Classic cars forum & vehicle restoration.

Big Supes · Joined: 14 Apr 2017 Posts: 3

Hi guys, newbie here!

I am currently restoring my p&j - a 1988 Nissan Fairlady Z and would like some advice on welding and what fillers to use in preparation for paint.

So far I have taken off the surface rust from the rear of the car and POR-15'd over the top.

[img]http://i.imgur.com/bP73tHH.jpg [/img]

You can see the worse areas pictures below.

(inside of nearside quarter panel)

In the top picture I intend to put a small plate behind the holes and fill them up with mig. I recall reading somewhere that you should avoid using standard filler as it attracts moisture? I was wondering what you guys use instead?

Cheers!

MikeEdwards · Joined: 25 May 2011 Posts: 2467 Location: South Cheshire

For that top one, I'd open that hole up to a regular shape and weld a plate in, with a butt weld if you possibly can. Then you can grind the weld down flat and you'll only need a very small skim of filler.

The trouble with welding a plate behind is that you've then got two metal surfaces next to each other, virtually impossible to rustproof, asking for trouble really.

On my project I've used epoxy primer directly over the welds (after grinding down) and then gone for either glassfibre filler (aka bridging filler) which generally is waterproof, and then standard filler on top if required as it's easier to get a decent top surface on.

On the panel in the second photo, I think I'd be trying to remove all that and make a replacement. It's not a difficult shape to replicate, maybe in one or two pieces if that makes it easier.

For inspiration I always point people at this thread: http://retrorides.proboards.com/thread/70135/panels

Rootes75 · Posted: Sun Apr 16, 2017 7:16 pm Post subject:

Agreed, I would opt for fabricating a new panel and cutting out all the rotten material. The new section can be made up of multiple parts if necessary if the shape is complicated.
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Various Rootes Vehicles.

Big Supes · Joined: 14 Apr 2017 Posts: 3

ukdave2002 · Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire

Avoid mig welding butt joints on body work; it creates a brittle line that is virtually impossible to planish without cracking or making more brittle, gas is better if you have access to it.

Don't use fillers until you are just about ready to paint, as they will absorb moisture; this is the main cause of paint micro blisters in paintwork If you are going to fill a while before the top coat is painted , use an epoxy primer.

Cheers

Dave

Big Supes · Joined: 14 Apr 2017 Posts: 3