Kato Kids 71' 240Z

[KatoKid]

This cars a keeper and I couldn't live with myself if I didn't do as much as possible to make it rust free so I bought some full length reproduction sills and plunged into the removal and replacement. I haven't done this sort of structural panel work before so I was apprehensive and also concerned about the shell bending once I removed the old sills so I decide to take it off the rotisserie for this work. I needed to build a trolley for latter panel and paint work anyway so I picked a couple of convenient points as mounting locations that would also ensure the shell was well supported while the sills were off.

[KatoKid]

After cutting away bits and pieces I realised how bad the RH Dog Leg was....the rear section of ridge that forms the bottom of the sill was completely gone where the sill joins the rear guard. This section is made up of 4 layers ....the inner sill, a strengthening piece, the outer sill and the 1/4 panel all needed to be reconstructed and the LH side was just as bad. I tackled the reconstruction of the basic inner sill and inner guard before I removed the rest of the sill.

Damn its hard to get a good looking weld without burning holes in the original steel! And that's with cutting it back to good metal too.

[bryan3976]

very nice progress im still scared to fix my sills

[Zedback]

I tackled the reconstruction of the basic inner sill and inner guard before I removed the rest of the sill.

Nice work, great to see you bringing her back from the edge.  I have the same to do on both sides of mine, which oddly enough is #00618 but plated 4/71.

[.]

Nice work, great to see you bringing her back from the edge.  I have the same to do on both sides of mine, which oddly enough is #00618 but plated 4/71.

oh you must have got one of the ones the mechanics held on to in Japan for a year to fang around in and then sent to Aus to sell

[KatoKid]

So once I had reconstructed the lower sill edge and inner guard sections on both sides it was time to tackle the actual removal of the old sills.

The reproduction sills are not an exact copy of the originals, not far off but they require trimming of the edges of the pressing so you really don't have good references when installing the new sills. I had some advice that it was critical that the new sills were welded back on in the correct location, otherwise the panel gaps between the doors and the sills would not be parallel. I tried hanging the doors and checking the gaps prior to removing the sills but this is a PITA as it takes ages to adjust and get the doors in the right location and then you have to remove them anyway to work on the sills and then refit them to check position of the new sills.....all seemed too hard so I decide to make some templates to ensure the lip of the sill that determines the lower door gap was in the correct position. Pictures explain better....

[KatoKid]

The actual removal of the old sills was pretty easy. Take the time to ensure you drill the spot welds out properly and they pretty well fall off, probably took about 45 minutes of drilling each side.

I used these P&N Spot Weld Drills, about $30 each and ended up having to use one each side. Keep the speed low and the pressure up and they work really well.

[KatoKid]

Once I had the sills off and had a look at the rust inside I was extra glad I had made the decision to replace them.

The front of the rocker box ( I think that's the correct term) on the RH side was in good condition but the LH side had rusted through so I had to make  a new section and weld it in after cleaning up and prepping the metal underneath. I managed to borrow a spot welder from a family friend and this made it a heap easier than using plug welds. The spot welder is only a single phase and doesn't have a lot of punch but for this simple two layer weld it was good enough. Once I have the new sills tacked on I will take the shell to a panel shop that has a full size 3 phase spot welder as most of the spot welds will be over 3 layers and the single phase just wont cut it in my mind.

Since I'm going to all this effort it didn't make sense to put it all back together without some additional rust proofing measures so I decided to go the full POR-15 route. Don't know if it really works but figure it cant hurt and besides it makes me feel better! Most of the rust in the rocker box was just surface rust which clened up pretty well. I followed the POR-15 clean and etch instructions and finally gave it 3 coats of grey after masking the edges that will be spot welded.

[MaygZ]

WOW!  You do good work.

[luvemfast]

WOW!  You do good work.

Agreed, looks like theres plenty to do too
Good luck and keep it up

[KatoKid]

Thanks guys.

I don't really have much experience with this sort of work and I find it takes a long time to complete just little fabrication jobs. Gets a bit frustrating sometimes and Ive got to remind myself to take the time to do it properly. Ive got impatient with a few things and ended up starting over as I wasn't happy with the end result.

Next up is installing the strengthening sections that run the full length of the rocker box. Ive got them made and cut to size so will hopefully get them installed in the next few days.

David.

[luvemfast]

take the time to do it properly. Ive got impatient with a few things and ended up starting over

One thing I've learn't from working in R&D is to just do it right.
Sometimes taking the shortcut, takes longer.

Keeping the motivation up is the hardest part when doing major work on cars and is the main reason you see unfinished projects come up for sale.

[KatoKid]

While I had the sills off I wanted to add some strength to the chassis....see this thread for details and thanks to all for opinions  http://www.viczcar.com/forum/index.php/topic,7610.0.html

Engineers may still want more but it was easy to do and I believe adds some meaningful stiffening.

Had some beads rolled into them and then used the borrowed spot welder to install them with full seam welds at both ends where it joins with the original sections. Particularly strengthens the rear dog leg area where 2 post hoist pads are normally placed to lift the car.

[KatoKid]

Dog leg area...

[MaygZ]

Looking very neat.  Good work.