Sunroof patch help

[240z71]

Hey guys

 

Over the weekend I had a go at patching the sunroof in my 240z and I would say that it went pretty good. The only bad spot I can see is at the front were the two edges meet, its formed a bit of a valley. I was wanting to know if there is a way I can pull the two edges back up, the bit of aluminium on top of the roof is shaped off another 2 seater s30 roof so the closer I can get to that the better.

 

Thanks

[PeterAllen]

DO NOT USE A METAL HAMMER.

 

A hammer will stretch the metal and it appears to be the right size, just the wrong shape. Place a bit of 4" x 2" across the top (like the al strip) and strike the roof underneath with a piece of 4 x 2 held in your hand. You may want to have someone else strike the smaller block with a metal hammer. Just start at the an end and see if it works.

 

Don't be concerned that you will have to use bog, it's magical stuff these days.

 

 

PS. See the thread in Introductions about donating to the site.

[gav240z]

Did you use a MIG welder? Looks like the kind of warpage you get from too much heat.

 

If I understand what Peter is saying, is that you want to use a block of wood to spread the impact out over a larger area. Not an isolated area with a hammer as it will stretch the metal and lead to other sorts of issues.

 

Good on you for giving it a go, I'm still a bit nervous about trying until I'm more confident in my Oxy welding or Tig welding skills. I do have a spare turret as a just in case.

 

Where did you source your patch piece? Did you roll it up on your own?

[PeterAllen]

I would approach a sun roof repair like this:

 

Roll an oversize sheet to get the shape - not much it in it really.

Lay it over the opening and mark out the actual size.

Cut it 10 mm oversize.

Use a joggler to create a flange, it will give strength to the new section and help minimise distortion -

Use a SPOT WELDER - through the door openings.

 

If you have to use a MIG, punch holes in the flange for spot welds and have someone hold a block of copper (or other heat sink material) on the underside as you weld to minimise distortion.

 

Gavin - When I removed the drip rails I use a bit of gas to warm the lead to brush it off. The unattached roof just went crazy with the heat from the gas. Those roof curves have got stress runs all over the place and they take off with any heat.

[240z71]

I got the patch panel from making some aluminium strips shaped to a 240z roof and then went to pick a part armed with a cordless grinder and searched for a roof with the same profile as the aluminium, ended up cutting it out of the front of a 1998 ford laser which fitted perfectly. Then cut to size and supported it. I will get around to donating trust me it's just that I'm 16 going on 17 and with VCE and life time and money are tight. But I will do it. Gav I agree with the warping but I made sure that I could touch it before doing the next weld but maybe not long enough. I will try and work it but overall I think it looks good just that front edge which I might just need to give a little boy or mabye lead filler? I'll attach more pics

[240z71]

Excuse the mess 

[reverendzed]

I'd forget the idea of led fill - If you go with a professional body filler together with a long sanding board for shaping and then a coat of filler glaze you should be able to get a consistent shape, you don't want to end up with a hump or a flat spot - you need to get a consistent shaping over the entire roof.  Mick from Adelaide might be able to chime in here!

Cheers,

Rev

[240z71]

I gave what peterallen suggested with some bits of old train rail and it really helped basically flattened that valley right out but still kept the overall shape, worked a treat. I will finish the welding fully first I think before doing more with the train rails though. I'll probably do it to all the side edges as well as they have a minute version of what the front had or would this make it loose the tension the roof needs to hold its shape. Yeah I never was to set on using lead filler in the body and  with today's bog technology no point really.

 

Thanks guys

 

[gav240z]

Good work it's awesome you're giving it a go, when I was your age (geez that makes me sound old) I was too scared to give it a go. Not sunroof repair but battery tray rot and welding in general.

[zzzzed]

I'd forget the idea of led fill - If you go with a professional body filler together with a long sanding board for shaping and then a coat of filler glaze you should be able to get a consistent shape, you don't want to end up with a hump or a flat spot - you need to get a consistent shaping over the entire roof.  Mick from Adelaide might be able to chime in here!

Cheers,

Rev

 

Your on the money Dave. I have a 1 meter long block made from firm rubber. It takes sticky back sand paper

It is ideal for getting filler and primer dead flat. I also have an air long block and a 8" orbital sander I call the bog buster  to knock the bulk of it of faster. Then I finish it off with the standard long block

 

[240z71]

Hey guys

 

I've done some more work on the roof and I've got a few more questions, I'm starting to get the right shape for the roof by smacking out the valleys between the new bit of metal and the original roof. For this I've started to use a curved dolly with a flat bit of steel on the top of the roof and hitting up with the dolly. It's starting to look good but will I start stretching the metal if I do it to much?. which Leads to my next question, in parts of the roof it's got a good amount of tension and is about as firm as a normal roof but in others it's a bit spongy and pushy, is there a way to get some good tension and firm it up but keep the shape?

 

Thanks

[reverendzed]

You can attempt to apply some heat on the metal that requires shrinking and when hot (not quite glowing) cool rapidly with wet rags which causes the metal to contract.  Others may be able to give you a more detailed process, however that is what I have done in the past.

Cheers,

Rev

[gav240z]

Rev replied just before me but I'll post this anyway....

 

which Leads to my next question, in parts of the roof it's got a good amount of tension and is about as firm as a normal roof but in others it's a bit spongy and pushy, is there a way to get some good tension and firm it up but keep the shape?

 

What you are describing is 'oil canning', thank god for Wikipedia.

http://en.wiktionary.org/wiki/oil-canning

 

So yes it sounds like you've stretched the metal, you can try and 'heat shrink' it but I've not actually done this before myself. My fender on the passenger side had a long scrape along it and we popped it back but it has a bit of oil-canning going on I was told we could 'heat shrink' it to stop it doing this.

 

Probably not the best demo, but here goes.

[reverendzed]

Here's one that demonstrates what I was saying

[Sirpent]

It can be done cold, no heat, I should know I spent 2 days straightening out Simon's roof which looked like a group of Balkan folkloric dances had done a jig on it. This also resulted in me suffering tennis elbow for 2 months.

 

http://www.viczcar.com/forum/index.php/topic,7841.45.html

[240z71]

Wow you guys are awesome, think ill get the shape right first and then give shrinking a go, or should i shrink it first?

[zzzzed]

Get the shape right first mate. And then search heat shrinking on YouTube

[zzzzed]

If you can't get hold of a oxy for heat shrinking it can be done with a large butane tourch. It's not ideal because it spreads the heat to wide but it can be affective.

[240z71]

Hey guys

Pulled the Z into the sun to have a look after i finished shaping. I think there is still some areas i cant get to until i take the skin off and if still got to shrink it but might wait a bit to do that. Would be awesome if you guys could take a look and tell me if you can see anything unusual

Thanks

[chris240]

Yes, someone has stolen your guards , bonnet and hatch....

 

Impossible to tell from pics, but the roof contour "seems" ok. You really need to park another zed next to it, at least for a sanity check..

 

[240z71]

Yes, someone has stolen your guards , bonnet and hatch....

 

.You really need to park another zed next to it, at least for a sanity check..

 

 

HaHa. Yeah i decided to put the hatch on to see if the whole show flowed nicely. If only it was as easy as parking another zed next to it, Don't know of another one within about a 2 hour drive