The before pics look like this:
I had been told and read "Don't try this, send it to Dan Petchel. It's equivalent to an engine rebuild."
It doesn't require technical expertise. It took 3 days with occasional help from another person to hold things etc. This was essential, together with perseverance.
Parts bought:
*The black 3M weatherseal everyone seems to use but you can only get from USA it seems. Other types would do.
* Foam sheeting from E-Bay 1/4 inch thick. £7
- example: Mine was "Foam Sheet 1/4 x 60 x 47 in". eBay item 330682379609.
* Hessian Jute from Ebay. £6
- example: Mine was "Upholstery Hessian Jute 12oz 72in x 1m. eBay item 200532111422.
* Polyester webbing from ebay. £5
- example: Mine was "Polyester Herringbone Webbing Tape (75mm width, 5m length). Ebay Item 120930946153. Get wider if you can.
* Porsche outer cover from Design 911 or equivalent. £100. Part number: 90156503541/1.
* Dan Petchel's front seal $100 or so. This is effectively the seal used on early 911s as I understand. Some SC owners have the wrong/later seal, which is too thick.
Tools used:
* Various screwdrivers
* A heat gun (Essential)
* Contact adhesive
* Spray adhesive (non contact)
* Rivet gun and 3/8 rivets
*Dremel tool i'd recommend
Stripping the roof is hard on the hands at times. It is not difficult as such. Fairly obvious what to do. Remove guttering, side seals e.t.c There are good instructions for this online.
There are comments on the web about these floating nuts holding the clips. Unscrew the clips (these are the clips which the roof frame slots into when you extend the roof fully).
For each clip, the two screws were screwed into a plate. That plate is now only held in place by the material/webbing on the reverse side of the roof. No big deal if you are redoing the whole roof as I was - you might be removing them anyway or replacing them. Forget them. Just don't throw the roof around so they are lost completely. If they move, fine. No big deal.
My roof was so old and original the material under the outer cover almost came away in my hands. Here is the stripped roof:
Key step: Before you remove the webbing completely, tape up the roof with heavy duty tape. Diagonally and straight across. Then remove the webbing carefully and remove the rivet heads remaining.
I got to this point in about 2.5 hours.
Now go and remove your old front windshield seal. Dry fit the new one. I'm not going into that here.
Now is where a professional would have a big advantage because they probably have a jig setup to hold the floating plates. You need to bear in mind at this point that only the two outer plates are fixed. The middle plates are all floating. If you take the tape off, or don't tape them up properly you aren't stuck, but it increases difficulty and extends time.
The key in my view at this point for the DIY'er is to now carefully take the roof and put it back on the car. Take your time here. You'll then be in this scenario:
Key step: Now you need to take your time and measure the gaps. You need to do this part properly. Make sure that your gaps between outer and inner and between inner and centre plate are consistent on each side. Also parallel running from front to back of the car.
The other key aspect is that you need the distance between the front of the plates and windshield to be the same as the front of the targa bar and the rear of the plates.
If you find you need to move the floating plates here, that's fine. Work out which tapes to cut and carefully move and remeasure.
Once you're happy tape up again. Tape thoroughly, even excessively.
Remove the roof gently and take back to your worktop. Tape up your floating nuts from earlier - just to hold them in place under your webbing. Extend the roof and glue the webbing in place, leaving enough to tuck under to the reverse side of the roof. Rivet in place. The rivets are then ground down.
Go back to the car. Put the roof back on the car and check you are still happy. I then glued another strip of webbing just back from the rivets to give extra security and widened my webbing.
Get your hessian sheet and lie it on the extended roof, making sure you have nice even overhangs. Spray the plates and webbing with upholstery glue. Put the first piece of the hessian in place and have someone hold that piece, sweeping their hand across it to flatten it out. Keep the first half foot pressed down while you gently stretch the rest across the roof, all the while the other person sweeping their hand across the roof to keep the hessian smooth.
Tuck the hessian under the roof and trim it down. The corners need to be nice and flat. No ugly folds.
Put it back on the car again to a) check again b) make yourself feel better to see a roof on the car as you'll be a bit tired at this stage.
Foam is now added on top using a similar approach to the hessian. I then just cut the foam around the edges i.e. I didn't fold it under as I wanted as little material as possible on the reverse side of the roof to keep it down.
The final step is the outer cover. This can only be done if the top is sufficiently hot. Not warm - it had to be hot for me. A carefully used heat gun was the answer. Try to fit it first without glue to get an idea front and rear. Leave the sides just now. Be very careful however, not to burn the top here.
Remember to collapse the roof slightly.
Once you have an idea of the strain required, apply your contact glue on the reverse side of the roof, where the vinyl will fold over. The key thing is to get the seam pointing up towards you with the roof upside down. This means there will be downward pressure on the seam. Make sure the seam is also over the edge of the plate if that makes sense. You really have to stretch the vinyl in a major way here to get this to work.
Start with the middle plate first and do front then back. Examine your work and look along the line from both sides of the roof. It's essential to get a nice downward slope on these edges.
I did the middle plate front and rear and then actually went back out to the car again. Once I knew the front was now flush with the windshield I had my line. I would then clip the part done in place with bulldog clips and go out to the car, take off the bulldogs and quickly check where the line was. I used chalk to mark inadequate parts.
This was the end result:
Putting the vinyl on is hard. It requires perseverance. I started without a heat gun and ended up redoing bits I had done already which I thought were good. That said, don't burn the roof! It may be worth heating from the reverse side and covering the roof to avoid any burns.
Go back and forward to the car regularly before you glue the whole roof and get a clear picture in your head of what you are expecting to see. If you look at the roof face on you will quickly see the parts which aren't good enough and parts which are fine. The good parts dictate the line the other parts of the seam need to follow. Mark them with chalk and then when pulling the seam over you know where you need to get the roof to.
I had a tough time with the vinyl and I went through three phases - hair dryer, oven (yes), heat gun. The heat gun and a real stretching of the vinyl over the edge got me there.
Front, back - middle then left and right. Finally the sides. Heating the roof again, after front and back was done got the final wrinkles out as I stretched the sides another inch and a half or so with the roof collapsed slightly.
No wind noise!
I hope that helps give an insight into this Porsche dragon.
Andrew