18 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Registered User
 
962porsche's Avatar
 
Join Date: Feb 2009
Location: branford ct
Posts: 2,333
you can butt weld in roof panels it's not realy all that hard at all . now that it's oil caned your adding 3 times the work . i could tell you what you should have done but it's to late for that now .
at this point you will need to heat srink the lows and high spots . to do this you will need a jeweler's tip on your torch . cold water and a srinking hammer or dolly . heat up the center of the low or hight spot and when it is still red work the metal in a circle from the center going around moving out . then when it's still red hot (do not let it cool ) take a rag with the cold water and cool it down fast . you can not let any thing get cool at all you have to do it when it is still all red hot .
Old 05-22-2012, 11:40 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by 962porsche View Post
you can butt weld in roof panels it's not realy all that hard at all . now that it's oil caned your adding 3 times the work . i could tell you what you should have done but it's to late for that now .
at this point you will need to heat srink the lows and high spots . to do this you will need a jeweler's tip on your torch . cold water and a srinking hammer or dolly . heat up the center of the low or hight spot and when it is still red work the metal in a circle from the center going around moving out . then when it's still red hot (do not let it cool ) take a rag with the cold water and cool it down fast . you can not let any thing get cool at all you have to do it when it is still all red hot .
Thanks for he tips on shrinking. What do you think of the prospect of just starting over?
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-22-2012, 01:18 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
962porsche's Avatar
 
Join Date: Feb 2009
Location: branford ct
Posts: 2,333
not knowing just how bad it is i can't really tell you .
i have never had to do it for a curved roof like a porsche only on big flat ones but at times we/i have welded a cross brace or two in across the opening to give it some support as we/i work on welding the new panel in then after it's all welded and ground down we/i then just cut the cross bracing out .
Old 05-23-2012, 09:56 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Jul 2011
Location: West Australia
Posts: 14
you know the easiest way is to cut the weld in the oil canned area, pop it back into place and re weld, dont use water and a rag, its not quick enough,use compressed air, but you must wait until the weld turns from yellow to red/orange or you end up blowing the weld out, only weld 1/4 an inch at a time cooling each time, this is how I do it and I have done dozens of mid panel repairs and only ever had oil canning when I got too greedy and tryed to weld more',
works for me, hope this helps,
cheers Russ...
Old 05-23-2012, 03:25 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #9 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by 962porsche View Post
not knowing just how bad it is i can't really tell you .
i have never had to do it for a curved roof like a porsche only on big flat ones but at times we/i have welded a cross brace or two in across the opening to give it some support as we/i work on welding the new panel in then after it's all welded and ground down we/i then just cut the cross bracing out .
I did something like that as well, but I put it just aft of the replacement panel.
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-24-2012, 04:53 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #10 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by rusty69911 View Post
you know the easiest way is to cut the weld in the oil canned area, pop it back into place and re weld, dont use water and a rag, its not quick enough,use compressed air, but you must wait until the weld turns from yellow to red/orange or you end up blowing the weld out, only weld 1/4 an inch at a time cooling each time, this is how I do it and I have done dozens of mid panel repairs and only ever had oil canning when I got too greedy and tryed to weld more',
works for me, hope this helps,
cheers Russ...
So you say compressed air works better than water? I'll give that a try.
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-24-2012, 05:13 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #11 (permalink)
Registered User
 
962porsche's Avatar
 
Join Date: Feb 2009
Location: branford ct
Posts: 2,333
the reason why you would not use air and cold water is the speed if it's cooling . you need to flash cool it to pull the metal back as fast as possable . i have been doing metal work for well over 30 years . if your trying to srink with using some thing like a red shop rag then no they hold no water you need to use a rag or sponge that holes allot of water .
you can at times use air to cool your spot weld quickly but you will find it twice the work if your trying to metal srink with air .
if you cut were the oil can is you will make your life a living hell this should not be done .
you then have the kerf of the cut you will have to deal with . this will no dought need to be welded and add way more heat to a panel .
when you weld in panels like this you need to keep it as cool as you can . you would want to give it one very little spot weld and that is all let it cool back down to metal temp then move across to the other side of the panel and again one very little spot weld and repeat untill the panel is welded in . at no time should you move on to the next weld if the last one have not cooled back down to metal temp .
you should not need to blow the welds with air after you do your weld . this makes for a very brittle weld . mig welds are a harder weld than a tig weld but flash cooling a mig weld after you grind it you may find it wil have a crack in the seam of the two panels your trying to weld together . you will want to set up your weld with the right heat and wire speed to weld the gage metal your working with . there is also the amount of gas your welder is putting out that too need to be right for the size of the welding your doing .
i see it all the time people just set the gas at the same LBS for every weld they are doing .
all three have to work together or you will find it hard to weld deferent gages of metals .
Old 05-24-2012, 05:39 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #12 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by 962porsche View Post
the reason why you would not use air and cold water is the speed if it's cooling . you need to flash cool it to pull the metal back as fast as possable . i have been doing metal work for well over 30 years . if your trying to srink with using some thing like a red shop rag then no they hold no water you need to use a rag or sponge that holes allot of water .
you can at times use air to cool your spot weld quickly but you will find it twice the work if your trying to metal srink with air .
if you cut were the oil can is you will make your life a living hell this should not be done .
you then have the kerf of the cut you will have to deal with . this will no dought need to be welded and add way more heat to a panel .
when you weld in panels like this you need to keep it as cool as you can . you would want to give it one very little spot weld and that is all let it cool back down to metal temp then move across to the other side of the panel and again one very little spot weld and repeat untill the panel is welded in . at no time should you move on to the next weld if the last one have not cooled back down to metal temp .
you should not need to blow the welds with air after you do your weld . this makes for a very brittle weld . mig welds are a harder weld than a tig weld but flash cooling a mig weld after you grind it you may find it wil have a crack in the seam of the two panels your trying to weld together . you will want to set up your weld with the right heat and wire speed to weld the gage metal your working with . there is also the amount of gas your welder is putting out that too need to be right for the size of the welding your doing .
i see it all the time people just set the gas at the same LBS for every weld they are doing .
all three have to work together or you will find it hard to weld deferent gages of metals .

I never considered the amount of gas to be an issue. I figured the gas was just a flux and I tend to use more than normal (because I weld in wind allot). I need to place an order with Eastwood for a shrinking hammer. What do you think about that heat absorbing putty they sell? Anything else you recommend I need?
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-24-2012, 09:25 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #13 (permalink)
Registered User
 
962porsche's Avatar
 
Join Date: Feb 2009
Location: branford ct
Posts: 2,333
we do have the heat putty in my shop . does it work yes to a point and we do use it from time to time .
the 1st thing is get out of the wind when you weld . then knowing what flux does controls the burn . if your welding 1/4 inch metal and your heat and wire is cranked up then you need to match the flux /gas to the amount of wire and heat . just as if your welding thin gage your turning down the heat and wire speed so then you will also need to back off on the gas/flux too . if youe just dumping gas/flux that will make you have to crank up the heat range to get the weld to penetrate .
Old 05-24-2012, 09:50 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #14 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by 962porsche View Post
we do have the heat putty in my shop . does it work yes to a point and we do use it from time to time .
the 1st thing is get out of the wind when you weld . then knowing what flux does controls the burn . if your welding 1/4 inch metal and your heat and wire is cranked up then you need to match the flux /gas to the amount of wire and heat . just as if your welding thin gage your turning down the heat and wire speed so then you will also need to back off on the gas/flux too . if youe just dumping gas/flux that will make you have to crank up the heat range to get the weld to penetrate .
Thanks for the tips, I did not know that. I'll probably just get some more material and start over.
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-24-2012, 11:15 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #15 (permalink)
Registered User
 
962porsche's Avatar
 
Join Date: Feb 2009
Location: branford ct
Posts: 2,333
if you need to get body tools check auto body toolmart . most of the time you will find the same products at less of a cost .
this is kind of pointless to tell you but get some metal the gage your working with and set up the welder with that 1st before you start in on the panels of the car .
if your using 75% argon / 25% carbon dioxide gas and welding 20 to 21 gage metal i set my regulator on the tank at 9 to 12 LBS .

Last edited by 962porsche; 05-24-2012 at 01:21 PM..
Old 05-24-2012, 12:55 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Jul 2011
Location: West Australia
Posts: 14
if you cut the weld where the oil canning is and past a bit, it usually just pops back up into place,
I only use a 1mm thin cutting blade in the grinder or fien cutter when I can borrow it,
doesnt leave much gap to fill,
air works best for me and is much quicker than water and rag, but I dont use it for shrinking only for welding,
I find it better to keep the heat out initially so I dont need to shrink it,
always have the gas up a bit as it adds to the cooling effect hence why gas is better than gassless for panels,
never had a problem doing it that way in all the years I been doing bodywork,
mind you my tecnique has got better with the invention of the thin blades in the last 10 years, they are a god sent,
everyone has their own way which is always better than the next blokes,
if your new to it ,practice on a bunky or an old panel and find the way that works for you,
theres always something you can take out of everyones advice,
cheers Russ...

Last edited by rusty69911; 05-24-2012 at 04:59 PM..
Old 05-24-2012, 04:55 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #17 (permalink)
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
Quote:
Originally Posted by 962porsche View Post
if you need to get body tools check auto body toolmart . most of the time you will find the same products at less of a cost .
this is kind of pointless to tell you but get some metal the gage your working with and set up the welder with that 1st before you start in on the panels of the car .
if your using 75% argon / 25% carbon dioxide gas and welding 20 to 21 gage metal i set my regulator on the tank at 9 to 12 LBS .
I was going to check locally tomorrow and if that doesn't pan out I'll check toolmart. Yes, I am using 75/25. Not really new to welding, but I still consider my self a novice and I have never really done anything quite like this. I used to run at about 13psi, and recently I turned it up to about 20.
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-24-2012, 10:07 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #18 (permalink)
 
Now available:  101 Projects for Your Porsche Boxster!
Registered User
 
j911brick's Avatar
 
Join Date: Mar 2004
Location: Republic of Texas
Posts: 1,771
So here is where I'm at.... I had a couple hours yesterday to work on the roof. I cut a relief where collapsed section was hoping it would go back to normal and I could reweld it. That didn't work at all. I called around looking for a shrinking hammer and my local paint store said to just use a drywall. I happened to be over at Harbor freight anyway so I picked one up $6.00, how can you lose? Bet $6 I spend in a long time. That hammer work wonder I don't know how I got along without it for so long. Probably buy a real shrinking hammer/dolly now. I have now straightened out quite a bit f the mess on the other half of the roof. I figured I should work on that before going to the caved in section I discovered though I could get the caved section to pop back out if I work the right area around where the cave starts.But then it caves again when I work another area. That's why I decided to work the other side and try to get it better first.

I also have a bad crease between the panel and the windshield. Another reason I was at HF was to pick op one dent pullers that weld the studs on. Its slow going and there is a learning curve, but it seems to be coming out OK.

Porsche 962: what do you think about slapping files and shrinking discs? I think I'm going to need a new plan to get out waves.
__________________
james
www.gruppe9autowerks.com

Its not how fast you go...its how you go fast
Old 05-26-2012, 07:35 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #19 (permalink)
Slippery Slope Victim
 
NY65912's Avatar
 
Join Date: Oct 2001
Location: Brooklyn, NY USA
Posts: 2,652
Garage
I've used a shrinking disc with very good results.

Shrinking Disc 4 1/2" - Wolfes Metal Fabrication
__________________
MikeČ

'85 M491 911: Dansk pre muffler, Sport Exhaust, Steve W 93 oct Chip

'80 SC IROC 3.8 PROJEKT, gone but never forgotten.
Old 05-27-2012, 03:59 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #20 (permalink)
Old 05-27-2012, 03:59 PM
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 04:22 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - 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.