Replacing 911 sills and Jacking Points

Mike · Post by **Mike** » Mon Dec 21, 2009 11:06 pm

Fantastic work as always Barry, photographic skills improving too I see!

Merry Christmas, Mike

Barry · Post by **Barry** » Mon Dec 21, 2009 11:07 pm

All being well, things should be looking something like this:

At this point you may want to lead-load the sill to B-post base, and the sill to rear wing joins. Also lead can be a get-out-of-jail-free card if your door gaps need some help. If you do go this route (as per factory), then I'd recommend the following precautions:

a) Seam weld right the way from the join of the B-post and the sill, all the way down the front of the rear outer wing / sill join. This obviously supplements the plug welds (which replace the factory spot welds), but also help to seal the joins from any flux.

b) After tinning, rinse the whole area with hot, slightly soapy water several times and dry with the air-line, before adding the actual lead. Once tinning is complete, the flux has done it's job, and the aim is to get well rid of it before shutting it in with additional lead. If tinned correctly, the lead will adhere and flow perfectly well without the flux.

Most problems with lead stem from flux that has been locked (soldered) into lap joints. Before long, the acid action starts to undo all of your hard work in these critical areas.

Anyway, a different car with a hint of lead:

Finally, a few words on preserving your work. Anywhere that is to be welded needs to be treated with a good quality weld-through primer following the removal of the factory paint around the seams (where required). Seam seal anywhere that would have been sealed orginally. After final painting, make sure that all repairs are carefully cavity waxed with a good quality product, injected using a compressor, rather than a pump-up DIY rig.

I think that's all for now, but I'm sure I'll think of plenty of bits to add later on ....

Barry · Post by **Barry** » Mon Dec 21, 2009 11:33 pm

911hillclimber wrote:This kind of thread is what DDK is all about to me.

From the car in the pics, the panel under the torsion bar looks quite good(?).
I seem to recall someone once made replacement panels for around the torsion bar/inner wing 'outer' and the bottom panel under the tube?

Look forward to the next 'paragraph' Barry.

The car used here as an example was very good generally (it was mainly here for some custom / replica work), but still illustrated how fairly mild outward signs could indicate more significant problems.

As for the torsion tube area, yes, most cars that come through here need at least some attention in this area. Its a bit labour intensive as there are four layers, plus the heater tube (which also rots): the rear of the inner sill, a reinforcing strengthener (sister?), then the heater tube, then the reinforcement for the torsion tube cover bolt holders, and finally the outer skin (inner wing). Needless to say, just about all of this work is hidden well out of sight

.

Barry · Post by **Barry** » Mon Dec 21, 2009 11:35 pm

Mike wrote:Fantastic work as always Barry, photographic skills improving too I see!

Merry Christmas, Mike

Thank you Mike, Merry Christmas to you as well. I'll ping you some of my non-car pictures for your thoughts

.

Barry · Post by **Barry** » Mon Dec 21, 2009 11:44 pm

hot66 wrote:
Barry wrote:
I thought it was about time I actually posted something that involved cars .
.... you mean just like the rest of us

Great thread as usual Barry Hope you're wrapping up warm in the workshop

It's certainly warmer than the house

. (Braces ready for sarky comment from Mr Donkin .... )

911hillclimber · Post by **911hillclimber** » Tue Dec 22, 2009 7:47 am

That torsion bar tube looks much like my car did in '88 when I restored it!
I think jacking damaged so much of the pvc coating in the early days it started thing off quickly.

As you say, there are several layers inside the area and difficult to 'join them up'
Do you use TIG much or only for the delicate areas Barry. I can gas weld like an angel and I arc and gas welded my car in 88 (not having the new-fangled MIG welder then)

I am thinking of getting a tig soon.

Love these types of threads!

sladey · Post by **sladey** » Tue Dec 22, 2009 9:04 am

Great thread Barry

Nige · Post by **Nige** » Tue Dec 22, 2009 9:23 am

Top stuff Barry and a great reference having just done similar work myself to my own car, though not as extensive as you post shows and I've probably used a touch more filler to get over my less expert repairs

Highfield · Post by **Highfield** » Tue Dec 22, 2009 2:07 pm

Great thread Barry and a reminder of why I would always get a professional to do bodywork - your pictures and words make it look and sound so straightforward, but I know there are many years experience used there.

I guess this is also why we always advise those cannot do bodywork to buy the best and most solid car they can at the outset.

Merry Xmas,

Ian

911hillclimber · Post by **911hillclimber** » Tue Dec 22, 2009 4:22 pm

When i did mine all those years back i was surprised how much panel work was hidden inside another.
Also, the way the rust had spread was quite alarming, and a small hole turns out to be huge in the cutting to find something solid and still thick enough to weld to.

I am in awe of those who can pull long mig welds on such thin and quite unpredicable metal.

I found the body work side really rewarding but very demanding.
No substitute for experience to get the good job at the right price.

Barry · Post by **Barry** » Tue Dec 22, 2009 10:47 pm

911hillclimber wrote:That torsion bar tube looks much like my car did in '88 when I restored it!
I think jacking damaged so much of the pvc coating in the early days it started thing off quickly.

As you say, there are several layers inside the area and difficult to 'join them up'
Do you use TIG much or only for the delicate areas Barry. I can gas weld like an angel and I arc and gas welded my car in 88 (not having the new-fangled MIG welder then)

I am thinking of getting a tig soon.

Love these types of threads!

I tend to use the TIG where there are panels that are to be planished afterwards which are either the repair pieces that are made on the bench (and so tidied up with a stake), or areas like door skin repairs (rare), or those rear wing panels.

The TIG really comes into it's own on these, as if you get the join right, you shouldn't need any filler wire, and you can just fuse the two parts together. When you then planish the join afterwards, you can get a lovely finish with no grinding, and perhaps just a light buzz with the DA sander for the ego (very important!).

So usually I use the TIG to make a repair section, and generally the MIG to weld it in, unless it's an outer panel that has good enough access to allow for a dolly behind it. To put it another way, the MIG probably runs for ten-fifteen hours for every hour the TIG does.

If you can gas weld, then you'd love having a TIG close at hand: makes gas welding look prehistoric, although gas leaves the metal very soft and workable (great for planishing). Against that, it needs to leave the metal ready for planishing and dollying, as you'll need to do plenty to tidy up all that distortion

. TIG's are as cheap as chips these days, so well worth getting one to try. The only thing is that you'd need pure argon for the TIG, and the MIG still needs Cougar 5 / Argoshield as they don't like pure argon (I did try, but it makes for a very 'noisy' weld

).

Barry · Post by **Barry** » Tue Dec 22, 2009 11:00 pm

One thing I did remember to mention today, was that when the outer sill goes on, one fore-aft reference that needs to be noted is the position of the front wing step / recess.

If you put the outer sill too far forward, ahead of the door, the front wing will develop an excessive door gap towards the base. Therefore, it is wise not to let the step in the sill run much more than 2 or 2.5mm ahead of the door skin. At the very least, be aware of this, as you won't want to be doing a final fit-up, only to find your front door gap is wrong.

In fact, with all bodywork, the general rule is to keep trying all panels time and again as you work, and certainly before welding each major stage.

911hillclimber · Post by **911hillclimber** » Wed Dec 23, 2009 6:41 am

Very interesting Barry. I am about to do a set of custom headers for my Lola Porsche race car, MIG tack and then TIG all those tubes. Today's plan is to have them tig'd by a local drag car chassis builder, but the cost of this will = a TIG unit, hence the thought to buy a unit, about £270 all done.

On the subject of sills:

At the time I used Dansk inner/upright member and outers too.

The inner fit was a gem. The outer was a horror. Likewise the two door skins....and I never got then smack-on. Irritates me 21 years later!
The new rear wings were Porsche, and a blind man could fit them with mm precision, just fantastic.

Will you take us through the front panel work next?

When does the Book get published?

Barry · Post by **Barry** » Wed Dec 23, 2009 12:33 pm

I'm sure I'll be able to find something or other to post about. TBH, I've always been a little concerned about being seen to be advertising with these sorts of posts. On the other hand, there were quite a few threads asking about sills, jacking points and floors at the moment, so I thought this particular area was appropriate to write about.

The 2.2S thread of Alan's will cover the entire restoration though, as it's his personal car, so we feel a bit more relaxed about telling the whole story, including a word or two on the metalwork

.

As for the TIG, if you can justify the hire of the extra bottle, it would be a good investment, and one that I'm sure you'd very much enjoy having to hand. I went for a DC only TIG (Kemppi), which has been fine for me, but if I was replacing it, I would be tempted to invest the extra for AC/DC for aluminium work

.

jtparr · Post by **jtparr** » Wed Dec 23, 2009 10:38 pm

nice work barry

makes great reading

make sure you have some time off over christmas !!!

regards
Jp