why is a rotten roof terminal?

[bmw9818]

just curious as to why having a rusty/patchy roof is terminal,

few rust spots and bubbling are easy enough to sort no?

[Brianmoooore]

The rust comes from the inside outwards. By the time bubbles appear on the outside, the inside of the panel will be a sorry mess indeed, and a roof transplant will be required.

[ross_jsy]

Because it's a £3k + job to do it properly, effectively writing off most the rotten shitters affected by it.

[harry_p]

No.

The rust usually starts between the sunroof tray and the underside of the roof.

By the time you see the bubbles the rust underneath and hidden inside this joint is a whole lot worse. You could grind out, treat and fill and re spray the roof, but you're only buying yourself a bit more time. It will come back, you might get a year, maybe two, but it will come back, and when it does it will be twice as bad.

The only proper cure for rust is to cut out completely and replace with good metal. The construction of the affected parts means fabricating and letting in new sections would be almost impossible, plus welding a roof skin is a sure fire way to get heat distortion in the panel.

So, the only realistic cure is a new roof skin and sunroof tray. Expensive dealer only parts ( if they still do them ) and major panel work to fit it.

The cost of a proper full roof replacement is probably more than most e30s are worth.

[polsta]

When people offer or would chop you a non sunroof roof from a breaker , is that structurally safe to just swap over with a rotten roof ? Or once done is it always weaker and for instance if you had a roll it would badly crumple ?

Always wondered

But re the OP question, it seems every seller of a car with a bubbly rotting roof just seems to think its a minor blister as if its nothing and a quick £50 no biggie fix and value the car the same as if it had a perfect roof

[harry_p]

Done properly it's fine. The standard roof is just spot welded along the gutters and screen openings and braised at the pillars.

You don't cut the pillars off and bung a new roof on, it's just the quickest way to remove it from the donor while keeping it's shape.

Once removed you would carefully pick it off the inner frame, and do the same to the roof on your car. The actual bit you change would only be the single skin roof itself. Which is why it's so time consuming and therefore expensive to do it properly.

[Brianmoooore]

A replacement welded by someone who knows what he's doing is every bit as structurally sound as a new shell. The relevant phrase here is "knows what he's doing."

[Grrrmachine]

By the time rust makes itself visible as a few small blisters on the outer skin, the metalwork under the headlining will look like this:



This means chopping the entire roof skin off at the top of the A-, B- and C-pillars, patching up the roof rails, reskinning it, then giving the entire car a respray. Sure, it can be done, but at what cost?

[Simon13]

E30 roofskins are not welded in but braized, its the cost of parts now that make it hard. Peoples perception is that the job is major major when its not really

My E30 needed a new sunroof tray and the actual skin was ok. I paid £95 for the tray from my dealer about 5 years ago. I gather they are £600 now? Mine was old original stock before e30s went mobile tradition and the big price hikes!

Are sunroof skins still available? non are NLA and have been for some time

[daimlerman]

To a skilled bodyman,such as beardymat,a roof skin replacement will be a pleasant way to while away a couple of days whilst earning a living.But to get the shell to a point where an expert can take over is time consuming as well.
The entire interior will need to be removed,for example...and if the roof is rusty,where else will be rusty as well?

Whilst pretty much any rusty part can be cut out and replaced,there has to come a point when it is just not justifiable to repair a shell,and for most of us,that point is roof skin rot!

[appletree]

I'm changing my roof from Sun roof to non sunroof doing it properly as BMW did it, and following some of x-works thread on the M3 also the skins are spot welded on which is why I have bought a spot welder so this shouldn't distort the skin. Personally I don't think I would entertain welding a cut off roof at the pillars.

Also there are no roofs left at BMW.

There's also issue's with the order of construction that will cause issues with being able to propperly rust proof the skin after you 're weld in the sunroof tray and skin, also to remove the brace you have to unpick or grind flush a folded joint which can't be remade and not removing it and the brace leaves potential rust traps.

Best repairs I've seen are Barry's, Xworks and jozi's


Here's my thread if anyone are interested

http://www.e30zone.net/modules.php?name ... 89&start=0

[Simon13]

Mine was repaired by the same guy that did Barrys

[HairyScreech]

Roof skins NLA?

That's a bit of a worry, expect it will be a part that comes back at 5x the price.

Not a panel that is available from any repro places?

Makes me glad to have a non sunroof car and a damn good reason to stick with the shell.

[Simon13]

i seem to remember it went like this, some of the seloc guys bought all the old stock of non sunroof rookskins from BMW. Their roll cages wouldn't fit in a car with a sunroof. i remember the surplus ones being sold on here for about £50 each!!

The roofskin with a sunroof is still available? didn't ratch buy one? plus they come with the sunroof tray attatched also

[TriggerFish]

Roof skins NLA?


Not a panel that is available from any repro places?

I've got a fibre glass one in my favourites at home. It's about £250 IIRC.

I'll see if I can dig it out later.

[appletree]

i seem to remember it went like this, some of the seloc guys bought all the old stock of non sunroof rookskins from BMW. Their roll cages wouldn't fit in a car with a sunroof. i remember the surplus ones being sold on here for about £50 each!!

The roofskin with a sunroof is still available? didn't ratch buy one? plus they come with the sunroof tray attatched also

No there NLA too, I rang the dealers a few months ago to be told you could order them once they had enough to do a batch, I asked what number they were up to and how many they wanted and when Cotteswold rang Germany they said they made a mistake they were NLA. The sunroof tray was still available but think they only had one left in Germany and it was £300+ +vat and in my opinion you can't really fit it properly with out removing the skin ( if you want to do it how BMW did it but then you still have to stich weld in the brace and then you can't get in the gap between the brace and the skin to clean it up and rust proof after the welding.

I think originally BMW welded the brace in then the tray next cleaned up all the weldscon the top side and then dropped the roof on top of that and than spot welded the skin to the roof and then folded over the lip.

I could be wrong as Ratches roof came with the tray in and the however this might just be how they supplied a spare roof as otherwise the buyer would need the tool to roll over the lip and having taken 3 roofs to bits all of them were painted in the small gap between the top of the brace and the roof skin.

The other give away is that the brace is spot welded in to the roof frame as such so a machine would have to get to both sides.

Simon do you have any pictures of yours? I'm still after any advice ideas

[HairyScreech]

Hmm, Out of interest what did roof skins cost prior to being NLA?

~ £500 odd wasn't it?

[jimbom30cab]

Worth cutting a good roof offs breaker if you get chance. I saw a good roof on Facebook for sale recently by BBB for £100

[Mitchen]

Where on facebook would one find such deals?

[ross_jsy]

Think I saw it on the e30 zone Facebook group?

[Simon13]

appletree, Barry i think still has pictures of it. They should still be on my 2dr resto thread somewhere probably from page 20 ish at a guess save you trawling too much!

[appletree]

Thanks Simon I'll have a look, Barry did send me his pics and it was good to get an idea how they did his , also x works thread was interesting, I asked him for some of his pics in high res but he's not got back to me yet....

As for the roofs yes, worth chopping them off breakers if rust free, and properly stored.

I have a non sunroof skin I bought off Jim, also sweep has sold a few and has a Non sunroof touring roof for sale at present.

I may try and do a wiki right up for changing a skin but think it will take a good bit of work to do one DIY but I've got about 6months to do it so can take my time.